Westinghouse Electric Corporation

Eaton Corporation

Jere L McKee

Lance Gula

Glenn R Thomas

Robert Michael Slepian

Richard Paul Malingowski

Kurt A Grunert

Thomas Alan Whitaker

William E Beatty, Jr

Todd Matthew Lathrop

William Ellsworth Beatty

Donald E Schlosser

Stephen A Mrenna

Joseph F Changle

David Michael Olszewski

H Richard Beck

James P Ellsworth

Melvin A Carrodus

William I Stephenson, Jr

Charles E Haugh

John P Majcher

David Herman Groves

Norman S Hoyer

James N Altenhof, Jr

Umesh C Patel

William E Smith

Semahat D Sinharoy

A circuit breaker includes separable contacts for movement between a closed position and an open position to switch electrical current. An operating mechanism moves the separable contacts between the closed and open positions. A sensor senses the electrical current and outputs a sensed current signal corresponding to the electrical current. A shunt shunts a portion of the electrical current. A trip mechanism employs the sensed current signal to produce a trip signal. A trip actuator trips the operating mechanism to move the separable contacts to the open position. The trip actuator includes a trip solenoid having a coil energized by the trip signal and also includes one or more loops energized by the shunted portion of the electrical current.

Electrical switching apparatus employing twice-energized trip actuator

A circuit breaker includes a housing, an operating mechanism and separable main contacts, and a rotatable crossbar which rotates to open and close the contacts. The crossbar interacts by way of a protrusion thereon with a rotatable, positive off-link. A handle mechanism is disposed in the housing and has a handle protruding from the housing which is normally movable from a closed to open disposition. However, if the operating mechanism has reacted in such a way as to open the separable main contacts but, in fact, they have not opened because, for example, they are welded shut, the protrusion on the crossbar will interact with the positive off-link and prevent the handle mechanism from moving to the opened position thus warning personnel that the contacts have not opened. There is also provided in association with the crossbar a cam which is spring loaded from the bottom against a portion of a cavity in a crossbar which interacts with a movable portion of the movable contact in such a manner as to latch it open when it has independently moved to an opened position relative to the rotatable crossbar. The cam rider reacts in such a way that it seals off or protects the aforementioned spring from gaseous arc products during the opening operation. There is provided on the trip mechanism a double pitch spring. The double pitch being such as to expand the range of the adjustment characteristic of the tripping mechanism.

Circuit breaker with welded contact interlock, gas sealing cam rider and

Circuit breaker with double rate spring

A circuit breaker has an electrically conductive blow open latch which forms part of the power circuit so that only short flexible shunts are needed between the latch and trip mechanism. Load current can be conducted from the contact arm to the electrically conductive latch solely through the interface between the latch and the blow open camming surface on the contact arm, and/or through additional short flexible shunts between the latch and the contact arm, preferably adjacent the pivot of the contact arm.

Circuit breaker with current conducting blow open latch

A multiple-pole ground fault interrupter, enclosed in an insulated housing, formed with multiple compartments, includes ground fault detection circuitry for detecting ground fault current that can be a personnel hazard. The ground fault interrupter includes a single trip solenoid assembly having multiple windings, each winding corresponding to one of the poles. The trip solenoid is mounted on a printed circuit board and electrically connected to the ground fault detection circuitry disposed thereon. The printed circuit board together with the trip solenoid assembly is disposed in a single compartment which reduces the amount of interconnection wiring between compartments, which, in turn, results in a reduced cost to manufacture the device. The use of a single trip solenoid assembly also results in the use of less components which further reduces the cost of manufacturing the device.

Dual wound trip solenoid

A crossbar assembly is formed from an elongated metal bar. A pair of contact arm carriers are slid onto the metal bar and welded in place. Molded electrically insulated sleeves are sliding received at each of the crossbar. The insulated sleeves can be either molded directly on the crossbar or molded separately, in which case, the sleeves are glued with epoxy and pinned to the crossbar to prevent axial movement of the sleeves with respect to the crossbar. The insulated sleeves are formed with a pair of plates disposed at each end. A pair of oppositely disposed slots formed in the plates is used to receive the ends of a cam roll pin assembly. Since the crossbar in accordance with the present invention does not require wrapping with insulating paper, the possibility of dielectric failure due to cracking of the insulating paper is eliminated. Also, since the contact arm carriers are welded to the crossbar instead of being stapled, the possibility of axial movement of the contact arm carriers during overcurrent conditions due to loose staples is also eliminated.

