Circuit breaker including mechanism for breaking tack weld

A remotely controllable circuit breaker comprising:

• a housing comprising a pivot opening having a first end and a second end;
• a first terminal;
• a second terminal;
• a set of first contacts mounted in said housing;
• an operating mechanism mounted in said housing and coupled to said set of first contacts for opening and closing said set of first contacts;
• a movable arm including a first portion having a pivot pivotally mounted in said pivot opening and a second portion, said pivot opening being substantially larger than said pivot;
• a set of second contacts comprising a fixed contact mounted in said housing and a movable contact mounted on the second portion of said movable arm, said fixed contact, said movable contact and said movable arm cooperating to provide a closed state, a pivot state and an open state, said set of second contacts being electrically interconnected with said set of first contacts between said first and second terminals;
• a remotely controllable solenoid including a member coupled to said movable arm, said remotely controllable solenoid moving said member between a first position and a second position to provide said open state and said closed state, respectively, said member having a third position between the first position and the second position;
• and
• means for biasing said movable arm toward said fixed contact to maintain said closed state,
• wherein said closed state is defined by the second position of the member of said actuator, with said pivot engaging the second end of said pivot opening and being apart from the first end of said pivot opening,
• wherein said pivot engages the first end of said pivot opening and is apart from the second end of said pivot opening in said pivot state,
• wherein said open state is defined by the first position of the member of said actuator, with said pivot engaging the first end of said pivot opening and being apart from the second end of said pivot opening, and
• wherein when said fixed contact and said movable contact are welded closed, said actuator provides insufficient force to move the member of said actuator to said first position until after said pivot moves apart from the second end of said pivot opening and at least substantially toward the first end of said pivot opening.

An electrical switching apparatus comprising:

• a housing;
• a movable arm including a first portion and a second portion;
• means for mounting the first portion of said movable arm for pivotal movement and longitudinal movement with respect to said housing;
• a fixed contact mounted in said housing;
• a movable contact mounted on the second portion of said movable arm, said fixed contact, said movable contact and said movable arm cooperating to provide a closed state, a pivot state and an open state;
• and
• an actuator mounted in said housing, said actuator including a member coupled to said movable arm, said actuator moving said member between a deactuating position and an actuating position to provide said open state and said closed state, respectively, said member having a pivot position between the deactuating position and the actuating position,
• wherein said closed state is defined by the actuating position of the member of said actuator,
• wherein said first portion of said movable arm moves to a first longitudinal position in said pivot state and in said open state,
• wherein said first portion of said movable arm moves to a second longitudinal position in said closed state, and
• wherein when said fixed contact and said movable contact are welded closed, said actuator provides insufficient force to move the member of said actuator to said deactuating position until after said first portion of said movable arm moves at least substantially toward the first longitudinal position in said pivot state.