US3194905A - Operating means for high voltage disconnect switch - Google Patents

Description

July 13, 1965 F. w. JEWELL ETAL 3,194,905

OPERATING MEANS FOR HIGH VOLTAGE DISCONNECT SWITCH Filed July 26, 1962 2 Sheets-Sheet 1 u Fig.2. g 56 19 59 5 135 I 24mo o .iI-"( 0 0 7| \Uez 2 Fiq.l. 9 27 5o 69 l -Q. 79 2 7 LL E.

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.ms M |s-- l8 WITNESSES mVENTORS Francis W. Jewell John H. Miles, Jr

y 3, 1965 F. w. JEWELL ETAL 3,194,905

OPERATING MEANS FOR HIGH VOLTAGE DISCONNECT SWITCH Filed July 26, 1962 2 Sheets-Sheet 2 Fig. 4

United States Patent 3,194,905 OPERATING MEANS FOR HIGH VOLTAGE DISCGNNECT SWITCH Francis W. Jewell and John H. Miles, J12, Portland, 0reg., assignors to Westinghouse Electric Corporation, East Pittsburgh, Pa., a corporation of Pennsylvania Filed July 26, 1962, Ser. No. 212,538 Claims. (Cl. 200-48) This invention relates, generally, to electric switches and, more particularly, to disconnect switches having pivotal blades.

In a copending application of E. F. Beach and C. W. Upton, In, Serial No. 98,240, filed March 24, 1961, which issued Febraury 26, 1963, as US. Patent No. 3,079,474 and is assigned to the same asignee as the present application, there is described and claimed a disconnect switch of the pivotal blade type in which an adjustable slip joint is utilized in the operating toggle mechanism of the switch to maintain rotary and swinging movements of the switch blade sequentially separated so that contact between the blade and the switch jaws may be completely broken by rotating the blade about its longitudinal axis before the blade begins its swinging motion, thereby reducing the effort required to operate the blade. It has been found that the blade of a switch of the type described in the aforesaid copending application, particularly a long blade for high voltage service, has a tendency to bounce during closing of the blade.

An object of this invention is to improve the switch disclosed in the aforesaid copending application.

A more specific object of the invention is to prevent the pivotal blade of a disconnect switch from bouncing during operation of the blade.

Other objects of the invention will be explained fully hereinafter or will be apparent to those skilled in the art.

In accordance with one embodiment of the invention, a relatively light spring is so disposed between relatively movable members of a slip joint in the operating toggle mechanism of a pivotal blade disconnect switch that the biasing force of the spring prevents bouncing of the blade, but does not prevent positive pressure between the members when the toggle mechanism is in the fully closed position.

For a better understanding of the nature and objects of the invention, reference may be had to the following detailed description, taken in conjunction with the accompanying drawings, in which:

FIGURE 1 is a view, in side elevation, of a disconnect switch structure embodying the principal features of the invention;

FIG. 2 is a view, in top plan, of the switch structure shown in FIG. 1;

FIG. 3 is a detail view, partly in section and partly in elevation, of a portion of the toggle operating mechanism of the switch, the toggle members being in the over toggle or fully closed position; and

FIG. 4 is a view, similar to FIG. 3, showing the toggle members in the under toggle position.

Referring now to the drawings, and particularly to FIGS. 1 and 2, the structure shown therein comprises a disconnect switch assembly generally indicated by the reference character 10. The switch structure comprises three spaced insulator stacks 11, 12 and 13 which are mounted upon a metal base 14. Each insulator stack comprises a plurality of insulators 15 which are pref erably comprised of porcelain or similar material, the number of insulators per stack being optional depending upon the voltage of the system in which the switch is to be utilized. These stacks 11 and 12 are mounted upon fixed pedestals 16, 16 which may be secured to the top of the base 14. The stack 13 is fixedly mounted upon a shaft 17, the end of which is rotatably mounted in a bearing 18 which is secured to the base 14.

