GB104886A - Improvement in Self-locking Door-locks. - Google Patents

Abstract

104,886. Lindberg, J. W. March 10, 1916, [Convention date]. Night-latches.-Relates to a latch-lock of the kind in which the bolt is held in an intermediate position when the door is open, the bolt being forced back by the contact of its bevelled end with the striking-plate and ultimately springing out to the fully shot position. The bolt 1 is shown in the intermediate position in Fig. 3, being held by the engagement of the horn 11 on the operating-member 9 with the hook 5 on the tail of the bolt or on the shoulder 4 of the plate 2 connected therewith. When the door is slammed, the bolt 1 is thrust back, and the member 9, being disengaged, is thrown forward by its spring, the bolt then shooting forward and being locked by the lever 6 falling behind the projection 3<1> on the plate 2. In unlocking, the horn 10 of the member 9 lifts the lever 6, and the horn 11 draws back the bolt. As the bolt returns from the withdrawn to the intermediate position, the horn 11 slides upwards against the face of the shoulder 4 till it catches under the hook 5. When the door is open, the bolt can be pressed back by hand so far that the lever 6 engages over the projection 3<1>, holding the bolt out of action. From this position, the bolt is released by turning the handle in the reverse direction to that used for opening, the horn 10 of the member 9 then acting on the rear surface of the projection 8. The lock is operated by a key through the pivoted arm 13, which may be controlled by levers 15. The guard 16 prevents operation by a wire inserted in the keyhole.