GB841472A - Improvements in and relating to air-break electric circuit breakers - Google Patents

Abstract

841,472. Air-break switches; actuation of switches; arc-rupturing in switches. ENGLISH ELECTRIC CO. Ltd. Sept. 7, 1956 [Sept. 9, 1955], No. 25846/55. Class 38 (5). The movable arcing contacts of an airbreak circuit-breaker are operated with lostmotion by the moving contacts and positively locked until the lost-motion has been taken up. The main and arcing fixed contacts 10, 12 are connected by a blow-out coil 16 adjacent to an arc-chute having runners 33, 34. The main moving contact 11 is mounted on arms 17 pivoted at 18 and having projections 26, 27 which can engage arms 23, also pivoted at 18, and carrying the moving arcing contact 13. The arms 17 are connected by a link 21 to a solenoid-closing, spring-opening mechanism 22. On opening, the mechanism 22 rotates the arms 17 in a clockwise direction opening contacts 10, 11 but the arms 23 do not move as a latching member 28, pivoted thereon engages a projection 29 in the breaker structure under the action of a spring-urged link 30 until a pin 23 on arm 17 engages the bottom of a slot in the link 30 and disengages the latch 28 justs a projections 26 on arms 17 engage the arms 32 to open the arcing contacts. During this movement of arms 17, a projection 38 thereon passes over a catch 37 on the member 28 to prevent its being released by vibration. On closing the projection 27 engages the arms 23 and the arcing contacts 12, 13 close just before the main contacts 10, 11.