A crank 19 is attached to the shaft 17 in any suitable manner at a point below the insulator stack 13 and is adapted for connection to any conventional means for operating the crank to effect rotation of the shaft 17 about its longitudinal axis.

A shaft 20 is fixedly attached to and extends upwardly from the top portion of the insulator stack 13 to thus comprise a rigid extension of shaft 17. The upper end of shaft 21) comprises a crank arm 21 which extends generally at an angle substantially horizontal with respect to the base 14 and perpendicular with respect to the axis of rotation of combined shaft 1'7 and 29.

The outer end of the crank arm 21 is forked at 22, 22, the fork elements 22, 22 being vertically aligned and apertured to receive a pin 24 upon which is received a ball 25 positioned between the fork elements 22, 22.

An eye bolt 26 is attached for universal movement with respect to the arm 21 by means of an aperture 27 at one end thereof, the aperture having an internal contour slidably mating in socket relationship with the ball 25. As shown most clearly in FIGS. 3 and 4, the other end of the bolt 26 is slidably disposed for longitudinal movement within a first bore 28 in one end of a forked link member 29 and a second bore 30 in link extension 31. The bores 28 and 30 are aligned by means of an integral bridging member 32 fixedly spacing the link extension 31 with respect to the link 29 so as to form a cavity 4 having an open side defined by a peripheral lip 5.

An adjusting nut 33 is threadedly disposed on a threaded portion 34 of the bolt 26 located intermediate its ends, and at the same time, the nut 33 is positioned within the cavity 4. The length of the nut along the bolt 26 is less than the breadth of the cavity for permitting predetermined limited longitudinal sliding motion between the bolt 26 and the link 29 which thus cooperate to comprise a slip joint 6 having its limits of movement defined by the vertical sides of the cavity 4. A notched flange 54 is provided on the end of the nut 33 adjacent the link extension 31. A pin 61 is disposed in one of the notches on the flange 54. The pin 61 is aligned parallel with the bores 28 and 30 and removably secured by any suitable means through suitable apertures in peripheral lip 5 of cavity 4. The pin 61 may be removed to permit adjustment of the nut 33 on bolt 26, whereafter replacement of the pin permits limited rotational movement of the nut with respect to bolt 26, but at the same time permits free movement of the nut 33 across the cavity as the slip joint 6 operates. A cap 64 covers the cavity 4 to protect the slip joint 6 from the elements. The slip joint 6 is so arranged that rotation of the crank arm 21 in response to operation of crank 19 provides for effectively lengthening the link 29 within definitely prescribed limits for substantially separating rotary and swinging movement of a blade 44 in a manner that will be apparent hereinafter.

In order to prevent bouncing of the blade 44 during closing of the switch, a relatively light compression spring 121 is disposed around the neck of the nut 33 between the flange 54 and the link member 29. The functioning of the spring will be described more fully hereinafter.

The forked link 29, shown in FIGS. 1 and 2, includes a pair of arms 35, 35 at the end opposite the slip joint 6, each of the arms terminating in an aperture 37 in mating relationship with a pin 39 which passes through the openings 37, 37 and opneings 40, 40 in a blade crank 3 42 which is integral with a tubular blade crank 43. The tubular switch blade 44 is fixed within the crank 43 and is rotatable therewith when the crank 42 is operated in response to the operation of the link 29 in a manner to be described in detail hereinafter.

The blade 44 is mounted for axial rotation within a pair of spaced aligned bearings one of which is mounted in a hinge casting 48 and the other of which is mounted in a hinge casting extension 49 which is attached to and spaced from the casting 4-8 by means of a pair of sub stantially parallel integral bridge members 5% 50, only one of which is shown in FIGURE 1. The blade crank 42 is carried between the bearings for the blade 44 in abutting relationship therewith so that operation of the crank 42 provides free rotation of the blade 44 about its longitudinal axis, but prevents any longitudinal motion of the blade 44 with respect to the hinge casting 48.

