Abstract: An improved circuit breaker includes a case, a movable arm, and a bumper retained within a receptacle formed on the case. The bumper is retained in the receptacle by a number of spaced ribs that engage certain portions of the bumper yet permit deformations of other portions of the bumper into an expansion region. By employing a bumper made of a material having a low coefficient of restitution, deformation of the bumper tends to dissipate the energy of a movable arm impacting the bumper. The bumper can be installed, removed, and replaced substantially without requiring the use of an adhesive. The movable arm engages the bumper on a corner of the bumper to provide the bumper with an effectively progressive spring rate.

Abstract: An improved circuit breaker includes an arc extinction system having one or more insulators that generates a desirable gas in the presence of an arc. The exemplary circuit breaker includes gas-generating insulators disposed at three sides of a stationary contact and an arc chute at a fourth side of the stationary contact. The gas promotes the desirable extinction of the arc in a number of exemplary fashions. The presence of the gas on three sides of the stationary contact can resist movement of the arc toward the gas, thereby substantially limiting movement of the arc in a direction other than toward the arc chute. The gas can remove heat from the arc, thereby promoting deionization of the plasma by forming neutral molecular species at a lower temperature state. The presence of the gas can reduce the concentration of ions and electrons within the interior of the circuit breaker and can increase the pressure within the circuit breaker, and these also facilitate extinction of the arc.

Abstract: A current limiting power switch has a monolithic stationary conductor with a conductor section that mounts fixed contacts that engage moving contacts on moving contact fingers to form a reverse current loop with the contacts closed. A terminal section projects transversely from one end of the conductor section and an arc runner section extends from the other end. The tapered arc runner has a generally laterally centered tapered area that gathers the arcs and urges them along a raised rib on the arc runner to an arc chute. A reinforcing rib running from the back of the conductor and arc runner sections to the terminal section resists distortion of the monolithic stationary conductor by the high temperatures and closing and electromagnetic forces during interruption.

Abstract: 0 A circuit interrupter arc chute includes first and second support portions, an exit portion supported by the support portions, and a plurality of arc plates supported by the support portions. The exit portion has one or more vent openings. The arc plates have a first edge offset from the exit portion and an opposite second edge distal from the exit portion. A plurality of insulating dividing members are disposed between the arc plates. The members have a first edge proximate the exit portion and an opposite second edge distal from the exit portion. The second edge of the members extends beyond the arc plate first edges and toward the arc plate second edges. The first edge of the dividing members extends beyond the arc plate first edge and away from the arc plate second edge.