US3244825A

US3244825A - Low break switch with straight line current path and torsion loaded arcing horn

Info

Publication number: US3244825A
Application number: US258229A
Authority: US
Inventors: Stanley C Killian; Oswald C Melbye
Original assignee: HK Porter Co Inc
Current assignee: HK Porter Co Inc; G&W Electric Co
Priority date: 1963-02-13
Filing date: 1963-02-13
Publication date: 1966-04-05
Anticipated expiration: 1983-04-05

Description

A ril 5, 1966 s. c. KILLIAN ETAL 3,244,825

LOAD BREAK SWITCH WITH STRAIGHT LINE CURRENT PATH AND TORSION LOADED ARCING' HORN 2 Sheets-Sheet 1 Filed Feb. 15, 1963 INVENTORS: v

dgz/ cad/1m y U C. 277% J0%ZW wlfM is April 1966 s. c. KILLIAN ETAL 3,244,325

LOAD BREAK SWITCH WITH STRAIGHT LINE CURRENT PATH AND TORSION LOADED ARCING' HORN Filed Feb. 15, 1963 2 Sheets-Sheet 2 55 INV'ENIORS United States Patent LOW BREAK SWETCH WITH STRAIGHT LINE CUR- RENT PATH AND TORSION LOADED AR'CIN'G HORN "Stanley C. Killian, Le Roy, N.Y., and Oswald C. Melbye, Bellwood, 151., assignors to H. K. Porter Company, Inc Chicago, IIL, a corporation of Delaware Fiied Feb. 13, 1963, Ser. No. 253,229 9 Claims. (Cl. 200-48) The present invention relates to load break switches, and particularly, to an improved distribution line switch and an improved quick break attachment therefor.

A load break switch for high tension transmission lines is conventionally comprised of a disconnect switch and an interrupter, the function of the disconnect switch being to interpose a large, circuit-opening, air gap in the circuit when desired and the interrupter functioning to prevent occurrence of or to break any are that may tend to strike between the contacts of the disconnect switch upon opening of the switch. Where line current, and consequently the tendency toward arcing is small, the interrupter may take the form of a rapidly acting quick break device operating in open air.

The art has previously proposed an effective economical disconnect switch comprised of a pair of opposed relatively rotatable insulators adapted for mounting on a pole or tower and for connecting the ends of two line conductors to the tower, a pair of generally L-shaped switch blades mounted respectively on the insulators and connected respectively to the lines, a contact structure on the free outer end of one blade, and means for rotating the other blade to move its free outer end into and out of engagement with said contact structure.

An effective, economical quick break device for disconnect switches has also been proposed comprised simply of a whip-like wire to be mounted on either the stationary contact or the movable blade of the switch, and an arcing horn to be mounted on the other of the blade and contact and including an abutment or detent for releasably engaging and flexing the whip during the initial stages of opening movement of the switch. As the blade and contact of the disconnect switch separate from one another, the whip and horn are disposed in series in and comprise the conductive path through the switch until such time as the disconnect blade is sumciently removed from its contact so that arcing will not occur between the two. The detent means on the arcing horn then releases the whip, whereupon the whip, due to its inherent resiliency and the flexed condition thereof, returns at high speed toward its starting position causing the circuit to be broken without arcing.

The object of the present invention is the provision of improvements in disconnect switches of the character described, in quick whip interrupting attachments, and in combinations of the two.

In particular, it is a first object of the invent-ion to provide in disconnecting switches of the character described an improved contact assembly for establishing a direct, straightdine current path between the two conductor blades of the switch thereby to enhance switch operation and improve the current transfer characteristics of the switch.

A second specific object of the invention is the provision of improvements in quick whip interrupting devices characterized in that the whip is loaded primarily in torsion rather than bending or flexing, thereby to improve its return or interrupting action and increase its service life.

In the latter respect, an object of the invention is the provision of an improved whip of generally L-shape having a whip leg and an integral base leg, the latter paralleling the axis of relative movement of the disconnect blade and contact, being anchored at its free end and journalled for rotation adjacent its opposite end, whereby said base leg is loaded in torsion upon movement of said whip leg in the initial stages of switch opening movement.

A further object of the invention is the combination of the above enumerated and other structural improvemerits in a compact and economical load break switch having improved operational characteristics.