The hinge casting 48 is pivotally supported by a pair of bearings which are fixed in opposite sides of the hinge casting 48 and extend through the sides of the casting. The bearings in the hinge casting 48 are aligned with threaded openings in a pair of spaced arms 55, 56 on a hinge support member 57. A pair of threaded pivot studs 58, 59 extend through the openings in the spaced arms 55, 56 respectively, and engage the bearings in the hinge casting 48 to provide a pivotal relationship between the casting 48 and the bearing support 57. The pivot 58 is comprised of electrically conducting material. Lock nuts 60, 60 are provided on the studs 58, 59 for retaining the studs in their properly adjusted position in the arms 55, 56.

As shown most clearly in FIGURE 2, the outer end of the tubular blade 44 is flattened as at 62 to provide suitable contact portions 63 engageable with contacts 65 on a fixed contact jaw 67. The fixed contact jaw 67 is of the reverse loop type having the characteristic of magnetically forcing the blade of a disconnect switch downwardly between the loops in a direction toward the base junction of the loop and against a blade stop 73 in response to momentary high currents. The jaw 67 may be composed of zirconium-copper, which, when heat treated, combines very high conductivity with excellent spring characteristics. The contact jaw 67 is fixedly attached to an insulator cap 69 by any suitable means, such as bolts (not shown). A terminal strap 71 is fixedly attached intermediate its ends to the insulator cap 69 by means of the aforesaid bolts. One end 72 of the terminal strap is a connector for connecting the disconnect switch in a circuit. The other end of the strap 71 is the stop 73 extending substantially perpendicular to the body of strap 71 and terminating at a point adjacent the contacts 65, 65 on the contact jaw 67 for engaging the blade 44- in the contact making position as shown in FIGS. 1 and 2. The insulator cap 69 is an integral part of the insulator stack 11. A terminal casting 74 is provided to complete connection of the disconnect switch in a circuit, and includes a terminal strip 75 at the outer side Wall, a pair of vertically aligned oppositely disposed apertures 76, 76 in the top and bottom walls of the casting for receiving the previously described shaft 20 which extends vertically therethrough, and a flange opening 78 on the inner wall for receiving one end of a tubular'conductor 79, preferably comprised of copper or otherelectrical conduct.- ing material.

The tubular conductor 79 also serves as a housing for a counter-balancing mechanism fully described in the aforesaid copending application. The other end of the tubular conductor '79 is fixedly attached to a flanged.

opening 35 in one end of the previously described hinge support 57 for connecting the hinge support and other In describing the operation of the switch blade opening and closing mechanism as thus far described, it is assumed that the switch blade is closed with the flat end of the blade horizontally positioned in engagement with the jaws 67 of the fixed contact means and in engagement withthe blade stop 73. Under these conditions, the toggle mechanism comprised of link 29, slip joint 6, bolt 26, ball 25, socket 27 and crank arm 21, is in an overtoggle position, as shown in FIGURE 2.

The overtoggle position of the mechanism when the switch is closed causes the flattened end of the blade 44 to be in full engagement with the fixed jaws 67. When the arm 21 is rotated counterclockwise as viewed from the top in FIGURE 2, the toggle mechanism moves through the dead center position to an undertoggle position to effect opening of the disconnect switch.

Just before the toggle mechanism is in the overtoggle position, the nut 33 in slip joint 6 is nearly abutting the end of the link 29, but is spaced slightly from the end of link 29 allowing the blade 44 to rest upon the step 73. As the toggle mechanism moves through the dead center position, the bolt 26 is permitted to slide longitudinally within the bores 28 and 30 to effectively shorten link 29 to permit the toggle mechanism to pass through the dead center position. At the dead center position, the nut 33 abuts the end of link 29 as shown in crosssection in FIGURE3. It is seen that in the overtoggle condition, the space between nut 33 and the end of link 29 introduces as mall amount of play in the linkage between the blade 44 and the arm 21. The reverse loop jaws 67 hold the blade 44 in the closed position in response to high faultcurrents, thus eliminating any necessity for any additional elements in the toggle mechanism to eliminate the play in the linkage.

