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Copying SPARLVE and RSE

Copyrights and the Stirling Phase Alternating Rotary Liquid Vapor Engine
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There are two half-baked notions here. The first one is fairly short and quite simple and starts like this:

COPYRIGHT (C) 2007 By Vernon Nemitz
Intellectual Property is described here. Modern Copyright laws give great power to the Copyright holder, regarding the making of copies of Copyrighted Intellectual Property into ANY medium. In this particular case, the author is allowing copies to be freely made into MOST media, provided the entirety of this Copyright notice/explanation is retained. However, if copies are made in the realization medium, the medium of constructed artifacts, the author MAY require a royalty payment to be made, of $10 per copy. In more detail, a copy of this engine that you make in that medium mostly by yourself and for yourself can be done for free. If you hire a "third party" to make of a copy in that medium, or if you make a copy in that medium and sell it, then the $10 royalty should be paid for that copy. (This is a small amount compared to the cost of making a copy of the engine in that medium, and the author hopes you will eventually deal with millions of them! Also, note that as time passes, while making/selling millions of copies, inflation can be expected to trivialize that royalty, by the time the Copyright expires.)

As additional logical support for some of the above statements, consider that a copyrightable document is generally supposed to be literary or artistic in nature (or even be a computer program). It is a modern thing to consider a work of engineering to be art (famous example: the Golden Gate Bridge in San Francisco), but documents describing aspects of the art of engineering (or describing any other art, for that matter, or even one particular work of engineering art) have been validly copyrightable for many decades. The present case is a document that describes (partly with diagrams and other variations of "artwork") the basics of how to build a gadget, which has a chance of qualifying as being "elegant", especially if it solves a problem well, that previously had not been solved well. (Even if it isn't "elegant", and is called "bad art", that piece of engineering is still qualifying as "art", heh.)

Next, suppose it is built, and the gadget without any documentation is handed over to somebody knowledgable in that field. Could we reasonably expect that person to be able to "reverse-engineer" the gadget? Doesn't reverse-engineering involve creating documentation describing how to build it? Even if there are few similarities of phrasing between the original and reverse-engineered documents, remember that that is equivalent to what can happen when text is translated to another language and back again. Copyright covers translation from the original language--the author's permission can be required. So it logically follows that copyright should be able to cover the translating of the artistry of a gadget-describing document into the realization medium, especially because that translation is reversable. In this particular case, the author's permission can generally be obtained for the low royalty/price of $10 per translated copy, in that medium, and is freely granted with respect to most other media. (If you have questions, ask! My email address is neither secret nor difficult for a search to find.)

Copyright law provides for significant penalties if a Copyright is violated, and the penalty can accumulate based on the number of violations. The author recommends that the Copyright on this particular Intellectual Property not be violated.

So, folks, the first half-baked notion here starts with a problem that modern Copyright laws have: They try to broadly cover copies made in so many different media, with more being developed all the time, that to avoid obsolescence and constant editing it is simpler for the laws to specify "any medium" than to specify a list. The suggested consequence is the idea that a Copyright may then be a better thing to have, than a Patent. Copyrights are easier and less expensive to obtain; the penalties for blatantly violating a Copyright can be about as stiff as the penalties for violating a patent, and the duration is much much longer! (In the USA that's 17 years for a Patent compared to something like 70 years after the death of the author, for a Copyright.)

Note that even if I am mistaken here about the breadth of modern Copyright law, even U.S. Patent law grants me a year after publishing an idea, to Patent it. Certainly nobody else can write a Patent application for this, partly because I'm declaring here-and-now that to do so, since it would be a translation of this document into the language of legalese, will also be a violation of this Copyright!

[NOTE added Nov 3, 2007: One of the links is "This Idea as a more ordinary Web page". A number of images having separate links on this page are embedded into that page, so you might prefer viewing the Idea in that format.]

The second notion here concerns the SPARLVE and RSE (variations on a theme, they are). Like most coined words, especially an acronym like SPARLVE, it looks ugly until you get used to it--but let me assure you it's even uglier if you can't pronounce it! (Thinking up an accurate description that made a pronounceable acronym took significant effort; the acronym is detailed in the subtitle of this Idea.) Anyway, for years I've been wanting to dream up a purely Rotary version of the Stirling Engine, one of the most energy-efficient engines ever invented. See the "Stirling Description" link. Please take some time to study that link, especially the engine diagrams, because I'm about to mention a number of things from that link, in order to show why a SPARLVE (mostly) qualifies as a Stirling (and an RSE can be exactly that).

To begin: A standard Stirling engine normally exhibits reciprocating motion of usually-two pistons, and if this can be replaced with rotary motion it would be even more energy-efficient. That is, reciprocating mechanical systems generally waste energy to make motion in one direction stop, and to start motion again in the other direction, so preventing that wastage automatically means efficiency goes up.

The two pistons of a standard Stirling engine are connected 90 degrees "out of phase" with each other. Please note that the word "phase" has a particular meaning here which is different from another meaning that was used in the subtitle, and will be explained later on. Here it refers to part of the 360 degrees of a full/normal rotation-cycle. Remember that a piston is usually connected to a "crankshaft", so that its reciprocating motion can be converted into rotary motion. One point in the cycle of a piston's motion is usually called "top dead center". At that point, a piston starting its motion for the first time MIGHT cause either clockwise or counterclockwise rotation of the crankshaft--most Stirling designs aren't picky about which way they rotate, and it can be troublesome to make one always rotate the same way when starting up. (Putting a flywheel on the crankshaft ensures it keeps rotating in the same direction, once started.) Heh, it can be troublesome even to get a Stirling started--many designs are not self-starting. Well, if one piston starts out at top dead center, and then it moves so that the crankshaft rotates 90 degrees, and now the second piston is at top dead center, this means that the second piston is 90 degrees out of phase with the first.

A SPARLVE and an RSE both feature at least two rotors, and in either engine the rotor shapes are distinctive enough that it can be easily seen that one is oriented 90 degrees out of phase with the other. (There is a variant design described later in which they are 60 degrees out of phase with each other; would that still qualify as a Stirling? Possibly so, because some variants of the Stirling engine have more than two pistons, and when the total is divisible by three, a 60-degree phase angle is not unlikely.)

In an original/standard Stirling engine, one piston is the power piston and one piston is called "the displacer". They are often different sizes to meet their specific purposes. Also, the power piston is "double-acting" --it is powered in both of the directions in which it moves. This is the main reason why the engine can work even though the two pistons are 90 degrees out of phase, instead of (like in other engine types that have two cylinders) 180 degrees out of phase. The power piston is pushed while the crankshaft rotates 180 degrees, and "pulled" (explained below) for the other 180 degrees of a complete crankshaft rotation, and the displacer is simply carried along for the ride.

The minimum two rotors in a SPARLVE --or the minimum two rotors in an RSE-- can be identical. This is workable because both rotors can act like power pistons and both can act like displacers, AND both can be double-acting. One consequence is that most variants of these engines should almost always be self-starting, and also almost always have a preferred direction of rotation.

A standard Stirling engine uses a gas (like air or hydrogen or helium) as its working fluid. The engine features a place which is always heated, and another place which is always cooled. (One of the major inefficiencies of early steam engines was that various parts of the machinery were alternately heated and cooled; in a Stirling this happens only to the working fluid; each piece of hardware stays at mostly the same temperature, which significantly helps its overall energy-efficiency). When the gas expands its volume in the hot zone, it pushes on the power piston, and when its volume contracts in the cool zone, it "pulls" on the power piston. I put that word in quotes because more accurately, a partial vacuum is created by the contracting gas, and gas in other parts of the system will act to fill that vacuum by pushing the power piston toward it. So, while it may be convenient to think that the piston gets pulled (and I will continue to use that word in quotes), it actually gets pushed in both of the directions it moves.

A SPARLVE or RSE also has an always-hot zone and an always-cool zone. An RSE, a true Rotary Stirling Engine, would use a gas as its working fluid, while a SPARLVE would use a substance that undergoes liquid-to-gas or gas-to-liquid "phase changes" (to invoke the other meaning used here, of the word "phase", regarding a state/type of existence). A possible problem is that the edge/surfaces of the rotors are alternately exposed to both the hot and the cold zones, and so at least the exposed parts of the rotors should be made of, or coated with, a thermally insulating material, to minimize temperature changes of the rotors (and to minimize energy wastage).

Each rotor of either a SPARLVE or an RSE is basically a simple disk of arbitrary thickness, with an axle through its geometric center and four particular features at the edge of the disk. Two of those features might be called "lobes", and the other two might be called "notches". Going around one rotor-disk, and starting at a lobe, then at 90-degree intervals you will encounter a notch, then another lobe, then another notch, and then you are back at the first lobe. The minimum two rotors are mounted in contact with each other so that either they are round-edge-to-round-edge, or one has a lobe fitting into a notch of the other, much like meshing gear teeth. For the moment, let's assume there are two actual gears behind-the-scenes, having 1:1 ratio, ensuring that the two rotors maintain their relative orientations accurately (the gears are not essential, as will be described later). In both a SPARLVE and an RSE, the notches must be larger than the lobes, and an RSE generally must have considerably larger notches than a SPARLVE (that's really the only required difference between the two, besides the choice of working fluid). I should state here that a variant design mentioned earlier could have six instead of four "particular features" per rotor--that's three lobes and three notches, of course (and leads to one rotor being 60 degrees out of phase with the other). Obviously it is physically possible for the rotors to have even more lobes and notches, but the "law of diminishing returns" happens to apply to implementing that. More about that below.

Now let's focus on a SPARLVE. I've created an animated .GIF to accompany this description (see link). DO NOT ASSUME THAT THE DIMENSIONS OR DIMENSION-RATIOS IN ANY OF THE IMAGES ASSOCIATED WITH THIS DOCUMENT ARE THE ONLY THINGS COVERED BY THE COPYRIGHT. Many obvious variations on the theme are quite possible, besides the things just mentioned in the previous paragraph, such as smaller rotors with relatively larger lobes, or larger rotors with relatively smaller lobes. The composition of the rotors is not specified, but it is obvious that they need to be made of something that can survive while doing the work expected of them. The axles in the animation are portrayed as points; it is obvious they need to be rather more substantial than that. Even the shapes of the lobes and notches might be varied. And while the word "HEAT" indicates the hot zone, it should be obvious from the portrayed effects of gravity (in the animation), upon the liquid in this particular portrayed orientation of a SPARLVE, that the place marked "HEAT" isn't the only spot that should be heated. (So why should the place marked "COOL" be the only spot that should be cooled, eh?) The word "zone" has been used here specifically to allow its extent to be arbitrary/whatever-works. And all of THAT is part of why this Intellectual Property is broad, not narrow. Got it?

You may wish to copy the .GIF animation and open it with a well-featured image viewer, especially one which can let you enlarge the image. You can easily see the 90-degree phase angle in the relative orientation of the two rotors, and the hot zone, cool zone, and "displacement zone" are clearly marked. You can see how gas that expands in the hot zone can push on lobes of both rotors, and how gas that contracts in the cool zone can "pull" on lobes of both rotors (making both of them double-acting, as previously mentioned, for both a SPARLVE and an RSE). The key fact behind a SPARLVE is that when a substance "changes phase" from a gas to a liquid or vice-versa, there is typically a 1000:1 change in the volume of that substance (some can do better; the steam-to-water ratio is actually 1600:1). The high relative density of a liquid provides an easy way to transfer significant amounts of substance from the cool zone of a SPARLVE into the hot zone, without reciprocating motion (or special plumbing with one-way valves) being involved.

In order to maximize the percentage of fluid that changes phase in a SPARLVE, it is necessary to NOT over-heat the fluid. There is a technical thing known as "the heat of vaporization" which must be added to convert a liquid, at the boiling point, into a gas. The gas will automatically exert pressure on its surroundings, and in a SPARLVE it powers the rotors. If there is strong resistance to its expansion, then the temperature may need to be raised some to increase the gas pressure. But we don't want to over-do this, because in the cool zone of a SPARLVE, we want a significant part of that gas to condense back into the liquid state. The hotter it is above the condensation point, the more difficult that will be, to do, because we have to first cool the gas down to the condensation point and THEN also remove the "heat of condensation" (identical in magnitude to the heat of vaporization) for it to become liquid. And this has to be done rather quickly, if you want to see a fast-rotating SPARLVE.

Fortunately, we likely need only a few milliliters (cubic centimeters) of liquid in a SPARLVE (the needed quantity is directly related to the third measurement-dimension, the thickness of the engine, not shown in the animated .GIF). Most of the "working volume" of the engine, the space in which boiling/displacing/condensing happens, will be occupied by gas. Such a small amount of liquid means it can fairly easily be raised to its boiling point, allowing faster start-up of the engine, and faster boiling/condensing for faster rotor motion. This might be improved by selecting a low-boiling-point liquid that also has (compared to water) a modest heat of vaporization/condensation (ethyl alcohol, for example). Thus the total magnitude of heat energy that must be added to boil the liquid in the hot zone, and removed to condense the liquid in the cool zone, can be very reasonable. A true Stirling engine is a pure "Carnot Cycle" engine, which requires large temperature differences between the hot and cool zones to maximize power production efficiency. See the "RSE-60" link, to see the Rotary Stirling Engine design that has three lobes and notches (six "particular features) per rotor.

Six MAY be better than four, but eight is very likely not better than six. Odd numbers are not possible unless one rotor has lobes only, and one rotor has notches only, in which case such an engine may be a "more accurate translation" of the original Stirling design from reciprocating to rotary motion, with only one power rotor--a dubious "advantage", that. See the "RSE-1" link for some diagrams that show the odd number of ONE feature per rotor.

But a SPARLVE is a heat engine that does NOT pay much attention to the Carnot Cycle to get its work done. See the link to the "Ice Engine", an Idea that was posted specifically to prepare the mental landscape for the SPARLVE. Both are phase-change engines, not Carnot Cycle engines.

One thing that a Stirling engine usually has, not previously mentioned here, is an add-on gadget known as a "regenerator". It's purpose is to pre-cool the gas moving to the cool zone, absorbing heat energy in the process, and to use that energy to pre-heat the gas moving to the hot zone (becoming itself cooler in the process). A regenerator makes a major contribution to the overall energy efficiency of a Stirling engine, and therefore this design (both SPARLVE and RSE) needs to have it, or an equivalent to it. How? In preparation for that, see the "Casing" link.

To help ensure that the hot zone and the cool zone are thermally isolated, when the casing of the engine is often likely to be made of metal, it is suggested that the casing be divided into three parts: a "cool zone assembly", an "axle zone assembly" and a "hot zone assembly". I'm calling them "assemblies" here simply because that might be an easier way to make them, than, say, to cast them into the correct shapes, or to machine them out of large blocks of material. I do not rule out the notion that somebody might decide to ignore the thermal isolation issue and construct the casing in a different way altogether, hoping to get around the Copyright. Sorry, every casing is going to need certain things in common (ways for thermal and mechanical energy to get into and/or out of the engine), and THAT's covered, regardless of details of construction. Of the two most obvious outer dimensions of the engine, the two diameters of the side-by-side rotors tends to approximately specify the longest measurement (call it "length"), while the diameter of one rotor approximately specifies the next dimension (let's call it "height" here). If we divide the height into roughly thirds, then each of the casing assemblies has approximate dimensions of the whole length and that one-third height. When combined into a complete casing, thermally insulating gaskets can be used, in fulfillment of the goal of this paragraph.

The hot-zone and cool-zone assemblies need a way for thermal energy to be transported from the exterior of the casing to the working volume of the engine. The assemblies could be solid chunks of material honeycombed with passageways for appropriate fluids, such as radiator coolant for the cool zone assembly and hot gases for the hot zone assembly. Or the casings might constitute a thin shell of material surrounding the working volume of the engine, with lots of heat-conducting fins. No matter what variation of these notions is tried, for a SPARLVE we now need to remember that we need not have a huge temperature gradient, which makes adding a regenerator fairly easy. For an RSE the task is less obviously managed, but not impossible (especially if yet another variation of the design is used; more on that below).

Now see the "Regenerator-1" link, for a SPARLVE. It portrays a system in which a heat-carrying fluid is passed through the cool zone of the engine, then through a heater, then through the hot zone of the engine, then through a radiator, and then back through the cool zone. For energy-efficiency purposes, this fluid needs to have as much as possible of a special property known as "heat capacity" or "specific heat", which is the quantity of heat that must be added or removed to change its temperature by one degree. To see why we want to maximize that property, let's imagine some Quantity X of this fluid NOT passing through the cool zone assembly of the engine, but just sitting there occupying space. As the vapor inside the working region reaches the cool zone, some of its heat can be passed to the exterior fluid. It should be obvious that the higher the heat capacity of that fluid, the more heat it can absorb before we MUST replace that warmed fluid with a new batch of cool fluid, if the overall goal of the engine's cool zone is to be met. In essence, then, the higher the heat capacity of this exterior fluid, the more slowly we can pump it through the the other parts already described--and the more slowly it moves, the less energy is spent in moving it, and in overcoming friction-equivalent things like turbulence. From such simplicities do increased energy-efficiencies result.

The way that exterior fluid acts like a regenerator is somewhat subtle; it is an "indirect" regenerator that is being described here. Basically, when the fluid passes through the cool zone and picks up heat, this means that the fluid does not need to be heated so much, before it passes through the hot zone and gives off heat. Likewise, after giving off heat in the hot zone, it need not be cooled so much in the radiator, before once again passing through the cool zone. So we have replaced direct effect of a typical Stirling regenerator with the indirect effect of doing thermal regeneration in an intermediary fluid, between the actual heating and cooling parts of the engine. The main reason this was chosen has to do with the very small region in the center of the engine, where condensed liquid passes from the cool zone to the hot zone. It's just too small a region, and liquid passes through it too quickly, for any significant direct-regeneration effect to be possible there.

There is one drawback to the preceding. When first heating up the engine, rather more than a few milliliters of fluids must be warmed, since the intermediary regenerator fluid is now involved, too. It will take longer for the engine to start producing significant power.

In an RSE the situation is somewhat different, because the notches are much bigger than in a SPARLVE. Please review the "RSE-60" link showing three lobes and notches per rotor. The group of sketches there shows the variant design where one rotor is 60 degrees out of phase with the other. But it is an RSE, a Rotary Stirling Engine, where only gas is the intended working fluid. The rationale for the large notches derives directly from some of the basic facts about all Carnot Cycle engines.

First, the temperature scale that is used for the Carnot Cycle must be an "Absolute" scale, where Zero degrees is "Absolute Zero", the lowest theoretically possible temperature (that's about -273 degrees on the Celsius scale). When the properties of most gases are studied using an Absolute temperature scale, it normally is observed that if the temperature is doubled, then the volume of the gas doubles, too, if nothing interferes. If the gas is confined so that it cannot expand, then its pressure will double instead. In a Stirling engine, the gas is partly confined, so that it must exert pressure on the power piston in order to expand.

The relevant question is, "How much is the gas volume allowed to change, in a Stirling engine?" The answer to that question tells us much about what the temperature-difference should be, between the hot zone and the cool zone of the engine. If the engine allows a 3:1 volume change, then it logically figures that the hot zone should be three times the Absolute temperature of the cool zone. So if we expect the cool zone to be room temperature, which is roughly 300 degrees on the Kelvin absolute-temperature scale, then the hot zone needs to be 900 degrees Kelvin, to make the gas expand its volume three-fold. A slightly hotter temperature may be useful in getting more power out of the engine (via increased gas pressure), but a much hotter temperature is likely to actually simply be wasted energy, because the engine can't properly use the greater changes in volume that would be associated with the higher temperature.

