US3612790A

US3612790A - High-voltage electric switch having improved supporting base

Info

Publication number: US3612790A
Application number: US887498A
Authority: US
Inventors: Edmund W Kuhn
Original assignee: Westinghouse Electric Corp
Current assignee: CBS Corp
Priority date: 1969-12-23
Filing date: 1969-12-23
Publication date: 1971-10-12
Anticipated expiration: 1988-10-12
Also published as: JPS5128342B1

Abstract

A high-voltage electric switch comprising a plurality of spaced insulator stacks having a switch blade movably supported thereon and a contact jaw supported on one of the other insulator stacks and disposed in the path of movement of the switch blade. The insulator stacks are mounted on a common supporting base which includes a pair of generally parallel channel members and a pair of reinforcing members disposed between said channel members and spaced from the ends of said channel members.

Description

United States Patent [72] Inventor Edmund W. Kuhn Pittsburgh, Pa.

(21] Appl. No. 887,498

[22] Filed Dec. 23, 1969 [45] Patented Oct. 12, 1971 [73] Assignee Westinghouse Electric Corporation Pittsburgh, Pa.

[54] HIGH-VOLTAGE ELECTRIC SWITCH HAVING IMPROVED SUPPORTING BASE 8 Claims, 7 Drawing Figs.

[52] US. Cl 200/48 H0lh 31/00 Field of Search 200/48, 48 RP [5 6] References Cited UNITED STATES PATENTS 3,070,674 12/1962 Gusow 200/48 RP 3,284,590 5/1968 Hondalus 200/48 RP 3,316,366 4/1967 Silvy et al. 200/48 RP Primary Examiner-Herman J. Hohauser Att0meysA. T. Stratton and C. L. McI-Iale PATENTEDUCT 12 I971 SHEET 10F 2 HIGH-VOLTAGE ELECTRIC SWITCH HAVING IMPROVED SUPPORTING BASE BACKGROUND OF THE INVENTION This invention relates to high-voltage electric switches and, more particularly, to supporting base structures which form part of such switches.

In the construction of certain types of high-voltage switches such as polyphase or three-phase disconnecting switches, a plurality of pole units or switch units is mounted or supported on a common supporting structure in side-by-side relation. Each pole unit of such a switch normally includes a supporting base on which a plurality of spaced insulator stacks is mounted or secured with a switch arm or contact arm movably supported on one or more of the insulator stacks and a contact jaw supported on one of the other insulator stacks.

It has been found that in the operation of such a polyphase switch, when a short circuit or abnormal operating condition occurs in the electrical system in which the switch is connected, the supporting base of each pole unit of the switch is subjected to torsional or twisting stresses or forces due to the interacting effects between adjacent pole units.

In order to support each pole unit of such a polyphase switch both during normal and abnormal operating conditions such as that just indicated, various types of supporting base constructions have been proposed for such switches. One type of base structure which has been proposed for this type of switch includes a plurality of extruded aluminum structural members, such as described in U.S. Pat. No. 3,284,590. An important disadvantage of such a base structure is that it has been found to be prohibitive in cost. Another type of base structure which has been employed in polyphase switches of the type described includes a plurality of structural steel members and plates which are welded or bolted together, such as shown in U.S. Pat. No. 3,316,366 which issued Apr. 25, 1967 and is assigned to the same assignee as the present application. A base structure of the latter type has been found to have certain disadvantages in that it is relatively complicated in construction and requires a number of metal joining and forming operations to form a base structure having adequate resistance to the torsional stresses of the type described which may result during the operation of a polyphase or three-phase switch.

SUMMARY OF THE INVENTION In accordance with the invention, a high-voltage electric switch includes a switch blade or contact arm having one end movable into and out of engagement with an associated contact jaw. The switch blade and the contact jaw are supported on a plurality of spaced insulator stacks which are supported on and secured to a common supporting base. The base comprises a pair of elongated, metallic channel members, each of which includes a pair of spaced integral sidewall or flange portions connected by a bight portion. The channel members are disposed generally parallel to and spaced from one another with the corresponding sidewall or flange portions of the respective channel members projecting away from those of the other channel member in opposite directions. The base also includes a pair of reinforcing members disposed adjacent to and spaced from each of the opposite ends of the base. Each reinforcing member includes an elongated tubular member which is disposed between and generally parallel to the associated channel members. The tubular member is preferably circular in cross section and is formed from a metallic material which is preferably steel.

