US2579771A - Electric switch - Google Patents

Description

1951 P. WARREN ET AL 2,579,771

ELECTRIC SWITCH Filed April 25, 1948 2 SHEETS-SHEET 1 INVENTORS PICKETT L. WARREN FRANK E. 50 LTZ ATTY.

195] P. L. WARREN ET AL ELECTRIC SWITCH 2 SHEETS-SHEET 2 Filed April 25, 1948 FIG. 3

FIG. 5'

' INVENTORS PICKETT L. WARREN FRANK E. SCHULTZ Patented Dec. 25, 1951 UNITED STATES PATENT OFFICE ELECTRIC SWITCH Pickett LlWarren and Frank E. Schultz, Chicago,

Ill., assignors to Royal Electric Manufacturing Company, Chicago, 111., a corporation of Illinois Application April 23, 1948, Serial No. 22,856

14 Claims.

This invention relates to electric switches and more particularly to the contact making part thereof. One of the specific applications of the contact of the present invention is to an' outdoor disconnect switch of the type shown in United States Patent No. 2,306,117, issued December 22, 1942.

Switch terminals have heretofore been made which consist of a series of copper tubes or copper clad rods. Such tubes or rods are generally supported at one end and extend from the supported end as a cantilever to the portion thereof with which contact is made in operation of the switch. Such switches are frequently mounted outdoors where they are subjected to the weathering action, often becoming coated with sleet and ice. Under those circumstances it sometimes happens that one of a number of rod wire contacts has a larger accumulation of ice than do the others. It is one of the objects of the present invention to provide a switch contact construction of the type above set forth wherein the amount of flexing of the contact wires is not affected by the amount of accumulated ice. The cantilever ends of two or more contact wires or rods are so connectedtogether that the spreadin forces thereagainst are in opposite directions so that a spreading force applied to one of the contact wires is resisted by the other. As a result of this arrangement any tendency for excessive flexing of one contact wire is resisted by another contact wire. It is a further object of the present invention to pro vide a contact structure of the above mentioned of the contact rods or wires may be used to in- Cil crease the pressure of contact to be exerted against the switch blade and to correct any undue flexing of the wire contacts.

Disconnect switches have heretofore been made wherein the switch contact structure is pivotally mounted and so arranged that the blade and the contact are engaged at an angle to one another and the blade then turns with respect to the contact into a toggle position, at the same time swinging the contact into its fully closed position. It is one of the objects of the present invention to provide a switch contact of the above mentioned character with a fully housed reset spring so arranged as to assure movement of the contact structure to its normal open position upon release of a force that holds it in its closed position so that the contact will always be available to receive the switch blade.

The attainment of the above and further ob- 2 jects of the present invention will be apparent from the following specification taken in conjunction with the accompanying drawing forming a part thereof.

In the drawing:

Figure 1 is a side elevational view of a vertical break type of outdoor disconnecting switch embodying the present invention;

Figure 2 is an enlarged plan view of the contact structure at the top of one of the stationary insulators;

Figure 3 is a sectional view taken along the line 3 of Figure 2;

Figure 4 is a sectional view taken along the line 4-4 of Figure 3;

Figure 5 is a sectional view taken along the line 55 of Figure 3; and

Figure 6 is a sectional view taken along the line 6-6 of Figure 2.

Reference may now be had more particularly to Figure 1 of the drawing. The switch is an outdoor type vertical break disconnecting switch of a rating of approximately 15000 volts.

In Figure 1 there is shown an outdoor air break disconnect switch embodying the present invention.-- The contact making structure which is adapted to receive the contact making end of the swinging switch blade has been shown here as incorporated in one well known type of switch, specifically a switch such as is more fully shown and described in the patent to Dunlap, No. 2,306,117, issued February 22, 1942, to which reference may be had. It is, however, understood that the switch contact of the present invention is equally applicable to any of the switches of the type shown in the Dunlap patent and is of general application to other switches.

