GB486963A - Improvements in locks or latches - Google Patents

Abstract

486,963. Locks and latches. SANSOME, R. D., and PILKINGTON, W. Dec. 15, 1936, No. 34354. [Classes 44 and 65 (i)] A lock or latch bolt 19 enclosed in a casing 12 by a face plate 13 which has upward and downward extensions forming a finger plate 10, has dead locking mechanism mounted on the back of one of the extensions externally of the casing. The dead locking mechanism which may be enclosed by a casing formed by ribs 41, 42 cast or stamped on the back of the plate 10, consists of a spring loaded member 37 having a projection 38 which cooperates with a part 40 of the bar 33 to hold the bolt 19 in the position to which it has been moved by the handle 22. The member 37 may be operated by a finger piece 35 through a cam 36 as shown or may be directly attached thereto. The bolt 19 may be held in the shot out position by the arm 28 engaging behind the part 34 of the bar 33. This arm which is freely mounted on the member 24 is provided with a projection 29 which co-operates with shoulders 30 on a disc 31 fixed to the member 24. so that the latter can be turned through a considerable angle without affecting the arm 28. Normally the bolt is retractable by the inside handle 22 or by an outside key or handle acting through the member 28 which engages the part 32. If, however the outside key or handle is turned through a complete revolution the arm 28 engages behind the part 34. Specifications 399,348 and 412,212 are referred to.