Each reinforcing member also includes a pair of generally rectangular metallic plates which are disposed between and generally transversely with respect to the associated channel members and which are secured to the opposite ends of the associated tubular member. The pair of plates of each reinforcing member are also secured at the opposite sides thereof by suitable means, such as welding, to the respective channel members, more specifically to the bight portions of said channel members. In addition to the above pair of reinforcing members, the base also includes a pair of generally rectangular, metallic reinforcing plates which are disposed between the associated channel members substantially at the opposite ends thereof generally transversely with respect to said channel members. The latter reinforcing plates are secured at the opposite sides thereof to the associated channel members by suitable means, such as welding.

BRIEF DESCRIPTION OF THE DRAWINGS Other objects of the invention will be apparent from the following detailed description taken in conjunction with the accompanying drawings in which:

FIG. 1 is a partial view, in side elevation, of a high voltage electric switch structure embodying the principal features of the invention;

FIG. 2 is a top plan view of a portion of the supporting base which forms part of the switch structure shown in FIG. I;

FIG. 3 is a side elevational view of the supporting base shown in FIG. 2;

FIG. 4 is a bottom view of the supporting base shown in FIGS. 2 and 3;

FIG. 5 is an enlarged end elevational view taken along the line V--V in FIG. 3, of the supporting base shown in FIGS. 2, 3 and 4;

FIG. 6 is an enlarged view in side elevation of a reinforcing member which forms part of the supporting base shown in FIGS. 2 through 5; and

FIG. 7 is an enlarged view in end elevation of the reinforcing member shown in FIG. 6.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings and FIG. I in particular, there is shown a high-voltage disconnecting switch assembly 10 which normally forms one pole unit of a polyphase or three-phase high-voltage switch structure which includes a plurality of disconnecting switch assemblies each having the construction of the disconnecting switch assembly I0 and supported on a common supporting structure which may include a plurality of structurally supporting cross members, as indicated diagrammatically at 202 at 204 in FIG. I. In such a polyphase switch structure, a plurality of pole units, such as the disconnecting switch assembly 10, is mounted in side-byside spaced relation upon the common supporting structure.

The disconnecting switch assembly 10 comprises three spaced

insulator stacks

32, 34 and 36 which are mounted upon a common supporting base 30 which will be described in detail hereinafter. The operating parts of the disconnecting switch assembly 10 which are mounted at the upper ends of the

insulator stacks

32, 34 and 36, as viewed in FIG. I, are described in detail in U.S. Pat. No. 3,194,905 which issued July 13, I965 to F. W. Jewell et al. and which is assigned to the same assignee as the present application. Each of the insulator stacks 32, 34 and 36 comprises a plurality of insulators which are preferably formed from porcelain or other suitable electrically insulating material. The number of insulators required in each of the

insulator stacks

32, 34 and 36 depends upon the voltage of the electrical system in which the disconnecting switch 10 is applied. As illustrated, the insulator stacks 32 and 34 may be mounted upon the fixed pedestals or spacers I32 and 134, respectively, which, in turn, may be secured to the top of the associated supporting base 30. As described in the last mentioned patent, the insulator stack 36 is mounted upon a shaft 165, he lower end of which is rotatably mounted in a bearing member 163 which is secured to the top of the associated supporting base 30. As shown in FIG. I, an operating lever or crank arm 162 may be secured to the shaft I65 at the lower end of the insulator staff 36 to rotate the insulator stack 36 with the crank arm 162 being adapted for connection or coupling to any conventional means for operating the crank arm 162 to effect rotation of the associated shaft 165 and the insulator stack 36 about its own longitudinal axis. A shaft 169 is secured to and extends upwardly from the upper end of the insulator stack 36 to thus form an operative extension of the shaft 165 which is provided at the lower end of the insulator stack 36 in order to positively connect the crank arm 162 and the insulator stack 36 to the balance of the operating mechanism of the disconnecting switch assembly which will be described hereinafter. The shaft 169 passes through an opening provided in the terminal end casting or member 120 which is substantially aligned with the axis of rotation of the shaft 169 and the insulator stack 36 and has mounted at the upper end thereof a crank arm 110 which is rotatable with the shaft 169 and which extends generally at an angle or generally transversely with respect to the axis of rotation of the shaft 169.

