Molded case circuit breaker

摘要

A current-interrupting section of a molded case circuit breaker includes fixed contact shoes and a rotary bridge-type contact shoe held in a contact shoe holder. A pair of pressure springs is assembled in the contact shoe holder to press the rotary contact shoe to the fixed contact shoes. The pressure spring is torsion coil springs and have U-shaped offset arm portion drawn out from the center of the coil. A pair of the torsion coil springs is arranged above and under the rotary contact shoe. Furthermore, legs of the torsion coil springs at ends are hooked to sidewalls of the contact shoe holder. The offset arm portions at the center of the torsion coil springs engage the rotary contact shoe at positions symmetrical with respect to the rotational center of the rotary contact shoe.