GB734717A - Latches for doors - Google Patents

Abstract

734,717. Latches. PARKES& SONS, Ltd., J., BUTTER, F. J., and ORDIDGE, E. F. April 1, 1954 [April 25, 1953], No. 11493/53. Class 44. In a door latch, a spring-loaded latch bolt has a longitudinal guideway on the side of the bolt head 10 remote from the striking face in which is mounted a spring-loaded auxiliary slide 22 that is held back by an abutment projecting into the recess 29 in a striking plate 30 when the bolt head enters the recess the abutment being of such size and shape as to allow the bolt head to pass it. When held back the slide 22 permits the nose 27 of an arm 28 to move into the rear of the bolt head 10 to secure the bolt in the shot position. The auxiliary slide 22 is dovetailed into a channel in the bolt head 10 and its rear portion 23 comprises two lugs which slidably embrace the wide central portion 16 of the bolt lath 11. By sliding the auxiliary slide 22 to the narrow portion 17 of the lath it can be completely removed from the bolt. In the condition shown the latch is out of engagement with the striking plate 30 and the rear portion 23 of the auxiliary slide prevents the nose 27 from locking the bolt. When the bolt is moved inwards by the striking plate 30 the rear of the bolt head forces the auxiliary slide 22 inwards also, but whereas the bolt is free to spring into the recess of the striking plate the projection 31 engages the leading end 21 of the auxiliary slide and holds it in the withdrawn position which permits the nose 27 to engage the rear of the bolt head 10 to secure it. To release the latch the nose 27 is deflected downwards by the camming action of the follower 13 on the arm 33 of a bell crank lever on which the nose 27 depends ; at the same time a pin 15 on the follower engages the bolt and withdraws it from the recess in the striking plate.