General Electric Company

Joseph M Palmieri

Keith W Klein

Roger N Castonguay

Raymond K Seymour

Linda Yvonne Jacobs

Erich J Pannenborg

James I Smith

Joseph B Kelaita

Robert Allan Morris

Graham A Scott

J Peter McCuin

David Arnold

Dennis J Doughty

Franco P Pardini

Donna C DeRosier

George J Boucher

Gregory C Eckart

James M Mitsch

William J Ashline

Thomas G Hampton

David S Parker

David J Trudel

Edward K Howell

Richard E Bernier

Edward E Kim

David J Meiners

Michael C Von Kannewurff

Richard A Dziura

George J Lawrence

Morris J Kornblit

Karen B Kowalczyk

Eric D Juntwait

Franklin P Palaia

Mario A Tacinelli

Eva E Matias

Stephen R St John

A spring-loaded cam electrical connector is used to rapidly connect circuit breaker load terminal straps with the associated electric distribution system wire conductors. Rotation of the cam in one direction traps the end of the wire conductor between the bottom of the cam support and the circuit breaker load terminal strap to make the electrical connection while rotation of the cam in the opposite direction releases the end of the wire conductor to break the electrical connection.

Circuit breaker line and load terminal

An electronic circuit interrupter is protected against thermal damage upon loosening of the lug connectors that connect the circuit interrupter with the load circuit. Thermal sensing elements attached to the lugs connect with the circuit interrupter trip unit to initiate circuit interruption when the temperature sensed exceeds a predetermined value.

Digital circuit interrupter thermal protection circuit

An arc isolation shield for molded case circuit breakers is inserted between the circuit breaker case and cover and attached to one leg of the operating cradle. The knee of the circuit breaker moveable contact arm contacts the bottom of the shield and moves the shield in unison with the contact arm to protect the contact arm, contact braid and operating spring upon contact separation under severe overcurrent conditions.

Circuit breaker contact arm and spring shield

Molded case circuit breaker accessories using slightly modified circuit breaker cases are described. Several of the accessories utilize a microswitch to provide remote indication of an auxiliary function. One modification of the circuit breaker case includes upstanding posts to capture and position the microswitch while a further modification utilizes the magnetic trip unit adjustment screw and a support plate.

Molded case circuit breaker accessories

A molded case circuit breaker for residential use employs an additional safety feature to ensure a fail-safe condition in the event that the circuit breaker is installed within a circuit that may be subjected to an excessive over-current fault that disables the circuit breaker trip unit. The integral bimetal-fuse within the circuit breaker trip unit responds to interrupt circuit current before any damage can occur to the associated electrical wiring system.

Fail-safe residential circuit breaker

An electric circuit breaker operating mechanism includes an insulated armature latch which prevents deleterious arc formation between the operating mechanism cradle and the armature latch surface when the circuit breaker contacts are separated under overcurrent circuit conditions. The insulated armature latch carries a tolerance take-up spring which interacts between the operating mechanism cradle and the circuit breaker trip bar assembly to insure free travel of the operating cradle during contact separation.

Molded case circuit breaker insulated armature latch arrangement

A molded case thermal-magnetic circuit breaker having improved low current magnetic trip response pivotally arranges the magnet within the circuit breaker thermal-magnetic trip system for controllably moving toward the latching armature assembly. The movement of the magnet decreases the magnetic separation distance between the magnet and the latching armature to optimize the magnetic trip forces and thereby enhance low current magnetic trip response.

Thermal-magnetic trip unit with low current response

A circuit breaker latch assembly eliminates the need for polishing the opposing latch surfaces to reduce static surface friction and lower the latching force. The end of the circuit breaker cradle operator is offset relative to the restraining surface of the armature-latch to reduce the static friction that must be overcome to move the armature-latch away from the cradle operator. Subsequent release of the cradle operator then allows the circuit breaker operating mechanism to separate the circuit breaker contacts upon the occurrence of predetermined overload current conditions.

Molded case circuit breaker low friction latch assembly

An arc gas controller-insert is used with molded case circuit breaker covers to direct the flow of arc gases that occur during intense overcurrent circuit interruption. The gas controller-insert provides access to the line and load terminal lugs for connection with and disconnection from an associated electrical power distribution system while controlling the egress of the arc gases.

Molded case circuit breaker arc exhaust gas controller

A molded case circuit interrupter of the type employing a thermal-magnetic trip unit to interrupt circuit current utilizes a flexible electrical braid conductor to connect between the thermal-magnetic trip unit and the movable contact arm. A helical spring arranged around the braid conductor at the welded connection with the movable contact arm provides long-term strain relief. A metal phosphate coating on the surface of the circuit breaker operating cradle and latch assembly eliminates polishing while insuring release of the cradle from the cradle-latch interface surfaces.

Molded case circuit breaker braid conductor with strain relief

A compact circuit breaker containing an electronic trip unit for interrupting overcurrent conditions within a protected circuit is made operable over a wide operating current range by means of current transformers having multiple turn primary windings. The primary windings are selected to provide a constant ampere-turns ratio to the current transformers without changing the size of the secondary winding or the volume of the transformer core.

Compact circuit interrupter having multiple ampere ratings

A compact circuit breaker utilizing an electronic trip unit for overcurrent determination contains a compact slot motor and a compact arc chute to minimize and control the arc that occurs when the circuit breaker fixed and movable contacts become separated upon intense overcurrent conditions. The fixed contact is arranged on a fixed contact arm that includes an arc runner for rapidly directing the arc into the arc chute. The arc chute includes a keying arrangement which cooperates with slots formed within the circuit breaker case interior sidewalls to orient the arc plates relative to the arc runner.

Current limiting circuit breaker compact arc chute configuration

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Southington, CT, United States of America

Joseph M Palmieri