US3875355A - Disconnect switch - Google Patents

Abstract

A high voltage disconnect switch in which the hinged member pivotally supporting the switch blade is composed of aluminum alloy, the sleeve for rotating the blade is composed of copper alloy with copper alloy conductors on opposite sides of the contact surface of the sleeve, and the circuit through the switch passing through the sleeve and conductors rather than through the hinged member.

Description

[ Apr. 1,1975

United States Patent [191 Frink et al.

3 299 240 1/1967 200/48 A 3,566,056 2/1971 Joseph et 200/48 R P Primary Eraminer-Robert K. Schaefer Assislan! E.\'aminerM. Ginsburg [73] Assignee: Westinghouse Electric Corporation, Attorney, Agent or Johns Pittsburgh, Pa.

Sept. 11, 1973 Appl. No.: 396,163

ABSTRACT A high voltage disconnect switch in which the hinged [22] Filed:

[52] U S Cl 200/48 A member pivotally supporting the switch blade is com- [511 In. .Cl 01h 31/00 posed of aluminum alloy, the sleeve for rotating the 200/48 R, 48 P1, 48 A 200/48 KB, 48 CB, 48 V, 48 SB blade is composed of copper alloy with copper alloy [58] Field of Search.............

conductors on opposite sides of the contact surface of the sleeve, and the circuit through the switch passing through the sleeve and conductors rather than through the hinged member.

2830 l44 Fjcllstcdt 200/48 A 8 Claims, 6 Drawing Figures Pi-EIENTEUAPR H975 SHZET 1 [IF 3 DISCONNECT SWITCH CROSS REFERENCE TO RELATED APPLICATIONS This invention is related to those disclosed in the applications of Russell E. Frink and Stanislaw A. Milianowicz, Ser. No. 469.5 86, filed May 13. 1974, Ser. No. 469.931. filed May 14, 1974. and Ser. No. 468,332. filed May 8, 1974.

BACKGROUND OF THEINVENTION 1. Field of the Invention This invention relates to disconnecting switches and, more particularly, to rotating conducting structures which form part of such switches.

2. Description of the Prior Art Disconnect switches of various types are disclosed in US. Pat. Nos. 3.201.535, 3.240.887, 3,243,561, 3,366.753, and 3,544,742. A disadvantage of most disconnect switches is that they are fabricated from copper alloys which are costly and relatively heavy. As shown in Patent No. 3.544.742. disconnect switches are currently being fabricated with copper and aluminum parts. because aluminum is less costly and lighter than copper. However. other problems have been incurred with aluminum. That is particularly true where the disconnect switch is used outdoors and subject to varying weather conditions. Ordinarily, aluminum oxidizes readily in air; but in wet weather, it enters into electrolytic action with copper. Thus, there has been a problem of corrosion and therefore of deterioration of electrical contact at joints between copper and aluminum parts.

SUMMARY OF THE INVENTION It has been found that the foregoing problem may be overcome by providing a disconnect switch comprising a pair of stationary contacts at spaced locations, a switch blade pivotally movable between open and closed positions with one of the stationary contacts, means for pivotally mounting the switch blade at a location spaced from one of the stationary contacts and comprising a stationary frame, the other stationary contact being electrically connected to the stationary frame. the stationary frame supporting a movable sleeve in which the blade is rotatably mounted, means rotating the blade in the sleeve when the blade is pivotally moved between the open and closed positions, conductors mounted on the stationary frame and positioned with respect to the movable sleeve for engagement and disengagement with the mounting sleeve when the blade is in the closed and open positions, respectively.

The advantage of the device of this invention is that electric current is not conducted through a hinge joint as in disconnect switches of prior construction, but rather the current is transmitted through moving copper contacts on which the contacting areas are plated or clad with silver to provide satisfactory contacting surfaces.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevational view of one pole of a three-pole disconnecting switch structure;

FIG. 2 is an enlarged plan view taken on the line 11-11 of FIG. 1;

FIG. 3 is a vertical sectional view taken on the line IIIIII of FIG. 2.

FIG. 4 is an end elevational view taken on the line IV-IV of FIG. 3;

FIG. 5 is a vertical sectional view of another embodiment of the invention, and

FIG. 6 is an end elevational view of the device shown in FIG. 5.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIG. I a disconnect switch is generally indicated at l0'and it comprises three spaced insulator stacks 12, 14 and 16 mounted upon acommon base support 18. Each of the insulator stacks l2, 14, 16 comprises a plurality of insulators which are preferably formed from porcelain or a similar material. Ashaft 20 is secured to the upper end of the insulator stack 14 and the assembly of the shaft and stack are rotated by an external operating mechanism (not shown) through a crank member oroperating lever 22.

