US3646288A

US3646288A - Disconnect switch utilizing insulating base having integrally formed insulator bushings

Info

Publication number: US3646288A
Application number: US68108A
Authority: US
Inventors: Robert E Perry; Eugene Gorin
Original assignee: ITE Imperial Corp
Current assignee: ABB Inc USA
Priority date: 1970-08-31
Filing date: 1970-08-31
Publication date: 1972-02-29
Anticipated expiration: 1989-02-28
Also published as: CA937271A

Abstract

A hook disconnect switch having a base member formed of an insulating material and insulator units integrally joined thereto. Two insulators are aligned at an angle relative to one another and support the jaw and pivoting end of a switch blade. The orientation of the insulators significantly reduce cantilever forces imposed by horizontal incoming lines upon the insulators. The base member provides a means for rigidly positioning and supporting the hook switch assembly, as well as enhancing the dielectric strength of the insulators. The design and orientation of the insulators further reduce overall switch size and considerably reduce the effect of contamination for all mounting positions of the switch.

Description

Elnited States Patent Perry et al.

[54] DISCONNECT SWITCH UTILIZING INSULATING BASE HAVING INTEGRALLY FORMED INSULATOR BUSHINGS Feb. 29, 1972 [5 7] ABSTRACT A hook disconnect switch having a base member formed of an insulating material and insulator units integrally joined thereto. Two insulators are aligned at an angle relative to one another and support the jaw and pivoting end of a switch blade. The orientation of the insulators significantly reduce cantilever forces imposed by horizontal incoming lines upon the insulators. The base member provides a means for rigidly positioning and supporting the hook switch assembly, as well as enhancing the dielectric strength of the insulators. The design and orientation of the insulators further reduce overall switch size and considerably reduce the effect of contamination for all mounting positions of the switch.

7 Claims, 10 Drawing Figures Patented Feb. 29, 1972 5 Sheets-Sheet 2 FIZZ-.44..

Patented Feb. 29, 1972 5 Sheets-Sheet 3 Patented Feb. 29, 1972 5 Sheets-Sheet L Patented Feb. 29, 1972 3,646,288

5 Sheets-Sheet 5 DISCONNECT SWITCH UTILIZING INSULATING BASE HAVING INTEGRALLY FORMED INSULATOR BUSHINGS The present invention relates to hook-operated disconnect switches and more particularly to a novel compact, one-piece insulator base assembly for hook disconnect switches having angularly oriented insulators with insulator skirts at an angle to the mounting surface and which is designed to obtain maximum self-cleaning of insulator units under rain conditions so as to combat contaminated atmospheres and to create a novel, pleasing appearance.

Disconnect switches find widespread use throughout the power transmission and distribution field. One type of disconnect switch, commonly referred to as a distribution switch, is normally provided for use as a disconnect switch for substation and other applications and is employed at a variety of distribution voltages and currents anywhere in the system such as from substation transformer secondaries to distribution transformer primaries. Switches of this type are usually employed in distribution networks in the range from several thousand to more than 20,000 volts at 200-600 ampere ratings and are typically mounted out of doors such as, for example, on poles, substations, wood and metal structures, or other suitable supports. The distribution switch is provided with a hookoperated latching device which normally requires the operator to be provided with a long hook stick or pole which may be inserted into a pull-ring in order to unlatch the blade of the switch and separate it from its associated jaw. Such switches are typically mounted underhung from crossarms on wood poles or on vertically mounted trusses of substation structures, and provided for selective connection or disconnection of load and supply lines connected to associated equipment. The switch jaw and blade pivoting assemblies are normally supported by end caps provided on insulators which, in turn, are mounted upon a metal baseplate which is electrically insulated from the powerlines connected to the distribution switch pads.

The incoming conductors connected to the switch from the load and source ends of the system are normally mechanical anchored to grounded parts (base). Therefore, separate suspension insulators must be provided, which insulators are exposed to continuous tensile pull, while supporting the lines connected thereto.

The present invention is characterized by providing a distribution switch of novel design in which the switch supporting insulators-base unit are combined into an integral unitary member of reduced size, capable to withstand tensile and cantilever forces of incoming lines with metal parts designed to receive these lines directly without the need for suspension insulators not heretofore possible in conventional mountings for distribution switches.

The present invention is comprised of a pair of insulator bushings preferably integrally formed with a base portion of substantially the insulating material and having its insulator units aligned at an angle relative to one another so as to provide increased supporting strength for the distribution switch, high resistance to cantilever forces imposed upon the supporting structure and increased dielectric strength beyond that normally provided by conventional supporting insulator assemblies and to further provide reduced overall structural size and dimensions while retaining all of the other advantages of conventional distribution switch supporting assemblies.

It is, therefore, one object of the present invention to provide a novel supporting assembly for use in connection with distribution switches.

