This lock appears courtesy of it’s current owner : Lynn Collins of the USA.
This is an example of a Chubbs “ New Patent ” lock for an iron door or safe.
I think the name “ New Patent ” was coined because the design was so different to anything that came before it.
The levers all have the same distinctive shape, which has coined the other name for these locks : “ Kidney lever locks ”
There are no false notches or any of the later anti-picking designs, indeed this lock had only four levers, yet was considered secure enough for use on a safe !
In common with earlier detector locks it has two bolt stumps and two sets of gates, one for the primary locking bolt and the other for releasing the detector.
Safes of this era had the bolts attached directly to the lock bolt, which required a large heavy key and a robust design.
This lock had special significance for me as it was the first lock I ever removed from a safe. I was however persuaded to part with it and it is now in the Lynn Collins collection.
Here the engaged detector can be seen, as you can see it is quite different to the Improved patent lock in that it is a simple hook catch in the end of a lever.
Smaller locks often have steel guard plates to prevent a steel wire being used to release the detector by simply pushing the steel hook aside.
A wide range of locks were made using this detector design, everything from tiny cabinet locks up to large padlocks and door locks.
It was this design of lock that was picked by A.C.Hobbs at the time of the Great Exhibition of 1851.
