Gould Inc.

I-T-E Imperial Corporation

Charles T Robins

Carl E Gryctko

Albert Strobel

A relatively high current capacity molded case circuit breaker having arcing and main contacts and an arc chute to receive and extinguish arcs drawn between the arcing contacts is provided with a trifurcated magnetic arc runner extending from the stationary arcing contact well into the arc chute. The outer sections or legs of the arc runner extend generally parallel to the forward surface of the terminal strap on which the stationary contacts are mounted, and the center leg of the arc runner is curved forward so that the free end of the center leg extends forward of a substantial number of plates in the arc chute. The center leg is shaped so that during opening of the circuit breaker the movable arcing contact moves in close proximity to the center leg and in so doing encourages arcs which may form between the main contacts to extinguish rapidly.

Trifurcated arc runner

A single pole molded case circuit breaker having a wire grip load terminal with a clamping screw is provided with a slidable insulating shield movable automatically between an active and inactive position when the circuit breaker contacts are closed and open, respectively. In its active position, the shield blocks access to the clamping screw. The latter is accessible when the shield is in its inactive position.

Safety shield for terminal

A plurality of single pole circuit breakers stacked side-by-side are interconnected by a tie rod connecting the magnetic armatures of their respective instantaneous trip means. When one pole is caused to trip because of a fault condition a driving cam formation on the releasable cradle of the faulted pole engages the armature moving it in the tripping direction substantially beyond the point required for releasing the cradle latch in the faulted phase. Substantial movement beyond cradle release is permitted even though the magnetic air gap at the armature is small in that after this gap is closed the magnet is moved bodily in the tripping direction. This added movement assures that the tie rod shall transmit sufficient motion to all non-faulted poles to cause tripping thereof.

Narrow multi-pole circuit breaker having bodily movable instantaneous

A plurality of single pole circuit breakers stacked side-by-side are interconnected by a tie rod connecting the magnetic armatures of their respective instantaneous trip means. When one pole is caused to trip because of a fault condition, a driving formation on the releasable cradle of the faulted pole delivers a hammerlike blow to a cam means on the magnetic armature. The energy imparted to the armature by this blow causes the latch carried thereby to move in the tripping direction substantially beyond the point required for releasing the cradle latch in the faulted phase. This added movement assures that the tie rod shall transmit sufficient motion to all non-faulted poles to cause tripping thereof.

Growing community of inventors

Swarthmore, PA, United States of America

Charles T Robins