GB191000088A - Improvements relating to Automatically Locking Locks for Doors and the like. - Google Patents

Abstract

88. Leistler, A. Jan. 1. Night - latches. -In a night-latch of the type in which a doublelocking bolt is held in the withdraw position until the door is closed, the tumbler notches 5 in the bolt are bevelled to allow the bolt to shoot without the use of the key, and the retaining - means comprises a. pivoted lever 10 engaging a pin 12 on the bolt. The detent lever 10 is actuated by a spring bolt in the usual manner or by means of a rod 32 connected to a lever 30, the free end of which bears against a catch member 29 mounted in the top edge of the door and co-operating with a striking-plate 16 in the door frame. The striking-plate 16 is pivoted, so that it operates the catch 29 to actuate the detent mechanism when the door is closed, but allows it to pass freely when the door opens. A similar striking-plate is provided for the spring bolt when that form of construction is used. A cam-piece 37 pivoted on the pivot of the lever 10 is employed to place the detent mechanism in an inoperative position. A pin 39 on the cam passes through a slot in the casing and is engaged by a lever 42 pivoted on the outside of the casing. By means of a tool inserted through the edge of the door and adapted to catch into a hook 43 pivoted to the lever 42, the cam 37 can be turned, the pin 38 thereon then lifting the lever 10 out of engagement with the pin 12 on the bolt, and at the same time the edge 40 of the cam bearing against the bolt spring 15 and rendering this inoperative. The parts are held in this position by the hook 43 engaging a fixed ledge 46 on the casing, as shown in full lines in Fig. 10. In the usual form of detentreleasing mechanism, a pin inserted through the releasing bolt and the casing to hold this bolt in the withdrawn position, and a pin inserted to hold the main bolt-spring inoperative, effect the same object. The tail of the bolt is forked, the tumbler 4 being mounted within the fork and engaging notches in each branch. Latches, preventing operation of. - A plate 21 mounted on the outside handle spindle 20 of the ordinary latch, extends down to the keyhole and prevents the operation of the latch and therefore the opening of the door should the key be left in the keyhole on the outside.