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Some people (myself included) find it easier to remember a combination than
to always remember to grab their house key upon leaving. Realizing you left your key at home doesn't
make it reappear in your hand, but a combination you use every day
should become second nature.
An automatic door opener
is a real help to handicapped people, but is generally not considered
much more than a cool factor for most other people.
However, having an electric lock and door opener that are interfaced with a fire alarm
may save your pet's lives, and will "highlight" the escape route even for
people while venting smoke from the area at the same time.
If the alarm was accidental or something trivial, having the door
open itself has the added benefit of venting the smoke so that
the alarm will stop on it's own once the source of the smoke is
taken care of.
When you're out of the house, you probably want your pet to be
inside so that they don't run off and get themselves into danger,
or just plain run away. But if, heaven forbid, there was a fire in
your house, your pet would have no way to escape.
A keyless entry lock on a residence really shouldn't have a code on both sides unless it's specifically
needed for whatever reason (if there's glass near the door there should be an alarm instead of a double sided lock)
but if it is indeed set up this way, a fire alarm interface is even
more important, because it could now save people's lives as well
But how does it work?
Basically, you've got a keypad on the door, which is set up with a
door open button. If you just want to unlock the door, you enter your code. When the
lock is unlocked, the door can be opened either manually, or
by pressing the door open button. The door will then slowly swing
open, and either remain open for a predetermined delay, or
stay open until the button is pressed again. On the inside, there
should be a box toggle switch that allows you to set the lock to either remain unlocked,
or lock automatically upon closing the door. There should be a
button labeled "lock/unlock" and another one that says
This system should omit features like "audit trail" and 100's of
user code capacity, because most homeowners don't need features
like that and removing them should lower the cost without
reducing the reliability of the system. It should have, say, 4
user codes that can be added and removed at any time, either
by entering an existing code or by pressing buttons on the inside
of the door while it's open, then programming via the keypad.
Extra functions such as time/date for automatic removal of a
temporary code, more memory capacity and audit trail can be
selected at purchase time at an additional cost.
Also, if you're worried about a glass pane in or near the door, or if you have
young children who are difficult to keep from running outside
unsupervised, you could even have a second keypad on the inside,
if you feel you really need it. With the fire alarm auto-open and
the fail-safe lock, it wouldn't be as much of a danger as a double
sided lock normally would be. Maybe a fire alarm switch that is
wired to cut power to the lock when pulled could be provided as well.
The control circuits should be inside a box which is near the door,
which of course is baked in a number of systems. This one system
should control both the door opener and the locking mechanism.
This way, the keypad would not require weird tools to open,
without compromising security. The keypad is nothing more than
just that- a keypad, with lights to give feedback to the user.
It can be replaced separately from the control box should it
stop working for whatever reason.
The lock itself should be "fail-safe"- that is, it locks when power is
applied, and unlocks when power is lost. This could be either a
magnetic lock, an electric strike or a solenoid-operated deadbolt
which can be either surface mounted or installed into the door.
Basically anything that prevents the door from opening when it
has power, but allows it to open without power, can be hooked up.
For security a UPS should be present with enough capacity to
keep the system functional for, say, 12 hours. But a would-be
burglar wouldn't even know if the lock was fail secure, or fail safe,
nor would they know how long the batteries would last before
it came unlocked. If a burglar knows little about any given lock,
mechanical or electrical, the likelihood of them being able to
defeat it is very low unless they resort to using a hammer, and ax or a saw.
Hopefully someone would hear them trying to break in if they
resorted to such extreme measures
For interface with a fire alarm, there are 2 options. The door can
be fitted with a microphone that listens for the sound of an
existing, stand alone battery fire alarm
(which is "learned" upon setup by setting off the alarm while the
door is in learn mode)
or if the home already has a central fire/burglar alarm system, or one will
be installed along with the door, it can be hooked up to the relay
output of the fire alarm.
When the door gets an alarm signal, it will unlock and automatically
swing wide open, and remain open until either the alarm stops
or the close button is pressed and held for 3 seconds.
When the door is in the alarm condition, it will not automatically lock upon closing, regardless of the position of the toggle switch.
It can still lock, but only by pressing the lock button on the inside
with the door closed, or by entering the code on the outside,
again with the door closed.
This prevents accidentally locking yourself or other people out
in the event of a false alarm, as well as allowing the fire department
to enter if there's a real emergency.
I know that one could probably build a system like this with the
right equipment and the ability to program such things, but the
idea here was to make a control box, keypad and door opener
that are designed to work together and can do all this stuff
already, without requiring special programming or additional
pieces of electronics (except for of course a fire alarm)
and all you need is a simple electric lock to complete the system,
without additional features that many keypads have that you may
not really need that tend to increase the cost of the keypads.