Crossbar assembly

A molded case circuit breaker is provided with a quick change current transformer assembly. The current transformer is used to sense overcurrent conditions and apply a signal to an electronic trip unit to trip the circuit breaker. The quick change assembly includes an insulated removable plate located adjacent an open cavity in the housing in which the current transformer is located. The current transformer is donut-type disposed about a load-side conductor located in a cavity in the housing rigidly fastened to the circuit breaker frame. In order to replace a current transformer, the insulated backplate is removed. Next the load-side conductor is unfastened and removed from the circuit breaker housing. The current transformer is then removed from the circuit breaker housing. In order to install a new current transformer, the steps are reversed. A force transmitting spacer is disposed adjacent a bight portion of a shunt, connected between a pivotally mounted contact arm and a load-side conductor. The force transmitting spacer transmits magnetic repulsion forces generated between the load-side conductor and the depending leg of the shunt adjacent the load-side conductor to the other depending leg of the shunt. By disposing the force transmitting spacer into the bight portion of the shunt the compression action required between the depending legs of the shunt is eliminated or reduced, thus reducing the blow open time significantly.

CT quick change assembly and force transmitting spacer

A circuit breaker having a trip mechanism comprising a primary armature which is attracted toward a bimetal by magnetic flux produced by a predetermined overcurrent flowing through the bimetal to unlatch an operating mechanism and open electrical contacts, includes a pivoted supplemental armature which is also attracted toward the bimetal by the overcurrent and which bears against and urges the primary armature toward the bimetal to thereby reduce the predetermined overcurrent at which the breaker opens the electrical contacts. The supplemental armature comprises a flat strip of magnetically permeable material which is bent at one end to form a hook which merely drops into a recess in the breaker housing. Integral flanges on the strip form a magnetic yoke which concentrates the magnetic flux to increase the sensitivity of the magnetic trip function.

Circuit breaker with low current magnetic trip

A molded case circuit breaker is provided with a quick change current transformer assembly. The current transformer is used to sense overcurrent conditions and apply a signal to an electronic trip unit to trip the circuit breaker. The quick change assembly includes an insulated removable plate located adjacent an open cavity in the housing in which the current transformer is located. The current transformer is donut-type disposed about a load-side conductor located in a cavity in the housing rigidly fastened to the circuit breaker frame. In order to replace a current transformer, the insulated back-plate is removed. Next the load-side conductor is unfastened and removed from the circuit breaker housing. The current transformer is then removed from the circuit breaker housing. In order to install a new current transformer, the steps are reversed.

CT quick change assembly

A cam roll pin assembly includes a cylindrical portion having an extending axle at each end for receiving a small roller and a relatively larger roller. The smaller roller is provided for engaging the cam surface on the contact assembly. The larger roller is received within a slot. Retaining rings are used to secure rollers on the axles. With such an arrangement the rollers are able to rotate independently. Thus, during a blow open condition, the contact points of the cam roll pin assembly can rotate in opposite directions without causing relatively large frictional forces on the cam roll pin which can slow down the blow open speed.

Cam roll pin assembly

An electrical contact material characterized by a pressed and sintered powder of silver composite with about 5 weight percent of graphite fibers.

Circuit breaker contact containing silver and graphite fibers

A circuit breaker apparatus characterized by a molded case containing a circuit breaker structure for opening and closing a circuit which structure comprises a releasable lever operable between latched and unlatched positions corresponding to open and closed circuit conditions, latch means including a latch lever for the releasable lever, interconnected toggle connected to the latch lever and that are biased to the unlatched position of the lever, and a movable trip bar responsive to predetermined overcurrents and having a projection contacting the toggle links for holding the links in the unbiased position.

Circuit breaker with shock resistant latch trip mechanism

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 circuit breaker characterized by a movable contact carrying arm movable about a pivot and a helical torsion spring movable on the arm to and from the pivot for applying a varying force as the arm moves from closed to open positions.

Circuit breaker contact arm with variable force pivot

An electric circuit breaker with blow open contact arm characterized by a pair of separable contacts one of which is mounted on a contact arm that is rotatably mounted on mounting bracket. The contacts maintain a repulsion magnetic force which operates to separate the contacts when a predetermined current overload occurs. A trip mechanism is connected to the mounting bracket or automatic opening of the contacts in response to a predetermined current overload condition. The contact arm comprising a cam and the mounting bracket comprising a cooperable cam follower whereby the contact arm is movable to an open contact independently of the mounting bracket.

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Zelienople, PA, United States of America

Jere L McKee