The further rotation of the arm 21 toward the undertoggle position from the dead center position effects a lengthening of link 21 through the operation of slip joint 6 wherein bolt 26 slides longitudinally in bore 30 on extension 31 and in bore 28 on link 29 until the adjusting nut 33 abuts the end of extension 31. It is seen that the lengthening of link 29 through the operation of slip joint 6 eliminates any longitudinal pull on link 29 as arm 21 rotates, but transmits lateral force applied by arm 21 to bolt 26 so that the link 29 provides a lateral force on crank 42 to rotate blade 44 in hinge member 48 to effect disconnection between the blade 44 and contact jaws 67.

Thereafter, continued movement of the arm 21 carries nut 33 into engagement with theinner end of link extension 31, thus preventing further lengthening of the link 29 so that continued movement of arm 21 provides a longitudinal pull on link 29, which force is transmitted to pin 39 and crank 42 to swing blade 44 and hinge 48 upwardly about pivot pins 58, 59 until the blade is in a parts of the structure in circuit relationship with the substantially vertical position.

To close the disconnect switch, the crank arm 21 is moved in a clockwise direction, thus swinging the blade 44 between the jaws 67 where it engages the stop 73. As explained hereinbefore, the spring 1249 is provided in the slip joint 6 to prevent bouncing of the switch blade when it engages the'stop 73. When the switch blade 44 first engages the stop 73 the members of the slip joint 6 are in the relative positions shown in FIGURE 4. The righthand end of the nut 33 engages the link extension 31, and the spring 129 which is disposed between the flange 54 on the nut 33 and the link 29 prevents bouncing of the blade 44 by preventing the link 29 from moving relative to the nut 33 and the bolt 26. However, Whenthe switch blade is in the closed position and the toggle mechanism is in the overto'ggle position as shown in FIG. 3, the spring is compressed and the nut 33 engages the link 29 to apply positive pressure on the link 29 through the toggle .mechanis'm. The nut 33 should be so adjusted that when the switch blade is closed the spring 126 is fully compressed and positive pressure is applied on the link 29 when the toggle mechanism is in the overtoggle closed position.

When the switch blade is opened the nut 33 engages the link extension 31 and the spring 120 is expanded to take up any lost motion between the bolt 26 and the link 29. Thus, the spring 120 aids in forcing the blade 44 to remain in the proper open position.

As explained hereinbefore, further rotation of the crank arm 21 after the switch blade 44 engages the stop 73 effects movement of the toggle linkage through the center and to the overtoggle position whereupon extension of slip joint 6 occurs so that the fiat end of the blade 44 is rotated into engagement with the fixed contact jaws 67 while the blade itself rests on stop 73. In this manner the switch blade is actuated to its fully closed position.

From the foregoing description it is apparent that the invention provides for preventing the bouncing of a pivotal switch blade during operation of the switch without interfering with the sequential operation of the rotary and swinging movements of the blade. The mechanism herein described is simple in construction and efl-lcient in operation. It may be economically manufactured and installed.

Since numerous changes may be made in the above described construction and difierent embodiments of the invention may be made without departing from the spirit and scope thereof, it is intended that all the matter contained in the foregoing description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limiting sense.