Another object of the present invention is to provide a novel unitary one-piece supporting assembly for mounting and supporting distribution switches and having self-cleaning angularly oriented insulator portions extending from an integral base portion.

Still another object of the present invention is to provide a novel unitary one-piece supporting assembly for positioning and supporting electrical switches of the distribution type and comprised of a centrally located relatively short base portion having radially aligned insulator bushing portions for supporting the jaw and blade elements of a distribution switch wherein the orientation of the insulator bushing portions is such as to provide substantially increased resistance to cantilever forces. The compact switch with short base lends itself for mounting on single structural member on low profile substation structure used in more modern design with pleasing appearance and economy.

These as well as other objects of the present invention will become apparent when reading the accompanying description and drawings in which:

FIG. I is a perspective view showing a typical mounting of a convention prior art distribution switch and supporting assembly.

FIG. 2 is a perspective view showing a combined insulator and base support assembly designed in accordance with the principles of the present invention.

FIG. 3 is an elevational view showing the structure of FIG. 2 with a distribution switch mounted thereon.

FIG. 3a shows a sectional view of the assembly of FIG. 3 looking in the direction of arrows 3a3a'.

FIG. 3b is a sectional view of thejaw section of the switch of FIG. 3 looking in the direction of arrows 3b3b'.

FIG. 30 is a sectional view of the blade portion of the switch of FIG. 3 looking in the direction of arrows 3c-3c'.

FIG. 4 is an elevational view of a preferred embodiment of the present invention employing a distribution switch.

FIG. 4a is a view of the base portion of the apparatus of FIG. 4.

FIGS. 4!) and 4c are typical alternate sectional views of one insulator of FIG. 4 looking in the direction of arrows 4b4b and 4c-4c, respectively.

Referring now to the drawings, FIG. 1 shows a conventional prior art distribution switch assembly 10 which is assembled on a pair of crossarms M and 12 mounted upon vertical pole 13. A channel-shaped base assembly 14, preferably formed of steel, is secured to crossarms 11 and 12 by means of a pair of

channels

15 and 16 of much smaller cross-sectional configuration which embrace crossarms l1 and I2 therebetween by means of the fastening assemblies 17 (only two of which are shown in FIG. 1, it being understood that four such fastening assemblies are provided). The channel-shaped base 14 is provided with suitable openings (not shown) for securing a pair of insulators with steel caps 18 and I9 thereto which, in turn, support and have downwardly depending therefrom a respective pair of

insulators

20 and 21. Insulator 20 is provided with a jaw assembly 22 which may be selectively latched with the end 23a of a blade 23 pivotally mounted at 23b by a suitable supporting assembly 24 secured to the bottom end of insulator 21. The supporting assemblies 22 and 24 are further provided with

clamping assemblies

22a and 24 a, respectively, for clamping the ends of an associated conductors 25 and 26, respectively, which may, for example, be the source and load ends of a powerline in a distribution network.

Since the incoming cables are energized they must be insulated from ground by suspension insulator assemblies designated generally by the numerals 27 and 30, respectively. Each of the assemblies is provided with a first end 27a and 3011 which is mechanically coupled to the channel-shaped base portion 14 so as to be securely anchored thereto. The opposite ends thereof, namely, ends 30b and 27b, are mechanically coupled to the ends of incoming cables 25 and 26 whereby the suspension insulator assemblies carry substantially the entire supporting load imparted to the distribution switch base assembly. The connectors 27b and 30b are further provided with cable portions 251: and 26a, respectively, for electrically connecting the cables 25 and 26 to the distribution switch so that the electrical current path extends from cable 25, extension 25a, jaw 22, blade 23, cable extension 26a and cable 26, whereby the

insulators

20 and 21, as well as the suspension insulators 27 and 30 electrically insulate the high tension lines from the base support 14.

FIGS. 2, 3a and 3b show one disconnect switch assembly of the present invention which is comprised of a solid unitary insulator assembly 40 having a base portion generally designated by the numeral 41 and having insulators generally designated by the numerals l2 and 43, respectively. The base portion 41 has a substantially triangular shape comprising a bottom section 44 integrally formed with the diagonally aligned

sections

45 and 46. A vertically aligned supporting rib 47 joins bottom section 44 to substantially the apex of the diagonally aligned

sections

45 and 46 to provide additional rigidity and strength to this unit. The bottom section 44 is provided with three indentations along one vertical side thereof and designated by numerals 44a, 44b and 44c (FIG. 30). Each of these indentations are adapted to receive a substantially C- shaped metallic clip such as, for example, the

clips

48 and 49 which are provided for clamping the insulator assembly to a supporting surface. The top and bottom surfaces of each of the clips are provided with suitable apertures for receiving fastening means 50 and 51, respectively, which may, for exam ple, be bolts passing through such openings and having their bottom end portions free to make threaded engagement with a suitable tapped aperture provided either in a supporting plate or in the form of a nut which may cooperate with the

bolts

50 and 51 to firmly secure the insulator assembly to the supporting surface (not shown for purposes of simplicity). It should be noted that indentation 44c is substantially elongated to permit mounting clip 49 to be positioned at any location therealong. Clip 48 may be positioned so as to have its bolt 50 pass through the cutaway region formed by surface 44a or may be aligned so as to have its bolt 50 pass through the open region defined by cutaway portion 44!; thereby providing a universal arrangement allowing for mountings over rather a large dimensional span.

