Door lock with alternative keys - extra key controls cam to release selector system for alternative keys

摘要

A door lock with a sliding member (1) on the door which engages a hole in the door frame, has a special latching mechanism with a plate (12) at the end of the sliding member, with a slot (14) which engages a pin (15) which enables it to occupy alternative positions so that a finger (11) can be engaged or disengaged in a toothed face (8) on the end of a plate (3) which is actuated by the key (10). This enables different types of key to be used. This alternative is permitted by a second latch with a vertically moving plate (16) which engages the pin (15) in its upper position, and engages a locking pin (19) below in its lower position. This vertical latch is raised and lowered by an eccentric block (23) rotated by another key (22) at the edge of the door parallel with the door lock.