Cam following bridge contact carrier for a current limiting circuit breaker

A current limiting circuit breaker comprising:

• a housing;
• a stationary contact assembly having dual contacts;
• a contact bridge movable between an open position at which the contact bridge is spaced from the stationary contacts and a closed position at which the contact bridge and the stationary contacts are in abutting contact;
• a contact carrier connected to the contact bridge for biasing the contact bridge toward the closed position, said
• contact carrier having first and second cam surfaces and a carrier roller which moves from the first cam surface to the second cam surface as the contact carrier moves from the closed position to the open position, said carrier roller moving along the first cam surface exerting a closing force thereon until the edge of the first cam surface is reached and then moving along the second cam surface, said carrier experiencing a sharp decrease in closing force in response to a preselected amount of movement of the contact bridge as the carrier roller traverses the junction between the first and second cam surfaces.

A current limitng circuit breaker comprising:

• a stationary contact assembly having dual contacts;
• a contact bridge moveable between an open position at which the contact bridge is spaced from the stationary contacts and a closed position at which the contact bridge and the stationary contacts are in abutting contact;
• a contact carrier connected to the contact bridge for biasing the contact bridge toward the closed position;
• means for mechanically reducing the biasing force on the contact bridge in response to a preselected amount of movement of the contact bridge;
• and
• a roller and a spring engaging the roller and urging the roller against the carrier creating a closing force on the carrier as the roller moves along the carrier and a magnetic armature having one end abutting the carrier roller and the other end extending away from the carrier roller in a direction generally parallel to the carrier whereby as the end of the armature is attracted by the stationary contact assembly during opening the roller is urged away from the contact carrier thereby decreasing the closing force exerted on the carrier by the roller allowing the carrier to snap open the contacts.

A current limiting circuit breaker comprising:

• a housing;
• a stationary contact assembly having dual contacts;
• a contact bridge movable between an open position at which the contact bridge is spaced from the stationary contacts and a closed position at which the contact bridge and the stationary contacts are in abutting contact;
• a contact carrier connected to the contact bridge for biasing the contact bridge toward the closed position;
• means for mechanically reducing the biasing force on the contact bridge in response to a preselected amount of movement of the contact bridge;
• and
• a coil spring positioned in the circuit breaker housing and abutting the housing and the contact carrier for biasing the contact carrier toward the closed position.