VACUUM CIRCUIT BREAKER

PROBLEM TO BE SOLVED: To provide a vacuum circuit breaker for suppressing chattering while containing heat generation with a simple structure. SOLUTION: In the vacuum circuit breaker, a housing fixed conductor 20 in which a movable side conductive shaft 13 and a fixed side conductive shaft 18 are arranged in nearly identical axial line is fixed to an upper end lid 2 by a bolt; and a shock absorbing weight 21 which is arranged on nearly identical axial line as the amovable side conductive shaft 13 and the fixed side conductive shaft 18 and moves in the operation direction of a movable electrode 12 and a shock absorbing elastic body 22 interposed between the shock absorbing weight 21 and the upper end lid 2, and a return spring 23 which holds the shock absorbing weight 21 at a regular position on a connecting end face 19 side are housed in a housing space formed in the housing fixed conductor 20. While the housing fixed conductor 20 does not cause a positive slide and movement that make electric connection unstable, even if a shock is received in closing the circuit, the shock absorbing weight 21 makes repulsive movement to the upper end lid 2 side, and absorbs and attenuates the shock energy in closing the circuit as a kinetic energy. COPYRIGHT: (C)2011,JPO&INPIT