As illustrated in FIG. I, the disconnecting switch 10 includes a generally U-shaped relatively stationary contact assembly or break jaw assembly 40 which is mounted on and secured to the top of the insulator stack 32. The stationary contact assembly 40 includes a plurality of pairs of spaced contact jaws 43 which are mounted on and interconnected by an associated base member 41 which is forged or cast from an electrically conducting material, such as copper, and which is secured to the top of the insulator stack 32 by suitable means such as a plurality of bolts (not shown). A terminal pad 142 which is adapted to receive a terminal connector may be formed integrally with or secured to one side of the base member or terminal casting 41. Where desired, a relatively stationary arcing horn 45 may also be secured to the terminal casting 41.

In order to provide an electrically conducting path between the stationary contact assembly 40 and the electrically conducting parts of the disconnecting switch 10 which are mounted on top of the insulator stack 34 when the switch 10 is in a closed circuit operating condition, as shown in FIG. 1, a movable switch blade or contact arm 50 is provided. The blade 50 is elongated in shape and includes a main body or central portion which may be generally tubular in configuration and which is formed from an electrically conducting material, such as copper or aluminum. The blade 50 also includes an end portion at its left end which may be generally rectangular in cross section to provide high-pressure contact areas which are adapted to engage the contact jaws 43 of the stationary contact assembly 40. Where desired, a relatively movable arcing horn 51 may be mounted at the free or left end of the blade 50 which is adapted to cooperate with the relatively stationary arcing horn 45 previously mentioned.

In order to support the blade 50 for rotation about its own axis and for arcuate movement about an axis which extends generally perpendicular to the axis of the blade 50, as viewed in FIG. 1, the right end of the blade 50 may be secured to a generally tubular crank member 60 for movement therewith, as described in detail in the Jewell et al. patent previously mentioned. In order to support the crank member 60, as well as the blade 50, for rotation about a common axis which extends longitudinally of the blade 50, a hinge member 70 having a generally tubular portion is provided and the crank member 60 is rotatably supported on said hinge member, as described in the Jewell et al. patent previously mentioned. An electrically conducting path may be provided between the crank member 60 and the hinge member 70 by one or more resilient electrically conducting members (not shown) disposed between the crank member 60 and the tubular portion of the hinge member 70. I

In order to support the hinge member 70 for rotation about an axis which is generally perpendicular to the axis of the blade 50 and to support the blade 50 which is assembled with the hinge member 70 as just indicated for arcuate movement or travel about said axis, the spaced arms 82 (only one shown) of the hinge support member or frame 80 are disposed on opposite sides of the hinge member 70. The hinge member 70 includes a pair of hinge portions which project generally perpendicularlywith respect to the axis of the tubular portion of the 1 hinge member 70 with the hinge member 70 being pivotally supported between the arms 82 of the hinge support frame 80 by electrically conducting hinge pins or studs 81 as described in the Jewell et al. patent. The electrically conducting hinge pins 81 which support the hinge member 70 may be electrically connected to the hinge member 70 by one or more resilient electrically conducting members (not shown) which may be disposed inside the generally tubular hinge portions of the hinge member 70 to engage both the hinge member 70 and the hinge pins 81 which are secured to the arms 82 of the hinge support frame 80. In order to provide an electrically conducting path between the hinge support member and the terminal casting 120, an electrically conducting tubular member 152 may be provided which structurally and electrically connects the hinge support member 80 and the terminal end member 120. The electrically conducting member 152 may also serve as a housing for a counterbalancing mechanism which is described in detail in U.S. Pat. No. 3,074,474 which issued Feb. 26, 1963 to E. F. Beach et al. and which is assigned to the same assignee as the present application.

In order to operatively connect the crank arm 110 which is mounted on the shaft 169 which is secured to the top of the rotatable insulator stack 36 and the crank member 60 and to actuate the movement of the blade 50 during opening and closing operations of the disconnecting switch 10, the disconnecting switch 10 includes the operating link which is pivotally connected to the crank member 60, the slip joint 92 and the universal joint which operatively connects the slip joint 92 to the crank arm 110. The slip joint 92 and the universal joint 100 are described in detail in the Jewell et al. patent previously mentioned.

