GB717554A - Improvements in or relating to actuating mechanisms - Google Patents

Abstract

717,554. Linkwork. GENERAL CONTROL CO. July 22, 1952, No. 18547/52. Class 80 (3) [Also in Group XXXVII] In mechanism for operating a switch or other device such as a valve or detent, successive strokes in the same direction of a spring- returned slidable actuator alternately engage two interengaging spring-biased pivotal or slidable switch-operating members which are thereby moved from one to the other of two limit positions. In the form shown in Fig. 1 the switch-operating members comprise two similarly-shaped pivoted arms 36a, 36b which are interconnected by a spring and are formed at their ends so as to interlock in either of two limit positions, Figs. 1 and 2. The actuator 41 comprises a spring-loaded plunger to which is pivoted an arm 55 having a finger which, when the actuator is depressed, engages the end of one arm 36 and thus moves both arms 36 to the opposite limit position. The arm 55 is biased to a central position, by a spring 59. The arms 36 are carried by shafts mounted in two bosses in the frame 20, one of the shafts carrying at its other end an arm 31, Fig. 6, having a tab thereon to contact the actuating pin of a switch S. In a modification, the arm 31, and switch S are omitted and each shaft carries an insulating arm 63, Fig. 10, having a silver alloy or other contact 61 secured to a channel member thereon, said contacts being respectively engageable with two pairs of fixed contacts mounted on an insulating panel secured to the frame. In a further modification the shafts carry arms which may be linked to a mechanical device such as a valve or detent. In a still futher modification, Fig. 12 (not shown), the pivoted arms 36 are mounted on a sheet metal frame and themselves each carry a contact, said contacts being respectively engageable with two pairs of fixed contacts. In this construction the actuator may be depressed by hand or by a solenoid. In the form shown in Fig. 14 the actuating pin of a switch S' is engaged by a chamfered collar on one of a pair of spring-loaded slidable rods 81a, 81b whose upper ends have each a conical recess for co-operation with a pin 89 pivoted to an actuator 88 which is upwardly biased by a leaf spring. In the position shown the rod 81b is in its uppermost position, with the chamfered collar abutting a fixed way 82, and holds depressed the rod 81a. On descent of the actuator 88, the pin 89 engages the conical recess in the rod 81b and depresses said rod until the rod 81a is released and is moved by its spring to a position wherein it holds the rod 81b depressed. The rod 89 is urged to a central position by a spring-pressed pin 96 which bears against the pivoted block carrying the pin 89.