We claim as our invention:

1. In an electric switch, in combination, a crank arm rotatable about a fixed axis, stationary contact means spaced from said axis, stop means adjacent said contact means, a switch blade mounted for swinging into engagement with the stop means about an axis fixed between said contact means and said crank arm axis and lying in a plane at right angles to the crank arm axis, said blade being rotatable about its longitudinal axis to engage said contact means when the blade is in engagement with said stop means, an arm fixed on said blade, toggle means connecting said blade arm to said crank arm and including a slip joint comprising a pair of members mounted for relative axial movement within predetermined limits and pivotally connected respectively to the blade arm and the crank arm for swinging the blade during part of the rotary movement of said crank arm until the free end of the blade engages the stop means, adjustable means on one of said members for engaging the other member to determine the limits of relative movement between the members, resilient means disposed between said adjustable means and said other member of said members to prevent bouncing of the blade when it engages the stop means, and said resilient means permitting the adjustable means to directly engage said other member during a further portion of the rotary motion of the crank arm to thereby rotate the blade about its longitudinal axis.

2. In an electric switch, in combination, a crank arm rotatable about a fixed axis, stationary contact means spaced from said axis, stop means adjacent said contact means, a switch blade mounted for swinging into engagement with the stop means about an axis fixed between said contact means and said crank arm axis and lying in a plane at right angles to the crank arm axis, said blade being rotatable about its longitudinal axis to engage said contact means when the blade is in engagement with said stop means, an arm fixed on said blade, toggle means connecting said blade arm to said crank arm and including a slip joint comprising a pair of members mounted for relative axial movement within predetermined limits and pivotally connected respectively to the blade arm and the crank arm for swinging the blade during part of the rotary movement of said crank arm until the free end of the blade engages the stop means, adjustable means threaded on one of said members for engaging the other member to determine the limits of relative movement in opposite directions between the members, spring means disposed between said adjustable means and said other member of said members to prevent bouncing of the blade when it engages the stop means, and said spring means permitting the adjustable means to directly engage said other member during a further portion of the rotary motion of the crank arm to thereby rotate the blade about its longitudinal axis.

3. In an electric switch, in combination, a crank arm rotatable about a fixed axis, stationary contact means spaced from said axis, stop means adjacent said contact means, a switch blade mounted for swinging into engagement with the stop means about an axis fixed between said contact means and said crank arm axis and lying in a plane at right angles to the crank arm axis, said blade being rotatable about its longitudinal axis to engage said contact means when the blade is in engagement wtih said stop means, an arm fixed on said blade, toggle means connecting said blade arm to said crank arm and including a slip joint comprising a pair of members mounted for relative axial movement within predetermined limits and pivotally connected respectively to the blade arm and the crank arm for swinging the blade during part of the rotary movement of said crank arm until the free end of the blade engages the stop means, an adjustable nut threaded on one of said members for engaging the other member to determine the limits of relative movement between the members, said nut having a neck portion and a flange portion, a spring surrounding the neck portion between the flange portion and the other member to prevent bouncing of the blade when it engages the stop means, and said spring permitting the nut to directly engage said other member during a further portion of the rotary motion of the crank arm to thereby rotate the blade about its longitudinal axis.

4. In an electric switch, in combination, a crank arm rotatable about a fixed axis, stationary contact means spaced from said axis, stop means adjacent said contact means, a switch blade mounted for swinging into engagement with the stop means about an axis fixed between said contact means and said crank arm axis and lying in a plane at right angles to the crank arm axis, said blade being rotatable about its longitudinal axis to engage said contact means when the blade is in engagement with said stop means, an arm fixed on said blade, toggle means connecting said blade arm to said crank arm and including a slip joint comprising a pair of members mounted for relative axial movement within predetermined limits and pivotally connected respectively to the blade arm and the crank arm for swinging the blade during part of the rotary movement of said crank arm until the free end of the blade engages the stop means, an adjustable nut threaded on one of said members for engaging the other member to determine the limits of relative movement between the members, said nut having a neck portion and a flange portion, a spring surrounding the neck portion between the flange portion and the other member to prevent bouncing of the blade when it engages the stop means, said spring permitting the nut to directly engage said other member during a further portion of the rotary motion of the crank arm to thereby rotate the blade about its longitudinal axis, and notches in said flange portion for adjusting the position of said nut on said one member.