In an RSE the cooled gas gets pushed into a notch of one rotor. Even with large notches, compared to a SPARLVE, the space available is not especially great, compared to the space that the lobes of the rotors can traverse while being "pulled" by gas contracting in the cool zone, and in turn pushing that gas into the notch. A gas-volume change of 5:1 might be expected, perhaps. If so, this means that the hot zone should have five times the Absolute temperature of the cool zone, for an RSE to be maximally energy-efficient. That could be 1500 degrees Kelvin, which is quite hot, to be sure (approximately 2250 degrees on the Fahrenheit scale).

But, how quickly can we quintuple the Absolute temperature of a gas, and cool it down again? This is crucial, if we want an RSE to have a decently fast rotation rate. If we can't do it, then we need a smaller gas volume ratio in the engine--fairly easily done by using a different lobe size, relative to the rotor diameter and notch size. On the other hand, maximum efficiency of a Carnot Cycle engine depends on maximizing the temperature difference it employs! This trade-off between what is desired and what is possible is why a number of research engines would probably have to be built, to find the best compromise that we can engineer. (Now remember that in a SPARLVE, the typical 1000:1 ratio between gas and liquid phases allows smaller notches, a not-extreme temperature difference, and a possibly easier heat-transfer situation. That's why the author of this document tends to prefer the SPARLVE design.) Fortunately for any corporation not wanting to be annoyed with royalty payments while conducting such research, a corporation is legally a person, and making research-engine translations of this document can fall under the "free if built by self for self" clause of the Copyright notice.

Anyway, a regenerator can come in handy for an RSE, indeed! So please now see the "RSE-regenerator-1" link. Again a high-heat-capacity fluid is used, but this time its function is purely as a regenerator, and there are four fluid-travel loops (for any version of an RSE where each rotor has both lobes and notches; if the engine rotors are lobes-only and notches only, then only two fluid-travel loops are needed). The regerator fluid absorbs heat from the "displace" zone of the engine, as gas is rotated from the hot zone to the cool zone. Note that in the animated SPARLVE portrayal, it can be problematic to define where the hot zone ends and the displace zone begins. We obviously don't want a regenerator removing heat from the working gas before it has finished expanding and pushing on the rotor lobes! And that's (A) partly why the regenerator for a SPARLVE was chosen to be an indirect thing, and (B) why the version of the RSE that has triplets of lobes and notches on each rotor was portrayed in the "RSE-60" sketch: It possibly allows the different zones to be better-defined.

Nevertheless, that sketch also clearly reveals that there is still a significant problem with respect to trying to transport significant quantities of heat when space (gas volume of notch) and time (inversely proportional to rotation rate) are limited. (There may even be a slightly better layout for directions of fluid flow than presented in the diagram; feel free to experiment!) Certainly the first problem is why it was mentioned in the linked sketch that yet another variation of the RSE design is likely needed, to take full advantage of a regenerator.

You may recall that near the start of all these descriptions it was mentioned that the engine would feature at least two rotors. See the "Unfinished" link for a sketch showing an initial exploration of a 3-rotor design. It was also previously mentioned that I've been thinking about Rotary Stirling Engines for a long time, and that sketch relates somewhat to the prior descriptions in this document, and to an early effort, posted at the "Yet Another Heat Engine" link a few years ago, as well as to the new design at the "3-Rotor RSE" link.

Many variations on the generic theme of the SPARLVE and RSE, as presented here, are possible. It is in the author's best interest to mention at least one example of such variation, so how about an engine in which the rotors are not all the same size, or an engine with four axles/shafts for the rotors? See the "RSE-4-2" link, which shows both at the same time.

And now we are done with Regenerator stuff. The only remaining thing to discuss is a comment made early-on about pretending that 1:1 gearing is located behind-the-scenes, to ensure that the rotors stay properly/relatively aligned--and that the gears aren't really necessary. The simple explanation begins by asking you to go back and look again at the animated .GIF. It was constructed from 18 separate images, at 10-degree intervals of rotation. Suppose we had 18 rotors on each axle of the engine, and also on each axle neighboring rotors exhibit 10-degree phase angles. It should be obvious that in the overall assembled engine, no matter what its position in the total 360 degrees of one full rotation cycle, there will always be some of the rotors having lobes in notches, effectively acting as gear teeth. (18 rotors per axle is probably excessive, in fact.) Therefore no ordinary gears are needed.

Be careful when installing all those rotors in the same overall engine case, however! Some ways of doing it will lead to engines that cannot work! That will be because a pathway will exist for the working fluid to flow without exerting pressure on any of the rotor lobes! Either the rotors (or groups of rotors) on each axle must be isolated, in terms of fluid flow, or an installation pattern that resembles a "herringbone gear" will need to be used. Those statements are best explained with some accompanying sketches; see the "Offset Rotors" link.

The next sketch is at the "Gears" link; scroll down to the gears; both helical and herringbone gears are portrayed. But since gears have far more lobes and notches than are practical for this Intellectual Property, I've taken the liberty of severely distorting and modifying the herringbone-gear sketch, to try to show what the surface of a SPARLVE or RSE rotor might look like, with a lobe and a notch separated by nearly 90 degrees (okay, I admit my sketch isn't quite up to the intended result; they're more like 60 degrees apart. So?). See the "Herringbone Rotor" link.

In conclusion, if you imagine this rotor meshing with another, contacting where that central horizontal line would cross the front of the portrayed rotor, then one lobe is meshing at the center, and another lobe is either just-beginning or just-ending its meshing at the edges (depending on rotation direction). Therefore they can mesh well enough, for an entire rotation, to eliminate synchronizing gears (and their associated cost and energy losses).

Vernon, Nov 02 2007

Stirling Description http://www.stirling...e=public&faq_id=1#1
An excellent description, with diagrams of the original Stirling engine. [Vernon, Nov 02 2007]

(?) Animated .GIF http://www.nemitz.net/vernon/SPARLVE.GIF
A SPARLVE in action. Do you see the dripping condensate? [Vernon, Nov 02 2007]

RSE-60 http://www.nemitz.net/vernon/RSE-60.GIF
A variant design with the rotors 60 degrees out of phase, relative to each other. [Vernon, Nov 02 2007]

RSE-1 http://www.nemitz.net/vernon/RSE-1.GIF
A variant design with one lobe on one rotor and one notch on the other rotor. Heh, the modern extensions to Copyright Law (that made it so powerful that I'm invoking it in the first part of this Idea) are sometimes called the "Mickey Mouse Law". Any resemblance to a certain cartoon character that you might notice in this image is strictly coincidental. (Really! In terms of mass manufacturing, circles are easier to cut out than other shapes.) [Vernon, Nov 02 2007]

Ice Engine Ice_20Engine
An Idea previously posted here, partly to explain the power of a phase-change engine in defiance of the Carnot Cycle, and partly to prepare the way for the SPARLVE. [Vernon, Nov 02 2007]

Casing for a SPARLVE or RSE http://www.nemitz.net/vernon/Casing.gif
This is just a basic sketch, enough to present the basic idea. [Vernon, Nov 02 2007]

Regenerator-1 http://www.nemitz.net/vernon/Regen-1.gif
A SPARLVE may require regeneration to be done indirectly, instead of directly, due to limited space and time in which it can operate. [Vernon, Nov 02 2007]

RSE-regenerator-1 http://www.nemitz.n...ernon/RSEregen1.gif
Direct regeneration in an RSE is more possible than in a SPARLVE, but it has its own limitations. [Vernon, Nov 02 2007]

Unfinished sketch http://www.nemitz.n...rnon/RSE-3study.gif
This is presented to show that I've thought about a LOT of variations on this theme. [Vernon, Nov 02 2007]

Yet Another Heat Engine Yet_20Another_20Heat_20Engine
An earlier attempt along the lines of a Rotory Stirling Engine; it says so in one of the annotations. I'll be updating that Idea with the next link here, which, except for lacking all the gear teeth described there, pretty closely matches what I was describing. [Vernon, Nov 02 2007]

3-Rotor RSE http://www.nemitz.n...rnon/RSEnoregen.gif
No regenerator needed, as explained elsewhere. For those who have trouble understanding how it can work (and also how it applies to the "Yet Another Heat Engine"), imagine hot gas expanding from the heater into the engine, pushing on the rotors. Imagine gas contracting inside the radiator, "pulling" on the rotors. Simple. [Vernon, Nov 02 2007]

RSE-4-2 http://www.nemitz.n...rnon/RSE-4study.gif
Not well named, this variation has 4 rotors, a 2:1 size ratio, and 2 notches on 3 of the rotors. [Vernon, Nov 02 2007]

Offset Rotors http://www.nemitz.net/vernon/TWOROTOR.GIF
Two rotors on the same axle are portrayed. If there were a few more, it would be easy to see lobes-like-gear-teeth all the way around the circumference, SOMEWHERE. [Vernon, Nov 02 2007, last modified Nov 03 2007]

Herringbone Rotor http://www.nemitz.n...ernon/HerrRotor.gif
This sketch attempts to portray how, if the lobes and notches are spaced around the perimeter of a rotor, two such rotors can still be engaged throughout a whole rotation. [Vernon, Nov 02 2007]

Patent FR2662468 http://v3.espacenet...C&IDX=FR2662468&F=0
a modular rotary heat engine [xaviergisz, Nov 02 2007]

This Idea as a more ordinary Web page http://www.nemitz.net/vernon/SPARLVE.htm
Most of the above linked images are embedded into the page, so you don't have to go out of your way to see them. [Vernon, Nov 02 2007]

Tri-Dyne http://www.deadbeat...iptoid/tridyne.html
A purely rotary internal combustion engine, once featured in great detail in the magazine "Popular Science" (July 1969 if I recall right). [Vernon, Nov 02 2007]

DE19711084 http://v3.espacenet...&F=0&QPN=DE19711084
another rotary heat engine [xaviergisz, Nov 02 2007]

Gears http://www.roymech....Hellical_Gears.html
Sorry folks; looks like in the hurry to post all the links quickly one got confused with another, and ended up getting left out. Both helical and herringbone gears are described. Be sure you scroll down that page far enough to see them. [Vernon, Nov 03 2007]

Copyright has its limits http://en.wikipedia...ptions_to_copyright
Copyright protects the expression of the idea, not the idea itself. [david_scothern, Nov 03 2007]

Braille copies http://en.wikipedia...t#Accessible_Copies
Translation into braille does not require permission from the copyright holder. [david_scothern, Nov 03 2007]

3-D printing http://fabathome.or...php?title=Main_Page
For anyone who doesn't believe that atoms can be digital data-representation/storage, per the DMCA.. [Vernon, Nov 04 2007]

HB Lite HB_20Lite
I think I'll wait for this version [simonj, Nov 05 2007]

Some Rotary Stirling Engines http://www.rotarystirlingengines.com/
Most of these are rather more complicated than the Ideas presented here. [Vernon, Nov 14 2007]

A 3D artwork described in words Art_20Deco_20Telescope
As mentioned in an annotation. [Vernon, Nov 15 2007]

Rotary Rocking Chair Rotary_20Rocking_20Chair
Guess who thought that one up. :) [Vernon, Nov 15 2007]

rotary positive displacement engine http://www.google.c...AAAAEBAJ&dq=6142758
some prior art that you are building on.. [afinehowdoyoudo, Nov 17 2007]

Leidenfrost effect http://en.wikipedia.../Leidenfrost_effect
[afinehowdoyoudo, Nov 17 2007]

ROVAC http://books.google...%22%20rovac&f=false
ROVAC is mentioned in an annotation here. [Vernon, Mar 08 2010]

3D Printing Legalities Rising http://arstechnica....novative-future.ars
Many of the annotations to this Idea are about the legalities of patent law vs copyright law. It appears that some of the stuff I wrote about 3D printing is starting to be figured out by other people, heh! [Vernon, Nov 11 2010]

Copyright Power http://www.wired.co...t-to-the-batmobile/
[david scothern] and I had a significant discussion about using the copyright law to legally protect hardware. This legal ruling, if it survives (it might be appealed), could be the first chink in the wall between copyrights and patents. And, personally, I think the more that 3D printing "takes off", the more that people are going to try to squeeze copyrighted designs through that chink! [Vernon, Feb 03 2012]

Copyright extension of designs https://hardware.sl...ault-on-3d-printing
Here's an update on the law, relevant to a major discussion in the annotations. What do you think of my position now? [Vernon, Aug 08 2016]


       Well good for you! I know from your other idea that you wanted a purely rotary stirling engine and, although it may take days to read all of the idea and links, it seems that's exactly what you've done. It also seems you've even gotten a Copyright to go along with it.   

       It may be a little beyond my understanding since Stirling and the like aren't exactly my forte, but this is incredible stuff. Could very well be your best work in the engine department I reckon. A 3-rotor phase changing bun for you [+].   

       Just out of curiousity, how long did it take from the start of this whole thing to the posting here?
acurafan07, Nov 02 2007

       [acurafan07], this didn't take all that long to write a first draft; I'm a competent touch-typist. But all those images kept me busy for more than a month. And some of the text couldn't be properly written until after certain images were done.   

       [bigsleep], the RSE-1 sketch describes problems that it has, and solutions. If you were talking about the solutions described, and not the sketch, then I think I can agree with you. Although I tend to prefer designs in which both rotors act as power rotors and as displacers.
Vernon, Nov 02 2007

       I'm afraid you can't use copyright as pseudo-patent protection. Copyright only protects the particular embodiment/form of an idea, not the idea itself. In this case your protection is only to what you have written in the written form.   

       You are correct that a written document such as this could be used as prior art to prevent someone else from patenting it. You are also correct about the grace period, although (to my knowledge) this hasn't been tested in court. See my 'ideas marketplace' post for similar ramblings.   

       I'm not a stirling engine expert so I won't comment on this idea except to say that there seems to be similar inventions on the patent databases.
xaviergisz, Nov 02 2007

       [xaviergisz] wrote: "Copyright only protects the particular embodiment/form"   

       You seem to be missing the "translation" point, that the author's permission can be required to translate a copyrighted work. How does a physical copy not count as a translation?
Vernon, Nov 02 2007

       OK, believe what you want to, but I'm telling you that there is a considerable amount of case law confirming what I have said.
xaviergisz, Nov 02 2007

       idea comes with a free ladder
xenzag, Nov 02 2007

       Great to see you're still around [Vernon].
phoenix, Nov 02 2007

       Copyright protects anyone from duplicating this post in their own writing it does not protect the idea from being produced by anyone who reads it. Under the current rules, it may provide documentary evidence of the date of this idea which would prove origination of the idea in a patent case. That is all it does. (US IP law, at least). Furthermore, somone reverse engineering a device, and creating their own documentation to do so, in no way violates the documentation of the original creator, unless they take material from the original in doing so. And as a simple aside, it is far better to print out the idea and get it notarized with the date (cost $2-3 most states) to protect it. Mailing it to yourself in a sealed envelope also works, with the postmark providing the date, but this is less reliable.
MechE, Nov 02 2007

       Patenting is not an easy task. To the best of my knowledge it works like this. You establish prior art and get a year to file a patent (after that year the idea doesn't really belong to you anymore). You then have to make a working prototype and have an air-tight description of how it works (so that nobody can find a loop-hole and steal your idea), usually requiring a patent lawyer and thousands of dollars. The patent alone is hundreds of dollars I believe, and then you always have the cost of the prototype.   

       I used to be concerned about having my ideas stolen after I posted them, but then I realized that by the time I could be in any position to file patents, my ideas relating to internal combustion engines will likely be outdated.
acurafan07, Nov 02 2007

       Another note, again US IP law only, but a preliminary patent application is relatively inexpensive and simple to file. This provides concrete legal protection of the idea while you are developing the documentation and doing the prior art search required for the preliminary patent, although only for a limited period.
MechE, Nov 02 2007

       [xaviergisz], I respect case law, but since Copyright Law has been modified, to cover more media in which a copy might be made, has that been tested yet?   

       The patent you linked appears to be just a variation of a gear pump (different-shaped gears). It doesn't have the 3 rotors of the "Yet Another Heat Engine", which are important to its operation, and it doesn't have the larger-than-lobe-size deep notches, that either a SPARLVE or an RSE would have. I know of an internal-combustion-engine design that resembles a SPARLVE more than that one does (link added), but even it doesn't have its rotors all acting as power rotors.   

       [MechE], I think most patent lawyers don't recommend the mailing-to-yourself thing, although notorization is good. Here, the HalfBakery always date-marks all new posts (and mere users have no control over that), which should be good enough until I can afford more formal patent protection.   

       [acurafan07], a working prototype USED to be required for all inventions, but nowadays that rule only-and-specifically applies to perpetual-motion-machines. But you still need lots of $$ just to get a patent properly legalese-formatted.
Vernon, Nov 02 2007

       Hearsay suggest strongly that online posts are generally not acceptable in court for concerns of this nature. While the date stamp is indicative, it is to easy for someone to tamper with. (Even if you personally don't have access) I would go with the notary. And for an individual to file, while not cheap, a patent with background search (which is the major legal expense) shouldn't run more than $1500-2000. The prelim is under $100 last I checked.
MechE, Nov 02 2007

       I hurt myself scrolling down to the bottom of this idea.
normzone, Nov 02 2007

       [Vernon], I think a court would ask whether the device was _primarily_ intended as a work of art, or as an engine. Given that you state that it will take time, "for the engine to start producing significant power" and cite this as a drawback, it will be classed as an engine, an invention that should be patented, not a work of art subject to copyright laws. I've no doubt that other statements made in the idea would be viewed in a similar light.
david_scothern, Nov 02 2007

       [MechE], I'm not surprised, but there is more than one way to validate a Web page's date. There is, for example, the "mission" of www.archive.org, which already has been involved in various legal issues, and so MUST maintain accurate dates of the data it archives. I've submitted an appropriate page to them (see the "ordinary Web page" link), as one of several relevant things to do, in dealing with the overall legalities.   

       [david scothern], consider a Review of an already-existing device (for an example, there is the Popular Science article mentioned at the "Tri-Dyne" link). Often this is a thorough description of the device, including its drawbacks, and that document, including diagrams/images, is entirely normally Copyrightable written material. Here the Review simply precedes the actual existence of the device. Why should that make a difference? Indeed, the "imagination" factor here (crucial to all works of art) is far higher than in an ordinary Review!
Vernon, Nov 02 2007

       It makes a difference, in that the material is copyright, but said copyright does not protect the design. All it protects is the author's description of it, not anyone's rights over the tri-dyne engine itself.
david_scothern, Nov 02 2007

       [bigsleep], sorry, but I also don't at this time have the $$ to build one.   

       [david scothern], I do understand where you are coming from, but this does not seem to take into account modern changes to Copyright law, covering more media into which a copy might be made. Consider a translation of this page into sign language. What is sign language? It is a language made from SHAPES. So is Braille, in fact. Well, if Copyright law can govern the translation of a document into the shapes of sign language or Braille, why can't it govern the translation of a document into the shapes described in the document, one aspect of the language of engineers (which as previously mentioned are reverse-translatable into another document)?   

       [xaviergisz], your second link is a closer match. But that inventor went to a lot of trouble to pipe the working fluid through the rotor axles, so that it generates an action/reation/jet effect as it leaves the rotor lobes and enters the working volume of the engine. Most of the parts have complicated shapes, so manufacturing that engine on a large scale would be significantly more expensive than making the engines I have described here, where expanding gas merely pushes on the rotor lobes.
Vernon, Nov 03 2007

       [bigsleep], the discussion is fine; I do say, after all and right up at the front of the Idea, that there are TWO notions presented here. That the engine will work is not likely to be argued about. Which leaves.... :)
Vernon, Nov 03 2007

       [Vernon], I'll point out again that, if the patent/copyright argument hinges on whether this is a work of art or not, a judge would decide whether this was primarily intended as a work of art or as an invention. Note: Decide, not ask. Rather than argue that sign language and milled steel are equivalent, you need to research whether the invention explained here can be protected by copyright.   

       Furthermore, to take you on on your own ground, translation into braille is legal without permission from the copyright holder in both your country and mine (see link entitled "braille copies").   

