Patent ID: 7777601

Claim:
A circuit breaker comprising an opening/closing mechanism and a movable contacting device, each being accommodated in an insulative case, wherein the movable contacting device comprises: a crossbar linked with the opening/closing mechanism and carried to pivot cooperatively with the opening/closing mechanism; a movable contact arm engaged, to be cooperational with the crossbar, with a shaft fitted into mutually opposing recesses in the crossbar; and a movable contact arm support fixed to the insulative case accommodating the opening/closing mechanism and having mutually opposing through-holes through which the shaft is passed; wherein the movable contact arm is configured so that the movable contact arm slides between surfaces of the movable contact arm support having the mutually opposing through-holes, a single-pole portion of the movable contact arm comprises two movable contact arm members arranged in parallel and each having a movable contact at one end, and a shaft-supporting portion at other end, in which an elastic member is sandwiched between the movable contact arm members, and an anti-attraction member is sandwiched between portions of the movable contact arm members, closer to the shaft than a middle point between the movable contacts and the shaft.