CIRCUIT BREAKER

PROBLEM TO BE SOLVED: To provide a circuit breaker that provides stable tripping characteristics and good productivity. SOLUTION: A circuit breaker includes a switching mechanism 19 and an overcurrent tripping device 10 for causing it to effect tripping operation that are provided within a mould container. The overcurrent tripping device comprises an L-shaped yoke 27, an arm chair 13 movably born by the yoke, a return spring 14 for holding the arm chair at a predetermined position, a coil 11 through which a circuit current flows, and an oil dash pot 15 that is received within the coil and attracts the arm chair to cause the switching mechanism to effect tripping operation when overcurrent flows to the coil. An unit case 23 for housing the overcurrent tripping device is provided. After having mounted the yoke and coil from the side to the unit case, the oil dash pot passes through the coil from a vertical direction of the unit case and is fit together into a hole 27c provided at the yoke to get fixed. COPYRIGHT: (C)2005,JPO&NCIPI