GB445150A - Improvements in and relating to electric circuit breakers - Google Patents

Abstract

445,150. Liquid - break switches. BRITISH THOMSON-HOUSTON CO., Ltd., Crown House, Aldwych, London. May 10, 1935, No. 13796. Convention date, May 10, 1934. [Class 38 (v)] A liquid-break switch comprises a pair of insulated lead-in conductors extending through a cover into a casing with a fixed contact structure connected to the lower end of each, a bridge member for interconnecting the structures and movable downwards to open circuit, the structures and bridge being immersed in the liquid, and an insulating baffle carried by the conductors and extending at least at its edges below the liquid. The baffle is substantially continuous between the conductors and between the conductors and the casing-wall so as to have a confining effect on the liquid-body surrounding the contacts into which the bridge is lowered, and has apertures at opposite edges thereof adjacent and opposite the structures for the immediate and direct escape of gas formed at the structures upon opening circuit. In a simple form, Figs. 1 and 2 (not shown), an insulating plate immediately above the fixed contacts covers the whole space except for cut-away parts adjacent the tank walls and each break, and in order to accommodate excess pressures, this plate may be slidable on the lead-in insulators and have spring control allowing it to yield upwards Fig. 3 (not shown). In Fig. 4, a baffle is located with its plate 27 above the oil level and has side parts 28, 29 extending the length of the tank and under the oil so as to create an air pocket of such dimensions as to prevent oil-throw and to expel the arcgases through passages 281, 291. Alternatively, the side walls of the tank may be made flexible for this purpose. In Fig. 5, (not shown), the baffle is completely immersed and the side walls extend to the contacts, but in Fig. 6, the side walls 31, 32 extend to the bottom of the tank and are apertured at 34, 35 adjacent the breaks to allow egress of gas. Specifications 11448/04, [Class 38], and 371,340 are referred to.