Abstract: A circuit breaker comprising an electrically insulating housing, an overcurrent sensor in the housing, a stationary and a movable contact in the housing, and a latch mechanism coupled to the movable contact. The latch mechanism is tripped in response to a sensed overcurrent; an overcenter spring is coupled to the movable contact for opening and closing the contacts with a snap action when the latch mechanism is tripped. An elongated handle member extends through a handle opening in the housing and is movable axially between a contacts open position and a contacts closed position. Handle link means couples the handle member to the latch mechanism and translates a longitudinal movement of the handle member into a rotational movement of the handle link to urge the latch mechanism into the contacts closed position.

Abstract: A circuit breaker incorporates a collapsible telescoping linkage installed between its control handle and electrical contacts. The collapsible telescoping linkage is normally locked in an extended position to open and close the contacts as the control handle is moved between its off and on positions. The circuit breaker includes an electromagnetically operated armature operable in response to an overload condition to unlock the collapsible telescoping linkage to allow the linkage to collapse and instantaneously break the contacts. Thereafter, when the control handle moves to its off position, the linkage is locked in its extended position so that upon subsequent movement of the control handle to its on position the circuit breaker is automatically reset.