Westinghouse Electric Corporation

Stanislaw A Milianowicz

Russell E Frink

Nagar J Patel

Edward J Klimek

Norman Davies

Peter M Kowalik

Charles K Wallace

Robert N Krevokuch

Fred Bould

Mark L Lotzmann

William Q Aglietti

Russell W Long

Henry J Remic

Henry J Remic, Jr

Steven J Swencki, Jr

Paul T Bottegal

William O Aglietti

Brian F McDonnell

Alexander V Donatelli

A spring charging mechanism for electrical circuit breakers and transfer switches of the type in which a spring is charged by rotation of a shaft. The charging mechanism has a charging shaft with two independently operating ratchet mechanisms coupled thereto. One ratchet mechanism may be driven by hand while the other may be separately motor-driven or held stationary by a bracket. The ratchet mechanism which is not in operation acts as a locking device which prevents rotation of the charging shaft in the discharge direction while allowing rotation in the charging direction. The charging mechanism is adaptable for either hand or motor-driven operation or both. It also features an inexpensive and easily-installed flexible, resilient, insulating sleeve which insulates the charging mechanism from the operator, and a key arrangement for coupling a handle to a ratchet mechanism which distributes stress within the handle and protects the handle fastening screws from destructive shear stresses.

Spring charging mechanism for circuit breakers and transfer switches

A circuit breaker having a contact movable between open and closed positions, includes a closing spring assembly having a closing spring and first and second brackets. The closing spring assembly is chargeable when in a reset position in which the first bracket is hooked by a first hook. The closing spring is charged, manually or electrically, with support of the second bracket being transferred to a second hook. The closing spring is discharged to close the circuit breaker, with the closing spring assembly moving from the reset position to a discharged position in the process. The closing spring assembly is then moved as an integral unit, back to the reset position, with the closing spring again being charged, enabling the circuit breaker to immediately reclose in the event of a trip due to a transient condition. An improved breaker operating mechanism and power operated charging mechanism, are also disclosed.

Circuit interrupter having improved operating mechanism

A circuit breaker, and method of constructing same, in which a levering-in mechanism may be added after the circuit breaker has been assembled. The circuit breaker includes a chassis having first and second side plates which define upwardly open slots, which enable the levering-in mechanism to be 'dropped in' to the correct position of an assembled circuit breaker, with bottom portions of the slots functioning as half bearings. First and second retainer plates with downwardly open slots are respectively attached to the first and second side plates, to complete the half bearings and hold the levering-in assembly. The levering-in mechanism includes a threaded shaft having a traveling nut, with a bushing on the shaft being held radially, but not axially, by a bracket member, with the bushing also functioning as a non-stress stop for the traveling nut. New interlock arrangements are also associated with the levering-in mechanism, including interlocks which: (1) prevent access to the levering-in mechanism, (2) place the circuit breaker in a trip-free condition, and (3) discharge closing spring, in response to predetermined conditions.

Drawout switchgear with improved levering-in mechanism and interlock

A circuit breaker having a trip actuator which mechanically trips the breaker in response to an electrical trip pulse. The trip actuator includes first and second parallel magnetic circuits, with the first circuit having a lower reluctance than the second circuit. A magnet provides magnetic flux for both circuits. A pivotally mounted clapper has a first position in which it is releasably held in the first circuit by a magnetic force, and a second position. Bias springs urge the clapper towards the second position, with the bias springs providing a biasing force which is less than the magnetic force holding the clapper. The electrical trip pulse creates a magnetic flux which opposes the magnetic flux in the first circuit, switching the magnetic flux to the second circuit. The clapper member pivots to the second position, and a trip link associated with the clapper actuates a trip mechanism.

Circuit breaker having a trip actuator

A circuit breaker having a chassis, an electrical contact structure, and a shock absorber mechanism. The contact structure includes a movable first electrical contact and a second electrical contact. The first contact has a first movement range. The shock absorbing mechanism, which absorbs energy from the movement of the first contact, includes a metallic bar pivotally mounted on the chassis, and first and second limit members fixed to the chassis. The first and second limit members define a second movement range which overlaps the first movement range. A spring weakly biases the metallic bar towards the second limit member. The first contact, during movement thereof to an open position, strikes the metallic bar. Kinetic energy is removed from the first electrical contact by the metallic bar without bounce of the electrical contact, and the metallic bar pivots against the first limit member, transferring the shock of stopping the first contact to the chassis.

