GB140180A - Improvements in or relating to electric switches - Google Patents

Abstract

140,180. Crabtree, J. A. Feb. 20, 1919. Snap-action switches.-In switches of the type having a pivoted operating-member and a pivoted contact member interconnected by a spring element pivoted to both so that both ends of the spring element move in the action of closing or opening the switch, and the spring element and operating lever serve as the two arms of a toggle; the spring element itself serves as a medium whereby the initial positive movement of the contact member is produced. In the arrangement shown in Fig. 2 applied to a tumbler switch, the tumbler knob 1 and the contact member 3, both pivoted on the same pivot pin on the bridge 2, are connected together by a telescopic spring element consisting of a pin 8 pivoted on the tumbler and working telescopically against the action of the spring 9 in a socket part 7 pivoted at 6 on the contact member. The socket part is formed with a U-shaped extension 5, one arm or other of which, as the tumbler knob is actuated, engages with one or other of the abutments 4 depending from the bridge socket and serving as a fulcrum point about which the spring element may be turned by the knob in order to displace the contact member positively in the initial movement before the spring element crosses the dead-centre position to produce the quick action. The spring itself may come into engagement with the fulcrum. Specifications 140,179 and 140,181 are referred to.