       (On another note: As you rightly judged, I think the idea seems sound - provided that effective sealing is used. I have no argument with you there!)
david_scothern, Nov 03 2007

       [david scothern], I agree that a judge could render a decision, and I'm sure precedent could play a large role in that decision, but part of my argument here is that recent extensions to Copyright law are in certain respects UNprecedented. And judges usually render decisions after hearing "arguments". I have more!   

       For example, let's start from way out in left field, and examine the word "sexy". The dictionary provides such definitions as "risque`", or "exuding sexual attraction", but the word is often used in a manner such that its meaning could be "encourages one to think about the sex act". By that definition, then, the sex act itself must be the very essence of "sexy".   

       Well, the logical corollary to that is, a gadget constructed from a text/diagrams description is itself the essence of its description; i.e., it is just as much a COPY of the description that was used to construct it, as it is an actual gadget. I have called it a "translation", and that is still an accurate call, because the "language" of that description, the essence of the actual gadget, is different from the original text/diagrams. Still, the gadget remains the essence of its description AND unoriginal: a copy, that is. Since Copyright law covers the making of copies, quite clearly...   

       What is the judge's logical decision?
Vernon, Nov 04 2007

       Copyright doesn't mean a great deal. It doesn't protect anything that's actually functional, it's more about presentation. Different legal jurisdictions apply this in different ways, but either way anyone could (theoretically) build this Halfbakery idea and have now worries about copyright infringement. There might be an interesting discussion about content vs presentation here as this idea is presented through a website that has a particular copyright-able image.   

       Software patents and copyright are the grey area where copyright does show a relatively strong protection for IP.   

       The fact that this post exists means that the invention is in the public domain. That torpedoes any chance of a patent in most, if not all, jurisdictions too.   

       Finally - apologies to [Vernon]. I haven't actually read the engine aspect of the idea properly. I just saw "copyright" in the title and then skimmed the annos. (Which may make this comment redundant too. I'm not an expert in copyright law, but I don't think "It's art" is going to wash as a copyright defence)
Jinbish, Nov 04 2007

       I haven't heard of these recent extensions to copyright law. Could you elaborate?   

       One of the big conceptual differences between copyright and patents:
- copyright infringement requires proof of actual copying; whereas
- patent infringement only requires that the same invention was made; even if the same invention was conceived independently (i.e. without knowledge of the other).

       This is based on the premise that each problem has only a small number of solutions (i.e. inventions) whereas plays/songs/novels come in infinite/unbounded variety.   

       Thus it is important that there is a register of patents, and the patents on the register are assessed for validity - so a person can know if they are infringing.   

       On the other hand copyright doesn't require such a register - copying (plagarism) should be completely self-apparent.
xaviergisz, Nov 04 2007

       [Jinbish], an invention can be public knowledge for a year before it actually by-default falls into the public domain. A patent obtained within that time will be valid.   

       [xaviergisz], the "Mickey Mouse Law" basically extended the copyright period. The Digital Millenium Copyright Act, while famous for such things as illegalizing efforts to break copy-protection, also had to extend the range of media into which copies can be made. A digital copy (a sequence of 1s and 0s) bears no physical resemblance at all to the original, yet it is considered to be equivalent to the original. Note that because of such things as encryption and data compression, there could actually be a very very large number of sequences of 1s and 0s, all of which are equivalent to the original. Then there is the physical form in which those 1s and 0s are stored, from the ancient history of Jacquard Loom through magnetic rings of early-computer "core" memory, to holography and DNA --and who knows what the future holds? So I interpret all that as basically saying that, "If you can retrieve some semblance of the original copyrighted thing from the copy, then that suffices to define the copy." The corollary is that the medium doesn't matter, and thus gadgets can qualify as copies of their descriptions. They even qualify as "digital" if you think of "atom-here=1" and "no-atom-here=0". See the "3-D printing" link.   

       Heh, I'd say that the only possible exception to the above definition of a copy, is "human memory". If you see/hear/sense something and remember it, then you have internally made a copy of it. While I'm sure various greedy copyright holders would love to charge you for having done that, there is no way the population will allow such a notion to become law.
Vernon, Nov 04 2007

       Holy verbosity Batman, that's 5,500 words, that's a record Shirley.
marklar, Nov 05 2007

       I still haven't read the idea, but the diagrams and animations are great. The idea is beautifully simple and I really want it to work, but have a pessimistic gut feeling that there is some reason why it wouldn't. So far, I haven't figured out what that reason is. Also, your design is much simpler than mine and therefore I hate you :P   

       However, in all the variations of your design, power is produced 50% of the time (or more accurately, for the outtie to innie distance for each outtie, per revolution, per rotor). The design for my engine had the same problem, which I solved. That is not something I want to discuss here as I'm currently applying for patents. <rant>Having read ALL the crazy documentation involved (which makes your text look like a Haiku) I can assure you that your idea is not protected. Apply for a patent, IT'S FREE. You then have a year to complete the process and pay money, during which time you publish your idea and try to get enough interest to warrant paying the fees.   

       I'd love to post my engine related ideas on the bakery, but the ego boost is not worth the risk. Decide which you want more, kudos or investors.</rant>   

       BTW, I think your engine would need to be high speed, low load as it will be hard to seal the compartments without creating wear, so there will be some seepage.   

       Also, consider putting the copyright information in a seperate linked idea or on your own website. I'm not sure if it would be possible to cover an engine under copyright if you used it as the basis of a story involving an inventor (eg, the flux capacitor)
marklar, Nov 05 2007

       Kinda sucked the fun out with your long copyright statement, but if you're really trying to go large with this, then I can certainly understand your need for having that up front.   

       Watching your GIF, there isn't anything for the working fluid to react against on the stationary part of the motor. There's a vane on the rotor, so the fluid can push against that, but there's nothing stationary in the housing to prevent the working fluid leaking back into the cold section. I know it's a very simplified diagram, but then again...   

       Is that a detail you left out? It would be a super-simple feature - analagous to a reed valve, and perhaps nothing more sophisticated than exactly that. You'd probably want another one shortly before the meshing area where the two rotors meet, too. Or is there something about the thermodynamics that I don't understand?   

       This design is so simple, so obvious. I have half a mind (jokesters will interrupt here with "we know!") to machine one of these up out of aluminum - with the reed valve - and put it on top of the woodstove, big heatsink on top and a fan geared to the output. I've got a sneaking suspicion it would work.   

       Brilliant. Love it.
elhigh, Nov 05 2007

       [david scothern], regarding seals, they have their uses, but are not necessarily essential. The "Tri-Dyne" engine had NO seals. It could easily run at 12,000 RPM and it produced 4HP per cubic inch of displacement (I take that to mean it guzzled fuel, going that fast). The trick it used was very-close-tolerances on the machining. 0.004 inch gaps, at most, between the rotor and the side wall, and the rotor lobes and the outer casing. I guess the explanation is, it ran too fast for there to be time for much gaseous material to leak through those cracks. This implies, of course, that a slower-running engine might indeed need seals. Or even closer toleranaces in construction. I saw an ad the other day, somebody was looking for someone who could machine stuff within 0.0004 inches, a tenth the gap-size in the "Tri-Dyne".   

       [marklar], by word count alone, this is not a record Idea. There's one titled "12864" that's over 11,000 words. However, if all the bytes of all the images associated with this Idea are included in the count, then perhaps this takes the record. Bytes aren't words, though, so the comparison isn't simple.   

       Next, when you said you read "ALL the crazy documentation", were you talking about the annotations here that discussed the copyright situation? My starting point is that Copyright Law has been changed in recent years and made more powerful thereby. The full extent of that power hasn't been tested in court yet, so far as I know.   

       Next, I'm not certain what you meant about the engine producing power only 50% of the time, since Stirlings are double-acting, and that feature was retained here. It may be convenient to open the animated .GIF with a viewer program that can let you "play" it one frame at a time. If a rotor that has 2 lobes is oriented so one lobe is at top and the other lobe is at bottom, then one lobe is being pushed by expanding gas in the hot zone, and the other lobe is being "pulled" by contracting gas in the cool zone (with "pulled" in quotes explained in the main text).   

       Rest assured that I am pursuing more means of protection than just Copyright. Regarding kudos, it seems to me possible that if the idea is published and receives kudos, then investors would have a reason to think they wouldn't be wasting their money.   

       [elhigh], the Wankel semi-rotary engine (in production for Mazda RX-7 cars) has seals on the sides of the rotor, as well as on the edges of the rotor lobes. Making seals that could stand up to internal-combustion temperatures and pressures took a LONG time, but it is a developed technology. And these engines don't need that extreme of temperature or pressure, anyway.   

       Next, I'm not sure what you are talking about, "there isn't anything for the working fluid to react against on the stationary part of the motor". The working fluid pushes on both rotors of the animated .GIF, which rotate in opposite directions. The fact that one rotor is 90 degrees out-of-phase with the other makes no difference, to the fact that expanding gas can push against both rotors. The stationary casing merely helps define the working volume, in which gas can expand, to push on both rotors. (And in the cool zone, gas contracts, "pulling" on both rotors.) That engine should be self-starting, reliably in the same direction, no special valves needed. If the notches were enlarged and the working fluid was always a gas, so that the SPARLVE animation was instead an animation of an RSE, it should still reliably self-start in the same direction, no special valves needed (but seals might be needed, depending on the fine-ness of its construction, as described near the start of this anno).   

       Feel free to build several, if you wish. I'm only interested in a royalty if you sell those copies.
Vernon, Nov 05 2007

       I would just like to anno postively about chapters 1-4 of this idea, looking foward to reading chapters 4-12
evilpenguin, Nov 05 2007

       [elhigh] I have access to a friend's lathe this evening. I am making 2 out of aluminium, a 2-blade and a 3-blade. I've even bought a multimeter and temperature probe. Now I'm just trying to find a blow torch for the heat source.   

       [david_scothern] I think that lubricating the cylinder with a suitably thin oil should reduce/prevent leakage.   

       [Vernon] I think that there will be a big loss in efficiency due to the thermal conductivity of the block. If my first model is moderately successful, for the second model, I'll slice the block and bond an insulator between the halves before machining.   

       This is fun, I get to play with tools again :o)
marklar, Nov 06 2007

       [marklar], I don't know if you have gotten around to reading the main text yet, but there is some stuff in there about the thermal issue you mentioned, and dealing with it. Even the rotors may need some thermal isolation, perhaps a thin layer of silicone, since they are alternately exposed to the heated and cooled zones as they rotate. Nevertheless, enjoy! Also, just because I have a chance to say this before [bigsleep] (did you see his annos?), there appears to be some interest in a video of the result. Any way of making one of the sides of your model out of plexiglas? :)
Vernon, Nov 06 2007

       I can't see that the inside would look all that interesting. I'll certainly show it open and turning from external force, then show it running with something attached to the axle, like a motor used as a generator and a torch bulb.   

       I don't have a way to measure RPM and torque, can anyone think of some way to do this without buying expensive measuring equipment?   

       Also, I'm thinking of trying to find a petrol camping stove for the fuel source so I can measure fuel usage. Or I could get scales sensitive enough to measure the weight change of a gas canister. Any other suggestions?
marklar, Nov 06 2007

       If a picture is worth a thousand words, how many pictures does a Vernon idea take?
RayfordSteele, Nov 06 2007

       <smacking forehead> Criminy. Yes, of course, seals on the stationary part are unnecessary.   

       With seals, you could get by with just the one rotor, but it adds a moving part that would eventually wear out.   

       More rotor diameter = more torque. And you'd want the rotor to be as light as possible, preferably with as little heat capacity of its own as possible.   

       Okay, I'm caught up. Never mind me.
elhigh, Nov 06 2007

       I was thinking that the rotor should be hollow and perhaps ceramic. That stuff F1 brake pads are made of maybe.   

       BTW, production is delayed till the weekend :o(
marklar, Nov 06 2007

       [marklar], from your description I get the impression that you might need to include 1:1 gears to ensure the two rotors stay aligned as they turn. One alternative that might be worth experimenting with, though, starts with the thin insulating layer on the rotor surface: if it is a high-friction substance like silicone, then the two rotors might simply be in contact, and friction will keep them aligned as they rotate. Can't say how long it will last, though "rolling resistance" is what's involved here, often a low wear-and-tear factor.
Vernon, Nov 06 2007

       I hereby state my intention to construct and sell a heat engine which has certain conceptual similarities to the engine outlined here, that is, the heating of one region and the cooling of another will cause boiling and condensation, respectively, the resultant pressure change doing work. My heat engine will have, as its core, two rotors which will be large, hollow cylinders with walls twelve millimetres thick, made from LM-25 aluminium.   

       Six axial slots shall be equi-spaced about the circumference of each rotor.   

       Of these, three will be rectangular in cross-section, with 1.5-millimetre radii in the internal corners to facilitate manufacture and reduce stresses. These three will accommodate projecting lobes, which will be pushed outwards by springs in the bottom of each slot. Strip seals round the bottom of each will prevent gas leaking under the lobe.   

       The remaining three will be profiled to accommodate the lobes mounted on the other rotor. The lobes shall be a modified involute (gear-tooth) profile, and shall be manufactured in plastic in order to give a low stiffness and ensure load-sharing (and thus contact) along the whole face, for maximum sealing when the projecting lobe on one rotor is accommodated by the appropriate slot in the adjacent rotor.   

       Each rotor will be supported by some arrangement of bearings. In this preferred embodiment, the rotors will be supported on a roller bearing at one end and a ball bearing at the other. The machine will be operated with rotor axes vertical in normal running, in order to ensure that the ball bearing is always loaded in one axial direction and thus is not at risk of skidding and damage under any operating conditions.   

       The casing will be made from cast aluminium. The external face of the hot zone will have a black anodized finish, as it will act as the focal point of a solar concentrator. The cool zone will be provided with an inset copper block, whose external face will be milled flat and equipped with bolt-holes to allow for a water-cooled heatsink, or preferably a heat pipe suitable for dumping heat into an underground sink.   





       The point I make here is that, while the above would clearly be an infringement of a patent (should one exist), it cannot be a translation of [Vernon]'s original post. Nowhere does the original poster mention:

       - LM-25 aluminium (specific grade, to facilitate casting of a high-strength component)
- Modified involute (not just a gear tooth, but a gear tooth whose design has been tuned for maximum functionality)
- Radially moving lobes (removes the problem of tolerance stack-up between features forcing larger-than-desirable clearances between static and rotating parts)
- Strip seals between the individual lobes and their rotors, to reduce leakage under said lobes - [Vernon] nowhere suggests making the lobes separate, and thus is not faced with this problem
- Low lobe stiffness in the axial direction, for conformity and sealing
- Vertical axis, for the specific purpose of preloading bearings for maximum life
- Features to allow for use of a solar concentrator , and to allow mounting of heatpipes to dump heat to earth.

       None of the above would invalidate the original poster's patent. However, as a translation - by definition - includes no new information (if new information is included, it is a new piece of work) - then my posting cannot be a translation of yours (nor yours of mine). It's quite obvious that I put original thought into it. As a result, I would not be in breach of copyright if I built it.   

       To put it another way, should you incorporate the ideas of anyone who posts on this, you would (by your logic) be in breach of their copyright, as you would have "translated" their idea. Equally, if anybody reviewed your machine, they would have violated your copyright, too. Copyright only protects your work as published, not the idea behind it.   

       Maybe, if you wrote down an exact and exhaustive description of every tiny feature in your design (similar to the exact and exhaustive description which is a 3-D printer's data file) you could copyright that and argue that the physical manifestation of that exact design was also protected. It would be worthless, however, because I could produce something that worked just as well, based on the same principles, but in a different implementation. Copyright doesn't generalise.
david_scothern, Nov 10 2007

       [david scothern], actually, Copyrights DO generalize to a limited extent. Otherwise there would be no such thing as "plagiarism". I'm not sure what % of copied text can be modified, before the author of the original text cannot claim plagiarism to have occurred, but it is definitely something greater than 0% --which means that there is indeed some generalization of that text covered by Copyright Law.   

       I ask you to think again about the emerging technology of 3D printing. The exhaustive description you talk about would obviously specify the "printing" of a particular version of the gadget, and it should be really really obvious that Copyright should be able cover the printing of 3D copies thereby. But how similar could another version be, without "plagiarism" being a valid objection to it? You can bet that this issue will end up in Court, not long after it is generally realized that 3D printing is setting Copyright Law on a collision course with Patent Law. And so I have generalized my description in the main text here, the better to ensure that all sorts of possible translations will be unable to avoid plagiarism. Heh, how well will your engine work if the two rotors have to be taken out?   

       One other thing. If you make a physical translation/copy of what I have described in the main text, and sell it, presumably you would want to make a profit from the sale. Do you have an estimated cost-of-making and selling-price? By what percentage would the sale price be affected if the $10 royalty I've requested was added? You may have written your annotation to point out a particular PRINCIPLE, but it looks to me that that principle boils down to: "The right to find a legal loophole to rip off someone who isn't trying to be greedy". How much negative publicity are you willing to put up with?
Vernon, Nov 10 2007

       As I've pointed out, it's neither a translation nor a copy. It uses the same core idea, certainly, but looks nothing like the machines described here and includes a high percentage of new content (all of the engineering detail needed to make it work). Don't be threatening me with some nebulous publicity campaign - if you're serious about this idea then it needs a patent, period.   

       What I'm trying to point out is not that "I have the right to rip you off", but rather "If this idea is worth ripping off, someone will if you don't cover yourself." And as for the "not trying to be greedy", you're trying to exact royalties without bothering to pay for a patent...   

       Plagiarism is when it is recognisable as the original work, perhaps camouflaged with minor changes. My work is original - I've not copied yours in producing my text. I've read it, thought about it, extracted the idea, interpreted and contributed to it - the original thought should be glaringly obvious.   

       If you think that my additions might contribute, then you're welcome to include them in a patent with no strings attached. However, I'm retaining copyright on them.   

       Seriously - I'm not here to beat you down. You just happen to be extremely difficult to correct, even in the face of blinding common sense. Take the advice of the posters here, and patent it.
david_scothern, Nov 10 2007

       Just because you claim to have pointed out that what you described is "neither a translation nor a copy", that does not mean your claim is truthful. How many lawsuits in Hollywood have there been, after Person A shows a script to Person B, and Person B makes a show from a modified version of the script, without paying Person A? Copyrighted ideas, a group of new plot twists for example, have more protection than you realize.   

       Next, I was not being personal in my last annotation. While there is such a thing as "fair use", and it has been recently getting stepped on by greedy copyright holders via "DMCA takedown notices", even "fair use" has limits. You might be able to incorporate 1 paragraph of my description (equivalent, say, to 1 plot twist), without stepping across the line from "fair use" to "plagiarism". I doubt you can pick one paragraph of the main text here, and use it and ONLY its content, in making your copies of what I've described.   

       Next, the legal protections of a patent exist because of greedy people ripping off other people's ideas. It gives the little guys a chance to take on the big guys, and win. I wasn't being personal in talking about a negative publicity campaign; in this Age of the Internet, communications is a major weapon that the little guy can use, because the big guys didn't get that way without involving lots and lots of other people, most of whom are reasonably honest. Consider the case of the Sears Craftsman ratchet wrench, which had a nice new button to release a securely held socket. That button was a patented gadget, but Sears put it into production without paying the inventor, who sued. He won, true, but I wonder what Sears would have thought about a "Boycott Sears because they are thieves" campaign, as an alternative. Such a campaign could not have been easy to get started before the Internet, but today...how many big companies could afford to be up against that? And how many little companies could ever become big, if they were up against that?   

       Finally, I do not dismiss the notion of getting a patent. I'm merely pointing out here that recent changes to Copyright Law have made it more powerful--do you deny that?--and the full extent of that power has yet to be tested in court. And until I can afford a patent, Copyright is all I have, for protection, and most certainly for a year.
Vernon, Nov 11 2007

       I can produce my machine without needing to copy any of your paragraphs, fully or partially. What I need is the idea, not your words. Take a look at the body of text I produced above, and show me where I have lifted it from. You can't, because I didn't. On that basis it should be obvious that I can imitate your idea without copying your words; I could quite easily have fully outlined the working principles of the machine in the same way. This leaves you vulnerable.   