Circuit breaker with shock absorbing mechanism

A power circuit breaker having movable and relatively stationary contact assemblies operable between open and closed positions. The contact assemblies respectively include pivotally mounted first and second conductive members. The first and second conductive members are disposed in spaced relation in the closed position of the circuit breaker, to provide a first current loop having first and second legs defined by said first and second conductive members. A pivotable mounting arrangement for the second conductive member provides a second current loop defined by the second leg portion of the first loop and a third leg portion. The magnetic forces in the first current loop, which tend to pivot the second leg portion towards the third leg portion, are opposed by magnetic forces in the second current loop. Compression spacers provide parallel current paths which reduce the magnitude of current flowing through a pivotable joint of the relatively stationary contact assembly.

Circuit breaker having improved contact structure

A grounding switch device for a metal-clad switchgear is adapted to be inserted into a standard circuit breaker cell allows the bus and line conductors within the switchgear assembly to be grounded for maintenance. A plurality of fixed and selectable test ports are provided to facilitate various electrical tests. The ground switch device is disposed on a frame and contains a ground contact assembly for providing sliding contact between the ground switch device and the ground bus within the circuit breaker cell. The ground contact assembly is in electrical contact with a movable contact. The movable contact is adapted to engage a stationary contact mounted on a mounting plate, attached to the frame by way of an insulator. A selector switch assembly connects the stationary contact to either the upper bus terminals or line terminals in the metal-clad switchgear assembly. The contact portion of the movable contact is U-shaped having two spaced-apart blades. Each blade is adapted to be received in a jaw portion of the stationary contact assembly. The jaw portions of the stationary contact assembly are formed by a pair of U-shaped current loops having inwardly facing protrusions disposed intermediate the bight portion. These protuberances force the contact arm into the jaw when the switch is closed on a live circuit. A combination spring and damper is disposed adjacent the protrusion to provide contact pressure when the ground switch contacts are closed and also to prevent contact bounce which can cause arcing and welding of the assembly.

Contact structure for grounding switch

A circuit breaker characterized by a voltage-responsive device having an electromagnet including an armature. A linkage connects the armature to the trip latch of the circuit breaker in order to open the circuit breaker contacts when a voltage occurs that is less than a predetermined voltage value. Under normal operating conditions, when the contacts are closed, the armature is retained in place by an electromagnetic force, but is biased away therefrom when the voltage drops below that voltage value.

Circuit interrupter with undervoltage trip mechanism

The kinetic energy generated by the rapidly moving contact and coupled operating mechanism of a tripped circuit breaker or similar apparatus is dissipated by a compressible shock-absorbing assembly comprising a loose stack of freely-movable magnetized metal plates which is mounted in laterally-extending position on a stationary upstanding part of the breaker and is struck by a lever fastened to the main operating shaft of the breaker operating mechanism. The metal plates are freely movable toward and away from one another and are so magnetized that adjacent plates repel one another. The plates are accordingly normally spaced from each other and produce a series of sequentially-occurring impacts and collisions between the plates and the advancing striker lever when the breaker is tripped. The resulting series of momentum exchanges between adjacent plates and the lever quickly dissipates the kinetic energy developed by the trip sequence and brings the breaker operating mechanism and movable contact of the breaker to a smooth stop. The compressible multiple-impact assembly provides a compact shock absorbing means that is especially adapted for use in medium voltage circuit breakers (5 to 35 KV rating) of various types which is not only durable and efficient but very inexpensive and reliable. The improved shock absorber is also adapted for use in guns and the like which require a suitable means for counteracting the recoil produced when the gun is fired. In an alternative embodiment the metal plates are magnetized by induction using a permanent magnet or an electromagnet that is mounted within the circuit breaker and has pole pieces located on opposite sides of the stack of metal plates.