In general, the supporting base 30 of the disconnecting switch 10 is provided to support the weights of the insulator stacks 32, 34 and 36, as well as the weights of the parts of the disconnecting switch 10 which are mounted at the top of the respective insulator stacks, and also to resist the torsional or twisting stresses which result in the supporting base 30 where the disconnecting switch 10 forms one pole unit of a polyphase or three-phase switch structure due to the interaction of the respective pole units of such a polyphase switch structure during short circuit or other abnormal operating conditions. As previously indicated, the insulator stacks 32, 34 and 36 are supported on the supporting base 30 in spaced relation and are disposed generally perpendicular to the overall supporting base 30 as shown in FIG. 1.

More specifically, the supporting base 30 comprises a pair of

elongated channel members

33 and 35 which are disposed generally parallel to and spaced from one another, as best shown in FIGS. 2 through 5. The

channel members

33 and 35 are preferably formed from a metallic material, which is preferably steel. Each of the

channel members

33 and 35 includes a pair of spaced integral sidewall or flange portions, as indicated at 33A and 33C for the channel member 33 and as indicated at 35A and 35C for the flange member 35, which are interconnected by an associated bight portion as indicated at 338 and 358 for the

channel members

33 and 35, respectively. As shown in FIG. 5, the

channel members

33 and 35 which make up the supporting base 30 are assembled with the corresponding pairs of

side wall portions

33A and 33C and 35A and 35C, respectively, projecting outwardly or away from one another in opposite directions. The

bight portions

33B and 35B of the

channel members

33 and 35, respectively, are disposed in back to back relation and spaced from one another as shown in FIG. 5.

In order to provide the supporting base 30 with adequate structural strength to resist the torsional stresses which may result during the operation of the disconnecting switch 10, as previously mentioned, a pair of reinforcing members 20 is disposed adjacent to the opposite ends of the supporting base 30 and spaced from said opposite ends, as best shown in FIGS. 2 through 4. Each of the reinforcing members 20 includes an elongated tubular member 22 which is disposed between and generally parallel to the associated

channel members

33 and 35. Each of the reinforcing members 20 also includes a pair of generally rectangular plates 24 which are disposed between and generally transversely or perpendicularly with respect to the

channel members

33 and 35, as shown in FIGS. 2 through 4. Both the tubular member 22 and the associated generally rectangular plates 24 of each of the reinforcing members 20 are formed from a metallic material which is preferably steel. The tubular member 22 of each of the reinforcing members 20 is preferably circular in cross section and the associated generally rectangular plates 24 are secured to the opposite ends of the associated tubular member 22 by suitable means, such as welding, as shown in FIGS. 6 and 7. The generally rectangular plates 24 of each of the reinforcing members 20 are, in turn, secured at the opposite sides thereof to the bight portions of the associated

channel members

33 and 35 by suitable means, such as welding, as best shown in FIG. 5. It is to be noted that each of the generally rectangular plates 24 which form part of the reinforcing members 20 includes a pair of

recesses

24A and 248 at the opposite sides thereof to limit the portions of the plates 24 which must be welded to the associated

channel members

33 and 35 at the sides of each of said plates. If the recesses 24A and 24B were not provided in each of the generally rectangular plates 24, the entire sides of each of said plates would have to be welded to the associated

channel members

33 and 35 respectively in order to avoid the entrapment of certain solutions or liquids which are normally employed in the galvanizing of the entire supporting base 30 after the reinforcing members 20 are assembled with and secured to the associated

channel members

33 and 35 as shown in FIGS. 2 through 4.

