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syphon piston

when you don't have a pump handy (and you don't want to use your mouth)
  [vote for,

Syphons are a great way to empty vessels in a controlled manner.

To get a syphon working you need to partially fill the syphon.

There are several ways of doing this: sucking with your mouth, using a simple hand pump, or submersing the syphon in the liquid and blocking one end which is then removed and placed at a lower level.

sometimes none of these options are available.

A simple method of filling the syphon would be with a piston. The piston is inserted at one end of the syphon and a string is thread through the syphon to the other end. To fill the syphon the end with the piston is placed in the vessel, the string is pulled and the piston sucks the water through the syphon.

The piston could be anything that makes a reasonable seal with the syphon but also slides easily. This could be an elastic ball with a greasy or teflon coating. This could even be something as simple as a cylindrical stack of woven fabric.

xaviergisz, May 12 2007

(?) Standard toilet cystern http://www.darlingt...pairs/Overflows.htm
Scroll down. Syphon. Piston. [MaxwellBuchanan, May 12 2007]

Siphon tube starter http://www.freepate...ne.com/4112963.html
Pretty darn close - has the piston in a separate cylinder, with a cone to seal against the siphon tube [lurch, May 13 2007]


       simple, effective.
5th Earth, May 12 2007

       Baked. Widely known to exist. Widely seen in bathrooms everywhere.   

       This is exactly how the majority of lavatory cisterns work (at least until recently - newer designs differ). When you pull the chain or press the lever, a loose-fitting disc is pushed or pulled up the "up" leg of the siphon. It lifts a slug of water over the top, and this is enough to start the siphon.   

       Incidentally, this is why pulling the chain or pressing the lever slowly on an old-style loo won't work: the disc doesn't seal very well, so it won't lift the slug of water unless you do it quickly.   

       So, [m-f-d] widely known to exist. Or at least very widely existing.
MaxwellBuchanan, May 12 2007

       ah, so that's how a toilet cistern works.   

       I think the application of this idea is sufficiently novel not to warrant an mfd, but I'll let others decide. btw, if you genuinely want to mark it for deletion, you have to write it out in full.
xaviergisz, May 12 2007

       I think the idea of pulling something through a long pipe on a piece of string is novel enough. I was thinking how useful this would be for syphoning petrol (gas).
Ling, May 12 2007

       some kind of umbrella type gizmo would improve this so that there is less resistance on the way down and a tighter fit on the way up.
po, May 13 2007

       Hmmm. I'm not sure about the mfd - your invention is intended as a general principal, so I think any particular embodiment counts. So, I still suggest [EDIT - mfd removed] but I am happy to leave it to a majority decision.   

       Re the umbrella gizmo, [po], some cisterns incorporate something similar: the piston (actually just a disc) has a hinged portion like a trapdoor which closes as the piston is raised, but can open upwards to allow the following flow of water.   

       Cunning people, sanitary engineers. They may have been using nuclear fusion cesspits for decades, for all I know.
MaxwellBuchanan, May 13 2007

       [MaxwellBuchanan], I fail to see how your toilet diagram mimics the form or use of the described device. Sure, it uses both the words "siphon" and "piston", and they're both attached to a tube, but there the similarity ends. I don't see the idea as a "general principle" idea at all, but a very specific product, with a specific description, which functions in a specific fashion that is different from how the diagrammed toilets work. Specifically, if nothing else, the use of a vacuum to pull the fluid through, rather than using the piston to "[lift] a slug of water over the top" (your words), i.e. positive pressure.   

       The idea is, as [Ling] described, "pulling something through a long pipe on a piece of string". Okay, it uses the siphon effect, but by your argument, we have to delete every internal combustion idea on this site, because they all use the general principle of IC, which is known to exist.
5th Earth, May 14 2007

       [5th] fair enough - like I said, I'm easy.
MaxwellBuchanan, May 14 2007


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