GB189800330A - Improvements in Locks. - Google Patents

Abstract

330. Brett, W. Jan. 5. Locks, key; keys.-The lock a is provided with a spring bolt d, which is operated indirectly by the key shown in Fig. 9, through the pivoted plate f. This plate is pivoted on the key pintle g, and engages the stud h on the bolt d to retract the latter. The plate f is normally locked by pins k, which are carried by blade springs l and engage in corresponding holes i in the plate. The back of the cover plate b, Fig. 8, is provided with a stop n, which is formed, as shown, with wards corresponding to the wards o on the key. The key is inserted in the keyhole m and turned until it engages the stop n. It is then pressed in until its projections j enter the holes i and disengage the pins k from the plate f, after which a further rotation of the key effects the rotation of the plate f to retract the bolt. The bolt is protected from direct operation, such as by picking, by the partition s and a longitudinal guard-plate, the plate f being rabbeted at u so that it lies flush with the guard-plate. The ends of the pins k also normally lie flush with the surface of the plate f, so as to give no indication of their position. A stop bar q is preferably provided, to prevent the operation of the lock by an improper key having projections j of greater length than the thickness of the plate f. The sliding catch v is adapted to engage the tail of the bolt, to hold the latter when retracted, when desired.