In addition to the reinforcing members 20, a pair of generally rectangular reinforcing plates 26 is disposed substantially at the opposite ends of the supporting base 30 with said plates being disposed between and generally transversely or perpendicularly with respect to said channel members, as shown in FIGS. 2 through 5. Each of the reinforcing plates 26 is secured at the opposite sides thereof to the

respective channel members

33 and 35 by suitable means, such as welding, with the reinforcing plates 26 being formed from a metallic material which is preferably steel. Each of the reinforcing plates 26 includes a pair of

recesses

26B and 26C at the opposite sides thereof for the same reasons previously described in connection with the plates 24. Each of the reinforcing plates 26 also includes a central opening, as indicated at 26A, to permit the mounting of strain insulators (not shown), where desired, to permit the supporting of associated electrical conductors which may be associated with or connected to the disconnecting switch 10. It is important to note that the reinforcing plates 26 provided substantially at the opposite ends of the supporting base 30 structurally complete a boxlike structure which is formed by the overall supporting base 30 and also assist in providing the supporting base 30 with resistance to the torsional or twisting stresses previously mentioned. Where desired, additional reinforcing plates such as the reinforcing plate 27 may be disposed between and secured to the

channel members

33 and 35 at axially spaced locations along the overall length of the supporting base 30 to provide additional rigidity in certain applications.

Referring again to FIG. 1, it is important to note that the construction of the supporting base 30 permits the mounting of the pole units of a polyphase switch structure, such as the disconnecting switch unit 10, to be mounted on common structural cross members such as those indicated diagrammatically at 202 and 204 in FIG. 1 with the opposite ends of the supporting base 30 of each pole unit of disconnecting switch overhanging the associated structural cross support members by a predetermined distance, as indicated at 210 in FIG. 1.

For example, in one typical application of the disclosed construction of the supporting base 30, each of the reinforcing members was approximately 16 inches long and were each spaced from the adjacent end of the supporting base 30 by approximately 11 inches to permit a maximum overhanging distance of each of the opposite ends of the supporting base of approximately 30 inches where desired. The positioning of the reinforcing members 20 adjacent the opposite ends of the supporting base 30 transmits the torsional stresses or forces which may result during short circuit conditions to the reinforcing members 20 and then to the common supporting structure as indicated diagrammatically at 202 and 204 in FIG. I and limits the deflection of the supporting base 30 at different points during such operating conditions to predetermined minimum values which avoid any consequent damage to the disconnecting switch 10 during such operating conditions. The improved torsional rigidity of the supporting base 30 has been found also to result in equal structural restraint of all of the insulator stacks 32, 34 and 36 regardless of the relative position of the supporting

cross members

202 and 204 within a limited range of locations which extends from right at the opposite ends of the supporting base 30 to locations which result in a predetermined overhang distance at each end of said base as previously indicated.

In the overall operation of the disconnecting switch 10, as described in greater detail in the Jewell patent previously mentioned, when the shaft 165 is rotated by an external means through the crank am 162, the blade 50 is first rotated about its own axis to effect a disengagement of the free end of the blade 50 from the contact jaws 43 of the stationary contact assembly 40. Continued movement of the crank arm 110 in the predetermined direction actuates an arcuate movement of the blade 50 along with the hinge member 70 in a clockwise direction aboutthe axis defined by the hinge pins which support the hinge member 70 until the blade 50 is in a substantially vertical position as viewed in FIG. 1 which is angularly displaced from the position of the blade shown in FIG. I by substantially During a closing operation of the disconnecting switch 10, the crank arm 162 is actuated in the opposite direction to thereby actuate the crank arm in such a direction as to first actuate the blade 50 from the substantially vertical position just indicated to a position which is substantially parallel to the supporting base 30 as shown in FIG. 1. Further rotation of the crank arm 110 then rotates the blade 50 about its own axis to establish contact pressure between the free end of the blade 50 and the stationary contact assembly 40. In summary, the operating mechanism of the disconnecting switch 10 separates the rotary movement of the blade 50 about its own axis which is necessary to either disengage the left end of the blade 50 from the stationary contact assembly or to actuate said blade to fully engage the stationary contact assembly 40 and the generally arcuate movement of said blade between the open and closed positions just described.

It is to be understood that the teachings of the invention may be applied to other types of high-voltage electric switches whose operating parts may differ from those of the disconnecting switch 10 as illustrated.

