GB761691A - Improvements relating to locks - Google Patents

Abstract

761,691. Locks. REMPLOY, Ltd. May 4, 1955 [May 4, 1954], No. 12986/54. 'Class 44. Relates to a lock in which a spring-loaded bolt is controlled by co-operation between a pin and a cam track so that after alternate movements of sufficient extent into the lock case, the bolt can be moved by the spring to a partially shot and to a fully shot position, the pin being carried by the look case and the track being carried by the bolt or vice-versa, and the pin being movable relative to the member carrying it, in a direction substantially at right-angles to the direction of movement of the bolt. According to the invention the track consists of four limbs and four stations each at the junction of two limbs, the limbs being so shaped that in travelling round the track, the pin reaches each station by part of a limb inclined to the direction of movement of the bolt, and on reversal of movement of the bolt, leaves each station by part of a limb lying substantially parallel to the direction of movement of the bolt, and the movement of the pin is subject to frictional resistance sufficient to assist the pin in entering the correct limb on leaving each station. As shown, a latch bolt 8 which is operable by a key-operated lock on one side of a door and by a knob on the other side, is movable by means of a crank 32 fixed to a hub 33 coaxial with a hub 24 of the knob and carrying a pin 34 which engages a slot 36 on a lug 38 on the bolt. The pin 34 is loaded by a spring 40 and the slot 36 is curved such that the pin deadlocks the bolt in the fully shot position thereof. A lost motion connection 42 between the hub 24 and the hub 33 and a further lost motion connection 44 between the hub 33 and a tongue 22 permits the bolt to be retracted from a partially shot position without movement of the knob and lock, when the door is slammed. The hub 24 incorporates a cylinder lock by which to lock the knob to the lock case. The bolt is controlled by a pin 46 on a freely rotatable lever 48 and the pin-co-operates with a track 50 in the bolt face. The pin 46 is spring-loaded on to the track which is formed with four limbs providing stations 54, 56, 58 and 60 for the pin corresponding to the partially shot, the fully shot, and the fully withdrawn positions of the bolt 8. Ramps 62 on steps 64 ensure unidirectional movement of the pin round the track. The bolt may be retained in the withdrawn position by a plunger 66. Specification 641,335 is referred to.