       Consider an author doing research for a book. He reads an entry for, say, Barbados in Encyclopaedia Britannica, and uses the information he finds as background for a scene. Can the publisher of the encyclopaedia sue him? Of course not. Copyright covers the presentation of facts, not the facts themselves. The sky is blue in Barbados whether the E-B says it is or not (unless it's raining...). Similarly, the physical principles of your idea are valid, with or without your particular wording or recognisable modifications thereof.   

       And yes, you said what I did - patents are to stop greedy people ripping off others' ideas. Copyright isn't - it's to stop people passing off other people's published work as their own.   

       No negative publicity campaign could work, given the number of people who have advised you to get a patent, and your refusal. It would just make you look mule-headed - they warned you, you ignored them, they were right, you were surprised.   

       The DMCA may have strengthened copyright law. Nowhere is there the faintest indication that copyright now protects the idea behind a product or machine. 3-D representations may well be covered too, but only in terms of their physical characteristics, not their working principles.   

       Find me a source on the web somewhere (editing Wikipedia doesn't count!) that goes against what I'm saying here. At the moment it's just your words vs mine, neither of which have any real value.   

       Also, demonstrate where I translated your text to produce my description above. Remember, a translation cannot incorporate significant new ideas. If you can't demonstrate it, how can you argue that a physical model is a translation?   

       If you really want to protect this until you have more money, hide it. Take it off the site and sit on it for a while. Money > kudos in this case, given that the kudos could stop you ever getting money, whereas the money (in the future) wouldn't stop you getting kudos!
david_scothern, Nov 11 2007

       There's always the pain-in-the-ass factor. Copyright protected or not, if anyone were to build this and profit from it, it would be a long (and expensive) legal battle to prove your case (even if you're completely in the right).   

       And what's more, after a year it would be fair game for anyone to use if it remains unpatented. The worst part is that if you patent it any time after a year from posting this and someone can prove it, the patent could be considered invalid (since prior art would have been established over a year before patented).   

       It's too bad that the vast majority of ideas here aren't ever prototyped due to lack of funds. If only some investors were to see some of the ideas here, everyone would win. But I guess then it wouldn't be the halfbakery anymore.
acurafan07, Nov 11 2007

       [david scothern], I see you are ignoring the schematic drawings which are part of the overall document; if each picture is worth 1000 words, how many paragraphs have you copied, in making your copy of what I have described? Some of the schematic drawings clearly specify the use of a Heater and a Radiator; in what way is a solar collector not a heater? You might successfully argue that a "water cooled heat sink" not a radiator, but that depends partly on the exact definition of "radiator", and there isn't just one.   

       Here is some relevant text: "The composition of the rotors is not specified, but it is obvious that they need to be made of something that can survive while doing the work expected of them." And here's the gist of something you wrote: "My heat engine will have, as its core, two rotors which will be ... made from LM-25 aluminium." In what way does that substance not qualify as what I described?   

       Next, you are mistaken in saying that I have ignored advice about patenting; I have instead stated that I can't afford it at this time. I'm not aware that when someone agrees to patent something, the funds for doing so immediately appear.   

       Next, you are STILL ignoring the fundamental fact that Copyright covers the right to make COPIES. It is the definition of "copy" that we technically are arguing here. Why should a copy made on a futuristic 3D printer be considered different from a copy made in a traditional machine shop? Far enough in the future, and you won't be able to tell them apart without a microscope; to the Mark I eyeball they will both simply be copies of their descriptions.   

       I will agree with you that the principle of something's operation may not be copyrightable material, but to USE that principle you need the something-operating --a device, which will be a copy of some description. And Copyright is going to Officially cover any such copy, eventually. I'm simply betting that it actually already does so, generally unrecognized, thanks to the DMCA. Because everything that physically exists can be described digitally, which thus makes the description a copy of the thing that exists. Even analog representations of something can be described digitally. The advent of 3D printing simply reverses some of the preceding, and means that physical objects can be copies of digital data. And the DMCA is about rights regarding copies of digital data, isn't it? Q.E.D.   

       Next, in an earlier annotation you wrote: "If this idea is worth ripping off, someone will if you don't cover yourself." This may be translated as saying, "If you want to get paid for your original effort, you may have to make even greater effort." THINK about that in terms of ordinary employment: It implies that you might have to beat up your boss in order to get a paycheck! Now while I have little doubt that such does occassionally occur in some times and places, we may agree that that is far from the norm. But you are implying that with respect to inventing, the NORM is to be ripped off. Yet we live in a culture that has, through representative legislation, decreed that an idea should be its originator's property for a limited time. If this is what the culture has decreed, then why should the norm be to try to find ways to ignore/avoid/get-around that decree? I could imagine that part of it is simply a backlash due to excess greed by idea-owners. And some of it could be habit, due to the frequency of backlashes. But does that habit/attitude need to be applied when the idea-owner is NOT being greedy? So I recommend that if the SPARLVE and/or RSE ideas are perceived to have value, then the person doing the perceiving should pause, take a deep breath, and consider, "If the culture has decreed that the originator of an idea has ownership rights, and if those rights are not being tied to exhorbitant demands, then is there any rationale for trying to deny those rights?"   

       The answer to that will separate the thieves from the mostly honest ordinary folk. And the logical thing to do to self-revealed thieves is to put them out of business.   

       Finally, with respect to hiding this idea, I've made my choice to make it public and will stick with that choice. I'm gambling that within a year I can file a patent; I'm gambling that recent Copyright Law may make patenting it unnecessary. I'm even gambling that--no, that notion shall remain hidden for a time, heh. :)
Vernon, Nov 12 2007

       You're quite right, we're arguing over the definition of a copy.   

       You say that the rotors shall be made from something suitable, I shall make mine from LM-25 aluminium. Undoubtedly, LM-25 is something suitable. However, should you say to a minion, "Make it in something suitable", he would not automatically make it from this grade of aluminium. It might be 18-8 stainless, or ceramic, or titanium, or LM9 or Hykro...   

       Hence my choice cannot even have come from reading your idea, let alone been copied directly. I couldn't get around your patent this way, because a patent doesn't care about such specifics.   

       You're putting up defences as if you had a patent, in short.   

       I've written a description of a device using your principles, which you admit aren't copyrightable. You have successfully demonstrated that I have used the same principles - you describe a general class of materials that will do the job, I pick a specific material to do the job, the principle is the same - but you cannot demonstrate that I have repeated your words or some closely linked form of them to do so. Can you?   

       On that basis, I can write my own description, original work - and you can't deny it, I haven't stolen my writing from anybody - taken from my understanding of your idea. From that, I can go ahead and manufacture them.   

       Before you can claim that your argument that "the physical is a copy of its description" is valid, you need to prove that there can be only one description. Otherwise, how is my machine a copy of your description and not of mine? Seeing as two completely different machines working on the same principles are possible (Wankel vs flat-12, both work on the suck-squeeze-bang-blow IC engine principle), such that a simple written description would be enough to distinguish the two, how can you claim that one is a copy of the other? It's fallacious.   

       And before you wander off into a diversionary explanation of the differences between the Wankel and the flat-12, an alternative example would be your rotor with its integral lobes, and mine with separable, spring-loaded lobes. The principles and purposes are the same, but a couple of sentences would distinguish the two rotors completely. One description would therefore not suffice for both designs - in your words, "seals are optional", whereas for mine, seals are mandatory, and therefore the description of one rotor could in no circumstances be a copy of the other, despite being part of machines that work on the same principles.   

       To turn the argument round, material has been produced on Stirling engines which is still in copyright. Have a look at rotarystirlingengines.com for example. If your argument were to hold, then a very general description of a heat engine that turned a thermal gradient into rotary motion by the action of a working fluid would immediately put you in breach of copyright, regardless of whether the copyright belonged to an inventor or someone who was writing for an encyclopaedia.   

       As for "If you want to get paid for your original effort, you may have to make even greater effort", yes, that's the world we live in. If you want to get paid for your original effort, you have to avail yourself of the protections of the law. I get paid because I have a contract with my employer. If I decided, wrongly, that my contract with my previous employer applied to my new job because I was under its terms when my new job was offered, I would have no legal recourse when I wasn't paid. A clever thief has no protection when the police get him, even though his theft may have taken considerable original effort. You want the law to help you, you have to stick with what it says.   

       You wrote somewhere that "human memory is the only storage excluded". Surely, if your idea has been read, digested, processed and then I have designed a machine on its principles, I have not just copied your copyright material, but rather absorbed the principles and come up with something based on them.   

       Show me how I have taken your words, not your principles. Can you? If I haven't, you're unprotected. "I can't afford a patent" is no defence; you didn't ever have to make it public. You could just as easily have posted all the "copyright supersedes patent" stuff, using a dummy idea.
david_scothern, Nov 12 2007

       [david scothern] wrote "how is my machine a copy of your description and not of mine?" Simple. Mine is, as you admit, the BASIS of yours. You CANNOT construct it without rotors and lobes and larger-than-lobe-size notches, or more than just 2 rotors), and a hot zone and a cool zone. You cannot expect it to work efficiently without thermally isolating the hot and cool zones from each other, even if your description has not included that. You even said you wanted to use the phase-change notion. And "Fair Use" only lets you copy-for-free a limited quantity of things that I have described, possibly just one.   

       Regarding your turning around my argument, that has its points, but even if we take out the stuff that all Stirlings have in common (hot zone, cool zone, thermal isolation) and take out stuff that may be newer than the Stirling but are in the public domain (lobed rotors and even your variable vaned rotors), we still have more than just one new notion presented here, although the most important is the larger-than-lobe-sized notches, for completing the rotary curcuit that the working fluid takes. Second is the indirect regeneration I have described; you may have not included regeneration in your description but without it your engine will be much less efficient than with it.   

       Finally, in publishing this I am adding to a body of work which reveals certain skills. Perhaps someone will hire me just to obtain exclusive rights to the next, as yet unpublished idea. Why not?
Vernon, Nov 12 2007

       Absolutely. If someone hires you for your abilities, I will be the first to congratulate you - It would be fantastic to see one of us achieve the goal of a job where we are paid to have ideas.   

       You miss my point. Of course the principles, the hot and cool zones, the lobed rotors - they are present in both designs. But if we're about protecting copyright, by saying that this machine is the embodiment of your description, then in order for my machine to be a copy of yours, my description of it must be a verbatim, or near-verbatim copy too. It's not. I've introduced new notions too - just as new as yours - the sealed, conforming, spring-loaded vanes being the prime example. In that way, my design is based on your principles, as yours is based on general Stirling principles.   

       The novel features of mine, such as preloaded bearings and sliding vanes, have been seen elsewhere in the public domain. They're still novel in this application. Similarly, lobed rotors have been seen on other machines in the past (gerotor pumps,for example, which is more or less what your machine physically is, albeit working on different principles - but we can't copyright principles).   

       Phase change, too, is not a new development for heat engines. A condensing steam engine uses it; so do coal fired power stations.   

       The novel bit of your idea is the principle of it; the building blocks (gerotor design, Stirling cycle) are well known. You can't claim them as your own; and you can't copyright the principle.   

       Fair use lets me lift bits of your text word-for-word, but doesn't prevent me acting on the ideas carried by the whole piece. I may only be able to photocopy a percentage of a map, but I can use all of it to get directions.
david_scothern, Nov 12 2007

       I told myself I wasn't going to get into the copyright discussion, but I can't help myself.   

       Consider a Chinese car mechanic who doesn't speak English and has no access to the internet. If he builds an engine identical to yours he has not copied it, so even under your theory (which I disagree with) you would have no protection.   

       Something I was wondering about is toy models of film characters. Obviously the name is protected, but are the characters protected by their appearance in a film, or are they only protected once an authentic toy is produced?
marklar, Nov 13 2007

       Characters are protected by a very specific branch of copyright law, I think.   

       The fact that machines can be invented simultaneously by two different people is a good point. Because of it, the burden of proof would be on the plaintiff to prove that the defendant had copied their work. Given that you can't even prove that my written words - which are there in plain view - are a copy of yours, I fail to see how you can prove that Mr Wong's heat engine can only have been produced by reverse engineering your own.   

       This leaves aside the whole question of whether your interpretation of the law is correct, and how you get around the following:   

       "Human memory is not subject to copyright, though greedy people would like it to be so."   

       If your idea, once in my brain, is not subject to copyright, then how can my own expression of the contents of my brain possibly belong to you?   

       As you say, my machine is based on the principles you outlined. I cannot produce it without features that work in the same way as yours. However, I will say now that my machine will be built from my description, not from yours. Furthermore, as you have not yet produced one (have you?) I won't be copying that either. Even if your "translation into realisation media" holds, you must still prove that my description is your work.   

       The mere fact that it embodies similar principles is not enough - we both agree on that. I must have stolen your text. I'll call on you again to demonstrate, line by line, that my text is stolen. Not that my sentences convey the same ideas - both of us could write a manual on how to fix a particular car, and neither of us would breach the other's copyright - but that my sentences started life as yours. If that is not possible, I suggest that your ideas have made their way into my copyright-free brain, and that I have then expressed the non-protected principles in a new way.   

       Come on, you're arguing against the obvious.
david_scothern, Nov 13 2007

       [david scothern], you noted that Copyright can protect images. You somehow continue, however, to confuse "principles", with "hardware". A "hot zone" is abstract until it is manifested, in which case the manifestation will have a certain shape that can be imaged and copyrighted. Your verbal description, if turned into hardware, becomes an obvious plagiarism when that hardware strongly resembles the descriptions I have presented, especially the imaged descriptions. For example, I have stated "disk of arbitrary thickness" and you have stated "cylinder", but they are physically the SAME. That object is in the public domain, of course, but both of us have also described very similar modifications to the basic shape (lobes and notches). I wrote: "Even the shapes of the lobes and notches might be varied.", and indeed, you have described variants. The overall assembly of parts, to make a whole engine, is something that can be copyable and therefore copyright-able, with Fair-Use limitations! So again I can ask, if in different words, "How can you expect to make a physical copy of your description that does not obviously resemble, beyond the limits of "fair use", at least one of the images that I have presented and copyrighted?"   

       Do remember that I am anticipating here a Formal Legal Collision between Copyrights and Patents, thanks to the advent of 3D printing. Your old-fashioned argument is apparently completely ignoring the consequences of that new development. And there will indeed be consequences, guaranteed.
Vernon, Nov 13 2007

       [Vernon], to have breached the copyright of your images, I would have had to have featured your images in my work, not just incorporated them in my thinking. The data conveyed in your pictures could have been conveyed by a near-infinite range of different images, of which yours is only a subset. Your copyright on the pictures, then, does not extend to all possible pictorial manifestations. I could, for instance, produce a detailed 3-D sketch of my design. It would clearly be a rotary Stirling engine, but that wouldn't make my 3D image identical to your 2-D drawings, even though it conveyed the same information. Similarly, you might give a 3-view of a house to an architect and ask him to produce an isometric representation. The copyright on that representation would belong to him, even though he hadn't added anything to the house design but simply recombined your facts as represented pictorially.   

       You can't claim that the copyright on everyone's annotations here belongs to you just because they probably had a look at your pictures to understand what you meant and make meaningful comments on it, can you? My annotation is similarly exempt (you didn't challenge my copyright on it, after all) and hence I am free to do with it as I wish. Published copyright material is in the public domain.   

       If I were to have read the Encyclopaedia Britannica's description of Barbados and written a poem about the beaches there (I'm not familiar with the place - can you tell? - but I'm kinda sure an island has beaches) - would E-B sue me and claim that their pictures were my poem? Or even if I wrote an essay on it?   

       You've still not addressed the possibility of someone else inventing this separately. They would have copyright, and you would have copyright, on your respective pieces of work. Neither could sue the other. Indeed, someone who wrote a magazine review of one of the machines could equally claim to have rights over the machines themselves! This isn't a conflict between copyright and patent, it's simply an impossible situation.   

       3D printing breaks no new ground either. As per [marklar]'s annotation, the particular likeness of a character is protected by copyright, which extends to plastic toy action figures based on that character. So, if I had an Action Man with a working rocket launcher, and some other manufacturer produced a spaceman with a working rocket launcher, I couldn't sue, because the character itself hadn't been used without my permission - even though the launcher might work in a similar manner. They work the same way, but they look different, and are therefore different in the eyes of copyright law. This position pre-dates the DMCA and is unchanged by it.   

       I've clearly stated that my machine would be based on my description, not on anyone else's. Consequently, you have to prove that my _description_ is a plagiarism, is recognisably your text, not just your idea. From Wikipedia: "A copyrighted work may contain elements which are not copyrightable such as facts, ideas, themes, or content in the public domain." Establishing that I have taken facts, ideas, themes, or public-domain content isn't enough.
david_scothern, Nov 13 2007

       [david scothern], you are correct in that there is a huge range of possible ways to depict something. Yet you ignore the basic fact that for a given image, there is a range of variations of that image which would be considered to be infringements upon a copyright of that image. This means that the huge range of possibilities must have subtracted from it the quite-large possible-infringement-range, to find the range of ways to make an image that does not infringe on the original. And 3D printing is going to lead to a closer association between descriptions and images and objects, than ever before, under Copyright law. It MUST, if one wishes to copyright the detailed instructions for making a unique chair on a 3D printer. Obviously somebody could construct a completely different sequence of instructions for printing an identical chair. The "print-out"/copy is the CHAIR, not just the instructions. And I repeat, Copyright is about who has the right to make copies. Period.   

       I'm aware that there could be a problem with independent invention. That's where it becomes important to be first. We already have rules about that.
Vernon, Nov 13 2007

       Pictures that look sufficiently similar to the original picture are, therefore, a no-no. However, my 3-D sketch of a vertical-axis machine - let it be a shaded cutaway (not a cross-section) - showing the novel features I described, would not and could not be identifiable as one of your pictures. None of them, for instance, are vertical-axis.   

       Maybe you can copyright the exact form of your chair. Perhaps it has distinctive ornamentation. However, that doesn't mean that all chairs infringe your copyright - that would be ludicrous. As long as they were sufficiently distinct from yours - totally different ornamentation, for example - they would not breach your copyright, yet they would still function as chairs.   

       Now those other chairs were around before yours was invented. I've got some in my kitchen. However, that doesn't mean that you have to ask some other chair copyright holder for permission before making your own design. Nor does the copyright on his particular product invalidate yours. They're different, even though the function is the same. Thus it is with our two designs. Their function is the same, but their form is different, and thus they are not copies of "the identical chair".   

       Critically, the exact form of the chair is precisely defined. It's not a copyright on "all chairs", or "all chairs with a number of legs that may be three, or four or more, but unlikely to be more than six". It's this exact chair. A turned wooden chair from a fine cabinetmaker will not be an infringement of the 3-D printed chair you've produced. This is because its form is different, not because it has a different function. Where your description is general and mine specific, there exists a notable difference which allows my description to be a separate piece of work to yours. If it doesn't, then you must cede your copyright to the first man who approaches you with a generic Stirling cycle description, preferably but not necessarily older than your design.
david_scothern, Nov 13 2007

       [david scothern], regarding chairs, please note that in my prior anno I specified "unique". You may thereby assume that it is not sufficiently similar to any existing chair, that a description of it would be equivalent to a description of the ordinnary average chair.   

       Nevertheless, you argue as if a new description of the chair could be created from a reading of the original description, and then the person making that description would have a right to make copies of the chair.   

