Abstract: An electromagnetic starter with an overload relay having magnetic flux shielding is disclosed for use in industrial contactor applications. The starter includes a multi-pole DC controlled contactor which is interlockingly coupled to an overload relay. The overload relay has a simplified interlocking connection to the contactor, which when made, corresponds to an abutting electrical connection between the contactor and the overload relay also being made. The contactor further has a guiding pin that promotes even contact closure within the contactor.

Abstract: A pair of pivoted links positioned at opposite sides of a movable armature and reversely oriented with respect to each other, have a pivotal connection at their opposite ends to a movable contact carrier and intermediate their ends to the armature whereby movement of the armature is amplified in movement of the contact carrier to permit reduction in the air gap between the armature and electromagnet core without incurring a corresponding reduction in contact carrier movement.

Abstract: In a molded case circuit breaker with an interchangeable thermalmagnetic trip unit, the C-shaped heater transformer core is permanently held in place in the casing by a load bus strap with the gap in the core facing the trip unit. When the interchangeable trip unit is inserted into the molded casing, a magnetically permeable member mounted in the trip unit is aligned in the gap in the heater transformer core. The bimetal of the trip unit is fixed at one end to an electrically conductive sleeve surrounding the magnetically permeable member and forming the secondary of the heater transformer. The length of the magnetically permeable member is selected to establish the current conditions at which the bimetal trips the circuit breaker.

Abstract: A subframe is coaxially pivotally mounted with a movable frame of the operating mechanism of a molded case circuit breaker and is locked to the frame by a bell crank pawl which is pivotally mounted on the subframe. A leaf spring assembly rigidly attached to the subframe overlies the movable contact finger to engage the same in the circuit ON condition of the circuit breaker to provide desired contact force. The bell crank pawl is released upon an incrementally small amount of initial movement of the movable contact arm in response to blow-open magnetic repulsion forces to release the movable contact finger for pivotal opening movement relative to the movable frame of the circuit breaker operating mechanism.

Abstract: A molded insulator has a bottom wall, opposed sidewalls, and a transverse end wall extending between the sidewalls but spaced from the end of the bottom wall to define an opening in the bottom. A distribution lug is inserted from an open end of the insulator against the end wall, and under projections on inner surfaces of the sidewalls to trap the insulator against the end wall, and under projections on inner surfaces of the sidewalls to trap the insulator against up and down movement. The lug is attached to a circuit breaker terminal at the opening in the bottom to trap the end wall between the lug and the circuit breaker, blocking withdrawal of the insulator. A depending rib provides distal end support, while lateral ribs abut edges of barriers in the breaker housing to maintain the assembly properly aligned for electrical spacing.