GB836839A - Improvements relating to interlocks - Google Patents

Abstract

836,839. Key locks; keepers. POWER EQUIPMENT CO. Ltd., CASTELL LOCKS Ltd., and HEATH, B. H. Feb. 6, 1958 [Feb. 8, 1957], No. 4426/57. Class 44 A key-operated interlocking device comprises a body member 1 providing openings 2, 5 for the reception of two removable members, one of which is a rotatable key 6, the body member 1 being furnished with at least one slidable plunger 7 which is located so as to project into the opening 2 for the other member 3 and to be displaced longitudinally when said other member 3 is entered into the opening 2, whereby the plunger 7 is moved from a position in which it prevents rotation of the key 6 and its withdrawal from the other opening 5 to one in which it permits the key 6 to be rotated to a position in which it is withdrawable from the other opening 5, the other member 3 being then trapped by the plunger 7 in the opening 2 into which it has been entered. As shown, the device comprises three plungers 7 which co-operate with spring-loaded pins 7<SP>1</SP>, slidably disposed in a plug 9 which is rotatably mounted in the body member 1, to prevent rotation of the plug 9 and, thereby, withdrawal of the key 6 associated with the plug, until the removable member 3, Fig. 4, is inserted in the aperture 2 is displace the plungers 7 and the pins 7<SP>1</SP> to a position which permits the plug 9 to be rotated allowing the key 6 to be withdrawn, this rotation preventing further movement of the plungers 7 and, thereby, removal of the member 3 from the aperture 2. The movement of the plungers 7 in the body member 1 is limited by a pin 15 engaging a portion 22 on each plunger, the portions being of reduced cross-section. The plungers 7 may be replaced by a stack of parallel plates disposed in a rectangular hole in the body member 1. The axes of the plug 9 and the aperture 2 may be other than parallel. The plug 9 is retained, in the body member 1, by a spring pressed detent 17 on the plug engaging a cavity 18 in the body member 1, and the upper end of the plug 9 is provided with projecting figures to receive only the correspondingly indented figured face of the key 6. The latter has a square shank 11 which fits into the opening 5 which is a square recess and, after rotation in the recess 5, is retained by a flange 20 against which it is urged by spring-biased plungers on the key 6. Alternatively the plug 9 may be associated with a separate lock secured to the body member 1, Figs 1-3 (not shown) and the lock may be of the figured type as described above or of the cylinder type. The member 3 and the body member 1 are respectively secured by screws or bolts to relatively movable parts such as a door and a frame.