The apparatus embodying the teachings of this invention has several advantages. For example, a high-voltage switch construction as disclosed includes an improved supporting base which is uniquely adapted to permit the use of steel structural members in a relatively simple construction while providing the resistance to torsional stresses or forces which are required in a polyphase switch structure due to the interaction of adjacent pole units during certain operating conditions. In addition, the disclosed supporting base construction permits the associated supporting cross members for the adjacent pole units of polyphase switch structure to be mounted either adjacent to the opposite ends of the respective supporting bases of the different pole units or to locate the supporting

cross members

202 and 204 inwardly from the opposite ends of the supporting base by a predetermined distance, as indicated by the axially spaced mounting holes 38 which are provided on the lower flange or

sidewall portions

33C and 35C of the

channel members

33 and 35, respectively as best shown in FIG. 4. More specifically, the disclosed supporting base construction lends itself to convenient assembly with the supporting cross members indicated diagrammatically at 202 and 204 in FIG. 1 by suitable fastening means such as a plurality of spaced bolts which may pass through the openings 38 provided in the bottom sidewall portions of the

channel members

33 and 35 as shown in FIG. 4.

The insulator stacks 32, 34 and 36 may be conveniently secured to the associated channel members and more specifically to the

upper sidewall portions

33A and 35A of said channel members by suitable fastening means, such as a plurality of axially spaced bolts which pass through the axially spaced openings 39. it important to note that the disclosed supporting base 30 also provides the necessary rigidity and structural strength to support the weight of each of the insulator stacks 32, 34 and 36 as well as the switch operating parts which are disposed on top of the respective insulator stacks. In summary, the applicant's construction permits the use of steel structural members to fonn an improved supporting base for high-voltage electric switches in a relatively less complicated overall structure while providing. the necessary resistance to torsional or twisting stresses which may result due to short circuit conditions in the operation of a polyphase or three-phase switch structure having a plurality of pole units disposed in side-byside relation.

I claim as my invention:

1. A high-voltage electric switch comprising a base, a plurality of spaced insulator stacks mounted on said base, a switch blade movably supported on top of at least one of said insulator stacks a contact jaw supported on top of another of said insulator stacks to be engaged by said blade in one operating position of said blade, said base comprising a pair of elongated, metallic channel members each having a pair of spaced sidewall portions, said channel members being disposed generally parallel and spaced from one another with the sidewall portions of each of said channel members projecting away from those of the other channel member in opposite directions, and a pair of reinforcing members disposed adjacent to and spaced from each of the opposite ends of said base, each reinforcing member including a metallic, elongated tubular member disposed between and generally parallel to said channel members and a pair of generally rectangular, metallic plates disposed between and generally transversely with respect to said channel members, said pair of generally rectangular, metallic plates being secured to the opposite ends of said tubular member and secured at the opposite sides thereof to the respective channel members.

2. The combination as claimed in claim 1 wherein the tubular member of said reinforcing is generally circular in cross section.

3. The combination as claimed in claim 1 wherein an additional pair of generally rectangular, metallic plates are disposed substantially at the opposite ends of said base between and generally transversely with respect to said channel members, said last-mentioned plates being secured at the opposite sides thereof to the respective channel members.

4. The combination as claimed in claim I wherein said channel members and said reinforcing members are formed primarily from steel.

5. The combination as claimed in claim 1 wherein each of the sidewall portions of said channel members at the top of said base includes a plurality of spaced openings and a plurality of fastening means is provided to secure said insulator stacks to said base, said fastening means being disposed to pass through the openings in the sidewall portions of said channel members.

6. The combination as claimed in claim 1 wherein the pair of generally rectangular plates of each of said reinforcing members are welded to the opposite ends of the tubular member of said reinforcing member and the sides of said plates are welded to the respective channel members.

7. The combination as claimed in claim 2 wherein an additionalpair of generally rectangular, metallic plates is disposed substantially at the opposite ends of said base between and generally transverse with respect to said channel members, said additional pair of plates being secured at the opposite sides thereof to the respective channel members.

8. The combination as claimed in claim 2 wherein the pair of generally rectangular plates of each reinforcing member are welded to the opposite ends of the tubular member of said reinforcing member and the sides of said plates of each member are welded to the respective channel members.

Claims

4. The combination as claimed in claim 1 wherein said channel members and said reinforcing members are formed primarily from steel.

7. The combination as claimed in claim 2 wherein an additional pair of generally rectangular, metallic plates is disposed substantially at the opposite ends of said base between and generally transverse with respect to said channel members, said additional pair of plates being secured at the opposite sides thereof to the respective channel members.