GB402396A - Improvements in or relating to electrical appliances (such as plug-and-socket couplings, switches and fuses) incorporating parts made from synthetic resin materials - Google Patents

Abstract

402,396. Switch bases; plug couplings; fusible cut-outs. CRABTREE, J. A., Endwood, Little Aston Park, Sutton Coldfield. April 20, 1932, No. 11268. [Class 38 (v).] To avoid the formation of a current-conducting track across the insulating base &c. of switches, plug-and-socket couplings, fuses, &c. owing to carbonization of the synthetic resin or other insulating material under the action of an arc, the insulating part has moulded therein a depression or projection or a series of depressions or projections situated substantially transverse to the arc. Fig. I shows a plug formed with one such depression b preventing the formation of a conducting track between the pins of the plug. Fig. 5 shows a series of staggered projections or bosses. Fig. 10 shows the base of a tumbler switch having a channel f<3>, leading to the well f containing the fixed contact, broken or interrupted by a series of depressions g. Fig. 12 shows a coupling-socket adapter having spring- biassed shutters j which automatically come together when the plug is withdrawn. The shutters j are formed with depressions n. Specifications 306,249, 324,973, [both in Class 38 (v), Electric switches &c.], 325,012, 325,013, 329,317, and 339.358, [all in Class 38 (i), Electric couplings &c.], are referred to.