Westinghouse Electric Corporation

Charles E Haugh

Glenn R Thomas

Stephen A Mrenna

Alfred E Maier

Lance Gula

Jere L McKee

Louis N Ricci

Charles R Paton

A circuit breaker with a force generate shunt characterized by a circuit breaker structure between spaced conductors with a fixed contact on one conductor and a movable contact on a contact arm that is movable between open and closed positions. A flexible shunt connected between the arm and the other conductor which shunt includes folded-over shunt portions that generate repulsion magnetic forces for pressing the closed contacts together and for expediting the contact arm open.

Circuit breaker with force generating shunt

A molded case circuit breaker includes a movable upper electrical contact carried by a contact member having an end portion with an arcuate cam surface formed thereon for engaging an outwardly projecting cam surface of a leaf spring. The leaf spring is secured to and disposed around an enlarged portion of a rotatable cross-bar of the operating mechanism of the circuit breaker. The leaf spring has an outwardly protruding cam surface and is mechanically configured to provide sufficient biasing force to the end portion of the movable upper electrical contact member to enable the upper electrical contact member and upper contact to move in unison with the cross-bar during normal operation of the breaker. Upon the occurrence of a high level short circuit or fault current of sufficient magnitude, the upper electrical contact rotate member and upper and the arcuate cam surface thereof is moved against the then stationary cam surface of the leaf spring. The arcuate cam surface of the leaf spring and the arcuate cam surface of the end portion of the contact member are configured to provide decreased biasing force as the upper electrical contact member rotates to its BLOWN-OPEN position. A detent or groove is formed along the arcuate cam surface of the end portion of the contacts member for receiving the outwardly projecting cam surface of the leaf spring to retain the movable upper electrical contact and contact member in a BLOWN-OPEN position, thereby minimizing the possibility of contact restrike.

Molded case circuit breaker with a movable electrical contact positioned

A molded case circuit breaker apparatus is taught with an operating mechanism which is triggered in response to the movement of a trip bar. The trip bar in turn is responsive to current flowing in the main terminals of the circuit breaker apparatus. The trip bar is responsive to electrothermal conditions as a gradual overload increases. It is also responsive to a short circuit condition due to a magnetic reaction between an armature and an electromagnet. The armature is flexibly attached to the trip bar for flexible movement in one direction and non-flexible movement in the other direction so that a short circuit may be accommodated by a relatively small air gap by non-flexible movement of the armature and the trip bar to cause a tripping operation. On the other hand, a wide range of angular movement is available for a high degree of calibrated reaction to a wide range of overload currents because the armature member is flexibly attached to the trip bar in one direction and is held stationary against the facing magnet even after the trip bar continues movement for an otherwise non-allowable increment of electrothermal calibration.

Molded case circuit breaker apparatus having trip bar with flexible

A circuit interrupter mechanism comprising an overcenter toggle linkage and a releasable toggle latch means for latching the linkage in a partially closed position.

Circuit breaker mechanism

A multi-pole circuit breaker characterized by a circuit breaker structure including a releasable arm for opening a circuit through the breaker, a bimetal element for each pole which is responsive to an overload current condition to effect release of the releasable arm, a latch bracket and a trip bar coaxially mounted and having an adjustment screw to vary the position of the trip bar in relation to the bimetal to change thermal rating of the circuit breaker.

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New Brighton, PA, United States of America

Charles E Haugh