At the upper end of the insulator stack 12 a terminal pad or stationaryterminal contact 24 is provided. Likewise. a terminal pad or stationary terminal contact 26 is provided at the upper end of the insulator stack 16. As shown in FIG. 1, astationary frame 28 is mounted at the upper end of the insulator stack 14 and the frame is spaced from thestationary contact 24 by aninsulator 30. Theinsulator 30 houses aninterrupter unit 32 which is not a part of this invention.

The disconnectingswitch 10 comprises aswitch structure 34 which includes a boom orblade 36 and ahinge structure 38. As viewed in FIG. 1, the right end of theblade 36 is in a closed position with respect to acontact jaw 40 which is an integral part of, or connected to, the stationary contact 26.

As shown more particularly in FIGS. 2, 3 and 4, theframe 28 comprises ayoke 42, a pair ofupturned flanges 44, and anaperture 46. Theyoke 42 provides means for pivotal mounting for a second orrotatable yoke 48 which is secured in theyoke 42 bypivot bolts 50. Thesecond yoke 48 comprises asleeve 52 in which a clamping or mountingsleeve 54 is rotatably mounted, for whichpurpose bushings 56 are provided and retained in place by asnap ring 58. Thebushings 56 may be of either conducting or insulating material.

As shown in FIG. 3, the left end portion of the boom orblade 36 is seated within themounting sleeve 54. The left end portion of theblade 36 includes a plurality of spacedradial slots 60 and anexpander 62 is located within the left open end thereof. Theexpander 62 includes a threadedaperture 64, abolt 66, and atapered plug 68. An inner surface portion is tapered so that upon tightening of thebolt 66 within theaperture 64 the'taperedplug 68 expands a plurality of split portions, such asportions 62a, 62b outwardly against the left end portion of theblade 36 and against the surrounding clamping or mountingsleeve 54. To help prevent rotational slipping of thecylindrical blade 36 within thecylindrical sleeve 54, a nut andbolt assembly 72 is provided therein.

As shown more particularly in FIG. 4, the outer surface of the left end portion of the clamping ormounting sleeve 54 has a substantially oval or elliptical crosssection with a horizontal axis, as indicated by thearrow 74, that is greater than the vertical axis, as indicated by thearrow 76. The arcuate surface portions of the surface at the ends of thelonger axis 74 are covered withsimilar claddings 78 of silver.

In addition, thesleeve 54 comprises anarm 80 which extends from the lower side thereof at an angle, such as about 45, and the lower end of the arm is rotatably mounted on the end ofarotator 82 through thebushing 115 which may be composed of electrically insulating or conducting material.Rotator 82 extends at a right angle from thearm 80 and at an angle of substantially 45 from a horizontal plane. A horizontal portion of therotator 82 has anaperture 84 and the rotator is secured by ascrew 86 to the upper end of theshaft 20 to which itis keyed at 87, whereby upon rotation of the lever 22 (FIG. 1), therotator 82 is turned.

As shown in FIGS. 2, 3 and 4, conductor means, such as a pair ofconductors 88 and 90, are mounted on eachflange 44 and extend upwardly and at an angle to positions on opposite sides of the clamping or mountingsleeve 54. Theconductors 88 and 90 have inturned portions88u and 90a (FIGS. 2 and 4) as well asupturned portions 88b and 901;. Eachconductor 88 and 90 is secured firmly on the correspondingflange 44 by abolt 92 and adowel pin 93 and is thereby held in position for engagement with the portions of thesleeve 54 covered by thesilver cladings 78. The contacting areas of theconductors 88 and 90 are also covered withsimilar claddings 94 of silver, where they contact thesleeve 54, and their ends which contact thealuminum flanges 44 are coated with tin to lessen the tendency for galvanic corrosion. By providing thesilver claddings 78 and 94, good electrical contact is maintained between thesleeve 54 and theconductors 88 and 90. For that purpose, theconductors 88 and 90 are spring-biased inwardly so that they engage the elongated axial portion of thesleeve 54, but do not engage the shorter axial portion when the boom orblade 36 is rotated.

In addition, to facilitate lowering and rotation of the boom orblade 36, a lever 96 (FIG. 2) is provided in conjunction with thesecond yoke 48. As shown in FIG. 2 when thearm 80 is moved from the broken line position (corresponding to the erect position of the boom 36) to the solid line position, the arm touches and moves thelever 96 in the clockwise direction whereby lowering of the boom orblade 36 is facilitated at least in the initial stage ofmovement and not left entirely dependent upon the rotation of theshaft 20.

