CIRCUIT BREAKER Russian patent published in 1998 - IPC

FIELD: electrical engineering. SUBSTANCE: circuit breaker has insulating housing that accommodates contact system, trip-free mechanism with operating handle joined through control rod to lever which is coupled with movable contact, disengaging lever, and spring-loaded disconnecting rack, as well as electromagnetic and thermal releases. Electromagnetic release is provided with spring- loaded direct-travel push-rod mounted between electromagnetic release head and disconnecting rack in projection slot of housing. With electromagnetic release carrying super-high current, its head acts on push-rod projection and the latter actuates movable contact for opening it; push-rod tip functions to disconnect the rack. Entire force developed by electromagnetic release is transmitted to disconnecting rack and movable contact due to direct-action design of push-rod. In addition, disconnecting rack has projection actuated in case of operation of thermal release by disconnecting lever thereby increasing angle of turn of disconnecting rack and ensuring release of trip-free mechanism in adjacent pole in case of multipole design of circuit breaker. EFFECT: reduced size of electromagnetic release coil, simplifier design and facilitated manufacture of circuit breaker, improved operating reliability of multipole circuit breaker. 2 cl, 2 dwg