US1873680A - Switch mechanism - Google Patents

Description

ATTORNEY A- T. TWISS SWITCH MECHANISM Filed June 18, 1927 mwl Mr E W 4 NM M Aug. 23, 1932.

WITNESSES: 4 1% I Patented Aug. 23, 1932 UNITEDTSTATETS PA ENT OsFFICE:

ALFRED T. TWISS, or rnArronn, :PENNsYLvANIA, AssieNon ro WESTINGHOUSE ELEC- 'rnrc -& MANUFACTURING ooivrr NY, conronArron or PENNSYLVANIA swrron. MECHANISM 7 Application filed June 18 1927. 'Serial No. 199,679.

My invention relates to switch mechanisms 7 and particularly that type known as disconnecting switches- Disconnecting switches of this type generally comprise a base member, apair of spaced insulators, terminal members for line Wires disposed on the insulators and: a flexible shunt for making and breaking the connections between the terminals. A pair otlinks are usually provided for supporting the flexible shunt, the supporting links being pivotally connected to one of the spaced; insulators at one of its ends, and a movableinsulator {or supporting its other end and adapted to connect the flexible shunt with the terminal dis.- posed on] the other spaced insulator. The movable. insulator is generally rotatably mounted midway between the spacedinsulators and adapted to rock to andtrom a position adjacent one of the insulators. This construction is undesirable in View of the strain on the insulator caused by the rocking movement about its pivot.

It is an object of my inven'tlon'top'rovide a disconnecting switch ofthis type having a movable insulator mounted-in such-a manner as to maintain it in perpendicular relation with the base member at alltimes, andv to cause such strain as the insulator:may be subjected to in breaking ice-seals on the switch jaws to be applied in a direction substantially parallel to its axis thus preventing the insulator'from being subjected to shear.- ing by strains in a direction angular-to its axis. 4 A It is another object of my inventionfto provide a switch mechanism of thistype, whereby the movable insulator is moved to and from its closed position in such a manneras to make possible the" construction of the electrical shunt of material having sufiicient stiffness to be self-supporting, thereby eliminating from the structure the usual links provided for supporting the shunt. 1 5

It is a further obj ect of my invention to provide a switch mechanism of this type having means for breaking a corrosive seal or a coating of ice that may form aboutthe switch,

.and interfere with, the opening movement thereof.

These and other'objects that may be made apparent throughout the further description of my invention are attained by means of; the apparatus hereinafter described and illustrated in the accompanying drawing,

wherein A a The single figure is a side elevational view of a disconnecting switch embodying my invention, I the disconnecting switch being shown in its closed position by heavy lines, in its open position by broken lines and in a fragmentary view of; a mid-position by dotted lines. l

j My invention comprises, in general, a base member 1, a pair of spaced insulators 2 and 3, terminal plates land 5 supported by the spaced insulators 2 and 3, respectively, line conductors 6 and 7 connected to the respective terminal members 4 and 5, switch jaws 8 disposed on the terminal member 4:, a movably the insulator mounted insulator 9 for supporting a contact 7 Qcom'prises an insulator seat 14 extending in substantially parallel relation 'to the base member 1', a pair of substantially parallel linkmembers 15 and 16,, the, members 15 and 16 each having "one end pivotally connected to an end ot'the seat'member'M by means of pivots 17 and 18, respectively, and their other ends pivotally connected to the base'member 1 by means of pivots 19' and 21, respectively.

The link member 16 is provided with an eX; tension 22 adapted to cooperate with an actuating mechanism23 for the mechanism 13.

The link 15 is provided with a slot 2 1,in which the pivot 17 is slidably disposed, thereby providing a limited amount of lost motion longitudinally. of the link 15. As may be seen from the drawing, the mechanism 13 is so disposed that, when the switch is closed,

the link-16 extends approximately along a straight line connecting the engaged contacts and the pivot 18.

In operating my invention from its closed position, as shown by the heavy lines 1n the drawing, the actuating mechanism 23 moves the extension 22 downwardly, turning the link member 16 in clockwise direction. The movable contact unit comprising the contact 11, the insulator 9, and the seat member 1a is held at only one place, namely, at the engaging contacts 8 and 11. The force applied by the link member 16 at the pivot 18, which force is at right angles to a line connecting the pivots 18 and 21, will also be "atapproxt mately right angles to a line extending from the engaged contacts 8 and 11 to the pivot 18. Consequently, the movable contact unit will be moved angularly about the engaged contacts 8 and 11, the leverage action resulting in a tremendous force which will loosen any corrosive seal or ice coating that may have formed on the contacts.

