GB641296A - Improvements relating to electric switches - Google Patents

Abstract

641,296. Tumbler switches. PARSONS, Ltd., C. H., and HANDLEY, G. B. Feb. 19, 1948, No. 4877. [Class 38(v)] In a tumbel switch for heavy currents, the contact-assemblies are separated from the terminals 18 by two insulating barriers 19 having slots 20, 21 to allow the passage therethrough of laterally-extending parts 15, 17 of the terminals. The dolly 11 is pivoted by trunnions 23 in recesses 23a in the barriers and has two projections 27, one on each side, which engage beneath contact blades 10, which are fixed to the parts 15 and have contacts 13 normally engaging fixed contacts 28 on the parts 17. Movement of the dolly from the Fig. 4 position causes the projections to separate the contacts. The switch may be arranged to close one set of contacts and open the other, simultaneously, by adjustment of projections 27, which may be extended to control any number of contacts. The contact springs 10, which are preferably composed of copper backed by phosphor-bronze strips, may be forked at the contact end, and the contacts 13, 28 may be of silver. The dolly is resiliently retained in its limit positions by a looped wire spring 25 and its movement cushioned by rubber pads 26.