Westinghouse Electric Corporation

Robert T Basnett

Joseph C Engel

James Alan Bauer

Walter V Bratkowski

Denis A Mueller

An E shaped stationary magnet/moveable armature combination for use in an electromagnetic contactor. The magnet has three legs; two outer legs and an inner leg. The armature can be a single, essentially rectangular bar or have three legs corresponding to the legs of the magnet. The moveable armature is caused to contact the magnet by a magnetic field created when electrical current is applied to a current carrying coil. An outer leg of the magnet and/or armature is arranged such that an air gap remains between an outer leg of the magnet and armature. The provision of an air gap in an outer leg reduces noise emitted from the electromagnet.

Tractive magnet with asymmetric permanent air gap

An electromagnetic contactor or controller is taught in which the voltage which is impressed across the electromagnetic armature winding is controlled with an algorithm to enhance the closing operation. A microprocessor is utilized to implement the algorithm.

Electromagnetic contactor with algorithm controlled closing system

A relatively small vacuum bottle is taught in which the fixed electrically conductive end of the fixed contact member has cup-like cylindrical walls for forming part of an arc chamber. A ceramic main body for the vacuum interrupter is axially aligned with the cup-like walls and extends therefrom to form an elongated portion of the interrupter. An external metallic bellows is attached to the other axial end of the ceramic member and extends the interrupter further. The other end of the bellows member is attached to a movable contact end piece. All of the attachments are vacuum tight. As the movable end member is moved into a disposition of electrical contact with the fixed end member the external bellows compresses at its pleats. On the other hand when the movable contact member is moved away from the stationary contact member the movable bellows expands at its pleats. The bellows is protected internally from arc heat, light and by-products by an annular constriction in the ceramic member. Alternately, the bellows and ceramic members are axially interchanged with one another so that the ceramic member moves with the movable contact member. In this case, the bellows is protected from the arc heat, light and by-products by an internal ceramic member which moves with the movable contact to seal off the region of the arc interruption from the internal portion of the bellows.

Vacuum interrupter with bellows shield

A vacuum contactor having a compact DC electromagnet with an improved force watts ratio. The DC electromagnet consisting of a dual pickup coil and holding coil winding assembly and a solid U-shaped core having removable legs secured to a base with an adhesive backed aluminum shim positioned intermediate the legs and base, the ampere turns of the pickup coil being approximately 7.5 times those of the holding coil with the legs of the core being approximately 1/3 the length of those in a conventional DC electromagnet having substantially the same force watts ratio. The shorter legs of the core reduce magnetic losses and provide increased magnetic coupling with the moving armature of the contactor closing mechanism. This allows the smaller magnet to exert a greater force upon the armature during closing of the vacuum interrupter. With decreased magnetic losses, the size of the windings can be reduced, facilitating removal of the heat generated therein and producing a small, efficient magnet.

Vacuum contactor having DC electromagnet with improved force watts ratio

A vacuum contactor with a kick-out spring that does not require readjustment after disassembly of internal portions of the vacuum contactor. Two separate frame members are secured fixedly against each other in register in the operational mode. The bottom portion of a vertically disposed kick-out spring is attached to a horizontal bar which captures a lever. The lever is interconnected with an electromagnet and with the contacts of a vacuum interrupter in an integrated system so that energization of the electromagnet forces the contacts to a closed state and exerts tension against the spring through the horizontal bar. Deenergization of the electromagnet allows the kick-out spring to relax its tension thus opening the aforementioned contacts. When the two frame portions are separated, the spring relaxes to a minimal tension disposition but is prevented from further relaxation because of a mechanical stop which prevents the horizontal bar from moving upwardly and yet allows the lever members to be disengaged from the horizontal bar.

Vacuum contactor with kickout spring

A vacuum contactor kickout spring adjustment apparatus providing for the controllable increase or decrease in the force of the kickout spring. The apparatus permits the insertion or removal of the kickout spring at a force substantially less than the normal operating force of the spring. The apparatus includes a base having a U-shaped bracket mounted thereto. Rotatively mounted intermediate the legs of the bracket is a locking block. A lever pivotally mounted on the base engages one end of the kickout spring. A rod engages the locking block and lever such that movement in one direction moves the lever to increase the force and the spring while the movement of the rod in the opposite direction accuses a decrease in the force of the spring.

Vacuum contactor kickout spring adjustment apparatus

A three-arm mechanical interlock for a vacuum contactor having one or more vacuum interrupters. The first two arms of the interlock multiply the angular rotation of a shaft connected to the moveable contacts of the interrupters. Shaft travel of about 4 degrees is increased to about 12 degrees at the end of the second arm of the interlock allowing the interlock pieces to be pressed rather than being machined. After the contactor has been opened, the third arm of the interlock transfers position to block the path of the other arms preventing the accidental closing of the contactor. The contactor may not be reclosed until the third arm is transferred back to its original position. Flat surfaces, preferably parallel, can be provided on the shaft and the bore of the first arm attached thereto to provide a self-aligning connection. An extension member can be fastened to the second arm to provide an additional interlock to another device.

Mechanical interlock mechanism for a vacuum contactor

Contact overtravel adjustment apparatus for a vacuum contactor. Two nuts, each having a plurality of radially spaced teeth about their periphery, are threaded onto the mounting stud or shaft of the moveable contact of each vacuum interrupter in the contactor. The first nut is positioned on the shaft to establish the contact overtravel gap. The second nut is used to lock the position of the first nut. A blade of a screwdriver is inserted between adjacent teeth in both nuts. Rotation of the screwdriver in one direction locks the two nuts while the rotation thereof in the opposite direction loosens the two nuts. The teeth allow the torque used for tightening to be applied to the nut with zero net torque being applied to the shaft of the moveable contact of the vacuum interrupter. The toothed nuts also provide for a more accurate setting of the overtravel gap adjustment.

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Hendersonville, NC, United States of America

Robert T Basnett