Improvements in Door Latches.

摘要

1,167,125. Latches. NATIONAL LOCK CO. 25 March, 1968 [21 Sept, 1967], No. 14321/68. Heading E2A. A latch comprises an adjustable, pivotable hook bolt 66 having two elongated slots 74, 75 through which pass respectively a pivot pin 54 and a control pin 57 urged together 'by a spring 76, the pin 54 passes also through inclined slots 64 in a pair of parallel arms 61 and through slots 53 in a pair of parallel bolt adjusting plates 51 and the control pin passes through arcuate slots 55 in plates 51. The reduced ends of a counter clockwise spring urged hub 41 are supported in apertures 52 in the plates and in the side walls of a latch housing and cover and a projection 46 on each side of an end of an arm on the hub extends into an opening in each arm 61. The hub is rotatable by a handle, whereby the arms 61 rise and are constrained to move forwardly. and the control pin 54 moves in the slot 74 in the bolt moving it longitudinally and disengaging the control pin 57 from an offset recess .56 of the slot 55, the bolt is then pivotable to unlatching position. The position of the bolt is adjustable by rotating a rod 89 through 90‹ so that screw threads on the rod are disengaged from threads in a passage in a yoke 79 having a lateral projection 81 engaging an aperture in each plate 51 .thereby freeing the bolt for movement to an adjusted position. The rod is then turned again through 90‹ to reengage the threads on the rod and in the passage. The rod has two flat opposed sides and the passage has two opposed smooth surfaces. The movement of the rod is limited to 90‹ rotation.