The several parts of the device shown in FIGS. 1-4 which are composed of an aluminum base alloy include the boom orblade 36, theframe 28, and therotator 82. Those parts which are composed ofa copper base alloy include the clamping or mountingsleeve 54 including thearm 80, as well as the oval or elliptical contact surface, and theconductors 88 and 90.

Another embodiment of the invention is that shown in FIGS. and 6 in which similar reference numbers refer to similar parts as previously set forth above, such as the boom orblade 36, which is composed of aluminum. This embodiment differs from that described above in that arod 98 provides for the mounting of theblade 36 on the right end portion thereof by aperipheral weld 100. Therod 98 includes ashank portion 102, which is seated in thesleeve 52 where it is mounted with bushings andsnap ring 58 in a similar manner. Theleft end portion 104 of the sleeve includes a longitudinal slot 106 in which acontact 108 is seated withopposite end portions 108a and -l08b extending beyond the periphery of theportion 104. A plurality of spaced bolts 110 are provided in theportion 104 for holding thecontact 108 securely in place. Therod 98 also includes anarm 112 by which the rod and the attachedblade 36 are rotated and lifted in a manner similar to that of the embodiment disclosed in FIG. 3. Therod 98, including theportion 104 and thearm 112, is composed of aluminum-base alloy and thecontact 108 is composed of a copper-base alloy. Like the end portions of the oval or elliptical contact surface of thesleeve 54, theopposite end portions 108a and 1081; of thecontact 108 are covered with silver claddings similar to thesilver claddings 78 as shown in FIG. 4. Accordingly, thecontact 108, like the mountingsleeve 54, is adapted for opening and closing a circuit betweenterminal contacts 24 and 26 when therod 98 is rotated.

As shown best in FIG. 3 for both embodiments of the invention, a lubricant is preferably provided at the joint 114 between thesleeve 54 and thebushings 56 in order to expedite rotation of the assembly within thesleeve 52. In addition, an electrical conducting grease is located in a joint 116 between thesleeve 54 and the boom orblade 36 as well as at the joints between theflanges 44 and the conductors S8 and 90. The oxide inhibiting grease has the purpose of maintaining good electrical contact between thealuminum blade 36 and thecopper sleeve 54 by preventing the aluminum blade surface from being oxidized due to exposure to the atmosphere. Hence, a satisfactory electrical path between thesleeve 54 and theblade 36 is maintained.

In operation, the boom orblade 36 is raised or lowered between open and closed positions with respect to thecontact jaw 40 primarily by rotation of theshaft 20. Upon clockwise rotation, as indicated by the arrow 118 (FIG. 3) therotator 82 moves the arm in a clockwise direction, and the force applied thereby causes the assembly of thesleeve 54 and theblade 36 to rise about thepivot bolts 50 in theyoke 42. Therotator 82 continues to move to the left as viewed in FIG. 4 until it occupies the position shown by the broken line in FIG. 2, whereupon theblade 36 is elevated to the open position with respect to thecontact jaw 40, which position is substantially vertical. Conversely, rotation of theshaft 20 in the counterclockwise direction of the arrow 120 (FIG. 3) will cause theblade 36 to rotate and lower to the closed position with respect to thecontact jaw 40, whereupon therotator 82 is again located in the position shown in FIG. 4, namely, adjacent to therighthand flange 44.

In the closed position of the blade with respect to the jaw, a circuit between thestationary contacts 24 and 26 includes theconductor 32, theframe 28, theconductors 88 and 90, the elliptical or oval contact portion of thesleeve 54, theblade 36, and thecontact jaw 40. As was set forth above, when thesleeve 54 is rotated clockwise by thearm 80, the surface portions of thesleeve 54 at the extremities of thelonger axis 74 are retated out of contact with thecontactors 88a and a as the smaller portion of the sleeve is rotated into position between those conductor extremities.

Accordingly, the device of this invention provides so-- l. A disconnect switch comprising a pair of stationary contacts at spaced locations. a switch blade pivotally movable between open and closed positions with one of the stationary contacts. means for pivotally mounting the switch blade at a location spaced from one of the stationary contacts and comprising a stationary frame, the other stationary contact being electrically connected to the stationary frame, the stationary frame supporting a movable sleeve in which the blade is rotatably mounted, rotating means rotating the blade in the sleeve when the blade is pivotally moved between the open and closed positions, the rotating means comprising a rotatable sleeve in which the switch blade is disposed and which is rotatably mounted in the movable sleeve, a clamping sleeve within the switch blade for holding the switch blade in tight electrical contact with the rotatable sleeve, the outer surface of the rotatable sleeve having an oval cross-section, and conductor means mounted on the stationary frame and positioned externally of the clamping sleeve for engagement and disengagement with said oval cross-section of the rotatable sleeve when the blade is in the closed and open positions, respectively.

