Hobbs 4-lever lock

[Cepasaccus]

Thanks. Grille gate of a vault or something like a private property?

I assume that this is intended as a 4-lever lock deceiving the customer. The talon is the full width of the bolt and so it is the longest bit in the middle of the bolt which is actually throwing the bolt.

[Tom Gordon]

Thanks. Grille gate of a vault or something like a private property?

I assume that this is intended as a 4-lever lock deceiving the customer. The talon is the full width of the bolt and so it is the longest bit in the middle of the bolt which is actually throwing the bolt.

Maybe there was another lock which used all the bittings and another key without the extra bittings.
one key would open both locks but one key would only open YOUR lock.

[chubbbramah]

I have a Hobbs double-sided grilegate custodial lock masterkeyed with compound levers. The belly has 2 different radii, each half the thickness of the lever, i.e. two different points on which the key step can bear. (Similar idea to masterkeyed wafers, but more difficult and expensive to make the levers, and cut the master and servant keys.) Sadly I only have one key for my lock, no way of knowing which it is.
Mine probably dates from 1930's when the prison was built. The patent dates from 1922, according to UNION Encyc of locks.

[Cepasaccus]

Maybe there was another lock which used all the bittings and another key without the extra bittings.
one key would open both locks but one key would only open YOUR lock.

That makes sense!