       I see that so far we have not mentioned the subject of "design patents", a special already-existing legal category. It is possible that in this particular case, the chair should have its design patented. On the other hand, Copyright Law regarding 3D printing SHOULD be just as effective. Here's a roundabout reason why:   

       Here is a conundrum for you: consider the well-known phrase, "God created Man in His image." There is a significant logical peculiarity about that phrase. That is, it is often claimed that God has no physical form, so how is it possible that there be an "image" of that form, which could have been copied as Man? Perhaps a more accurate way to make the original statement is to claim, "God created Man in His mental image." We are aware of something termed "the mind's eye" and associated mental/imaginary visualizations, right? It logically follows that just as I might imagine a unique chair, and construct it according to that mental image, God could in theory be claimed to have done the same thing with respect to imagining/creating Man. (Such a philosophy could also possibly someday prevent a religious war with nonhumanoid aliens who claim that God created them in His image!)   

       So if I write down a description of that chair, I am making a copy of that mental image. If I build the chair, I am making a copy of that mental image. And if you encounter either the description or the chair, and make some variant of it, then the degree to which it is similar to the original is the degree to which you could have committed plagiarism in violation of a Copyright. This should be true of the chair itself, a variant copy of the original, as well as the description!   

       Now apply that agument to your engine-description. I don't care how different is the description; I do care how similar is your copy of my engine. Because in the future of 3D printing, a printed object is totally equivalent to a printed book. You cannot legally print copies of a book without the copyright-holder's permission, right? Suppose I used a 3D printer to make a book; there will be some particular set of instructions, sent to the printer, to make that book. Obviously you could write a completely different set of instructions, to create an identical book. Well, we both know that the instructions AND the book are Copyright-able.   

       So, why should you be able to legally 3D-print copies of some other object, like a chair or an engine, just because your description, used to control the printing, is different?   

       You asked, "how can my own expression of the contents of my brain possibly belong to [another]?", and the answer to that depends on how closely that expression, of whatever type, resembles/is-a-copy-of another's copyrighted expression. Simple.   

       You might have noted that I created an Addendum to the linked page that is a "more-ordinary web page". You might not have noticed that I extracted stuff from various annotations here, but I was quite careful to copy from my own annotations only. I did not try to extend copyright over any other annotations here.   

       You wrote: "Where your description is general and mine specific, there exists a notable difference which allows my description to be a separate piece of work to yours. If it doesn't, then you must cede your copyright to the first man who approaches you with a generic Stirling cycle description, preferably but not necessarily older than your design." No, I'd say that's where a Patent would be applicable. To describe the cycle without specifying any hardware would be analogous to a "business method" patent. But to specify hardware you need to describe shapes. Shapes are copyable and therefore copyright-able, per the "books" analogy above (books come in various shapes and contain combinations of shapes of language symbols, right?). The shapes of a rotary Stirling engine can be quite obviously and significantly different from the shapes of a reciprocating Stirling engine. And even among the candidates for rotary Stirlings (see link), the shapes are quite varied.
Vernon, Nov 14 2007

       What it simply comes down to, under current US, and I believe EU law (yes even with the DMCA in the US) a copyright protects text, images, artistic works, and some concepts. Patent protects designs and devices. Simply put, no court, in the US, at least will accept this as protecting the construction of this device. A patent or evidence of initiating the patent process is the only thing that is legally recognized as doing so (limited protection on dated information does exist prior to the patent, but this is considered part of the patent process). Thus it doesn't matter whether or not a working copy is a "translation" the courts won't treat it as such. If you need to protect this investigate the preliminary patent process, it is not difficult and is relatively inexpensive.
MechE, Nov 14 2007

       [Vernon], please leave out your odd interpretation of the Bible. If the meaning is uncertain, you can't use it as if your own view is the only one. Myself, I believe that "in God's image" means, "having characteristics that reflect God's character, and point the observer to God".   

       So to summarize, your claim is essentially the following:   

       If I am to build my machine, there will be a similarity between the two, without which I cannot build it. It must have rotors with lobes and indentations, it must have a hot and a cold zone, it must involve a working fluid and it must rotate. You have stated this, with minor variations, in your own annotation.   

       You recognise that the principles behind your idea cannot be protected by copyright. What you protect is the implementation, and as both machines must be designed to work in the same way, they will have a similarity which represents a copyright infringement on my part.   

       Do I understand your point of view correctly?
david_scothern, Nov 14 2007

       [MechE], apparently you also are neglecting the future impact of what 3D printing is going to mean. Objects will become as printable as books. You might think of those printed objects as being 3D art, and art is Copyright-able regarding being printed, see? And if it is recognized that Copyright should apply for printing a copy of a 3D object, why shouldn't it be true for making in ANY other way a copy of that object? The ONLY wierd thing here is that I have described my 3D art in 2d images and in words. But why should that make a difference, when clearly it is a 3D thing that was being described? If I had done the same for some oddball/unique abstract sculpture (heh, see link!), would I not have rights over actual 3D copies of that sculpture?   

       [david scothern], a quite large percentage of all wars in History have been caused by religious zealotry/stupidity. And since the worst of today's religious zealots are literalists, If we wish the horrors they perpetrate to stop, then not only do we need to separate Church from State, all over the world, we also need to expose the illogical nonsense of literalism in Religion whenever possible. I therefore make no apology for pointing out that a common claim about God and Man is, when taken literally, utter nonsense. The claim MAY simply be a mistranslation of the original ancient claim; I don't know, and merely made a guess at an alternative, that does not qualify as obvious literal nonsense. And yes, I know there is more than one possible way to modify the original statement, to remove the nonsense. Your implied modification, for example, appears to refer to the mind or the soul of Man, instead of the body. Fine; both of those are also things that have no physical image. (You might re-read my last anno and note carefully where I used the word "claim"; I'm not wedded to what I wrote there.)   

       Anyway, there was a relevant reason for talking about the word "image", because it has different meanings, and I wanted to be sure that the ways in which I used it later on in that annotation were fully understood.   

       As to the rest of what you wrote, basically, "yes". The first part of this anno, to [MechE], may better explain the "why" of the position I have taken.
Vernon, Nov 15 2007

       Actually, I think of 3-D printed objects primarily as machine parts.
I stand by my statement, a court will not accept this train of thought. There may need to be a court case to clarify this decision, and maybe you will be it, but the defender of the idea will lose. Patents are relatively short for a reason, to encourage invovation(If an idea is locked up for life+75 then it is sort of hard to come up with any new ideas, since they vuild on each other). This is the way the laws are meant to be read, and any court interpreting them will interpret the laws so as to maintain this.


       Again, your interpretation is novel, and has some valid points, but it won't work. It runs counter to the intent of the law, and thus whatever changes to law or current interpretation thereof need to be made to counter it, will in fact be made.
MechE, Nov 15 2007

       [MechE], I fully agree that Patents are relatively short for a reason, and I actually support that reason. In a way, part of the reason I took the position I did was to point out the ridiculous-ness of long Copyright terms. I'd like to see just exactly how the inevitable Court clash, between Patents and Copyrights-of-3D-printed stuff (do note that individual pieces and moving mechanisms both CAN qualify as "art") is going to turn out. I'd kind-of like to see Patents extended a bit, and Copyrights shortened a LOT, and the two merging under one Intellectual Property umbrella.   

       And yes, I'm aware that a longer Patent period could lengthen the pace at which technology changes. There are plenty of folks who would say that would not be such a bad thing. :)
Vernon, Nov 15 2007

       Just to clarify, you are saying the following: Your copyright does not protect your idea per se. If I can find a way of producing a machine that works as described, without including concepts or features that are themselves covered by your copyright, I may legally do so. However, you hold that your machine contains certain elements that are necessary for the implementation of the idea, and thus my machine must also contain them, not because I am too lazy to make them differently, but solely and simply because I have no alternative. Consequently, your copyright (you claim) effectively protects your idea, for there would be similar features between the two which are as a practical matter indispensable to the realisation of the idea. Is that an accurate representation of your claims? There are no other reasons why I cannot produce my machine?
david_scothern, Nov 15 2007

       [david scothern], I wouldn't go so far as to accuse you of being lazy. I'd merely accuse you of making unauthorized sales of copies of my copyrighted shapes of engineering art. (Do remember that the main text of THIS Idea doesn't care how many copies one MAKES, it only is concerned with copies that are made AND SOLD. Others may be less generous with their copyrights, in the future.) If you can get decent Stirling engine power with shapes that are outside the range of variations that the word "plagiarism" can cover, more power to you!
Vernon, Nov 15 2007

       OK, but your argument against someone who was making them to sell would essentially be as I wrote in my previous annotation?
david_scothern, Nov 15 2007

       [david scothern], you wrote: "However, you hold that your machine contains certain elements that are necessary for the implementation of the idea, and thus my machine must also contain them, not because I am too lazy to make them differently, but solely and simply because I have no alternative."   

       Sorry, but I would not claim there is no alternative, nor do I need to make such a claim. I would simply claim that you have copied my copyrighted shapes. IF IT HAPPENS that only the range of shapes I've copyrighted can work, then in theory I win; Copyright Law will have given me the equivalent of a Patent, with less trouble and a longer term of enforcement. (And in practice Copyright terms should therefore be diminished!)
Vernon, Nov 16 2007

       So either:   

       - My machine is not covered by your copyright, and implements your novel principles without you having any legal recourse against me,   


       - Your copyright covers the full range of geometry that allows the implementation of your idea, so I cannot make and sell them without paying you a license fee. This view is supported by your claims as follows:   

       That I can't build it without rotors, lobes, larger-than-lobe-size notches, a hot zone and a cool zone. It has to be made from a suitable material, I can't avoid that.   

       That my lobes must have some specific profile, which will be a member of the general class of profiles that you mention in your description.   

       That the hot and cold zones must have a shape; you don't limit yourself to anything specific, so whatever shape I pick will be in general agreement with your description.   

       That I cannot, within the limits of fair use, make a machine from my description that does not obviously resemble at least one of your copyrighted images.   

       In the former case, I can make and sell without you having any legal hold over me, even though my machine contains all of the elements in your claims above (all of which are taken from your annotations, wherein you say that building one of these machines without the features listed is not possible); in the latter, you would claim that your copyright has sufficient extent to protect the idea, effectively in the manner of a patent.   

       I think that sums up the difference of opinion on copyright embodied in the previous ten thousand words. Do you agree with my statements here, or is there anything you would like me to clarify?
david_scothern, Nov 16 2007

       To annotators:   

       It would be wise to listen, or at the very least, assimilate the views of xavier(gisz). As a practicing patent official (operating for a patent office and not the litigating parties) he alone will offer the best opinion.   

       Vernon, although your interpretation of copyright may be correct and, by law, faultless, if you don't have the funds to protect the idea in the form of a patent you fall short, by a certain order of magnitude, of protecting it under copyright litigation.   

       David Scothern, you may well fall into a legal trap sprung by Vernon's copyright (Although I don't believe this to be true) but you will have either the order book, or venture capital to defend it.   

       Copyrights, under Roman-Dutch Law, are just that. You issue the right to *publish* information. For that you are compensated by it *not* being copied, or published with your authority, and/or where such authority is given, remuneration. Semantic arguments around *published*, *copied*, *verbatim* and even *rights* will, in the end, cost you more than any country specific patent, or international patent, ever will.
4whom, Nov 16 2007

       wow. Why do you want to make two ideas into one? The idea of using copyright to protect a mechanical design concept seems dubious and easily circumvented. Thats what patents are supposedly for.   

       The engine itself has some merits. I would not call it a Stirling cycle; it looks like a Rankine cycle (steam engine) with the boiler and condenser integrated into the engine. You may encounter several problems with the engine as proposed: Water will migrate between adjacent chambers. The "Leidenfrost effect" will impair the function of the boiler you have shown. The condenser part of the engine is another bottleneck to the flow of heat through the engine cycle, as you acknowledge. Having the cold and hot sides of the engine one either side of the rotors will cause heat leakage and other problems: the hot side will expand more and become wider (thicker) and create a gap between the rotors and side plates there. If you make that part narrower, the rotors will bind up and become damaged before the engine reaches operating temperature.   

afinehowdoyoudo, Nov 17 2007

       [david scothern], a minor nit is that I have no problem with you building anything you like. I specified in the Copyright Notice that I was only interested in a royalty if you sell something that resembles my description closely enough that my copyright would apply.   

       I agree that in a prior annotation I wrote stuff about how you couldn't build an engine similar to my description without it being TOO similar, but since then I have realized that there is a possibility that that statement was mistaken. There may be a way that's not covered in my descriptions, to get much of the effect that I've described, using significantly different shapes. If I had thought of such a variation you could be sure I would have written it down, but since I didn't, I have to be open-minded to the possibility that such a variation may yet be possible.   

       I agree that if Copyright Law as recently enhanced can't do what I deduce it can do, then I'm out of luck, unless I can get a patent within a year. Having posted the idea is still valid, though, as a way of verifying me as the originator.   

       [4whom] and [iron horse], the Digital Millenium Copyright Act has significantly increased the scope over which copyrights can apply. I will repeat one of the key arguments that I've raised, in case you missed it.   

       "... everything that physically exists can be described digitally, which thus makes the description a copy of the thing that exists. Even analog representations of something can be described digitally. The advent of 3D printing simply reverses some of the preceding, and means that physical objects can be copies of digital data. And the DMCA is about rights regarding copies of digital data, isn't it?"   

       The FORM of that digital data shouldn't matter to the DMCA; therefore Copyrights should now be able to cover shapes of engineering art.   

       [iron horse], the SPARLVE may not qualify as a Stirling to the extent that an RSE can, but both have similarities such that I felt it reasonable to describe them in one swoop.
Vernon, Nov 17 2007

       I don't think one can reasonably suggest that your machine can be built without rotors, provided with lobes which act as a surface for fluid pressure to act on, plus a hot and a cold zone to provide the thermal gradient the machine needs to work and a casing to keep the fluid from escaping. These, I would argue, are fundamental to the idea. A machine without a hot and a cold zone and a working fluid isn't a Stirling; a machine without rotors isn't a rotary Stirling, and without lobes you have no way of using the working fluid to create a torque on your rotor (unless you go for friction torque, but that would be closer to a quasiturbine, which is a different machine altogether). Can we agree that these are fundamentals of the idea?   

       If one generalises beyond this, we have a different heat engine altogether to what is described. Seeing as you are not trying to copyright "all heat engines", or "all stirling engines", or even "all rotary stirling (or Rankine, or whatever cycle is in fact embodied) engines", to have a hope of being seen as embodying the idea you have set forth, it must by definition have the above features.   

       If I'm wrong (which would strike me as odd; you've claimed these as fundamental on a couple of occasions, and they feature heavily in your images) then what are the features which make up the essence of a machine built according to this idea?
david_scothern, Nov 17 2007

       [iron horse], you seem to be mixing up the SPARLVE with the RSE. The RSE needs a hot zone that is much much hotter than the cool zone, but a SPARLVE doesn't. For that reason the Leidenfrost Effect should not happen in a SPARLVE; it is ideally supposed to involve both liquid and gas at the same temperature (the boiling point), that merely changes phase/state. In practice, of course, a few degrees of temperature difference will probably exist, and I admit that we do want the liquid to boil as quickly as possible. If this means we still have reason to expect the Leidenfrost Effect, then what of the orientation of the engine portrayed in the animated .GIF? The puddle of liquid is too big, until the last drops are boiling! Which may mean we have nothing significant to worry about.   

       The patent you linked is interesting! It certainly has lobed rotors. But it also has a more complex way of handling the working gas, with bursts of pressure being applied to the lobes. I'd tend to say that this might invalidate the versions of my design in which the rotors don't have BOTH lobes and notches, but it could be a close call.   

       [david scothern], this is kind of a silly statement you made: "I don't think one can reasonably suggest that your machine can be built without rotors" --because it is indeed MY artful design, and rotors and other shapes similar to what I've described are certainly fundamental/essential to the simplicity of this piece of engineering art. And so somebody else's design needs to differ in non-obvious ways. It CAN be done; other sorts of rotating shapes can be made to work in a Stirling type of engine (see the patent that [iron horse] linked). Turbines and Wankels have two rather different shapes, from what I've described. And rather more complexity, too, not to mention a likely decrease in efficiency. I note that your variant appears to add unnecessary complexity (extendable lobes) more to try to get around the solidly attached lobes I've described, than to decrease the costs involved -- more parts vs more-precise machining of fewer parts; your mandatory seals will wear out and need to be laboriously replaced, so in the long run, which engine is less expensive? HAH! How much royalty were you planning on adding to that cost, if your design didn't infringe, and was made in quantity by others, vs the $10 I've requested for physical/realization copies made of my original work? :)   

       Part of the overall plan, on publishing this Idea, is to point out that it could be much simpler and cheaper (and valuable positive publicity) for some company to be honest about their involvement with this Idea, than to try to steal it.
Vernon, Nov 17 2007

       [Vernon] - rotors, lobes, notches, hot and cool zones etc, they're not only essential to the function of your piece of engineering art, they're essential to the behaviour of any SPARLVE or RSE. I'm free to build and sell SPARLVEs or RSEs as described in the text, if I can do so without infringing your copyright.   

       The idea depicts a heat engine working on a rotor-lobe-notch system. I want a rotor-lobe-notch system. However, even though the idea's not patented, you're covered because the description's copyright, so I can't implement the rotor-lobe-notch system without infringing your copyright. Weird in the face of what the rest of the world thinks.   

       You do realise that if I make a similar machine, but in a different colour and with a different arrangement and proportions, it will be an original piece of art too? After all, two photos of the same bottle of drink, under similar lighting conditions, are both original works, even though they may look similar!
david_scothern, Nov 17 2007

       [david scothern], for the HalfBakery, "Weird in the face of what the rest of the world thinks" is the NORM. That's a major reason for posting these ideas here, rather than elsewhere. I'm fully aware that the interpretation I've made of recent Copyright Law is weird. But it is not obviously nonsense, either. Which makes it fun, too....
Vernon, Nov 18 2007

       But I need the rotor-lobe-notch system, and its description is available to me on a public website, unprotected by patent and thus (in the normal interpretation) free for my use. I can't make my machine work without it. Your copyright is trying to do a dog-in-the-manger act - to use this publicly-available idea would be an infringement of your copyright, so you've effectively got yourself a monopoly over an idea by stealth.
david_scothern, Nov 18 2007

       [david scothern], I wasn't the one who modified Copyright Law to allow the interpretation that I came up with. You should rightfully blame THEM for apparently allowing stealth monopolizations.   

       The logic I've used is almost inexorable, given the consequences of the triad of the reality of 3D printing, the fact that a solid object can be a means of storing digital data, and the DMCA regarding rights over digital copies. Since people WILL want rights over their digital copies, no matter what form those copies take, that's why a collision between Copyrights and Patents is practically inevitable.   

       And that's why I think the most reasonable response is to hack down the term over which a Copyright is in effect, to make it similar to the term of a Patent.   

       Next, you seem to be ignoring the fact that if I file for a patent within a year, I can get the NORMAL monopoly on the ideas presented here (and all I need for that is $$$). You can't get the patent because your design is so close to mine, which was published first. Just because it isn't protected by a patent now doesn't mean that you can get away with using the idea; plenty of patent-based lawsuits have arisen after (1) the ideas were put into use and (2) THEN the patents were granted. And those suits have generally been won by the patent-holders. So for a year, regardless of whether or not I have a patent, you should assume that I might yet be able to afford it, and then you would have to pay up, possibly to punitive degree, if you had put too-close-a-variant of my original engineering artwork into production and for sale, without paying royalties as a matter of honor. All that's true regardless of the Copyright situation!   

       I've merely pointed out that the recently revised Copyright situation appears to allow me to claim much of the effect of having a Patent, for a longer time and with less up-front expense. And for a year, it doesn't matter if I am right or wrong about that!
Vernon, Nov 18 2007

       Now there you're wrong. You've published before filing - and outside of the USA, that means your rights don't stand. I'm across the water. Had you filed your patent and then published, I think you would be protected, but over here I think you're out of luck. If [xaviergisz] is still reading, I expect he has more knowledge here and will tell us if I'm wrong.   