5. An electric switch, comprising, a crank arm rotatable about a fixed axis, stationary contact means spaced from said axis, stop means adjacent said contact means, a switch blade mounted for swinging into engagement with the stop means about an axis fixed between said contact means and said crank arm axis and lying in a plane at right angles to the crank arm axis, said blade being rotatable about its longitudinal axis to engage said contact means when the blade is in engagement with said stop means, an arm fixed on said blade, toggle means connecting said blade arm to said crank arm and including a slip joint comprising a pair of members mounted for rela tive axial movement within predetermined limits and pivotally connected respectively to the blade arm and the crank arm for swinging the blade during part of the rotary movement of said crank arm until the free end of the blade engages the stop means, an adjustable nut threaded on one of said members for engaging the other member to determine the limits of relative movement between the members, said nut having a neck portion and a flange portion, a spring surrounding the neck portion between the flange portion and the other member to prevent bouncing of'the'blade when it engages the stop means, said spring being compressed to permit the neck portion of the nut 8 to directly engage the other member when the toggle means is adjacent to an overtoggle position when the switch blade is closed, and said spring being expanded when the toggle means is in an undertoggle position and the switch blade is open.

References Cited by the Examiner UNITED STATES PATENTS 3,047,685 7/62 Sciscione 20048 BERNARD A. GILHEANY, Primary Examiner.

ROBERT K. SCHAEFER, Examiner.

Claims (1)

1. IN AN ELECTRIC SWITCH, IN COMBINATION, A CRANK ARM ROTATABLE ABOUT A FIXED AXIS, STATIONARY CONTACT MEANS SPACED FROM SAID AXIS, STOP MEANS ADJACENT SAID CONTACT MEANS, A SWITCH BLADE MOUNTED FOR SWINGING INTO ENGAGEMENT WITH THE STOP MEANS ABOUT AN AXIS FIXED BETWEEN SAID CONTACT MEANS AND SAID CRANK ARM AXIS AND LYING IN A PLANE AT RIGHT ANGLES TO THE CRANK ARM AXIS, SAID BLADE BEING ROTATABLE ABOUT ITS LONGITUDINAL AXIS TO ENGAGE SAID CONTACT MEANS WHEN THE BLADE IS IN ENGAGEMENT WITH SAID STOP MEANS, AN ARM FIXED ON SAID BLADE, TOGGLE MEANS CONNECTING SAID BLADE ARM TO SAID CRANK ARM AND INCLUDING A SLIP JOINT COMPRISING A PAIR OF MEMBERS MOUNTED FOR RELATIVE AXIAL MOVEMENT WITHIN PREDETERMINED LIMITS AND PIVOTALLY CONNECTED RESPECTIVELY TO THE BLADE ARM AND THE CRANK ARM FOR SWINGING THE BLADE DURING PART OF THE ROTARY MOVEMENT OF SAID CRANK ARM UNTIL THE FREE END OF THE BLADE ENGAGES THE STOP MEANS, ADJUSTABLE MEANS ON ONE OF SAID MEMBERS FOR ENGAGING THE OTHER MEMBER TO DETERMINE THE LIMITS OF RELATIVE MOVEMENT BETWEEN THE MEMBERS, RESILIENT MEANS DISPOSED BETWEEN SAID ADJUSTABLE MEANS AND SAID OTHER MEMBER OF SAID MEMBERS TO PREVENT BOUNCING OF THE BLADE WHEN IT ENGAGES THE STOP MEANS, AND SAID RESILIENT MEANS PERMITTING THE ADJUSTABLE MEANS TO DIRECTLY ENGAGE SAID OTHER MEMBER DURING A FURTHER PORTION OF THE ROTARY MOTION OF THE CRANK ARM TO THEREBY ROTATE THE BLADE ABOUT ITS LONGITUDINAL AXIS.

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