GB140179A - Improvements in or relating to electric switches - Google Patents

Abstract

140,179. Crabtree, J. A. Feb. 20, 1919. Snap-action switches.-In a switch of the type in which the pivoted operating-member and pivoted contact member have pivotally coupled to them a spring element at positions eccentric to their respective axes, stopping-means, engaged by a non-current carrying part of the contact member which moves in a direction away from the switch base, are provided for limiting the movement of the contact member both in its closing and opening operations. In the arrangement shown in Fig. 1 for a tumbler switch, the operating-tumbler 1 and the contact-carrying member 3 are pivoted on a common axis. A plunger pin 8 pivoted on the tumbler lever works within a sleeve 7 pivoted on the contact member, and a, compression spring 9 is arranged around the pin and sleeve and is compressed during the operating movement until the dead-centre is passed, whereupon the spring produces a quick action. The contact-carrying member is formed with two shoulders 11, one or other of which, at the limit of the angular upward movement which it makes away from the base in the switching on or switching off operation, engages the under edge 12 of the bridge 2, or an integral extension thereof, or a striking-plate secured thereto, which stops the contact member. The invention is applicable to a two-way switch, and the shoulders may engage the bridge at an angle. The means for producing an initial movement of the switch, described in Specification 140,180, may be employed.