       On another note though... similarity should be established according to whether I've copied your idea, or your machine. If I've copied your idea and am willing to take the risk of you getting a patent, I'm clear to go ahead and sell. If I've copied your machine, I'm in trouble. Given that the idea and the machine are identical (you've not built a machine) you're going to have to prove that I copied your machine and not your idea. That's going to be hard, because my machine contains features that are not in yours, whereas yours must contain features you've not described (bearings, for example) which are in mine. Who, then, copied who? My machine evidently incorporates the essence of your idea, but equally plainly is not a copy of yours, because it's different!
david_scothern, Nov 18 2007

       [david scothern], what you wrote could be the fundamental explanation for why the USA pulled ahead of the rest of the world, last century. Just imagine keeping an invention secret while you try to line up investors --who steal it. Here the one-year rule makes that rather tougher to get away with.   

       Even here, though, it is possible to publish something AND to declare while doing so that the idea is being placed in the Public Domain. If I had done that for this idea, then obviously not even I would be able to get a patent on it. What I did do, in publishing this, was quite clearly indicate, by requesting a royalty for certain copies, that it was NOT being placed in the Public Domain. That ought to count for something, even on the other side of the Pond.   

       After all, even there the Culture says that an Idea can belong to its originator for a limited time. Is there some particular reason it shouldn't, JUST because it wasn't Formally Registered before it was discussed? Has robbery so pervaded your culture that Honor cannot exist without the Government being involved? It looks to me like you can't even trust your closest friends, if you have an Idea, until you beg protection for it from the Government. Bah!   

       I despise the greed of organizations like the RIAA and the MPAA, but it looks like I can thank them for their efforts to get Copyright Law to become somewhat uniform around the world. Obviously we need to do the same for Patents, and I most sincerely hope that the Legal Collision discussed earlier here becomes the catalyst for that.   

       I suggest you wait for the results of the Collision. Or simply send me my small royalty if you sell an engine. It would be an honorable thing to do, wouldn't it? You'd be covering all the bases, and even if my Copyright interpretation didn't hold up, you could not be faulted for agreeing that the originator of an Idea should have some ownership rights. Indeed, if some competitor starts making these things, before the Legal Decision comes down, without paying the royalty, you could legitimately point out their lack of Honor, and add, "Since they reveal themselves to be dishonorable in that way, why shouldn't we expect them to be dishonorable in other ways, such as using poor-quality materials and making them with shoddy workmanship?"
Vernon, Nov 19 2007

       "Imagine"? Over here, we don't have to imagine. That's exactly how it works. At my place of work, we're very close-mouthed about patents, not least because we're worried our competitors will copy the idea if they get wind of it. For reference, our main competitor is one of the largest conglomerates in the world, and a big manufacturer of aero engines. When I have submitted patents to the company Patent Officer for filing, I have had to fill out a declaration stating that I have not made anyone outside of the company aware of the idea.   

       Entrepreneurial TV shows (Dragon's Den) tell their viewers that they must tell nobody about their idea before it's patented. This gives investors confidence that their money is going somewhere safe. After all, if the inventor hasn't been sensible enough to get basic legal protection, what else has he neglected to do?   

       Publishing information on a publicly available site puts that information into the public domain. The author retains copyright over his work, but not the ideas contained therein - we've established that.   

       One can certainly trust most close friends, most of the time. I don't think you'd claim that any society was free from its double-crossers though. For example, James Dyson spent years developing the cyclone-style vacuum cleaner. Fortunately for him, he protected himself with scores of patents. It went into production and was a success, rapidly imitated by (among others) Electrolux, who had essentially stolen the idea when he offered it to them. He took them to court and won, because he had the belief to patent his ideas, even though it put him up to his eyeballs in debt.   

       So having established that you're not covered by a patent, and in most countries cannot now be so covered, let's stick to the copyright discussion, shall we?   

       I think that now is probably the time to introduce the "idea-expression divide". This is a legal concept that basically says what has been mentioned once or twice already - copyright cannot protect an idea. More specifically however, it goes on to say (and I quote):   

       The protection established by the Copyright Act for original works of authorship does not extend to the ideas underlying a work or to the functional or factual aspects of the work. To the extent that a work is functional or factual, it may be copied, as may those expressive elements of the work that “must necessarily be used as incident to” expression of the underlying ideas, functional concepts, or facts. (end quote) - US Ninth Circuit, Sega vs Accolade, 1992.   

       And from a similar ruling by the Federal Circuit, Atari vs Nintendo, 1992: Under the Act, society is free to exploit facts, ideas, processes, or methods of operation in a copyrighted work. To protect processes or methods of operation, a creator must look to patent laws. An author cannot acquire patent-like protection by putting an idea, process, or method of operation in an unintelligible format and asserting copyright infringement against those who try to understand that idea, process, or method of operation. The Copyright Act permits an individual in rightful possession of a copy of a work to undertake necessary efforts to understand the work’s ideas, processes, and methods of operation. (end quote)   

       Similarly, the merger doctrine can be applied: The merger doctrine in copyright states that if an idea and the expression of the idea are so tied together that the idea and its expression are one - there is only one conceivable way or a drastically limited number of ways to express and embody the idea in a work - then the expression of the idea is uncopyrightable because ideas may not be copyrighted (quote from Michael D. Murray, University of Illinois School of Law).   

       Lexmark tried your trick, too. They fitted their toner cartridges with chips such that only their cartridges would work in their printers, and then sued a manufacturer who reverse engineered their chips, figured how the access code worked and implemented something similar. In ruling against them, the judge specifically pointed out:   

       "If we were to adopt Lexmark’s reading of the statute, manufacturers could potentially create monopolies for replacement parts simply by using similar, but more creative, lock-out codes."   

       The DMCA specifically permits reverse engineering, in particular in the case of software wherein it is necessary in order to allow third-party software to interface correctly with other programs. Earlier Copyright Acts also permit copying for the express purpose of reverse engineering - it is specifically permitted under the fair use exception.   

       So, I can make something as per your description; my machine and yours will be similar because they work the same way. That's expressly permitted by the merger doctrine and the idea-expression dichotomy. If you can prove, beyond that, that I copied your machine (which doesn't exist, and I couldn't have had access to it even if it did), then maybe you have a case, if you can demonstrate that my machine displays no creativity. Given that my design is materially different to yours, so that it will look different - different size and shape, different seals, vertical axis, specific bearing arrangement - good luck.   

       To the extent that a work is functional, or factual, it may be copied. You don't have a leg to stand on, sir.
david_scothern, Nov 19 2007

       [david scothern], OK, let us focus on copyrights. I'll start by pointing out that the two rulings you quoted pre-date the DMCA and 3D printing, and so may need to be revisited in Court.   

       Next, you quoted that things may be copied which are: "those expressive elements of the work that “must necessarily be used as incident to” expression of the underlying ideas, functional concepts, or facts." I suggest the word "googol" as qualifying. It was a word invented to express the idea/quantity of 10 raised-to-the-100th-power. Anyone can copy that word to express that idea. The inventor of the word tried to sue google.com, but hey, they had misspelled it! Perhaps deliberately (though I have my doubts).   

       The core idea here appears to be that a particular range of shapes for a Stirling engine can allow it to be purely rotary, easily transferring cooled shrunken working fluid to the heating zone of the engine, while keeping the zones in mutual isolation. An almost-laughable thing is, I've stated up-front that the entire Idea, as expressed in text and images, can be copied freely in those forms. No need to try to re-express it in alternate words/images, to get the idea across to others! (Unless it is claimed that I have done that poorly, but so far, no such claim has been made.)   

       Now, what I've done here is to claim Copyright on some of that range of shapes, as the rationale for requesting a royalty if the shapes are copied in 3D. I cannot say that I have covered the entire range; plagiarism of physical Art has its limitations.   

       The second legal case that you quoted appears not to apply here: "An author cannot acquire patent-like protection by putting an idea, process, or method of operation in an unintelligible format and asserting copyright infringement against those who try to understand that idea, process, or method of operation" --because "understanding" and "making copies" are two different things, and besides, nobody here has accused this Idea of being presented in an unintelligible format.   

       Your third point may be the most troublesome for me. "if an idea and the expression of the idea are so tied together that the idea and its expression are one - there is only one conceivable way or a drastically limited number of ways to express and embody the idea in a work - then the expression of the idea is uncopyrightable" --I again point out the word "googol" as an example of that. But I can also point out that "a work" as mentioned in the quote is typically another ARTISTIC EXPRESSION of the underlying idea. You haven't indicated that you want to express this idea as Art; you have simply indicated that you want to make slightly modified and inferior (in terms of functional lifespan) copies of my kinetic/engineering/Art, and sell them. I say, "Fine, for $10 each --which you will undoubtedly pass along to your customers, so it actually doesn't cost you a thing. How much more than that are you planning on spending, trying to create an alternative non-infringing Expression of this Idea?"
Vernon, Nov 19 2007

       [Vernon], copyright law allows me to ride roughshod over your "copyrighted shapes of engineering art", if they are what I need to make this machine work.   

       The Lexmark case I mentioned was an attempt to use the DMCA to lock out the competition; the ruling followed Atari vs Nintendo. No revisiting is required; it's been revisited under the DMCA. Law recognises that the Atari vs Nintendo ruling still stands; what companies do now is make their customers enter into contracts whereby they agree not to reverse engineer. You don't have that option.   

       Your "googol" example is irrelevant; short phrases cannot be copyrighted.   

       You may notice that the linked patent from [iron horse] used an abradable liner to minimise seal clearances. It also incorporates a movable rotor to allow for fine adjustment. I'll quote from the text of the patent:   

       "Many prior rotary positive displacement engines are victims of their own ingenuity in that the designs, while apparently functional on paper, are difficult if not impossible to carry out in metal, as the machining and tolerances required to limit leakage are simply too complex to provide a practical rotary positive displacement engine at a reasonable cost. Furthermore, many of the prior engine designs require clearances which are only achievable at ambient temperature, but not in operation at elevated temperatures."   

       I realise that you're trying for operation with minimal thermal gradient, so the elevated-temperature problem (or more particularly, the problem of high thermal gradient) is minimised, but that aside, I think that you should take note of the view of someone who produced a very similar machine and patented it.   

       Equally, my day job is as a transmissions engineer; I'm more aware than the average person of what tolerances are achievable in a rotating machine.   

       As for your piece of art... I don't want your expression, I want mine. You coming up with a new concept for a heat engine is great, and if you choose to make a piece of art incorporating it, that's fine - it will doubtless help people to understand the way a heat engine on these principles works. I don't wish to copy your piece of art, I'm making a machine that works in a similar way. If it's different, it's not a copy. If there is any resemblance, I'm in the clear insofar as that resemblance is due to its function. All of the ideas conveyed by your description and images are fair game; I may study them as much as I wish. There will be differences - some minor, some major - between your images and text and my machine; there will also be places in which your general terms and my specific choices are in agreement. Since I can demonstrate that I couldn't have done otherwise (in certain cases, e.g. I couldn't have avoided using suitable materials, or using lobes and notches) or that I felt that the approach offered in the idea was the best available (thermally separating the hot and cold zones), I am treading only where copyright law grants me the right to do so.   

       Were I to produce a machine that was dimensionally identical, that went beyond the general conceptual similarity that the idea requires, I would be liable for prosecution.   

       Be careful when you come to me with a machine that looks like mine though; if yours is so similar to mine, who is going to prove who built first and who copied? The idea was yours, certainly, but you're going to have to prove that you built a machine and that I had access to it before you can prove that I copied it. Proving access is a legal requirement for proving infringement, and I have no access to a machine you haven't built. Just showing that I read this description and exercised my right to implement the idea in the most appropriate manner gets you nowhere, especially in the light of the legal concepts I introduced you to earlier.   

       In any case, if it's the shape that you're trying to protect, I'll show my design to you, and if you feel that the shape is too similar to yours, offer me an alternative, no strings attached. I'll take it, provided that it doesn't reduce the competitiveness of my product in any way (higher cost, lower performance, etc). I'm not troubled about the shape as long as it works. If that's not good enough for you, then either it's the idea you're trying to protect, or I'm only aware of one "best" way to make that particular feature work, and hence I am free to use that way. There - I've given you a perfect opportunity to protect your shapes, if they really are what is critical.   

       And as for $10 per machine, what if I sell ten million of them? Saving $100 million would make quite a difference to the business case in anyone's books.
david_scothern, Nov 20 2007

       [david scothern], you wrote: "copyright law allows me to ride roughshod over your "copyrighted shapes of engineering art", if they are what I need to make this machine work." That may be true, but that IF in there is extremely important. You would have to prove that there is no other way, first! Since I don't claim that there is no other way, the burden of proof is on you, before you can take advantage of that loophole. I see you also wrote: "Since I can demonstrate that I couldn't have done otherwise (...using lobes and notches)", which isn't quite accurate; my Art specifies oversized notches for a SPARLVE, not just simple notches, like any ordinary gear could be considered to have. So let's see your demonstration of that aspect of your claim (especially since I've already thought of at least three alternatives, and am contemplating a fourth!). I see you also wrote stuff that included, "I'm not troubled about the shape as long as it works." How nice. Feel free to devise your own alternatives. I KNOW it can be done. If you think you can talk me into doing it for you for free, think again!!!   

       Next, the Lexmark case does not apply here, partly because you've mischaracterized one aspect of that case; Lexmark was trying to lock customers IN, not just competition out. It was the customers outraged at the excessive high prices of ink that led them to seek an alternative source, which then led Lexmark to try to add DMCA stuff. If the corporate rapaciousness/greed hadn't existed, the lawsuit would likely never have happened. So, note that I'm not trying to insist that you make use of my piece of engineering/kinetic/Art; I'm simply saying that if you do use it, or something close enough to it that "plagiarism" applies, then I deserve fair compensation for my efforts. Just like any other artist. Also, if you describe my Art as "the best available", what is your basis for claiming that you have some kind of free right to use it instead of a lesser/different alternative? I put significant effort into focusing on simplicity and efficiency; if you think that effort is worth something, why aren't you willing to pay for it?   

       Next, I did make note of that patent in a prior annotation. I said that it could possibly invalidate claims regarding the versions of the RSE in which some rotor(s) have lobes only and some other(s) have notches only. It doesn't affect my claims regarding SPARLVE or RSE rotors that have both.   

       Next, I notice you didn't bother to claim any rights on your variant of my Art. Obviously this means your competition can build exactly what you have described, and if your argument is correct, about it being sufficiently different from my description, they need not pay anything to either of us. Are you enjoying that?   

       Finally, you wrote, " And as for $10 per machine, what if I sell ten million of them? Saving $100 million would make quite a difference to the business case in anyone's books." Actually, that is the very essence of excess greed, and closely approaches "theft". You are saying that some company can arbitrarily add $10 per artwork over-and-above a reasonable profit, and keep it, instead of passing it on to the person who made it possible for the reasonable profit to be earned in the first place. The HONORABLE alternative, if you insist that the Artist doesn't deserve to be paid, is to not charge the extra $10 per artwork. That's why I described my requested royalty this way in my last annotation: "$10 each --which you will undoubtedly pass along to your customers, so it actually doesn't cost you a thing." In what way is (1) telling lies that that a requested/earned royalty is no such thing (2) adding the requested royalty amount to the overall price anyway, (3) and keeping it, not in essence a poorly disguised theft? And your competitor, of course, could sell for $10 less, without cutting down at all that "reasonable profit", right? THAT'S why I wrote in an earlier annotation: "Since they reveal themselves to be dishonorable in that way {not paying royalty}, why shouldn't we expect them to be dishonorable in other ways, such as using poor-quality materials and making them with shoddy workmanship?" YOU are describing a choice to pick an EVEN MORE DISHONORABLE path (to charge royalty and not pass it on)!
Vernon, Nov 21 2007

       Actually, Vernon, you're mistaken. In cases of alleged copyright infringement, the burden of proof is on the plaintiff. You have to prove that I copied your machine. For that, you have to prove that I had access to your machine.   

       You may certainly prove that I had access to this description and that you are the originator of the idea; that's not a point of dispute as it would be in a patent suit. However in this case, I can legally produce _the identical machine_, as long as I don't actively copy yours in doing so. That applies even if there are multiple ways of expressing the idea; identical implementations are no more than a pointer towards infringement. Unless the "preponderance of evidence" says that I have copied rather than independently conceived based on the idea and description here, I'm free. And if I've never seen your machine, you have not a hope of proving infringement. Still less so, because the machine does not exist.
david_scothern, Nov 21 2007

       [david scothern], your attempts to confuse "engine" with "engineering ART" are leading you to the wrong conclusion. The original main text is still here, that explains how this work can qualify as Art. So, if you make a copy of the 3D thing that I have described in words and 2D images, then you would be making a copy of a thing that was introduced as Art. It is ART that you would be copying and possibly plagiarizing.   

       Next, what I said you needed to prove is NOT the thing that you said I needed to prove. You basically said you could freely copy my Art if it was the ONLY way to achieve a particular process-result. I want you to prove THAT claim --and I know you can't, since I know of alternate ways to achieve the result. If you don't believe me, just promise to pay me after I prove MY claim, that there are alternate ways! (And follow through on that promise, of course.)
Vernon, Nov 21 2007

       I'm afraid I didn't mean to imply it had to be the only way. The truth of the matter is that it only need be a reasonable way of carrying out the task. This isn't an established legal test; it's just a pointer: If there's only one way to do it, I couldn't have done otherwise. If there are a limited range, it's more likely that I copied; if there are a million ways, yet our products are identical, then infringement is more likely still. So, I don't have to prove that the way I do it is the only way. Burden of proof of infringement (not similarity, note) firmly on you.   

       To get around any claims that my 3D metal object is your generalised written description (I could simply get summary judgement against you there), I will write my own description of what I plan to build first, and then build from that. Comparison of the two documents will easily debunk any suggestion of infringement.   

       As for "plagiarising your engineering art by making a 3D copy of it", the fair use exception allows "transformational" uses, in any case.   

       I quite understand that you don't want to do my work for me; I don't think that's an unreasonable position on your part. Tell you what, I'll show you my design, and you can tell me what bits you think are identical to yours, and I'll try to change them if I can without reducing its performance, value, etc.   

       I will thus be able to demonstrate that I gave you the opportunity to comment, to show that my machine was close to yours. If you don't, it will count against you, because it will appear as though you were trying to protect the idea, rather than some particular geometry that I happen to have accidentally (and unintentionally) hit upon in some million-to-one shot, while making a machine which works on the same publicly-available cycle as your own.   

       Basically it will look like I designed mine first, checked with you, and you either arbitrarily said "no, that's the machine i have in my head", or said nothing until I had built it, then claimed it was what you had in mind all along. In the first case, I will simply change my design (if I can) to avoid the duplication of your art that you're so concerned about - if the design is exactly what you had made and wish to protect; in the second case, you will look like you were shooting for entrapment.   

       I didn't ask you if you'd looked at the patent - I asked you if you'd noted what it said about seals. Essentially, the inventor held that using close clearances instead of seals resulted in a machine that could not be made to work well in metal. Plainly you just looked at the picture and skimmed the wording.   

       Oh, and you're plainly no economist. I haven't set a price yet, but I'm going to want a good profit margin and a competitive price. Ten dollars to you will interfere with both. That's not theft, that's sense. It's what capitalism is built on, and it's the consumer that wins. Of course I expect competition; there's no legal protection on the idea. I'm not worried by that; I'm just taking an eyes-open approach to the world. It's precisely because of those competitors that I'm not going to kick my heels for a year waiting for you to get a patent. That, again, would be daft.   

       And the savvy company doesn't grab the cheapest materials to make a quick buck. If we're in for the long game, we minimise our warranty costs by producing a good unit in the first place. I can call on my aerospace background in promotional literature, and back it up with good service and low failure rates. Avoiding throwing money away paying for a free idea is what my customers want me to do.   