Briefly stated, the switch of Figure 1 includes a base I at one end of which is mounted a stationary insulator 2 and at the other end of which is mounted a stationary insulator 3, and an axially rotatable insulator 4 the insulator pin of which extends through and is supported in a bearing 6 that is secured to the base I. Means is provided for axially rotating the insulator 4 as, for instance, by a crank 7 through the usual type of connecting rods. The insulators 3 and 4 include the usual type of insulator caps I 0 and H suitably secured to the respective insulators. A bearing stud I2 is bolted or otherwise secured to the insulator cap II, the axis of the stud being coaxial with the axis of the insulator and of the bearing 6. A current carryin supporting bar l4 connects the insulator 3 with the insulator 4, said bar being bolted having a bearing l5 in which the bearing stud I2 is journalled. The supporting bar It is of suilicient cross sectional area for the current carrying capacity of the switch. The bar 14 has a line conductor clamp l6 bolted thereto. A switch blade carriage 20 is pivoted on the cap ID as by means of a pivot pin 2| bolted to the carriage and forming trunnions for pivoting the blade. The carriage has a pair of upstanding ears 22 to which one end of a connecting rod 24 is joined by means of a universal coupling 25. The opposite end of the connecting rod is joined by a universal coupling 26 to a crank 21 that is rigidly secured to the-bearing stud I2 '50 that upon rotation of the insulator 4 the crank 21 acting through the connecting rod 24 and the cars 22 swings the blade 20 about the axis of the pivot pin 2|. The pin 2| is slidably en-- gaged by two rows of contact wires 3l3l that are mounted on a head 32 of metal of high current carrying capacity, such as copper, that is bolted to the supporting bar It, thus conveying current connections from the line conductor clamp It to the switch blade carriage. A switch blade 3'! is rigidly secured to the'carriage 20. said switch blade having a cam-shaped contact making end 38 of a shape shown more particularly in Patent No. 2,306,117. The portion of the switch thus far described is well known per se and is described merely as representing one type of switch blade or contact making member that may be used in combination with the improved contact s'tructure to form the improved switch.

The insulator 2 has an insulator cap 50 at its upper end to which is bolted or otherwise rigidly secured, in the usual manner, a contact base and terminal 4!, of copper or the like. The bottom of the contact base or terminal is of a generally circular shape to fit on top of the insulator cap it. The terminal includes a pair of arms 32-432 that extend'upwardly from the base of the terminal and then merge together to form a fiat surface 43 for receiving a line wire clamp ti l to be clamped to the surface 83.

Each of the arms 45 terminates at its upper end in a side member 4'5 in which is mounted a contact stud 46 in the form of a copper tube that is rigidly bolted in place in any desired manner as, for instance, by means of clamping lugs 58 that are bolted to the stud receiving side memoer 55.

The contact stud has rotatably mounted there on a contact carrier 50 comprising a pair of arms 5i---5l joined by a head portion 52 at one end and having cup-shaped spring housings tit-t3 at their other end, through which housings the stud extends, the carrier being rotatable on the stud. Inside of each of the spring housings 53 there is located a spiral clock spring 55. One end 56 of each clock spring extends through a slot 58 in the stud, and the opposite end 51 extends through a slot 51 in the housing, so that one end of each spring is anchored to the stationary stud and the opposite end of each spring constantly urges the carrier 50 in an upward direction about the stud 66 as a center. The outer wall of each housing 53 has as an integral part thereof a projecting stop 58 which cooperates with a similar stop 59 that is an integral part of each clamping lug 48. These stops limit the upward swinging of the carrier under the'action of the springs.

The head '52 of the carrier has a number of rod 4 receiving holes therein, the holes being in this instance in two rows of three holes to each row.

j The contacting members that are mounted on the carrier consist of a series of parallel tubes or rods 62 which are press fitted through the respective holes in the head and may, optionally, be soldered in place. Each contacting member 62 may be asolid copper rod or tube or, as in the preferred construction, consists of a spring .steel core that gives the contacting member the required resiliency, which core is copper clad. Each contacting member 62 extends rearwardly of the head 52 and is in sliding pressure engagement with the contact stud 46 so that upon swinging of the carrier 50 about the contact stud 4'8 as a center the rods 62 slide on the periphery of the stud 46 but maintain a firm pressure contact therewith.

din

" in place.

