Siemens Energy & Automation, Inc.

Bruce D Guiney

Bernard DiMarco

Neal B Reeves

David A Leone

James G Sepelak

Rodney C Kramer

Stephen Wells

Bradley J Lewis

A circuit breaker housing includes a base having a main portion and a separate subbase portion. The line contact arms for the breaker are mounted on the subbase portion and attached to the main portion which includes the load contact arms. The main portion of the base includes a bottom wall which insulates the load contact arms from the line contact arms along a portion of their lengths. In addition, the bottom wall forms a structural member which rigidly ties the two sidewalls of the main portion of the base. The bottom wall of the main portion of the base includes an opening through which line contacts coupled to the line contact arm make contact with load arm contacts coupled to the load contact arms. Adjacent to the opening, the main portion of the base includes vertical ribs directly tied to the bottom wall which strengthen internal and external side walls in the main portion of the base and reinforce the structural member formed by the bottom wall of the main portion of the base. The subbase may be attached to the base with screws, adhesives, a combination of screws and adhesives or by other methods.

Multi-part circuit breaker housing

A circuit breaker includes a cam assembly which holds the load blade in contact with the line strap during normal operation. The cam assembly includes a cam surface on a cam which can slide along the load blade and a bearing surface on the load blade. In normal operation, the cam is biased on the load blade so that the cam surface engages the bearing surface. The force applied by the cam surface to the bearing surface in normal operation is approximately parallel to the force applied by the load blade to the line strap, thus, the cam surface does not tend to slide along the bearing surface during normal operation. When a high overcurrent fault occurs, blow-open forces exerted between the load blade and the line strap cause the cam to pivot to a position where the cam surface no longer engages the bearing surface, allowing the load blade to swing free of the cam and break the contact between the load blade and the line strap. As the load blade swings free of the cam, it engages a further cam surface of the cam which reduces the biasing force essentially to zero, thereby increasing the opening speed of the blade. In addition, the frictional force of the further cam surface against the load blade prevents the load blade from reestablishing contact with the line strap until the mechanism trips, keeping the load blade in the open position.

Circuit breaker having a cam structure which aids blow open operation

A remote tripping mechanism for use with a spring loaded safety switch. In a preferred embodiment, the mechanism is made up of two cams with a compression type trip spring anchored between them. The two cams are held in the 'normal position' (the spring compressed) by a latch. In this position, the switch operates in the same manner as a conventional safety switch. A trip lever connected to a solenoid is positioned such that it is unobtrusive when the switch is turned ON and OFF. When the switch is in the ON position and power is applied to the solenoid, the trip lever unlatches the latch and the two cams separate. The first cam engages and lifts the bail, turning the switch OFF. The cams are reset by turning the handle to the OFF position. This compresses the trip spring and resets the latch.

Electrically tripped mechanism for knife blade switches

A safety switch is provided with an auxiliary contact that is actuated by the heel of the bail. The heel actuation enables the auxiliary switch to be easily installed and wired and enables the same actuator and bracket to be used for varying sizes of bails.

Bail actuation of auxiliary contacts

The invention provides a fuse clip guard and load shield for an electrical switch assembly of the type having a generally planar base and a pair of longitudinally extending substantially parallel insulating walls defining a longitudinally extending space for containing an electrical load terminal and a fuse clip. The fuse clip guard and load shield each have a lid portion pivotally mounted between the pair of walls and a gripping portion which may include a tab restricting movement of a fuse ejector handle.

Fuse ejector guard and terminal shield

A circuit breaker including a contact operating mechanism configured to prevent the switch handle of the circuit breaker from being placed in an OFF position when the contacts are not separable. In addition to the switch handle, the mechanism is operable with a tripping circuit which actuates the mechanism to urge the contacts apart when the current flowing through the circuit breaker exceeds the preset limits of the circuit breaker. When the contacts are not separable and the tripping circuit actuates the mechanism, the operating handle is restricted from being placed in the OFF position, thereby avoiding the possibility of indicating an incorrect position of the contacts.

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Tucker, GA, United States of America

Bruce D Guiney