Other objects and advantages of the invention will become apparent in the following detailed description.

Now, in order to acquaint those skilled in the art with the manner of making and using our improved load break switch, we shall describe, in connection with the acconr panying drawings, a' preferred embodiment of the switch and preferred manners of making and using the same.

In the drawings:

FIGURE 1 is a side elevation of a load break switch embodying our invention;

FIGURE 2 is a vertical cross-sectiona1 view of the switch taken 'substanially on line 22 or FIGURE 1;

FIGURE 3 is a fragmentary plan view, on an enlarged scale, of the contact and quick whip components of the switch; I

FIGURE 4 is a side view of the components shown in FIGURE 3; and

FIGURE 5 is an end view of said components.

As shown in FIGURE 1, the switch comprises a base 10 adapted to be secured to a cross arm of a pole or tower and mounting a stationary insulator 12 provided with a pull=oif eye 14 for attachment thereto of a conventional aerial conductor. The base 10 also mounts an oppositely extending rotatable insulator 16 provided wit-h a similar eye 18.

Each insulator carries a generally L-shaped

tubular blade

20 and 22, respectively, to which the live conductors are connected in any conventional manner. The leg-s of the blades parallel to the insulators are adapted to be disposed -in end-toend aligned relation. The stationary blade 20 at its outer end mounts a generally L-shaped bracket 24 carrying a U-shaped shoe or wishbone 26. Mounted on each leg of the wishbone is a floating contact 28. Each contact is mounted on the wishbone by means of a bolt 29 which extends through an enlarged hole in the respective leg of the Wishbone and is provided at its outer end with an adjusting nut which adjusts the spacing of the contact from the wishbone, and thus adjusts the spacing between the two contacts 28. Compression springs 30 bias the two contacts toward one another and normally maintain the two contacts in spaced generally parallel relation to one another, yet accommodate relative shifting and adjustment of the contacts to the position of a switch blade entering therebetween. As shown in the drawings, the contacts 28 are spaced axially outwardly from the free end of the stationary blade 20 and are disposed equal distances to opposite sides of the axis of the free end of said blade.

Each of the contacts 28 is preferably comprised of a unitary sheet of copper bent upon itself as indicated in FIGURE 5, and a wire braid 32 is confined between the base or inner end portions of the two plys of each contact, The wire braid extends between the respective contact and the blade 20 at the point where the bracket 24 is secured to the blade, thereby to establish direct, substantially straight or in-line electrical connection between the blade 20 and each of the contacts 28. To space the two braids from one another so that they do not interfere with entry of the movable blade 22 between the contacts 28, spaced projections 34 extend laterally from the bracket 24 between the two braids 32.

The movable blade 22 of the switch is flattened at its free end in a conventional manner for entry between and high pressure contact engagement (as determined by the springs 30) with the two contacts 28. In the closed position of the switch, as shown in FIGURES 1 and 3, the

blades

20 and 22 are disposed in axial alignment and the contacts 28 and braids 32 provide an in-line current path through the switch, which is an important factor in switches of the general character, serving to enhance switch operation and improve the current transfer characteristics thereof.

The apparatus thus far described constitutes the disconnect switch portion of the illustrated load break switch, the movable blade 22 being arcuately swingable about the axis of the insulator 16 into the contacts 28 and being arcuately swingable to a position spaced substantially from said contacts, as indicated by the left-hand dotted line representation in FIGURE 2, thereby to establish a large, circuit-opening air gap between the line conductors connected to the

blades

20 and 22.

The interrupting means incorporated in the switch assembly is of a type known in the art as the quickwhip. It comprises a relatively stiff but nevertheless flexible or resilient wire whip 38 secured to the stationary blade 20 and extending thereabove for cooperation with an arcing horn 36 carried by the movable blade 22. When the movable blade is opened, the horn 36 thereon engages the quick-whip wire 38 and carries the same with the movable blade by virtue of flexing or other movement of the resilient whip. Then, when the movable blade 22 is sufficiently separated from the stationary contacts 28 as to mitigate occurrence of arcing between the blade and the contacts (as indicated by the intermediate dotted line representation in FIGURE 2), the horn 36 releases the whip 38 whereupon the whip, due to its resiliency and stressed condition, returns rapidly to its initial position with respect to the stationary contacts 28 to perform a quick break or high speed interrupting function relative to the electric circuit. A

