The hole is shaped like the front silhouette of the dog, the perimeter of which is lined with levers that open the door when all pushed.

So only a pet with that exact profile of your dog would be able to "unlock" it simply by walking through.

Fully mechanical, no power or batteries needed and much more expensive and complicated than other dog security systems.

Plus it might be interesting to see the occasional dog in your living room that's the exact size of your dog.

Put a scale on it too so they weigh the same.

Hmm, maybe just a scale, that's actually kind of doable.

Pet Weight Triggered Door

Your pet walks up to the door and steps on a scale set to open the door within the range of your pet. So if your pet is 20 pounds, a pet that's 10 pounds or 25 pounds won't get in.

No batteries or power, and this would actually be pretty easy to make. In fact you could sell a retrofit to work with existing doors. Just a scale, an adjustment knob to calibrate it and a latch.
-- doctorremulac3, Mar 07 2024

NOT a monastery’s ’Anti-Gluttony door’ https://fakehistory...anti-gluttony-door/
[Voice, Mar 12 2024]

The outline thing wouldn't work for any dog that's not a constant cross-section along its length; or, conversely, maybe it would work for any really fat dog that could just squish itself against all the levers
-- hippo, Mar 07 2024


Yea, I like the scale thing. I’ll erase the outline deal.
-- doctorremulac3, Mar 07 2024


Slightly disappointed you're not suggesting many generations of selective breeding to create dogs with a more constant cross-section
-- hippo, Mar 07 2024


The dog could wear a collar with protrusions, like those studded collars that cartoon bulldogs wear. The door feelers could engage with the various length studs so that the collar operates as a key
-- pocmloc, Mar 07 2024


Also the "no power or batteries needed" statement is a bit of a red herring - it's super-easy to have an identifying chip in the animal's collar which is woken up by a powered reader near the door. This is exactly the same as how bank cards are read by a contactless reader, or passports are read by the scanner at the airport (passports are a bit smarter in fact: the reader's inductance coil wakes up the passport chip and reads the information and the photo off the chip. The reader then compares the photo to the optical scan of the passport data page and to the live image of you as you go through the security gate)
-- hippo, Mar 07 2024


Chip and pin is a system largely unknown in America, along with the other bank card/passport contactless technology common place in the UK and Europe, so they would need to catch up by about ten years before deploying to dog houses.
-- xenzag, Mar 07 2024


How many criminals can't weigh a cat? How many can?

It seems like every system in existence is like making your pet into a welcome mat for grabassery, latch not included.
-- 4and20, Mar 07 2024


They might weigh the cat and put a sandbag on the door and then reach up with a special tool to grab the doorknob I guess.

Or just break a window. Fewer scales and sandbags.
-- doctorremulac3, Mar 07 2024


//they would need to catch up by about ten years//

They'd be better off if they didn't, we'd be better off if we hadn't.
-- Skewed, Mar 11 2024


Re: the "No fatties allowed door"

Whoa!
-- doctorremulac3, Mar 12 2024



random, halfbakery