Adjacentits forward end each rod is looped in a direction away, from the opposite row of rOdS and then back in a direction towards the head 52 of the contact carrier. A loop of one of the rods 62 in the upper row of rods is indicated at 64 and a similar loop of one of the rods in the lower row of rods is indicated at 65. The end of the wire of the loop 64 is indicated at 66, and the end of the wire of the loop 65 is indicated at 61. The three ends 66 of the upper row of contact rods 62 are joined together. This is accomplished by extending the respective ends 66 into sockets in a bar 70 and then soldering them in place. Similarly, the ends 61 are secured to gether as, for instance, by extending these ends into holes in a bar H and then soldering them The two bars it-H are secured together in fixed spaced relationship by two stems 12 that are threaded at their upper ends into the bar iii and at their lower ends extend through holes in the bar H. The stems F2 are threaded at their lower ends. Nuts M thread on each oi the stems and thereby provide means for draw- 1y of the loop '64. This is provided in order to facilitate entrance of the contact making cam end 38 of the switch blade into position between the contacts.

A further explanation will now be given of the mode of operation of the switch. When the switch blade is in its open position the contact carrier 5! is in the position indicated in dotted lines in Figure 1, with the contact rods 82 extending upwardly and in a direction towards the switch blade. The carrier is held in that position by the springs 55, the stops 5859 determining the limiting position to which the springs move the carrier. When the switch blade ii? moves from the switch open position to the switch closed position the contact making cam end 38 thereof first engages the looped portion at of the contact structure. switch blade towards its closed position causes the contact making end 38 of the switch blade to swing the contact rods and the carrier 55 on which they are mounted towards the position illustrated in full lines in Figure 1. At the same time the contact making end 38 wedges its way inwardly between the two rows of contact rods 62 and by its wedging action spreads the two rows of. contact rods 62 apart. This camming and sliding action results ina firm pressure engagement between the contact rods and the cam contact making end 38. The contact rods 82 are flexible. The rows of contact rods thus flex apart Continued movement of the rating from the contact rods.

and the contact rods 62.

as the contact making member "moves between them. At the same time there is a tendency for the ends 65-41 of the rows of contact rods to move apart, which tendency is resisted by the bars --1l and thetie-in stems I2. The resil-. iency of the rods 62 from the point of engagement of each rod by the contact making member 38 to the ends 66-61 of the rods'is utilized to increase the pressure between the rods 62 and the cam 38. Furthermore, should any one of the rods be excessively coated with ice and thus tend to be pushed by the ice away from the'contact making structure 3 8, thatmovement is resisted by the other rods due to the tied in relationship of the ends 66-41 of the rods. As a result of this arrangement a very high contact making pressure is obtained between the contact making member 38 and the rods 62.

When the switch blade 31 is guided to the switch open position the blade 31 swings about its contact 38in a direction clockwise as seen in Figure 1. On the initial movement of the switch blade towardsfits open position the contact 38 swings the contact carrier 5| and the associated contact rods 62 upwardly about the contact stud 46 as a center. This upward swinging action s assisted by counter-balancing clock springs 55. As thecontact making member 38 and the contact rods swing about the respective centers 21 and 36 the contact 38 is gradually withdrawn from the rows of contact rods, ultimately sepa- At the same time a pair of arcing horns 10' that are secured to the contact base terminal 4| in any desired manner,

as, for instance, by pairs of set screws 'll'-'H'.

are sliding engaged by another pair of arcing horns 75 that are bolted or otherwise rigidly secured to the blade 31 in the usual manner so that any are that results from opening of the switch circuit takes place, between the pairs of arcing horns rather than between the contact 3' The contact carrier 51 reaches its limited upper position, namely, a position where the stops 58 engage the stops 59, just as the contact making end 38 leaves the contact rods. Whilethe blade is out of engagement with the contact rods the contact rods on the carrier are held in their switch open positions by the counter-balancing springs 55.

It is to be noted that the open ends of the cup-shaped housings 53 are in close proximity to and face towards the adjacent s des 45 of the contact structure. This therefore serves to inhibit the entrance of snow or moisture into the spring housings 53. It is also to be noted that the ends of theleaf springs enter slots in the tubular contact stud 46, asmav be seen from Figures 4 and 5. The ends of the leaf springs thus hold the contact stud 46 in position between the sides 45 of the terminal.