The horn 36 on the movable blade is generally constituted as shown in FIGURE 3. It comprises two wires or legs defining a quick-whip engaging portion therebetween, one of the legs simply being flared outwardly at its outer end and the other similarly flaring out but being turned back on itself and across the space between the two wires thereby to define a member 37 for trapping the whip between the two wires of the horn 36. Specifically, as the horn 36 moves toward the whip wire 38, the flared portion of the right-hand horn wire 36a engages the quickwhip wire and is biased outwardly thereby as the movable blade is moved toward closed position. The trapping portion 37 is set at about the same angle as the flare of the horn wire or leg 36a whereby it too is forced or flexed laterally outward to permit relative inward passage of the whip 38, whereby the whip becomes trapped between the two wires or legs of the horn 36 and the portion 37 thereof. Then, as the horn 36 is subsequently moved away from the whip, the whip is caused to follow the movement of the horn due to the placement of the trapping member 37.

According to the present invention, the whip 38 is generally of L-shape and includes a base leg 38a and a whip leg 38b. The base leg is secured to one end directly to the stationary blade 20, as indicated at 40. The leg then extends generally parallel to the bracket 24 through a bearing 42 adjacent the outer end of the bracket for guidance of the horizontal or base leg of the whip. I The wire then extends upwardly and outwardly transversely of the stationary contact assembly, as shown particularly in the end view of FIGURE 2, to form the whip leg 38b.

As a consequence of the mounting of the whip, the hori- -zontal or base leg thereof is loaded in torsion when the horn 36 compels the upright or whip leg of the wire to follow the movement of the movable blade 22. The resultant torsional loading of the base leg 38a, in combination with partial bending of the whip leg 38b as' depicted in dotted lines in FIGURE 2, results in application of a 4- return force of substantial magnitude without undue strain on the whip, whereby the same has a high speed action and long service life.

When the Whip leg 38b is released by the horn 36, it returns rapidly by virtue of its torsional loading toward its initial position with respect to the stationary contacts. If the whip were permitted to swing freely, or if it struck simply against a stop, the same would rebound back toward the movable blade 22, with the danger that an arc would be struck between the two

horns

36 and 38, thereby mitigating the intended purpose of the whip. According to the present invention, this disadvantage is prevented by provision of dampening means which converts the forces tending to cause to whip to oscillate or rebound toward the blade into forces at right angles thereto (i.e., parallel to the blade 20) whereby the whip may dissipate its momentum in the plane of the blade 20 without moving back toward the blade 22. The dampening means consists simply of a rod 44 (see FIGURE 3) fixedly secured to or formed integrally with the bracket 24 and wishbone 26 and extending into the path of movement of the whip leg 38b. The outer end of the rod 44 is inclined upwardly so as to engage the whip at the highest possible point thereon and forwardly of the end position accommodated by the rod for the wire or whip. The upright leg of the whip is so positioned that the same normally strikes the rod 44 at point A (FIG- URE 3), but the torsion load on the whip is such as to cause the whip leg 38b to flex in the direction parallel to the

blades

20 and 22 whereby the whip leg slides downwardly along the inclined surface of the rod 44 to engage in position B within a recess defined by the rod 44. By virtue of this lateral movement, the rebounding tendency of the whip is translated from a direction transverse to the blade 20 to a direction parallel to the blade 20 whereby the whip leg will vibrate in a plane parallel to the blade 20 and does not tend to move in a direction transverse to the blade, i.e., a drection wherein it moves back toward the movable blade 22.

From the foregoing description, it will be appreciated that the present invention provides an improved load break switch characterized by the combined and individual virtues of the in-line current transfer of the disconnect switch and the torsionally loaded and operated quick whip. These features, individually and in combination, enhance switch performance and operation and provide a reliable structure of low cost and long service life. Accordingly, all of the objects and advantages of the invention have been shown herein to be attained in a convenient, economical and practical manner.

While we have shown and described what we regard to be the preferred embodiment of our invention, it will be appreciated that various changes, rearrangements and modifications may be made therein without departing from the scope of the invention, as defined by the appended claims.