       So, to summarise:   

       Copyright infringement is about the act of infringement, not the similarity of the result. Identical products, both copyrighted separately by different people, are perfectly legal, with no opportunity for litigation. Unauthorised copying is what is illegal.   

       The burden of proof is on the plaintiff, not the defendant.   

       You have to prove that I had access to your machine.   

       Similarity, whether functional or otherwise - even total similarity - does not prove infringement.
david_scothern, Nov 21 2007

       Possibly further illustrating that this is turning into a dialogue of the deaf, I'm back again without even waiting for your response. I'm doing so because this is highly relevant:   

       Copyright is not available for articles with a utilitarian function. To quote the Copyright Act, the only protection available to utilitarian articles covers "features that can be identified separately from, and are capable of existing independently of, the utilitarian aspects of the article."   

       Yes, I know, yours isn't utilitarian, it's art. However, I'll quote the following from Bitlaw.com: "Take, for example, a painting of a futuristic looking automobile. Copyright protection would prevent the outright copying of the painting. In addition, copyright law would prevent the creation of a three-dimensional model of the automobile found in the painting. However, under the specific terms of the Copyright Act, copyright law would not prevent General Motors from making a working (hence utilitarian) automobile of the design found in the painting."   

       That is, if yours is art, you can't even attempt to sue me. Your art is protected, but if I make a heat engine that is very similar, you're out of luck.   

       And from a Second Circuit judgement dated 1985 (isn't the Internet great?): "For the design features to be conceptually separate from the utilitarian aspects of the useful article that embodies the design, the articule must stimulate in the mind of the beholder a concept that is separate from the concept evoked by its utilitarian function."   

       Seeing as I'm going to produce a totally utilitarian design, there aren't any copyrightable design features to quibble over.
david_scothern, Nov 21 2007

       [david scothern], you wrote: "Comparison of the two documents will easily debunk any suggestion of infringement." This ignores the new technology of 3D printing, in which two sets of instructions of how to print a solid object can be entirely different from each other, but the printed objects are identical. If those objects were books, or even various other things ("stabiles", perhaps), the infringement of Copyright would be obvious. Why should other shapes be exempted, just because they might have practical use? Do you not understand that a book is a 3D shape that has a practical use, yet Copyright applies? And so that is why I have claimed Copyright on the objects described, and not just the description alone. Therefore I don't care at all how different is your description; I care about how close a copy is your 3D object. And you most certainly have had access to the design of my copyrighted shapes.   

       I agree to review your description and images. As a hint, if you REALLY want something physically different, I'll say that one of the two rotors can be purely cylindrical, having neither lobes nor notches. There's no copyright possible on cylinders, see?   

       Next, I ignored the stuff about seals simply because you agreed with me that that doesn't especially apply to a low-temperature-gradient SPARLVE. I also ignored it even for the more likely case of an RSE, where a large temperature gradient is necessary, because the assumption was made that inexpensive materials would be used that can experience significant thermal expansion. Seals remain OPTIONAL, simply because it is possible to choose materials that don't expand so much, as to compromise the notion of using close tolerances. I understand that this can raise cost, but that is not the point. Have you ever seen these descriptions before?   

       First-generation technology: A fairly simple gadget that just barely works.   

       Second-generation technology: A very complicated version of the gadget that works very well.   

       Third-generation technology: A fairly simple version of the gadget that works very well. Often this means that special materials, unusual physical principles, and precision manufacturing are all involved. Look up the history of "scroll compressors" sometime.   

       The above points out that the patent you discussed is taking a second-generation approach to solving a problem, while I prefer a third-generation approach. The results are usually more efficient and last longer, even if they can cost more up-front.   

       You wrote, "I'm going to want a good profit margin and a competitive price. Ten dollars to you will interfere with both." Actually, that just means you don't know how to PRESENT your price. I hear that on the other side of the Pond, you folks are fond of gambling about most anything. Would you care to bet on what would happen if you added a message like the following to your price tag?   

       "The designer, not a member of our Company, requests $10 be added to this price. We acknowledge that this composition would not be getting manufactured if it had not been designed. If you believe that creative minds should be rewarded for their efforts, and if you think $10 is fair for this composition, then please add it to your payment. Note that if our competitors offer a similar composition without including this message, they are probably trying to rip off the designer, and may be trying to rip you off, too. Thank you."   

       The thing about Copyrights and Patents is that they can allow little guys to ENSURE they get paid by the big guys who are between them and the end-customers. The Internet, though, is allowing experimentation in pricing, directly between some artists and their customers. There is evidence that even when customers are allowed to set their own price, the artist gets paid more often than not.   

       Let's pretend that you actually make a thing that very closely resemble my design, and it is actually useful to the extent that you actually want to mass-produce it. (I'm aware of the possibility that your entire side of this discussion has basically been you taking a Devil's Advocate position, and of course this IS the HalfBakery, where Ideas may not work as well as expected.) I'm willing to gamble that if you reach the mass sales point, and include an explanatory request such as the above, then most of your customers would be willing to pay the extra $10, especially because I think that $10 will be a trivial fraction (<3%) of your "base" price. I would NOT hold it against your company, that some customers would not pay the royalty for their copies. Because this situation clearly makes them the thieves, and not you.   

       What you wrote about $10 interfering with sales implies that you would gamble that nobody would pay the extra $10. Thus it follows that if anyone actually does pay it, you have to pass it on to me.   

Vernon, Nov 22 2007

       [Vernon], the copyright extends to the non-utilitarian elements of the book - the content. It doesn't extend to the paper, covers etc. A book is, in fact, a perfect example of the point I was making.   

       To apply the law as it stands (not as it is inside one's head): Copyright doesn't cover the idea / principles in a written piece of work. Similarly, if the machine described is then built, copyright doesn't cover the functional elements (the bits that implement the idea/principles). Thus, whether it be a 3D data file or a 3D printed object, the protection is the same. Furthermore, the DMCA specifically allows me to decode the 3D data file to distil out the working principles and the working elements! Where is the problem that you think 3D printing raises?   

       As for "third generation" - look up gas turbines sometime. If a new design is 2% more efficient than a previous one, that's incredible. If that doesn't indicate a mature product, nothing does.   

       They have rotating parts in static casings, whose efficiency depends on low leakage between the two, while cost depends on (relatively) broad tolerance bands. You'll never guess what, we are very careful indeed about our seals - we don't just go for the tightest theoretical tolerances available.   

       I've thought more carefully about the thermals, too, and you've got much bigger thermal gradients than I had believed until now:   

       You're going for a phase change, hence an increase in volume, giving you a pressure which drives the machine. You suggest a volume change of 1000:1. I'm going to suggest a much smaller change for the sake of argument; let's imagine that at rtp the gas has 3 times the volume of the liquid. And for ease of availability of information, let that liquid be water at 100C and 1 bar (i.e. atmospheric pressure), turning to 4 bar steam. Steam at 4 bar is at approximately 140C. If you expand it back down to atmospheric, it drops to 100C again and condenses. Hence you must, unavoidably, deal with temperature fluctuations as the rotor rotates.   

       And finally, I don't know where you read that Brits were all gamblers. Our first and only Vegas-style casino has just been bounced by the courts.   

       On the basis that aesthetics and not functionality are protected by copyright, can we agree that this is not art? If it is art, then any similarity to my useful heat engine becomes irrelevant, because your art is built for aesthetics, whereas my machine is built for utility.
david_scothern, Nov 22 2007

       [david scothern], I agree that a book was a bad example, simply because its shape is classic and not copyrightable. A "stabile", however, despite being created for artistic purposes, can still be functional. It could function as a door-stop, or a paperweight, or a boat anchor.... Does that mean if I make copies of somebody's copyrighted stabile, a 3D shape, I can sell them as boat anchors without violating copyright? HAH!   

       What I created was specified to be Engineering Art. I even noted that if critics called it "bad art", it still qualifies as Art. But I think this Artwork includes elegance and simplicity, and so far there appears to be general agreement there.   

       I notice you made no comments about an alternate design in which one rotor was a plain cylinder. That is certainly elegant and simple, even if the other rotor doesn't qualify.   

       Next, gas turbines are entirely 2nd generation. You are confusing the generic "jet engine" with a specific type. 3rd generation jets are simple things like ramjets and scramjets (and if you want to see a 1st generation low-speed jet, look up "electrostatic lifter").   

       What you wrote about steam and temperature and pressure it at least partly correct, but I think you are missing something. The main text here indicates that we want the liquid to boil as quickly as possible, and so that COULD require a significant thermal gradient. But it also indicates that only milliliters of working fluid are likely to be used, which means less total heat is needed to convert that quantity of liquid into vapor, at the boiling point. Let's examine the true situation one step at a time.   

       1. Start with some liquid in the hot zone. We ignore initial warm-up time, and are now talking about liquid at its boiling point. A small amount vaporizes.   

       2. The vapor starts to exert pressure on at least one rotor lobe (depending on design chosen).   

       3. To the extent that the rotor does not begin rotating, the pressure against the lobe starts to increase. One consequence, in a limited and (temporarily) fixed volume, is that the boiling point of the liquid will begin to rise.   

       4. The preceding is why a greater temperature than the boiling point can be necessary. However, to the extent that the rotor begins to move, MORE LIQUID BEGINS TO BOIL. The pressure that caused it to move will be maintained by the additional vapor, until all the liquid has boiled.   

       5. The net result is that the pressure drop you described does not need to happen, until after the liquid has boiled, and if designed properly (correct quantity of liquid chosen), that's when the next lobe & notch should bring another splash of liquid into the hot zone.   

       I'm aware that the main consequence of the above is that the engine torque could be too low to be directly useful (gearbox needed). To get more direct torque you need more pressure and thus higher temperature and higher thermal gradient --and all the problems you have brought up, that can make seals necessary when ordinary-expansion materials are used. As Art though, seals remain optional, because production of large torque isn't a requirement, and so the thermal gradient can stay low. The goal is efficiency as the result of its elegance and simplicity, not power.   

       Next, what I read is that they don't tend to crack down over there on casual cash-involved gambling between individuals, like in a poker game at a pub, as has been known to happen over here. The result is that Brits, or at least a fair percentage of them, are willing to bet money on most any old thing. I'm pretty sure the gamble I offered falls outside the legal scope here, since neither your nor my already-existing money was on the line.   

       Next, the similarity remains possible, if you make only minor-variant copies of my copyrighted 3D shapes. To avoid that, you need the same generic function using a significantly different form. I know it can be done, but if I describe an alternate form, why shouldn't I copyright that, too? (Well, ONE way is a variant of something already in the public domain, and likely not enough of a variant to be copyright-able, heh.) Anyway, to the extent that you can't figure that puzzle out, that should be the extent to which you recognize that my elegant and simple copyrighted form has value worthy of being paid for, when somebody buys a copy of it.   

       I notice you didn't say yea or nay about the deal I offered. Instead you appear to be writing as if there is no Honor in somebody paying for something worthy, even when its not you who would be doing the paying. Why?
Vernon, Nov 23 2007

       Yes, you can copy their copyrighted stabile and use it as a boat anchor, as long as you leave out the aesthetic elements of it. That's what the law says. By the same token, you can copyright the aesthetics of whatever designs you come up with; the functional parts are unprotected because you don't have a patent. Copyrighting your shapes gets you nowhere - because my machine is useful, copyright is irrelevant.   

       Heck, the functional elements of our machines can be identical - even if I copied your 2D sketch (research exception, I can do that) and then extruded it in CAD and built the result, it would be entirely utilitarian in nature and hence entirely free from copyright. With minor revisions, I'm home free.   

       You're showing an utterly superficial grasp of copyright law. I'm not spouting my own opinions at you; what you're seeing is straight legal fact from an up-to-date version of your country's legal code. You may be arrogant enough to consider your own logic to be above the law - go ahead. The judge, on the other hand, will be bound by the law. Being logical isn't enough; nor is being persuasive. Being right morally wouldn't benefit you either. What you need, for the law's protection, is to be in line with the law - and you're not.   

       And your machine is a "third-generation" unit, designed for ultra-high-speed, low torque, efficient operation?   

       Sit down. You don't even understand the basic principles of the machine you're trying to operate, yet you pontificate over the fine details. Let me walk you through this one.   

       You want the operating pressure to be as low as possible. Let's take 0.01 bar above atmospheric. 10g of water (substitute alternative advanced fluid here if you will, the science is the same) is at 100C. You put in enough heat to raise steam at 1.00 bar; it's at atmospheric pressure and can do no work. You then heat it up enough for pressure to hit 1.01 bar and do work, maintaining that pressure and no more by boiling water as the chamber expands.   

       You need 22.5KJ to boil the 10g of 100C water and raise 1 bar steam. That steam does no work for you. You need a further 7.4kJ to put it up to 1.01 bar and make the machine run. Of the 30kJ in, only 25% does anything for you; the rest is dumped when you condense the steam. Contrast that with a machine running at just 5 bar - not a high pressure by any standards. 22.5kJ boils the water, 2250kJ heats it to 180 degrees. That 2250kJ is then available for useful work - 99% of the total input. If you understand your own idea properly, its efficiency is, like any other steam engine, driven by its operating pressure.   

       You're optimising in totally the wrong direction and have only a minimal qualitative understanding of the workings of this system. Drawing sketches of more possible embodiments doesn't get you further forward; what you need is a thermodynamics lesson - and some seals!
david_scothern, Nov 23 2007

       [david scothern], if you remove the aesthetic elements from a stabile, then you have modified the thing so that it no longer resembles the original. I was talking about making straight copies of the original, and selling them as boat anchors. YOUR argument is that if it is useful, then copyrighting it is worthless, and you are wrong, because of that example.   

       And, of course, you STILL are ignoring the consequences that 3D printing will bring. Printed works are typically copyright-able, such that you generally can't make copies without permission. Since 3D printing means that a wider variety of things than ever before can now be "printed works", it follows that Copyright Law will apply more widely than ever before. How can you be so knowledgeable of technology without knowing about how various rules of Society have had to change, as a consequence of technological developments? How can you ignore the very significant and relevant technology of 3D printing? Just because the Law hasn't formally noticed it yet is no excuse. It WILL, eventually, guaranteed.   

       Next, I think if you look close, you won't see any claim on my part that I expect a SPARLVE to run very fast. I even indicated that the faster you want it to run, the more difficult it is to add and remove heat, in the limited time available, during a rotation. That's why I mentioned that it might be good to use a different liquid than water, with a lesser heat capacity and heat-of-vaporization (and that throws off most of the numbers you presented, for water/steam). And here's something from a prior annotation I wrote: "[Tri-Dyne] ran too fast for there to be time for much gaseous material to leak through those cracks. This implies, of course, that a slower-running engine might indeed need seals." And therefore I said that seals were optional, depending on how much the clearances were, in its construction. Heh, if the kind of clearance commonly found between hard-disk-drive heads and platters was used, I'd be rather confident that seals would NOT be needed, even at a pretty slow rotation rate.   

       Third-generation gadgets are generally highly efficient; that's why they "work very well". Efficiency is not the same thing as being particularly fast or powerful. Ordinary reciprocating Stirlings are as efficient as Diesel engines. But because they lack the power of Diesels, that's why they aren't used all over. The goal of a Rotary Stirling Engine, of course, is to get even better efficiency.   

       Do remember that a phase-change engine is not the same thing as a Carnot Cycle engine (did you examine the "Ice Engine" link?); efficiency is reached two different ways. The best of both, of course, could lead to even higher efficiency, as per your description. But that REQUIRES a means of quickly adding and especially removing large amounts of heat, so that condensation occurs (and that thermal gradient in turn leads to thermal expansion issues that could make seals required too, of course). Well, all Stirlings have at least that heat-transport problem, even when phase changes are not involved. And the rotary versions described here merely exacerbates the problem, the need to move lots of heat quickly, if fast rotation is desired. And so, very few Stirling engines have ever been put into routine service.
Vernon, Nov 24 2007

       [Vernon], you're arguing with the law. If you're wanting to use a stabile as a boat anchor, your anchor can resemble your stabile insofar as you can keep the useful elements of it (the weight). It therefore resembles the original insofar as they are both equally useful as anchors. The law divorces the useful elements (the weight, primarily) from the decorative. That the resulting item would have little visual similarity (because a stabile is defined by its looks) merely highlights the deliberate, childish triviality of the example.   

       Right, so you're not going for speed, or power, or high temperature, or high pressure, just efficiency. It's to be better than a normal Stirling. You've noticed the use of seals in Stirlings? Coincidence.   

       And yes, change the working fluid to unobtanium to obfuscate things if you must; the principle is exactly the same. You've got to boil it, and you lose all of the energy required to do that when you condense it again. The efficiency of the boiling process depends on the ratio of energy required to boil to total energy in, and the pressure is driven by the difference between the two. Your efficiency improves with operating pressure. Never mind "it's not a Carnot cycle engine"; I've not discussed the operating cycle, just some basic physics you seem to be unaware of. In the above example, your machine would start from an efficiency of 25%; mine would start at 99% and lose a small amount through seal friction, which could be minimised (down to approx 2% of power output) by some basic tribology. So our two approaches to leakage and friction give us 25% vs 97% efficiency respectively, _and_ mine costs less. Even if you mortgage your house to make the components and leak not one atom of working fluid, my cheaper machine is four times better at achieving your stated design goal of efficiency - and more powerful to boot.   

       And as for the clearances used in a hard drive, you've plainly got not the slightest understanding of how they are achieved, nor the effects of inertia, shock loading, wear, temperature, manufacturing tolerance or operational reliability on a design. You're mechanically clueless, in other words. A hard drive head flies itself above the disk surface. It is mobile relative to the rest of the system, so it can adjust its position to maintain a constant clearance - the arrangement is self compensating; lift increases as the head approaches the platter. It can do this and have limited ability to survive shocks, because it has very low mass and inertia.   

       The design thus takes out its tolerances to a considerable extent, which is precisely what I am proposing.   

       Prior to this tolerance-resistant arrangement, drive capacities and reliabilities were dramatically worse. Read up on design for six sigma, process capability, etc, to discover how designers produce things that work.   

       And your understanding of copyright is still superficial. "Printed works are protected by copyright, so 3D printed works are protected by copyright". Well... it's not that simple. More accurately, "certain aspects of printed works are protected by copyright, and certain aspects of 3D printed works are protected by copyright", as follows:   

       "Protection shall not be available for a design that is dictated solely by a utilitarian function of the article that embodies it."   

       And again:   

       "In no case does copyright protection for an original work of authorship extend to any idea, procedure, process, system, method of operation, concept, principle, or discovery, regardless of the form in which it is described, explained, illustrated, or embodied in such work." Note the "embodied" bit, and the "in no case" bit. You can hold up obscure straw men one after the other, they all bounce of the "in no case".   

       Your principles, and the useful articles required to make them work, are open to be copied: "An article that is normally a part of a useful article is considered a “useful article”."   

       Fact. Legally valid since at least 1976, and unlikely to move in future just because utilitarian articles can be produced by some new process.   

       In any case, what makes you think that the law cares about the manufacturing process? You can no more send a written description to a 3D printer than you can send a written description to a CNC mill. A good-quality rapid prototyping process is a combination of SLS and high-speed milling; the only difference between this and conventional CNC is that the machining stock is laid down a step at a time and then milled instead of provided in bulk and then milled. Similar results can be achieved via 5-axis milling, in most cases. "3D printing" is just a buzz phrase for a process that doesn't differ materially from most other manufacturing processes. You must still develop a CAD file and toolpath, which aren't as simple as "copies of a description", and then send it to a machine.   

