Eaton Corporation

Westinghouse Electric Corporation

George A Smith

Thomas Kenneth Fogle

Mark L Lotzmann

Frank L Cameron

Thomas K Fogle

Larry S Lakes

Nathan James Weister

Robert N Krevokuch

Lawrence Joseph Kapples

Frank K Ostrowski

James R Hanna

A heat sink is for an integrally fused low-voltage power air circuit breaker including a line terminal and electrical bus work coupled to a current limiter. The line terminal, electrical bus work, and current limiter contribute to the formation of a thermal dam. The heat sink includes a heat exchanger structured to be coupled to the line terminal at or about the current limiter in order to expel heat from the thermal dam. The heat exchanger comprises at least one conductive member having a first end, a second end, and a plurality of bends therebetween. The heat exchanger includes heat reduction features, such as, for example, two conductive members having a number of air gaps therebetween to facilitate heat convection, a dark coating to expel heat, materials having a high thermal conductivity, and surface-enlarging mechanisms such as fins, flanges and apertures.

Electrical switching apparatus and heat sink therefor

An apparatus selectively connects a normal power line and an emergency power line to a load, and includes two interlocked switching mechanisms, each having individual interlocks, for selectively connecting the power lines to the load, and an interlock mechanism for interlocking the switching mechanisms in order that only one of the power lines at a time is connected to the load. The switching mechanisms may each have two drawout cassettes including associated switching devices for switching the power lines to the load and, also, including an isolated position for isolation of the associated switching device from at least one of the switched power lines and the load. Each switching device may be a circuit breaker having a trip unit for sensing current flowing from a power line to the load and tripping the circuit breaker. The interlock mechanisms may include keylock mechanisms which selectively disable closing of the switching devices. Each keylock mechanism may have individual locks on associated cassettes and a single key for operating only one of the locks. The individual interlocks of the switching mechanisms may cooperate with the keylock mechanisms to selectively disable connection of a power line to the load. Each key may be retained by an unlocked associated lock and may be removed from a locked associated lock.

Combination transfer and bypass isolation switch utilizing drawout

A powered mechanism displaces the toggle, handle or similar operator of a switch such as a circuit breaker, motor contactor or transfer switch. A linear induction motor drives a motor shaft between extended and retracted positions. A pair of S-shaped cam members pivot at one end on an axis, and a sliding pin carried on the end of the motor shaft rides along slots in the cam members. A couple engages over the switch operator and is pivotally attached to links that in turn are pivotally attached to the cam members, The links attach to the cam members at a point closer to the pivot axis of the cam member than the sliding pin in the slots, thus obtaining leverage. The slots have an inclined or curved section joined to a straight section. The straight section provides an idling action in that no force is applied to the operator via the couple as the sliding pin passes through the straight section, allowing the motor to accelerate unopposed. When the sliding pin is in the inclined or curved section, displacement of the motor shaft moves the couple, and therefore the switch operator handle.

Operator of a handle or toggle of a switch

An interlock for a pair of electrical switching devices includes plungers mounted through the switch housing and engaging the operating mechanism which opens and closes the switch. The plunger of each switch is coupled to a pivotally mounted cam plate by a pin which engages a camming slot in the cam plate for mutual movement of the plunger and cam plate. The cam plates associated with the pair of switches are connected by a connecting link for coordinated rotation. When one switch is closed, the operating mechanism extends the associated plunger which through the cam plates and connecting link raises the other plunger to block closing of the other switch. When a plunger is in blocking position, the coupling pin engages an overtoggle section of the camming slot of the associated cam plate such that a force generated by any attempt to close the associated switch is directed through the pivot axis of the cam plate and generates no component tending to rotate the cam plate. Hence, no force is transmitted to the connecting link or to the cam plate and plunger associated with the switch which is already closed. Opposed springs bias the respective cam plates toward the overtoggle position and urge the interlock to an intermediate position when both switches are open so that either may be closed. A single actuator can be used to selectively block operation of a single switch without transmittal of a force generated by an attempt to close the switch back through the actuator to a manual or motor operator.

