GB690530A - Improvements in and relating to automatic electric circuit breakers - Google Patents

Abstract

690,530. Automatic circuit-breakers. MECHANICAL PRODUCTS, Inc. June 11, 1951 [July 1 1950], No. 13820/51. Class 38 (v) [Also in Group XXXVI] A circuit-breaker comprises a two-part insulating casing 10, 12, held together by end caps 16, 18, and apertured at 32 to receive a resetting plunger 34, the casing being substantially sealed along its split 14 and about its aperture 32, against the escape of arcing products upon circuit interruption, by a fibre washer 40 positioned beneath the end cap 16 and a washer 38 fixed to the plunger 34. Further to obstruct the flow of arcing products, longitudinal recesses 62 formed in the opposed surfaces of the parts 10, 12, to receive conductor strips 64, 66, are made tortuous. The conductors 64, 66, are connected to the screwed end cap 18 and a terminal 54 and carry fixed contacts 22 which are bridged by movable contacts 68 carried on arms 70 supported by the extremities of the limbs of a pair of U-shaped bimetallic latches 72. The latches 72 engage ledges 74 on the plunger 34 under the pressure of springs 78 connected between the latter and the arms 70, a spring 80 holds the contacts 22, 68, closed. On overload the latches 72 leave the ledges 74 and the spring's 78 open the contacts 68, spring 80 moving the plunger 34 so that the washer 38 abuts the casing interior and seals the aperture 32. Depression of the plunger resets the breaker.