GB479320A - Improvements in and relating to deadlocking latch - Google Patents

Abstract

479,320. Door latches. YALE & TOWNE MANUFACTURING CO. April 5, J937, No. 9566. Convention date, June 17, 1936. [Class 44] In a night latch, the bolt has holding means adapted to assume a dead centre relationship when the bolt is fully projected into a, striker by the latch spring, together with an auxiliary spring-loaded bolt which when shot holds the holding means out of dead centre and permits of latching the bolt. The latch bolt body 16 is outwardly urged by a spring 17 mounted in a bore 18 and about a pin 19 located in the hole 20. The bolt is retracted by a U-shaped cam 26 connected to the body 16 by a bar 23. Located alongside the latch 16 and mounted for sliding along it is an auxiliary bolt 38 to which is attached a lever 40. This lever has a cam surface 41 which, when the auxiliary bolt is shot, lies underneath the portion 31 of the bar 23. When the nose 33 encounters a striker 37, the latch bolt and auxiliary bolt are retracted but when the latch bolt enters the striker the auxiliary bolt is left retracted, Fig. 6. This causes the cam surface 41 to be removed from underneath the portion 31 and allows the latch spring 16 and the spring 30 to force the lever 23 downwards and the pivot points 24, 25, 26a into a dead centre relation making the bolt 33 into a dead bolt. The bolt may be retracted by actuating the U-shaped cam through bar 63 which is operated either by a handle 61 or cylinder lock 62. The bolt may be held retracted by the slide plate 66 which co-operates with a detent member 67. The latch head 33 is separate from the latch body 16 and is attached thereto by a neck 36 which slides in a slot 34. The opening in the front plate 15 prevents movement in the direction of the slot 34. The latch is connected rigidly to the handle and cylinder lock by the bolts 68 which pass through ears formed on the casing 10. The Specification as open to inspection under Sect. 91 describes a modification in which the U-shaped cam 26 and bar 23 are applied to a dead bolt. This subject-matter does not appear in the Specification as accepted.