Yesterday I found a fascinating gate along my hiking trail: simple mechanical engineering that mimics advanced .

Let's say 4 different officers want to share the ability to unlock this gate independently, but they don't want to use a shared key for some security reasons. For example, they might want to quickly disable or replace one of the 4 keys in case its owner gets fired or leaks it.

How can they achieve this using common padlocks and iron moving parts?


And this is the mechanism. Can you guess how it works?

Hint: the iron disc carrying the locks can rotate, and the handle on the right can be lifted up.

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@codewiz So you unlock your own padlock, rotate the disk so its hole lines up with the handle's metal rod, and then you can pull up the handle because the rod passes through the now-freed-up hole?

It's certainly a very interesting approach, thanks for sharing!


Ciao Bernie, very long time no see, maybe you don't even remember who Patrizio is... 😀
However, I understand the mechanism of gate, but I'm curious.. and cannot arcive how the hypothetical 3 remaining authorized owners can "disable" the fourth owner'lock who is no longer authorized (without him returning key lock). I mean a clean way, not cutting lock with large wire cutters!

@Izio I knew a few people called Patrizio, but your profile doesn't give away a lot in terms of hints.

Have we been coworkers? Have we been together in the "servizio di leva"?

Anyway, welcome to Mastodon!

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