Motor and blade control for high amperage molded case circuit breakers

摘要

A high amperage molded case circuit breaker utilizing a ratchet adapted to be operated manually or electrically and carrying a spring biased clutch connecting the ratchet to a crank for rotating the crank to tense a helical closing spring. The ratchet is disconnected from the crank when the closing spring has a predetermined tension by a crank operated trip assembly while the closing spring axis passes close to the crank axis to exert a relatively low torque on the crank. The crank rotates a handle positioner to prevent manual operation of the ratchet after the spring is tensed, while electrical operation of the ratchet continues until a switch located in any one of a large variety of positions terminates electrical operation. Shock absorber action for the blades and carriers is provided by a plurality of large area elastomeric plates separated by metal plates and carried by the cover, while rebound and contact closure is prevented by hook members pivoted by the carrier crossbar to engage respective pins carried by one of the blade carriers.