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Self-Acting Fire Escape Dog Door

For "Home Alone" pets.
  [vote for,

Many dog owners leave their pets shut up in the house when they are out. There’s nothing wrong with this, and sometimes it’s necessary for the safety of the dog; in other cases, the dog is guarding the house.

However, the dog is at risk if a house fire occurs while the premises are unattended – the dog has no means of escape. A “dog flap” large enough to accommodate larger breeds will also allow a burglar to enter ….

So, what is needed is a Self-Acting Fire Escape Dog Door. The whole system is integrated into the door, allowing it to be quickly and simply retrofitted to existing premises with no architectural modifications beyond the lock strike and the hinges; but possibly, the unit could be supplied in uPVC complete with frame.

Externally, the door is indistinguishable from a standard door. The upper portion may be glazed or plain at the choice of the purchaser -–a number of styles would be offered. The lower third of the door contains a square (apparently decorative) panel, about 600 mm a side. Such panels are commonplace on many doors and would not attract attention; a moulding conceals the seam and weatherseal. The weather seal consists of an outer wiping silicone rubber seal, and an inner single-use 50 micron polythene or polypropylene membrane, which tears away as the panel is ejected.

The panel is retained by a set of vertical sliding latches, connected to pneumatic actuators; these would be rotary, and release the panel by tuning leadscrews which disengage the latches, allowing pre-tensioned springs to eject the panel outwards. Power for the actuators comes from a pair of CO2 cartridges in a casing within the door structure. The complete actuator system (pressure reservoirs, actuators) is duplicated to provide reliable operation.

Positioned at the top inner side of the door is a smoke/heat detection system. This would be a rate-of-rise or fixed-point detector, rather than an ionisation or optical detector, since the probably location of the door is a kitchen or utility room where smoke and/or steam may intermittently be present, leading to false alarms. Power is provided by a 9V lithium thionyl chloride battery, and a backup alkaline battery provides the power to operate the gas release valves. Battery life for the detector battery should be minimum one year.

A manual mechanical override system is provided for human actuation.

Since the door is cosmetically indistinguishable from a conventional door, and the locking mechanism should have at least the same rating as the perimeter locking system, fitting an escape door like this does not reduce physical security. However, the system can be defeated by dropping a smoke bomb through a letterbox or window which would cause the panel to release. Since this will also release the dog (who will no doubt be irritated and/or frightened by the smoke) this may not be as much of a problem as one might first envisage.

Extra: The door is equipped with an alarm to indicate it has activated. The frequency and volume of the alarm should be chosen so as to be uncomfortable to canines, so as to encourage them to vacate the room. If the alarm runs continuously the dog will retreat from the noise (which will be coming from the direction of its escape route), the sounder can either be a slave unit on the other side of the room, or cycled on a 1:4 duty cycle every 20 seconds to allow the dog to exit between bursts.

8th of 7, Sep 20 2002

I said I'm sorry http://www.minga.co...--Open-The-Door.jpg
Could you open the door? [thumbwax, Sep 20 2002, last modified Oct 17 2004]


       But what does it do to the cat?
thumbwax, Sep 20 2002

       The cat's paralysed after too many Botox injections. How do you think the fire started in the first place?
PeterSilly, Sep 20 2002

       read first two paragraphs - croissant
po, Sep 20 2002

       // But what does it do to the cat? //   

       Oh, don't tempt us.....   

       We presume that the house will be provided with a cat flap, to allow the obnoxious feline freedom to wander the neighbourhood, despoling flower beds, spreading fleas far and wide, killing small birds, and <SKRRRRRKKKK>
8th of 7, Sep 20 2002

       Any reasonably intelligent and tall dog should be able to open doors.
pottedstu, Sep 20 2002

       pottedstu: If you've gone out, the doors should be locked. If not, what's to stop the dog opening the door any time it likes and wandering off ? We know several dogs that can open doors. This is for emergencies only.
8th of 7, Sep 20 2002


       <Basil Fawlty> Manuel, please try to understand before one of us dies ... </Basil Fawlty>   

       The door is LOCKED, OK ? To keep the Bad Guys from stealing all your stuff, OK ? No key in the door for kitty or poochie to turn. So there has to be an "escape hatch" that is normally firmly closed, but that automatically opens in the event of fire.
8th of 7, Sep 20 2002

       What's to stop the dog starting a small bonfire, and slipping off in the resultant confusion?   

       (8th of 7: ok, point noted.)
pottedstu, Sep 20 2002

       pottedstu: Dogs are socially responsibe and can be taught from an early age not to play with matches - unlike cats who would not hesitate for a single moment to make a bonfire of all your posessions to keep them selves warm fi they felt like it, or indeed just for amusement. Nothing but a huge ego on four legs, coated in fleas. Yuk.
8th of 7, Sep 20 2002

       Instead of its own sensor, it could simply detect the squeaks of a normal fire detector.
pfperry, Sep 20 2002

       However the dog could learn to imitate these squeaks, either off it's own back or by the use of a squeaky Margaret Thatcher dog chew.
Aristotle, Sep 20 2002

       I like it, but it would be easy to silently drill into the door and break in.
danman, Jul 07 2009

       Why not use an intumescent dog shampoo? In the event of a fire, the residue left in the fur will expand, converting the dog into a large pseudospherical ball with a 30-minute fire rating.
MaxwellBuchanan, Jul 07 2009

       What a good idea. BorgCo are seeking backers for a technology demonstrator project in this field, starting with cats rather than dogs, as (a) they're smaller, (b) they're readily available, and (c) the chance of tossing cats into burning buildings is too good to pass up (Sure, the intumescent spray might work, but the control group will be highly gratifying).
8th of 7, Jul 07 2009

       Well, someone who is stuffing a smoke bomb into your house could just as easily break a window to get inside. Both strategies have the disadvantage of causing police services to be automatically notified, assuming your house has a proper fire alarm/door alarm. Breaking a window seems more effective; no smoke in the way to make searching the more difficult.
aguydude, Nov 04 2010

       // drill into the door and break in //   

       ... to a house where there's clearly a large dog in residence ...
8th of 7, Nov 04 2010


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