First GB lock patentIn 1778, the first British patent (No. 1200) for a mortise lock was issued to Robert Barron. He devised a double-acting tumbler system lock with greater security than the single acting tumbler lock used until that time. Without knowing it, Barron reinvented the ancient Egyptian lock which had gravity tumbler pins. In the Barron lock, each of several levers fall by gravity into corresponding slots on the bolt, thus preventing the bolt from being moved until a key raises all the levers to exactly the right level. Levers raised too high move into a slot above them in the bolt, also preventing the bolt from being moved. |