One may want to have a locksmith do the actual installation of
the door opener and lock, but interfacing this with a fire alarm
is easy. If it's not a central system with an output, or running the
wires is too much work, the system can be set up to listen for
the sound of the fire alarm.
Self-Acting Fire Escape Dog Door
Prior Art. [8th of 7, Jun 24 2011]
||So this is a numerical keypad lock that automatically
unlocks in case of fire?
||I think I've seen something like this before... now where
was it? Oh, that's right! I've seen these on college
campuses, government buildings, and corporate offices in
virtually every country I've ever visited. That's where I've
seen those things.
||//I think I've seen something like this before... now where was it? Oh, that's right! I've seen these on college campuses, government buildings, and corporate offices in virtually every country I've ever visited. That's where I've seen those things.//
-My college campus has doors that slam shut in case of fire. The trick is to be on the "not on fire" side when the doors come down :/
||//having the door open itself has the added benefit of venting the smoke//
-OOOr, when the door opens the rush of oxygen will cause a 1000 degree flash fire.
||Yeah, like the fires going to get that big before the fire alarm even goes off. How could there be a flash fire just seconds after the fire started? A flash fire happens when the fire depletes the oxygen in a given area, faster than air can get in.
||Try lighting a match near a fire alarm, and chances are it'll sound. Now open the nearest exit door just a few seconds after the alarm goes off. Does the match burn that much faster?
||It would have to be a pretty big fire to lower the amount of air in the room to the point of causing a flash fire when the door opens. Much bigger than a fire would get without setting off the fire alarm.
||The door merely unlocking itself probably isn't going to save any pets unless the door has no latch, or said pet is smart enough to actually turn the doorknob or lever, and is able to reach it.
||If the home that this is in has a handicapped person living there, then the automatic door opener on the entry would also be a big help to them. Maybe a keyfob could be provided as well as a code?
||This would be on the entry door to the building, not an interior door.
||You actually would probably want interior doors to CLOSE in a fire, to help prevent it from spreading and causing more damage, while giving people more time to escape, which they still can assuming the doors don't lock from the inside. If they did, it would be remarkably stupid to have them auto lock when they close unless said door is in a prison or other similar place.
||My point was that, unless there was something written
between all those lines that I failed to read, numeric
keypad locks are WKTE, as are locked doors that
automatically open in case of fire.
||// Try lighting a match near a fire alarm //
||We have, and you'd be truly astonished at how upset people get.
||//you'd be truly astonished// You're confusing the
first and second person, again, [8th].
Understandable, of course.
||No, you would be astonished (conditional future), since clearly you have never done this. We have done this, and we wouldn't be astonished any more, as we now have a very, very clear idea of exactly just how upset (and indeed "pissed off") people get when the fire alarms are set off.
||Particularly in the Royal Armouries, Leeds, on a busy day when the building is full of visitors.
||Ever heard of invisible fences? it involve shock
collars condition animals to fear moving outside of
a predefined area.
||In the same way, I think most animals would be
trained to believe that the front door is always
closed, and therefore think to check it in the
event of a fire.
||I think the best solution is the simplest one,
install a doggy door.
||That said though you seem to have a good
understanding of current locksmithing
technologies, and i think the auto door might
have other applications where it might be useful.
||Well, my "match near a fire alarm" example was essentially a response to the other person who said having an entry door swing open in a fire could cause a flash fire. It would have to get pretty big for a door opening to cause an FF, and the fire alarm would almost certainly go off before the fire got that big.
||The unlock and open input ideally would be designed such that a contact closure of any kind would be enough to trigger it. Thus you could wire it to a relay that activates upon recieving a remote signal from a keyfob, a switch elsewhere in the building (so that you could "buzz" someone in, but instead of a buzz telling them to open the door, it would open itself)
||If you're out of the house, having your dog come and go as he/she pleases may not be appealing to everyone. A doggy door only works for dogs up to a certain size, and after that you'd be "inviting" burglars, unless there's some kind of lock, then you get back into how does the dog get in/out, etc.
||I've heard of electronic locks that *unlock* upon recieving a fire signal, but I've never heard of one that actually opens the door.
||Since the control box has all the logic for this system built into it, one does not have to add additional relays, control devices and such in order to perform all the following additional door-opener related functions:
||Allow the lock to unlock without activating the door opener
||Unlock the door AND open it all the way when a fire alarm signal is detected, then close it 1 minute after the signal is "removed"
||Ensure that the door opener cannot be activated while the door is locked-that would be very bad news for the door opener!!