We claim:

1. In a switch of the character described, a pair of switch blades having free ends relatively arcuately movable away from one another to switch open position and toward one another to switch closed position, the free ends of said blades being in spaced axial alignment in closed position, a generally L-shaped bracket projecting structure mounted on said bracket and projecting there from into spaced axial alignment with the free end of said one blade and into the path of relative movement of the free end of said other blade, said contact structure comprising a pair of spaced contacts extending trans- -versely of the free end of said one blade to opposite sides of the axis thereof, and conductor braid extending substantially in a straight line between each of said contacts and the free end of said one blade.

2. In a switch as set forth in claim 1, projection means on said bracket extending transversely of said braids intermediate the free end of said one blade and said contacts for maintaining said braids spaced apart to facilitate entry between said contacts of the free end of said blade.

3. In a switch of the character described, a pair of switch blades having free ends relatively arcuately mov able away from one another to switch open position and toward one another to switch closed position, the free ends of said blades being in spaced axial alignment in closed position, a bracket projecting laterally from and forwardly beyond the free end of one blade to the side thereof opposite the side to which the other blade moves relative to the one blade, a wishbone on the outer end of said bracket including spaced legs extending transversely to opposite sides of the free end of said one blade, a spring pressed contact floatingly mounted on each leg of said wishbone, said contacts extending transversely of the free end of said one blade into spaced axial alignment with said end and into the path of relative movement of the free end of said other blade, and conductor means extending substantially in a straight line between said contacts and the free end of said one blade.

4. In a switch of the character described, a pair of switch blades having free ends relatively arcuately movable away from one another to switch open position and toward one another to switch closed position, the free ends of said blades being spaced longitudinally from one another in closed position, a generally L-shaped bracket projecting laterally from and forwardly beyond the free end of one blade to the side thereof opposite the side to which the other blade moves relative to the one blade, a wishbone on the outer end of said bracket including spaced legs extending transversely to opposite sides .of the free end of said one blade, a spring-pressed contact floatingly mounted on each leg of said wishbone, said contacts extending in spaced axially aligned transverse relation to the free end of said one blade at opposite sides of the axis thereof and into the path of relative movement of the free end of said other blade, conductor braid extending substantially in a straight line between each of said contacts and the free end of said one blade, and a pair of spaced projections on said bracket extending transversely of said braids intermediate the free end of said one blade and said contacts for maintaining said braids spaced apart.

5. In a switch having separable main contacts and a quick break attachment of the whip type, the improvement comprising a whip of generally L-shape having a whip leg disposed transversely of the plane of relative movement of the main contacts and a base leg disposed parallel to said plane and anchored at its free end, and means journalling said base leg for rotational movement adjacent its opposite end for loading said base leg in torsion upon relative separating movement of the main contacts.

6. In a switch having separable main contacts and a quick break attachment of the whip type, the improvement comprising a whip of generally L-shape having a whip leg disposed transversely of the plane of relative movement of the main contacts and a base leg disposed parallel to said plane and anchored at its free end on one of said contacts, means on said one contact journalling said base leg for rotational movement adjacent its opposite end, and an arcing horn on the other contact comprising spaced parallel resilient legs including outwardly divergent end portions and a trapping portion normally bridging between the two legs adjacent the bases of said divergent portions, the legs of said horn being engageable with said whip leg upon relative closing movement of the main contacts and being laterally deflectable thereby to cause said whip leg to be trapped between the two legs and said trapping portion of said born when the contacts are closed.

7. In a switch having a pair of separable main contacts, a quick break attachment of the whip type comprising a conductive whip on one contact of generally L-shape including a base leg extending parallel to the plane of relative separating movement of the contacts and a whip leg disposed transversely of said plane, said base leg being anchored at its free end to the one contact, means journalling the opposite end of said base leg on said one contact, and an arcing horn on the other contact engaging said whip leg when the contacts are engaged and including means for relatively pulling said whip leg with it during the initial stages of relative separating movement of said contacts, whereby said base leg is loaded in torsion, said arcing horn disengaging from said whip leg when the contacts are relatively separated to a predetermined extent whereupon said whip leg is rapidly returned to its initial position due to the torsional loading of said base leg.