In compliance with the requirements of the patent statutes I have here shown and described a preferred embodiment of my invention. It s. however. to be understood that the in ention is not limited to the precise construction here shown, the same being merely illustrative of the principles of theinvention. What We consider new and desire to secure by Letters Patent is:

'1. An electric switch having a switch contact comprising a contact rod carrier, a pair of spring contact rods secured thereto, each rod being ire of the carrier at an end of the rod, the rods ad- I jacent their ends being curved away from one 7 another and back towards the carrier for guiding a contact making member between them, the

rods being adapted to be engaged substantially midway between the carrier and said ends by a contact making member which is adapted to flex the engaged portions of the rods from their normal positions and change the spacing between the engaged portions of the rods, and means connecting together the ends of the rods so that the resiliency oi the rods between the engaged portions and the ends is utilized to maintainprcssure between the rods and a contact making member between them. 7

2. An electric switch having a switch contact comprising a contact rod carrier, a pair of spring contact rods secured thereto, each rod being ireeof the carrier at an end of the rod, the rods adjacent their ends being curved away from one I another and back towards the carrierfor guiding a contact making member between them, the rods being adapted to be engaged substantially midway between the carrier and said ends by a contact making member which is adapted to flex the engaged portions of the rods from their normalpositions and change the spacing between the engaged portionsof the rods, and means extending between the carrier and the engaged portions of the rods connecting together the ends of the rods so that the resiliency of the rods between the engaged portions and the ends is utilized to maintain pressure between th rods and a contact making member between, them.

3. An electric switch having a Switch contact comprising a contact rod carrier, a plurality of I spring contact rods secured thereto, each rod being free of the carrier at an end of the rod, the

rods adjacent their ends being bent back towards the carrier, the rods being adapted to be engag d between one another adjacent their bent back against spreading apart.

4. An electric switch having a switch contact comprising a contact rod carrier, a plurality of 7 spring contact rods secured thereto, each rod being free of the carrier at an end of the rod, the rods adjacent their ends being bent back towards the carrier, the rods being adapted to be engaged between one another adjacent their bent back portions by a contact making member which is adapted to extend between the rods and fiex the engaged portions of the rods from their normal positions and change the spacing between the engaged portions of the rods, and mean connecting together the ends of the rods to hold the ends against spreading apart, said connecting means being between the carrier and the engaged portions of the rods. I 5. An electric switch having a switch contact comprising a contact rod carrier, a pair of sprin contact rods secured thereto intermediate the ends of the rods, each rod being free of'the carrier at the two ends of the rod, a stud slidably engaged by one end of each rod as the carrier pivots about its axis, the rods adjacent their opand means connecting together said opposite ends of the rods.

6. An electric switch having a switch contact comprising a pivoted contact rod carrier, a pair of spring contact rods secured thereto intermediate the ends of the rods and with their axes at substantially right angles to the pivot axis of the carrier, each rod being free of the carrier at the two ends of the rod, a, stud slidably engaged by one end of each rod as the carrier pivots about its axis, the rods adjacent their opposite ends being bent back towards the carrier, the rods being adapted to be engaged substantially midway between the carrier and said opposite ends by a contact making member which is adapted to be positioned between the rods and flex the engaged portions of the rods from their normal positions and change the spacing between the engaged portions of the rods, and means connecting together said opposite ends of the rods.

7. In an electric switch, a contact structure including a contact rod carrier having a pair of spaced apart arms joined by a head portion at one end of the arms and pivotally mounted at the opposite ends of the arms, said head portion having a plurality of parallel holes therethrough, spring contact wires extending through and held in said holes at a portion of the wires spaced from one end of each thereof, the wires adjacent said one end being looped back in a direction towards said head, and means securing together the looped back ends of the wires, said securing means being spaced from the carrier.

