Abstract: A circuit breaker includes a housing, an operating mechanism, and a cassette. The cassette includes a separable current path having a movable contact arm, two arc receptors each disposed for receiving an electrical arc in response to a short circuit overcurrent condition, and two slot motors each disposed proximate the movable contact arm for magnetically driving the movable contact arm to a blown open position in response to a short circuit overcurrent condition. The slot motors each have two side legs opposing each other and defining a space therebetween for receiving the movable contact arm, each side leg having a magnetic core and an insulative layer and being biased toward the interior of the side walls of the cassette, wherein each side leg is restrained from being magnetically attracted toward the movable contact arm during a short circuit condition.

Abstract: An assembly for interacting with a circuit breaker operating mechanism of a circuit breaker including a housing and a pair of contacts within the housing, the operating mechanism arranged to separate the pair of contacts upon the occurrence of a trip event is disclosed. The assembly includes a plurality of linkages arranged to transmit mechanical energy from the operating mechanism to a plunger of an accessory device for changing a state thereof. The system of linkages is configured to compensate for any over-travel resulting from possible tolerance variations.

Abstract: A circuit breaker for a multi-pole electrical distribution circuit includes a cassette associated with each pole in the multi-pole electrical distribution circuit. Each cassette includes a housing, a pair of electrical contacts disposed in the housing, and a thermal and magnetic trip unit supported by the housing. The housing includes a first compartment having the electrical contacts disposed therein and a second compartment having at least a portion of the thermal and magnetic trip unit disposed therein. A wall separates the first and second compartments for isolating the second compartment from gasses generated by separation of the first and second contacts. A duct adjacent to the second compartment allows the gasses to pass to an exterior portion of the housing. The housing includes a pair of opposing slots formed therein for receiving edges of a load terminal.

Abstract: A current limiting circuit breaker mechanism having two pairs of separable contacts closely spaced for electrodynamic repulsion upon the occurrence of a short circuit overload condition utilizes a pair of arc chute assemblies to cool and extinguish the arc that occurs when the contacts become separated. The arc chute assemblies contain a plurality of arc chute plates supported by side supports. The arc chute plates are aerodynamically designed to facilitate the easy flow of the arc plasma gases into and out of the chute and provide minimal reflection of the arc plasma wave against the contact arm.

Abstract: A rotary contact arrangement for circuit breakers of the type including a pair of movable contacts (30,36), one arranged on each end of the rotary contact arm (32), utilizes a single pair of contact springs (38), one spring on each side of the rotary contact arm (32). The springs (38) are aligned to intersect the axis of rotation of the rotary contact arm (32) for automatic uniform contact force adjustment throughout the operating life of the circuit breaker.

Abstract: A decreased mechanical trip time latching system for use in a molded case circuit breaker assembly. The latching system comprising a quick release primary latch having a first primary latching surface and a second primary latching surface. Where the second primary latching surface engages a first secondary latching surface located on an interactive secondary latch, to prevent the rotation of the quick release primary latch. The first primary latching surface engages a cradle latching surface, located on a cradle, to prevent the rotation of the cradle. Assembled to the interactive secondary latch is a trip bar. Activation of the trip bar rotates the secondary latch so that the first secondary latching surface moves out of contact with the second primary latching surface just prior to the interactive secondary latch making physical contact with the quick release primary latch.