Multiple-impact shock-absorbing assembly for circuit interrupter and

Overheating of the contacts and associated current-carrying parts of a vacuum type circuit breaker is prevented by fastening a U-shaped heat exchanger component of non-magnetic sheet metal to a protruding portion of the stem that is located at the top of the breaker bottle and is integral with the stationary contact. The U-shaped heat exchanger component is secured in inverted position on the stationary stem and the downwardly-extending skirts of the heat exchanger are slotted to provide a series of spaced ribs which form planar grid structures that allow ambient air to flow through the heat exchanger component and enhance its heat transfer characteristics. The heat exchanger component is secured to the stationary stem by conical-shaped washers that curve toward and are compressed flat against the flat central portion of the heat exchanger component in sandwiched relationship therewith by a lock nut which engages threads on the stem and thus firmly clamps the various components together on top of the circuit breaker and the leaf conductor assembly that is fastened to the stem.

Vacuum circuit interrupter having heat exchanger for temperature control

The kinetic energy generated by the rapidly moving contact and coupled operating mechanism of a tripped circuit breaker or similar apparatus is dissipated by a compressible shock-absorbing assembly comprising a loose stack of metal plates and interposed springs which is mounted on a stationary part of the breaker and is struck by a lever fastened to the main operating shaft of the breaker operating mechanism. The metal plates are movable toward and away from one another due to the resiliency of the springs and the resulting multiple impacts between the plates and advancing striker lever produces a momentum exchange phenomenon which quickly dissipates the kinetic energy and brings the breaker operating mechanism and movable contact to a smooth stop. The compressible multiple-impact assembly provides a compact shock absorbing means that is especially adapted for use in medium voltage circuit breakers (5 to 35 KV rating) of various types which is not only durable and efficient but very inexpensive and reliable. The improved shock absorber is also adapted for use in guns and the like which require a suitable means for counteracting the recoil produced when the gun is fired.

Multiple-impact shock absorbing means for circuit interrupter and other

There is provided by this invention a vacuum monitoring device for use in vacuum circuit interrupters comprising a stacked resistor assembly as a voltage divider coupled to an internal shield of the vacuum bottle and a low voltage detection circuit for monitoring leakage currents under abnormal pressure conditions.

Vacuum circuit interrupter having vacuum monitoring apparatus

Vacuum circuit interrupter apparatus is taught in which a movable stem is interconnected with one of the separable main contacts thereof. Flat planar flexible conductors connected in parallel circuit relationship between the stem and a fixed terminal for the circuit interrupter system are utilized. Planar members are spaced from each other for enhanced heat dissipation characteristics. Furthermore, the planar members are generally self-supporting except for the flexibility associated with a particular shape, consequently are not likely to randomly touch other apparatus in a switchgear cabinet. Nevertheless, the amount of conductor represented by the parallel planar members is sufficient to conduct electrical current when the circuit interrupter is closed.

Stiff flexible connector for a circuit breaker or other electrical

Electrical apparatus and more particularly vacuum electrical circuit breaker apparatus is taught. The electrical apparatus has a cylindrical movable terminal stem which is to be interconnected with a fixed terminal by way of a flexible conductor which is nevertheless relatively stiff and self supporting. This is accomplished by using interlayered elongated rectangular plates or sheets between the two aforementioned terminals. Connection to the circular stem is made by utilizing offset tabs around the periphery of a central hole at one end of each of the sheets. The offset allows the tabbed opening to be inserted over the stem. After which the tabs are sandwiched or compressed to lie in the plane of the sheet thus causing the edges of the tab to flow around the stem reducing contact resistance. Because there are multiple sheets in each flexible conductor packet, the number of three point contacts between the flexible conductors and the stem is increased.

Electrical junction of high conductivity for a circuit breaker or other

A single barrel puffer circuit interrupter is taught. The single barrel accomplishes the multiple purposes of electrical insulation between terminals, basic support and puffer gas containment. The circuit interrupter has a movable nozzle-piston arrangement fixedly attached to a movable cylindrical hollow arcing contact. The nozzle slidably engages a second cylindrical, hollow arcing contact and is disposed in slidable but sealed relationship therewith at all times, thus providing a shield between the arcing contact and the barrel of the circuit interrupter. In addition, one of the arcing contacts overlaps the other in telescoping relationship when the contacts are closed. This provides a lost motion feature for the puffer. The lost motion feature allows the puffer gas to be compressed for a short period of time by the piston during a contact opening operation in a completely enclosed region before the gas is provided to the region of an electric arc between the opening contacts.

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Monroeville, PA, United States of America

Stanislaw A Milianowicz