GB1108438A - Improvements in lock constructions for closure members - Google Patents

Abstract

1,108,438. Locks. GENERAL ALARM CORPORATION. 14 Jan., 1966 [28 April, 1965], No. 14463/67. Divided out of 1.108,437. Heading E2A. A lock comprises a bolt 19, means operable to shift the bolt between locking and unlocking positions, a lock cylinder 29 operable from one side of the lock to operate the bolt shifting means, a rotatably mounted latch 42 manually operable from the other side of the lock and being shiftable axially between first and second positions the latch 42 operably engaging the bolt-shifting means in both positions, and means preventing rotary movement of the latch when the latter is in the first position, but being ineffective when the latch 42 is shifted to the second position whereby the bolt 19 may be actuated by the lock cylinder 29 or by rotary movement of the latch. As shown, the bolt 19 is shiftable by a lever 25 pivoted on a stud 43, Fig. 4 (not shown) and engageable through a pin 27 in a slot 28 in the bolt tail, projections 31 or 32 on the lever being engageable by a tongue 30 of the look cylinder. The latch 42 comprises a square shank 44 which is engageable in a square hole 26 in the lever 25. in which position a pin 45 on the latch 42 engages a recess 46 in the lock casing to prevent retraction of the bolt by the lock cylinder 29. In the second position, the pin 45 is disengaged from the recess 46, and in an outermost third position the shank 44 is withdrawn from the hole 26, in which position the bolt is operable only by the look cylinder, rotation of the latch 42 being prevented by a pin 47 and cooperating recess 49. The bolt 19 is protected against sawing by an internally floating hardened steel pin 106 and the lock cylinder is provided with a freely rotatable hardened steel ring to prevent unscrewing of the cylinder. A lock cylinder may be provided on both sides of the lock.