2. The disconnect switch ofclaim 1 in which the rotatable sleeve comprises a rotatable contact rotatable on the axis of the blade, the contact having long and short axis in a plane that is substantially normal to the blade, and the long axis engaging the conductor means when the blade is in the closed position with said one stationary contact.

3. The disconnect switch of claim 2 in which the conductor means comprises conductors disposed on opposite sides of the rotatable contact and engageable with the peripheral portions at the long axis of the contact and non-engageable with the peripheral portions at the short axis of the contact when the blade is in the open position with said one stationary contact.

4. The disconnect switch ofclaim 3 in which the peripheral portions of the rotatable Contact are covered with a cladding of silver and in which the portions of the conductor structures engageable with the rotatable contact are covered with a cladding of silver.

5. The disconnect switch ofclaim 1, in which the stationary frame comprises a first yoke, a second yoke rotatably mounted in the first yoke and comprising said movable sleeve, and the blade being rotatable in the sleeve on an axis substantially normal to the axis of rotation of the second yoke.

6. The disconnect switch of claim 5 in which the conductor means comprises conductors disposed on opposite sides of the rotatable sleeve. and the conductors and rotatable sleeve being composed of copper.

7. The disconnect switch of claim 6 in which the contacting areas of the rotatable sleeve and conductors means are covered with silver cladding.

8. The disconnect switch of claim 6 in which the joint between the engaging surfaces of the rotatable sleeve and the blade is coated with a conducting grease. and in which the rotatable sleeve is composed of a copper alloy and the blade is composed of an aluminum alloy.

Claims (8)

1. A disconnect switch comprising a pair of stationary contacts at spaced locations, a switch blade pivotally movable between open and closed positions with one of the stationary contacts, means for pivotally mounting the switch blade at a location spaced from one of the stationary contacts and comprising a stationary frame, the other stationary contact being electrically connected to the stationary frame, the stationary frame supporting a movable sleeve in which the blade is rotatably mounted, rotating means rotating the blade in the sleeve when the blade is pivotally moved between the open and closed positions, the rotating means comprising a rotatable sleeve in which the switch blade is disposed and which is rotatably mounted in the movable sleeve, a clamping sleeve within the switch blade for holding the switch blade in tight electrical contact with the rotatable sleeve, the outer surface of the rotatable sleeve having an oval cross-section, and conductor means mounted on the stationary frame and positioned externally of the clamping sleeve for engagement and disengagement with said oval cross-section of the rotatable sleeve when the blade is in the closed and open positions, respectively.

2. The disconnect switch of claim 1 in which the rotatable sleeve comprises a rotatable contact rotatable on the axis of the blade, the contact having long and short axis in a plane that is substantially normal to the blade, and the long axis engaging the conductor means when the blade is in the closed position with said one stationary contact.

3. The disconnect switch of claim 2 in which the conductor means comprises conductors disposed On opposite sides of the rotatable contact and engageable with the peripheral portions at the long axis of the contact and non-engageable with the peripheral portions at the short axis of the contact when the blade is in the open position with said one stationary contact.

4. The disconnect switch of claim 3 in which the peripheral portions of the rotatable contact are covered with a cladding of silver and in which the portions of the conductor structures engageable with the rotatable contact are covered with a cladding of silver.

5. The disconnect switch of claim 1, in which the stationary frame comprises a first yoke, a second yoke rotatably mounted in the first yoke and comprising said movable sleeve, and the blade being rotatable in the sleeve on an axis substantially normal to the axis of rotation of the second yoke.

6. The disconnect switch of claim 5 in which the conductor means comprises conductors disposed on opposite sides of the rotatable sleeve, and the conductors and rotatable sleeve being composed of copper.

7. The disconnect switch of claim 6 in which the contacting areas of the rotatable sleeve and conductors means are covered with silver cladding.

8. The disconnect switch of claim 6 in which the joint between the engaging surfaces of the rotatable sleeve and the blade is coated with a conducting grease, and in which the rotatable sleeve is composed of a copper alloy and the blade is composed of an aluminum alloy.

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