       You're clear, anyway, that several different "descriptions" - I'll assume we're talking about toolpaths - can produce the same design. Let's look at maths briefly. If A is identically equal to B, and C is also identically equal to B, then A must be identically equal to C. Here, you've admitted that description A and description C, both of which are different, can produce item B. Hence neither A nor C can be identically equal to B; they're just representations of it. The concept of "translating into 3D" is hence fallacious; the 3D object is a new creation. 3D printing might be new to you, but just because it uses the word "printing" in popular currency (not, generally, by the makers of the machine) doesn't make it any less a CNC unit, which predate the 1976 copyright act and thus are by no standards a new step.   

       CNC Laser cutters are analogous - they can cut, in steel, a 2D shape directly from a CAD file, and at very low cost. They've been around a long time too. If the "copyrighted shapes" drivel held, someone would have brought a successful case that would have sparked the very collision you're predicting. Can you find any? No. Copyright law applies to them in just the same way that it applies to anything else - aesthetics are protected, functions are not.
david_scothern, Nov 24 2007

       [david scothern], your attempts to confuse what I wrote are pitiful. I did not say I wanted to use a copyrighted stabile as a boat anchor; I merely said that if someone made close copies of it and tried to sell them as boat anchors, then copyright would still be violated. There is no doubt that exact copies of many large stabiles are useful as boat anchors; they even have holes for anchor chains. But this does not constitute an excuse to violate copyright, JUST because they have a use.   

       Next, I'm well aware that processes and such cannot be copyrighted. Here I'm talking about a particular shaped object, which EXEMPLIFIES (as in "example") a way to do a particular thing. But doing that thing does not require that particular shape, or even a roughly similar shape; therefore the shape CAN be copyrighted. It may be Kinetic Art instead of a stabile, but the principle is the same: you can't violate the copyright of a stabile, to sell it for a particular use, because there are public-domain shapes that can be used that way, that work just as well.   

       If you can't find or figure out the public-domain alternative in this case, that's not MY fault.   

       Next, I have not changed the working fluid to "unobtainium". I even mentioned a specific example, ethyl alcohol, which has a lower heat capacity and heat of vaporization/condensation than water (but then, MOST other liquids have those features, compared to water, in fact). The reason water is the commonest working fluid is partly because it is used in significant quantity and is common/cheap, and partly because of the high temperatures that are typically used/required in Carnot Cycle engines; water doesn't decompose easily. But since I was describing an engine with a low temperature gradient, and not a particularly high working temperature, AND one that uses only a few milliliters of working fluid, it follows that PLENTY of liquids are possible working-fluid candidates. Naturally, though, if you insist on high temperatures in YOUR engine, then you could easily limit your choices down to just water. That's YOUR fault, not mine.   

       Next, your "99%" efficiency claim is a joke. Or at best it is only the efficiency of PART of the engine. You can only get 99% efficiency out of a heat engine by raising its working temperature to many MANY thousands of degrees (or by having a supply of near-Absolute-Zero for a heat sink). I won't complain if you say you were talking about the effectiveness of pressurized-vapor-confinement in your design, but you phrased it as if you were talking about the whole engine's efficiency.   

       Next, I'm quite aware that modern hard-disk-drive heads interact with air to fly above the platters. Did you not notice the "heh" that started the sentence in my last anno, which mentioned disk drives? I was being humorous, about achieving such tolerances in an engine, while being serious about the consequences of an "if"! I've read that photons can have trouble getting through that gap; thus it logically follows that so also might vapor, especially, gee, if the vapor consisted of large molecules, like fully chlorinated octane, C8Cl18, for example. Of course, large molecules are still minuscule in comparison to even quite fine clearances in ordinary machinery, such as an engine. That didn't stop the Tri-Dyne engine from working well, though.   

       So seals are optional, and even the type of seal is optional. I might mention a kind of seal that could be used, and will never wear out or get used up, when the temperature is not too high. I think it's called an "oil seal", but I'm not sure. Let's imagine a SPARLVE made from glass. The glass rotors have their flat ends flush against the casing walls, and a layer of oil separates the two. It lubricates/enhances rotation of the glass rotor, and tends to discourage contained vapor pressure from leaking around the sides of the lobes (within limits, of course). If the outermost part of the lobes had a centimeter or two of contact-length with the interior curve of the casing, the oil seal could work there, too. Basically, the more the oil "wets" the glass, the harder it is for gas pressure to push the oil aside, and leak past the seal it makes. Especially when the gap is as small as possible (where the Van der Waals forces behind "capillary action" are maximized). Obviously this can work for metal as well as glass; I only mentioned glass here because many people have some experience with two small flat pieces of glass with water in-between them (microscope slides), and how little friction there can be between them.   

       Next, I'm still talking about things that you continue to ignore, with respect to modern Copyright law. Remember that 3D printing technologies are inherently DIGITAL, the ultimate descendants of "pointillism" Art. Each blob of material that goes into assembling the 3D printout is equivalent to a binary "1", each lack-of-a-blob is equivalent to a "0". The finished piece is quite literally "stored digital data". And the Digital Millennium Copyright Act is about rights regarding copies of DIGITAL data! Thus that fundamental thing about 3D printing, and not just the fact that it "prints" stuff in greater-than-2D, is why there will be a Legal Clash, eventually, between Copyrights and Design Patents.   

       Finally, I'm sure that if you found a $10 bill in the road, you would claim, "finders keepers". But if the $10 happened to be in a lady's purse along with an ID card, would you say the same thing? Well, then, What is the basis for thinking that an idea that clearly has ownership claims attached to it, when you know full well that ideas are ALLOWED to have ownership claims attached to them, is nevertheless free for the taking? Why are you avoiding discussing the gamble/deal I offered?
Vernon, Nov 25 2007

       Vernon, your so-called "protected" shapes are all public domain. The fact that there are other shapes that might work doesn't allow you to claim protection for the embodiment you have chosen. Insofar as the form is driven by the function, there's no protection.   

       As for the 99% claim, I was indeed referring only to the efficiency of this part of the process. If you wanted to do anything useful with your version of the machine (and I realise it's art, and you don't), you've said that you'd need a high-ratio gearbox to get useful torque, with their inherent inefficiencies; there are other losses to be considered too. However, most of these losses apply more or less equally to each type of machine; the point I was making was that I have a factor 4 advantage on you from the word go.   

       It's not the specific heat of vapourisation and the heat capacity that is important. It's the ratio between the two. And yes, there are better fluids than water - the OH bond gives strong hydrogen bonding, which leads to a high specific heat of vapourisation. However, without that OH group, the molecule is much more likely to be gaseous at room temperature; consequently you need a larger molecule which will have a high specific heat capacity. There's an optimisation to be done, but it's subject to some hard limits.   

       I don't see anyone claiming that the tri-dyne was efficient? It worked (at a guess, at a reasonably high pressure, Wankel-style) but it was an engine, not a high-efficiency work of art.   

       Oil seals look like a good idea (subject to heat generation from oil shearing). We use them at work on inter-shaft applications; it's important to ensure a good through-flow of oil to prevent excessive heat build-up and tar deposition. Seals, in general, look like a good idea, in fact...   

       Where in law does it say that your shapes are copyright because there are other ways of doing the same job? I've already told you that I can copy directly every useful aspect of the machine; that copyright law deliberately exempts these aspects from protection in deference to patents.   

       And these wretched stabiles? If the close copies carried over the aesthetics, then those elements would be the ones cited in an infringement action. Aesthetic elements are "those that evoke an impression in the mind of the viewer that is separate from the function of the object". So if they were gratuitously copied, then yes, trouble would follow and rightly so. However, just producing a similarly heavy object with an attachment for an anchor chain would carry over the functionality while plainly leaving no room for allegations of improper similarity. It's self-evident.   

       And whether a 3D object is stored digital information or not, I can legally reverse engineer:   

       - Documents
- Data files
- 3D objects

       to extract their working principles and use them in my own creations, subject to other people's patent rights. So even if a 3D object is "stored digital data" - and that's a simplistic approach; they're no more so than a CNC-cut version of a parametric solid model - no further protection is extended to it as a result.   

       The DMCA, if you must keep pulling it up, criminalises the circumvention of access controls protecting digital data, with exceptions "for research and reverse engineering". Why does that help your case? You don't have any access controls on your 3D object, the information is there "as ones and zeroes".   

       And I might offer people the chance to give you $10 - not as the designer, but as the initial creative spark. It depends how nice you are for the rest of the discussion...
david_scothern, Nov 25 2007

       Geez, I'd wager that this is the longest legal "discussion" on the 'Bakery.
acurafan07, Nov 25 2007

       [david scothern], you wrote, "Insofar as the form is driven by the function, there's no protection." My point is that since there are other forms that can achieve the function, the particular forms I chose are NOT driven ("forced to take those shapes") by the function. What they do have is elegant simplicity in achieving the desired function, and so far as I know, elegant simplicity just about always counts as "aesthetic". And so, if you make/sell too-close copies without permission, it would logically follow, per your own argument regarding stabiles, that you could be violating Copyright. Caveat: You seemed to have claimed that all my shapes were in the public domain, but you didn't present supporting evidence. If some aren't PD, then I should have rights over the making of copies of those copyrighted shapes.   

       Next, you wrote, "a larger molecule ... will have a high specific heat capacity", but this isn't the whole story. Some of that comes from the mass of the molecule, but some comes from the strength of the Van der Waals forces between molecules, and mass isn't a significant factor there. Thus some small molecules can have strong enough forces to be liquid, and other large molecules can have weak enough forces to be gaseous, at STP. So we have quite a range of options from which to select an alternative to water and its (annoying in this context) hydrogen bonds. One of my favorite speculations along this line involves silicon dioxide. Normally it occurs in long long molecular chains (even in grains of sand), but what if you had a sample consisting ONLY of 3-atom molecules of silicon dioxide? Since the molecule is rather heavier than gaseous carbon dioxide, it might be a liquid at STP, and be a nearly ideal working fluid here. How much it could be messed with (heated) before it spontaneously polymerized and jams the engine remains to be seen, heh.   

       If you saw the image at the Tri-Dyne link, you may not have "seen" how it operated. The central rotor swept its lobes through a significant volume, and managed a typical engine compression, squeezing the vapor into a notch on one of the side rotors--amount of compression thus depends on the size of the notch. After combustion, simple rotation continues with the expanding gas pushing against the back side of the rotor lobe (not the side that compressed the vapor). The third rotor acted as a barrier/valve to open/close the intake and exhaust ports. With 3 lobes, there were 3 combustions per revolution of the central rotor. The Popular Science article said that the inventor had to fit two spark plugs, fired alternately, to cope with a rotation rate of 12,000 RPM, 36,000 sparks per minute. Hmmmm...in 1969 the Wankel was still under development because they didn't have good enough seals to long-term withstand combustion temperatures and pressures. The Tri-Dyne got around that by having close tolerances instead of seals. Perhaps that wasn't good enough, since it never got mass produced. So...I wonder how effective a Tri-Dyne type of engine would be, if MODERN Wankel sealing material was added?   

       One thing I forgot to mention about the oil seal I described in my last anno; it should be immiscible with the working fluid. I suspect this means that the "oil" needs to be a polar molecule like water, while the working fluid needs to be nonpolar, since we don't want the equivalent-to-hydrogen-bonds that lead to high heat of vaporization, that normally go with polar molecules, in the working fluid.   

       One of the things I was trying to point out, in prior annos, was that between 3D printing and the DMCA, new factors are now in place that should lead to revisiting of old legal conclusions. The 3D-print method may be able to produce exactly the same thing as the CNC method, but the former is more OBVIOUSLY digital, in what it produces, because of the process used. The DMCA had to DEFINE digital data, so that its regulations would have something upon which it applied. It is that definition, added to facts about 3D printing, which leads me to the position I've taken. The material of a constructed object is, at any given point, either there or not-there. 3D printing MAKES objects that way, but the result lets us realize that EVERY object equally qualifies as digital data (its material at any point is either there or not-there), no matter how it was made. To be effective for the long haul, the DMCA can't be too concerned about the FORM that digital data takes, since technological progress tends to make some forms obsolete (floppy disks), while bringing us new forms (flash drives). Controlling rights to copy copyrighted digital data, regardless of form, makes the DMCA very powerful. When added to 3D printing, the key observation is that 3D printing lets the form BE the digital data. So if you copy the form you are copying the data, obviously. A modified form could still be a copy of MOST of the data, and qualify as plagiarism. Thus, if copying is done without permission of the copyright holder, the logic implies that a formal DMCA cease-and-desist notice could in theory be issued.   

       The preceding is logic-in-a-nutshell, and is intended to be explanatory rather than inflammatory. I appreciate your willingness to accept the compromise/gamble I suggested in a prior anno. The wording of the explanation/message mentioned at that time is open for discussion. Thank you.   

       Here's a teaser. Have you ever heard of something called a ROtary Vane Air Conditioner (ROVAC for short)?
Vernon, Nov 26 2007

       I suggest that the exemption for utilitarian elements still stands. If one could copyright one's own implementation of an idea on the basis that there were other ways to fulfil it, then the exception for useful items would be meaningless.   

       Similar elements within a computer program are not themselves proof of infringement; there is a possibility that two programmers could hit upon the same algorithm. The existence of other suitable algorithms does not allow a company to claim infringement if someone else solves the problem the same way. The same argument applies to this case - both of us can independently use the same solution. After all, it would be immoral if, having both innocently and independently conceived the same design, one inventor could be sued for copying the other.   

       Not being aware of any other way to realise this idea, it is unsurprising that my design will be based on the information presented here, both in text and image.   

       Not intending to get into semantics here, but "driven" doesn't have to mean "forced"; I meant something more akin to "guided" or "directed". Here's something from Circular 40 of the US Copyright Office; a fuller description of what constitutes a useful article and the protections extended to it:   

       <Quote> A “useful article” is an article having an intrinsic utilitarian function that is not merely to portray the appearance of the article or to convey information. Examples are clothing, furniture, machinery, dinnerware, and lighting fixtures. An article that is normally part of a useful article may itself be a useful article, for example, an ornamental wheel cover on a vehicle.   

       Copyright does not protect the mechanical or utilitarian aspects of such works of craftsmanship. It may, however, protect any pictorial, graphic, or sculptural authorship that can be identified separately from the utilitarian aspects of an object. Thus, a useful article may have both copyrightable and uncopyrightable features. For example, a carving on the back of a chair or a floral relief design on silver flatware could be protected by copyright, but the design of the chair or flatware itself could not.   

       Some designs of useful articles may qualify for protection under the federal patent law. For further information, contact the Patent and Trademark Office at Commissioner of Patents & Trademarks, U S Patent & Trademark Office, P O Box 1450, Alexandria, VA 22313-1450 or via the Internet at www. uspto.gov. The telephone number is (800) 786-9199 and the tty number is (571) 272-9950. The automated information line is (571) 272-1000.   

       Copyright in a work that portrays a useful article extends only to the artistic expression of the author of the pictorial, graphic, or sculptural work. It does not extend to the design of the article that is portrayed. For example, a drawing or photograph of an automobile or a dress design may be copyrighted, but that does not give the artist or photographer the exclusive right to make automobiles or dresses of the same design. <end quote>.   

       I think that the exempting of "machinery" from copyright at the beginning of the quote, and the exemption of an automobile design, even one that has been rendered artistically, from protection are significant here. The copyright covers the original description, but not the finished object.   

       The discussion might also benefit from some background on how today's 3D printers compare to CNCs. Fundamentally, they don't take a model and treat it as "blob here, no-blob-here" in a representative digital manner. They actually take only a surface model, which itself is a heavily reduced mesh of points in trios defining triangles - a .STL file. The stereolithography machine (or similar) then lays down material in layers and glues or fuses it, building it up until it reaches the height of the surface as interpolated at that point. In that sense they can only contain such information as was passed to them, which itself is only a representation of the surface of the part. For reduction of material used, some types create simple internal truss structures to support the surfaces; these structures bear no resemblance to the original model.   

       More serious machines - those intended to produce parts that can be used directly in load-bearing applications - use powdered metal and sinter it with a laser. The resulting process is rather like welding; it doesn't lend itself to the production of discrete dots. The finished part will be sintered, which destroys any internal structure put in by the process in favour of a more uniform arrangement and high strength. Better surface finish is achieved by combining this with a surface milling operation.   

       STL files, for reference, can equally be processed for 3D printers or for CNC mill (I used to create them with a laser scanner for CNC application; our software supplier used similar scanners, the same processing software and a range of 3D printers). I don't think there's a fundamental difference in the eyes of the law.   

       On the subject of the DMCA, I'll reiterate - it criminalises the act of circumventing access controls for certain purposes, with a prominent exception for research and reverse engineering. It doesn't control who can make copies, per se - and if I want to reverse engineer it to develop a competing product, it allows me to do so (as per the Lexmark case, for illustration).
david_scothern, Nov 26 2007

       [david scothern], it appears you have a good case. It logically follows, after all, that the purpose of Design Patents is just exactly for those cases where the Art is inseparable from function.   

       Which means only in the US would a patent on this be respected, and I have only a year to file for it. I might mention that such a patent could be used to forbid foreign importation to the USA of unlicensed copies, just to see if the notion bothers you any. On the other hand, if you do the compromise/gamble thing mentioned previously, that would be license enough. Let me reiterate my preference for wording that could shame or guilt-trip your competitors into getting a similar license. (If you click my name below, you will have access to my email address where we can discuss that privately.)   

       I see I forgot to mention that the Tri-Dyne engine uses the 4-stroke cycle, compressed into a single rotation of the main rotor. It was also designed by a Brit, so if it appeared in Popular Science in 1969, it was probably patented and by now that patent has almost certainly expired. [edit] After thinking about it for a bit, I must say that the Tri-Dyne actually takes 1-2/3 rotation to do the equivalent of a 4-stroke cycle. On the intake stroke, fuel/air mix enters behind an initial lobe. Compression happens as the NEXT lobe acts on it. Power pushes on the back side of that lobe (not the initial one), and then exhaust is performed by the lobe that follows the one that got powered. So, from when the initial lobe is in the notch of the barrier/valve, just before intake begins, to when the lobe that did the exhausting is in the same place, that's 1-2/3 rotation.[/edit]   

       ROVAC was also described in Popular Science quite a few years ago, and so that is probably in the public domain now, too. A slight variant of its rotor design is sufficient to work in conjunction with a purely cylindrical rotor, for a SPARLVE.
Vernon, Nov 27 2007

       You're entirely correct that a US patent would prevent parallel imports.   

       And further to that, you guessed correctly that I was simply playing Devil's advocate. I'm glad this has all ended amicably; if you do take this one forward and I can be of use, I can be reached at my halfbakery moniker with "@yahoo.com" added. I'll be happy to provide my services at no cost, and ask for no rights either. I have limited skills in the field of mechanical design, including design for CNC, generic design for manufacture and casting pattern making.   

       And forgive me for getting hot under the collar at certain points too...
david_scothern, Nov 28 2007

       [david scothern], even if you aren't actually planning on making lots of copies of a SPARLVE or RSE, you are still free to make some just to see how well they work. It still would be an Honorable thing for you to ask for $10 each on my behalf it you sell them, but if you make only a few for study purposes, selling them is not a likely thing. Guys who like toys tend to keep them. :)   

       Hey, [marklar], haven't heard from you in a while about your desire to build a couple. How goes it?
Vernon, Nov 29 2007

       I'd still like to and there is a guy that will machine them for me, but I've been tied up with a couple of other projects recently.
marklar, Nov 29 2007

       [marklar], thanks for the quick reply. Hope the quagmire is escaped sooner rather than later.
Vernon, Nov 29 2007

       //could be the first chink in the wall between copyrights and patents. And, personally, I think the more that 3D printing "takes off", the more that people are going to try to squeeze copyrighted designs through that chink!//   

       Let's keep the racist epithets to a minimum, mmmkay?
ytk, Feb 03 2012

       Note that as of a decade or so ago, the US is "first to file" not "first to invent", so the methods of documenting the idea date mentioned in my, and other early annos are no longer relevant. If you need to protect an idea, file a preliminary patent while you do the development work.
MechE, Jan 15 2024


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