Interlock for electrical switches

A handle actuator is provided for a circuit interrupter that has a handle or toggle pivotally movable between operative positions. The handle actuator has a pair of pins that fit tightly on the handle, a pair of retainers coupling the pins in a rigidly spaced parallel relationship, and a pair of flanges fixed to the circuit interrupter via a base. The flanges are disposed on opposite sides of the handle and have arcuate slots that guide the pins coaxially with the pivot axis of the handle. The ends of the pins extend through the arcuate openings of the flanges and are received in the retainers. Connecting links pivotally couple the pins with a drive input for selectively driving the pins against the handle to move the handle between the operative positions. The relative position of the pins on both sides of the handle is constant, preventing wear on the handle due to rolling of the pins against the handle, impacts with the handle permitted by lost motion, or bending and twisting forces.

Handle actuator for a circuit interrupter handle

A transfer switch mechanism is provided for operating the handles of a pair of circuit interrupters. The transfer switch mechanism has a lever arm movable between advanced and retracted positions, the lever arm having a gripping portion permitting handhold for manual operation. The lever arm turns an axle via a ratchet assembly with pawls that permit the axle to turn in one direction but oppose movement of the axle in the direction counter to that direction. The axle turns a crank, and a pair of connecting rods have proximal ends coupled to the crank. The transfer switch mechanism further includes a pair of handle-engaging heads, each of which has opposed abutment surfaces that removably receive the handle of one or the other circuit interrupters between the opposed abutment surfaces. A base is fixed relative to the circuit interrupters and movably supports the lever arm and the handle-engaging heads. The connecting rods have distal ends respectively coupled to one of the two heads such that operation of the lever arm between the advanced and retracted positions causes the abutment surfaces to drive against the handles and thereby move the handles between operative positions.

Transfer switch

A mechanism for bypass isolation switches of the type comprised of at least three circuit interruption devices each having a handle has at least three switch gears, one positioned over each circuit interruption device and having either a drive gear or a spacer gear therebetween. A cam having a mouth which engages the handle of the circuit interruption device is eccentrically mounted on each switch gear. A stop is provided on at least one gear to permit the gears to rotate only 180.degree.. Since the drive, spacer and switch gears are interconnected, the cams must move or not move simultaneously. As a result, the at least three circuit interruption devices are operated simultaneously.

Five gear isolating mechanism for bypass isolation switches

An uninterruptible power source having a static transfer switch which switches rapidly between a commercial power source and an alternate power source is removed from service by a maintenance bypass switch having a first switch in series with the uninterruptible power source and a second switch which shunts the uninterruptible power source and the first switch. The first and second switches are circuit breakers having handles which toggle between open and closed positions. The maintenance bypass switch includes an operator which operates the two circuit breakers in opposition with a closed transition so that one switch is always closed. An interlock prevents operation of the maintenance bypass switch when the alternate power source of the uninterruptible power supply is selected by the static transfer switch. An isolation switch between the uninterruptible power source and the commercial power source and also shunted by the second switch of the maintenance bypass switch is open together with the first switch of the maintenance bypass switch when the uninterruptible power source is to be isolated for maintenance.

Electric power system with maintenance bypass for uninterruptible power

A high voltage circuit interrupter, having telescopic tubular insulating and conducting casings, contains an expulsion end sealing construction which hermetically seals and controls the expulsion rate of the interrupter. The expulsion end includes a sleeve, a thin, rupturable diaphragm affixed against the sleeve by cyanoacrylate cement, and an end cap. Epoxy cement is applied into the cap so that the space between the diaphragm and the end cap are filled forming a sealant layer therebetween. A main ferrule secures the strain element, and an auxiliary ferrule secures both the main ferrule and the end cap onto the end of the tubular insulating casing.

Method of assembling a controlled seal for an expulsion fuse

Controlled seal for an expulsion fuse and method of assembling same

A current limiting fuse with an indicator characterized by a generally tubular, electrically insulating casing having a pair of tubular terminal members at opposite ends of the casing. A fusible element extends between the terminal members and through the casing. An indicator plunger extends from one end terminal member and is movable between a retracted and extended positions and is biased in the extended position. A restraining wire extending between the other end terminal member and the indicator plunger. The wire having a smaller diameter portion in the casing. An electrically conductive grease disposed between the plunger and the tubular terminal member.

Growing community of inventors

N. Huntingdon, PA, United States of America

George A Smith