Hi there

I have studied Bramah and his locks for sometime now, yet there are a few nagging questions that I have never been able to gain clarity on. I am wondering if anyone may be able to help fill these gaps?

1. Did Bramah's lock patent expire in 1812 (1798+14 years)? If so, am I correct in assuming that after this time other locksmiths were free to copy his design?

2. Did the presence of the term 'Patent' stamped on the lock surface, denote that the lock wasn't actually made by Bramah themselves? The reason I question this is that many locks display 'Bramah - 124 Piccadilly - Patent' on them which makes it seem that they are indeed manufactured by Bramah.

3. Besides a blank lock plate surface, what other text might one see stamped on a Bramah 'copy' lock? By using the term 'copy' I refer to any lock not made by Bramah themselves.

Many thanks to anyone that can help me.