GB459868A - Improvements in or relating to electric circuit-breakers - Google Patents

Abstract

459,868. Liquid - break switches. REYROLLE & CO., Ltd., A., Hebburn-on- Tyne, ALLAN, A., Cragside, Ashleigh Grove, Tynemouth, and BLANCH, N. R., 155, Victoria Road West, Hebburn-on-Tyne. July 16, 1935, No. 20281. [Class 38 (v)] A circuit-breaker comprises a tank A containing insulating liquid, an arc control device D into which the movable contact H can project to make contact with a normally fixed contact therein, lead-in conductors G, G<1> for connecting the two contacts to the external circuit, and means whereby the arc control device and the normally fixed contact within it can be withdrawn from the tank independently of the movable contact and the lead-in conductors. In the arrangement shown, the arc control device D is mounted on an insulating bracket B<1> carried by a cover plate B which normally closes an orifice in the wall of the tank. The plate B is bolted to a flange C<1> on the end of an arm C pivoted on an external lug A<3> on the tank wall, so that the plate, and with it the arc control device D, can be withdrawn from the tank by rotating the arm C. The arm C may be made detachable, so that the same arm may be employed for a number of circuit-breakers. The lead-in conductors G, G<1> pass through insulating bushings F, F<1> supported by the rear wall A4 of the tank. The upper conductor G terminates in a butt contact G<2> normally engaging an external terminal D<1> on the device D, and the lower conductor G<1> has a sliding connection G<3> with the movable contact H. The arc control device consists of an insulating structure with vents D<2>, the arrangement preferably being such that the magnetic force exerted on the arc by the current flowing through the lead-in conductors causes the arc substantially to seal the vents, as described in Specification 435,308. The insulating structure may be built up of superimposed plates of insulating material or may be divided longitudinally into two or more parts held together by clamping devices as described in Specification 452,146.