8. In an electric switch, a contact structure including a contact stud, a contact rod carrier journalled on said contact stud, a pair of contact making spring wire rods carried by the carrier and slidably engaging the stud and exerting a spring pressure thereagainst, said wires extending also from said carrier in a direction away from the stud and being then looped back upon themselves in a direction away from one another and then towards the stud, and means interconnecting the looped back ends of the wires so that the interconnecting means causes the looped back ends of the spring wire rods to resiliently resist spreading apart of the spring wire rods between the connected ends and the carrier.

9. In an electric switch, a contact structure including a contact stud, a contact rod carrier pivoted to swing about an axis extending through the stud, and a plurality of contact rods mounted on the carrier intermediate their ends with one end of each wire slidably engaging the stud and exerting a spring pressure thereagainst, each wire being looped back adjacent the opposite end thereof in a direction towards the carrier, and means securing together the looped back ends of the wires.

10. An electric switch having a contact stud, a ccntact wire carrier pivoted on the stud, a plurality of contact making spring wires mounted on the carrier intermediate their ends in two rows, the wires making sliding pressure engagement with the stud, the rows of wires being bent away from one another at their opposite ends for guiding a contact making member between the rows of wire and the wires adjacent said opposite ends being looped back towards the carrier, means mechanically connecting the ends of the wires of one row with the ends of the wires of the other row, and a contact making member movable into and out of position between the rows of wires and into and out of engage- 'ment with the respective wires of the rows, said contact making member swinging the carrier about the stud from a carrier switch open position to a carrier switch closed position and flexing the wires out of their normal positions to secure pressure engagement between the wires and the contact making member.

11. An electric switch having a contact stud, a contact wire carrier having a pair of arms pivoted on the stud, the arms being joined at one end by a head portion, a plurality of contact making wires mounted on the head portion intermediate their ends in two rows and each extending in opposite directions from the portion of the carrier where they are mounted, the wires making sliding pressure engagement with the stud for extending circuit cbnnections from the stud to the contact making member, and a contact making member movable into and out of position between the rows of wires and into and out of engagement with the respective wires of the rows, said contact making member swinging the carrier about the stud from a carrier switch open position to a carrier switch closed a contact wire carrier having a pair of arms 0 pivoted on the stud, the arms being joined at one end by a head portion, a plurality of contact making wires mounted on the head portion intermediate their ends in two rows and each extending in opposite directions from the'portion of the carrier where they are mounted, the wires making sliding pressure engagement with the stud for extending circuit connections from the stud to the contact making member, the rows of wires being bent away-from one another at their opposite ends for guiding a contact making member between the rows of wire and the wires adjacent said opposite ends being looped back towards the carrier, means mechanically connecting the ends of the wires of one row with the ends of the wires of the other row, and a contact making member movable into and out of position between the rows of wires and into and out of engagement with the respective wires of the rows, said contact making member swinging the carrier about the stud from a carrierv switch open position to a carrier switch closed position and flexing the wires out of their normal positions to secure pressure engagement between the wires and the contact making member, each arm having a cup-shaped spring housing at the pivoted end thereof through which housing the stud extends, and a carrier counterbalancing spring in each housing, each spring constantly biasing the carrier to its switch open position.

13. In an electric switch a switch terininal, a contact carrier having a pair of arms, a shaft rotatably mounting the arms of the carrier to the terminal, each of the arms having a cupshaped spring housing centered along the longitudinal axis of the shaft, each end of the shaft having a slot formed therein, each cup-shaped housing having a slot therein, each housing having therein a carrier biasing clock spring one end of which extends into the slot thereof and the other end of which extends into the slot in the adjacent end of the shaft, and a switch contact member carried by the contact carrier.

14. An electric switch having a contact stud. a contact wire carrier pivoted on the stud, contact making spring wires mounted on the carrier intermediate their ends, the wires making sliding pressure engagement with the stud, the portions of the wires that extend from the carrier in a direction away from the stud being looped at their ends in a direction back towards the carrier, means mechanically connecting the looped back ends of the wires, and a contact making member movable into and out of position between the wires at their looped back ends and engaging the wires between the carrier and their connected looped back ends and flexing 10 the wires apart to secure pressure engagement therewith, whereby each wire is pressed towards the contact making member on both sides of the point of engagement between the wire and the contact making member.

PICKET'I L. WARREN.

FRANK E. SCHULTZ.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS

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