GB517054A - An improved latch or lock - Google Patents

Abstract

517,054. Latches. SPIRAL LOCKS, Ltd. Nov. 29, 1938, No. 34764. Convention date, Dec. 23, 1937. [Class 44] In a latch or lock of the kind in which the main bolt 13 is normally retracted, but is projected by contact of a striking bolt 1 with a striking surface on the jamb or frame, the main bolt 13 is connected to an actuating member 18 which can be operated by a handle, and the arrangement is such that when the striking bolt makes contact with its striking plate, the main bolt is partially projected and the actuating member 18 is moved into an operative position and effects complete projection of the main bolt, while when the latter is to be retracted, member 18 is operated by the handle and partially retracts the main bolt, complete retraction of which, together with the resetting of the striking bolt, being effected by contact of the head of the main bolt with its striking plate. The main and striking bolts are inter-connected by a lever 6, pivoted to the casing at 7, and having pin and slot connection with each bolt, the pin 12 on the main bolt working in a wide slot. The member 18 is pivoted to the pin 12, and has a slot 19 in which work's a fixed pin 20, the slot being shaped as shown and having a notch 22 into which pin 20 can enter to prevent retraction of bolt 13. The follower 26 has a tooth 25 which engages the weighted end of member 18 to lift the latter and retract bolt 13, and a weight 30 which brings it to the position of Figs. 1 and 5 on release of the handle. The latch plate 31 has a projecting striking member 33 and a slot to receive the nose of bolt 13, which is bevelled on the side remote from the door frame.