The angular movement of the movable contact unit continues until the pivot '17 engages the inner end of the slot 24. The left hand end of the seat member 14 is thereafter forced to move upwardly as it moves to the right, so that angular movement about the'engaging contacts is terminated and the movable contact unit is maintained in approximately the same angular position and moved to the open positionshown in dot and dash lines.

Since the mechanism is arranged in the form of a parallelogram, it will'm a'intain the seat member 14 in substantially horizontal position parallel to the base member and the insulator 9 in substantially vertical position throughout its movement. These positions are not maintained exactly, however, since the initial angular movement'necessarily changes the angular positions to a slight extent.

As may also be seen from thedrawing, the weight of the insulator tends to maintain the disconnecting switch in either its open and closed position, as the case may be.

Arcing horns 25 and 26 are provided on the terminal member 4 and the contact member 11, res'pectively,'and I have designed the arcing horns 25 and 26 so as to'limi't the :arcing period when opening or closing the disconnecting switch to a'minimum. It can be seen from the drawing that the, arcing horns start immediately to; separate after the main contacts part as shown by the dotted lines in the drawing, the various parts of the switch being so designed as to cause the are thereafter to be drawn between the arcing horns and protect the other parts of the disconnecting switch. 7

Accordingly, I have provided a disconnecting switch comprising a base member supporting a pair of spaced insulators, terminal members disposed on the insulators, a flexible shunt for electrically connecting the terminals, one end of theflexible shunt beingcarried by a movable insulator, a mechanism for supporting and actuating the movable insulator so that the movable insulator will be maintained in a position perpendicular with respect to the base member at all times, a slot provided in said mechanism for causing a slight rocking action of the contact member during the initial opening movement of the disconnecting switch, and a pair of arcing horns for cooperating in such a manner as to limit to a minimum the period of arcing when closing or opening the disconnecting switch. The construction of this disconnecting switch permits the use of shunts of heavier structure than has heretofore been practicable in view of the stresses caused by the bending of the shunt. The structure in my invention minimizes the stresses incident to the bending of the shunt, inasmuch as it merely displaces its normal bend from one position toanother.

While I have illustrated and described but one embodiment of my invention, it will be apparent to those skilled in the artthat varioi'is changes, modifications, substitutions, additions, and omissions may be made in the apparatus without departing from the spirit and scope of theappended claims.

I claim as my invention:

1. A circuit interrupter provided with separable contactmembers --ri1gidly supported upon stationary and movable insulating members, mechanism for actuating and for retaining said movable insulating member in substantially vertical positionduring its movement and means torti'lting said movable insulator and, therefore, said attached contact member at the initial movement of separation of the contact members.

2. A circuit interrupter provided with separable contact "members rigidly supported upon stationary and movable insulating members, a linkage mechanism for actuating and for retaining said movable insulating member in substantially vertical position during its movement 'one of thelinks of said mechanism having a. slotted connection whereby the insulator carrying the movable contact 'member is tilted during the initial movementl-ofseparation of said contact members. I

8. In an electric switch, the-combination of a fixed contact, a movable contact, a device 'formoving said movable contact'comprising four members pivoted to each other in "approximately the form of a parallelogram'and including a stationary base member and an opposite member which carries the movable contact, the pivotal'connection between the contact-carrying member and one oi"? the adjacent members having a. lost motion, and means for actuating sa-id contact-moving device, whereby, in opening the switch, the blade carrying member is first moved 'a-ng-ularly about the engaging contacts to loosen the same in the event they have been frozen to each other before moving the movable contact bodily away from the fixed contact.

4. In an electric switch, the combination of a pair of contacts one of which is movable into and out of contact with the other, a memher for carrying said movable contact, a stationary member, a first and a second link member each pivoted to'the contact carrying member and to the stationary member in approximately the form of a parallelogram and with the first link extendingapproximately along a straight line extending between its pivotal connection with the contact carrying member and the contacts in engaged position, the second link having a longitudinal slot in which the pivotal connection with the blade carrying member isreceived to provide a lost motion between the blade carrying member and the second link, and actuating mechanism connected to the first link, whereby, in opening the switch, the lost motion permits the first link to move the blade carrying member angularly about the engaged contacts for breaking any corrosive or ice seal that may have formed, after which the movable contact is moved bodily away from the cooperating contact andis maintained substantially in a given angular .position.

In testimony whereof, I have hereunto subscribed my name this 4th day of June,

ALFRED T. TWISS,

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