8. In a switch of the character described, a pair of switch blades having free ends relatively arcuately movable away from one another to switch open position and toward one another to switch closed position, the free ends of said blades being spaced longitudinally from one another in closed position, a bracket projecting laterally from and forwardly beyond the free end of one blade to the side thereof opposite the side to which the other blade moves relative to the one blade, a contact structure mounted on said bracket and projecting therefrom into axial alignment with the free end of said one blade and into the path of relative movement of the free end of said other blade, conductor means extending substantially in a straight line between said contact structure and the free end of said one blade, a generally L-shaped whip mounted on said one blade and said bracket, said whip including an elongate base leg paralleling the free end portion of said one blade and a Whip leg projecting outwardly from said one blade adjacent and transversely of said contact structure, said base leg being secured adjacent its free end to said one blade and being journalled adjacent its opposite end in said bracket, and an arcing horn on the free end of said other blade engaging said whip leg when said other blade is engaged in said contact structure and including means for relatively pulling said whip leg with it during the initial stages of relative movement of said blades away from one another.

9. In a switch of the character described, a pair of switch blades having free ends relatively arcuately movable away from one another to switch open position and toward one another to switch closed position, the free ends of said blades being in spaced axial alignment in closed position, a bracket projecting laterally from and forwardly beyond the free end of one blade to the side thereof opposite the side to which the other blade moves relative to the one blade, a Wishbone on the outer end of said bracket including spaced legs extending transversely to opposite sides of the free end of said one blade, a spring pressed contact floatingly mounted on each leg of said wishbone, said contacts extending transversely of the free end of said one blade into spaced axial alignment with said end and into the path of relative movement of the free end of said other blade, conductor means extending substantially in a straight line between said contacts and the free end of said one blade, a generally L-shaped Whip mounted on said one blade and said bracket, said whip including an elongate base leg paralleling the free end portion of said one blade and a whip leg projecting outwardly from said one blade adjacent and transversely of said contacts, said base leg being secured adjacent its free end to said one blade and being journalled adjacent its opposite end in said bracket, an arcing horn on the free end of said other blade engaging said Whip leg when said other blade is engaged in said contact structure and including means for relatively pulling said whip leg with it during the initial stages of relative movement of said blades away from one another, and a snubber extending angularly outward from said bracket and wishbone into the path of return movement of said whip leg, said snubber including a portion in said path of return movement 7 inclined to said path and toward a recess in said snubber for converting the return movement of said whip leg into movement parallel to said one blade.

References Cited by the Examiner V UNITED STATES PATENTS 9/1932 Alsaker 200-48 8 F011 ZOO-'48 X Kelly 200-62 X Zemels et a1 200 48 Pahl 200-48 KATHLEEN H. CLAFFY, Primary Examiner.

ROBERT K. SCHAEFER, Examiner.

Claims

8. IN A SWITCH OF THE CHARACTER DESCRIBED, A PAIR OF SWITCH BLADES HAVING FREE ENDS RELATIVELY ARCUATELY MOVABLE AWAY FROM ONE ANOTHER TO SWITCH OPEN POSITION AND TOWARD ONE ANOTHER TO SWITCH CLOSED POSITION, THE FREE ENDS OF SAID BLADES BEING SPACED LONGITUDINALLY FROM ONE ANOTHER IN CLOSED POSITION, A BRACKET PROJECTING LATERALLY FROM AND FORWARDLY BEYOND THE FREE END OF ONE BLADE TO THE SIDE THEREOF OPPOSITE THE SIDE TO WHICH THE OTHER BLADE MOVES RELATIVE TO THE ONE BLADE, A CONTACT STRUCTURE MOUNTED ON SAID BRACKET AND PROJECTING THEREFROM INTO AXIAL ALIGNMENT WITH THE FREE END OF SAID ONE BLADE AND INTO THE PATH OF RELATIVE MOVEMENT OF THE FREE END OF SAID OTHER BLADE, CONDUCTOR MEANS EXTENDING SUBSTANTIALLY IN A STRAIGHT LINE BETWEEN SAID CONTACT STRUCTURE AND THE FREE END OF SAID ONE BLADE, A GENERALLY L-SHAPED WHIP MOUNTED ON SAID ONE BLADE AND SAID BRACKET, SAID WHIP INCLUDING AN