The diagonally aligned

sections

45 and 46 are each provided with recesses for receiving the bottom end of any insulator. Only one such arrangement is shown in FIG. 3 for purposes of simplicityfAs can be seen therein, diagonally aligned section 45 has an opening 52 for receiving and embracing the smaller diameter end portion $30 of insulator 43. In actuality, the insulators are first produced and are then inserted into a mold provided for forming the base portion 41 of the assembly. The smaller diameter and portions of each insulator protrude into the mold so as to cause the insulating material poured into the mold to surround and embrace the end cap portion 430 and thereby be integrally joined thereto. The end cap portion 43a may also be provided with an annular flange 43b for enhancing the supporting strength of the structure.

The insulators may have hollow core (such as, for example, the hollow interior 43c) and have an undulating exterior surfaceconfiguration 43d to increase creepage distance (which is typical of such insulators). The opposite smaller diameter end 436 is secured to a disconnect switch jaw assembly 53 which is provided with a caplike portion 54 which receives and embrances the portion 43e of insulator 43. End cap 54 is preferably rigidly joined to portion 43c of the insulator by means of a suitable adhesive or epoxy which fills the hollow interior space 55 between cap 54 and insulator portion 43.

The end cap 54 has integrally joined thereto a terminal portion 55 provided with openings 56 for bolting a suitable clamp thereto in order to join one free end of an incoming conductor (not shown for purposes of simplicity). The jaw portion of assembly 53 is further comprised of a blade-engaging portion 58 (note also FIG. 3b) which mechanically and electrically engages the blade assembly in manner to be more fully described.

The insulator 42 has its upper free end joined to receive a metallic end cap 59 which is further integrally joined to a terminal pad 60 having opening 61 for securing a terminal clamp thereto in order to join the remaining cable to complete the electrical path through the distribution switch. A blade pivoting portion 62 is also joined to end cap 59 (note especially FIG. 3c) and is provided with a suitable opening 63 for receiving a fastening assembly comprised of bolt 64,

spring washers

65 and 66, wedge-shaped members 67 and 68 (for proper distribution of contact pressure) and nut 69. This assembly is employed to pivotally mount the blade assembly thereto. The blade assembly is comprised of a pair of blade members 70 and which can clearly be seen in FIG. 3c to be positioned on opposite sides of the blade pivotally mounted section 62. The fastening assembly urges the two

portions

70 and 71 of the blade assembly into good wiping contact with the pivotally mounting portion 62 as can best be seen in FIG. 3c. Openings 72 (only one of which is shown in FIG. 3 for purposes of simplicity) are provided for receiving a suitable pin, which, when appropriately positioned, limits the amount of angular travel which the blade may experience in moving to the open position. A 90 span between fully closed and fully opened may be obtained by positioning a pin with an opening 72 so as to abut the shoulder 73 provided on blade mounting assembly 62. Removal of a pin from the openings 72 permits a larger angular travel, since the blade is then free to move past shoulder 73 so as to move through a total angle of approximately 135 from the fully closed to the fully open position.

The jaw engaging portion of the switch blade is provided with a latching assembly mounted between the two blade portions 78 and 71 (note blade portion 73 has been broken away to expose the latching assembly). The latching assembly is comprised of a pin 74 secured between the two blade portions. A pull ring 75 is provided with a cylindricalshaped projection 76 for receiving pin 74 so as to mount the handle between the two blade portions 70 and 7!. A tortion spring 77 is positioned around the cylindrical projection 76 and has a first end thereof extending through an opening 78 in pull ring 75 and has a second end thereof resting in groove 79 of arm 81 of a latching member 80. Pull ring 75 is provided with an opening 83 for receiving the hook and of a hook stick (not shown) typically employed for opening such distribution switches. The opposite portion of pull ring 75 is provided with a projection 84 for bearing against arm- 81 of latch member 80.

Latch member (note especially FIGS. 3 and 3b) is provided with an opening 85 for receiving a pin 86 which pivotally mounts the latch member between the

blade portions

70 and 71. Pin 86 has a length greater than the distance between

blade portions

70 and 71 and is provided with a first clip 87 bearing against the exterior surface of blade portion 70 and a second clip 88 provided at its opposite end. A compression spring 89 is positioned between exterior surface of blade portion 71 and one surface of a washer 90 which is positioned just to the left of clip 88 so as to cause the compression springs 89 to urge

blade portions

70 and 71 toward one another and thereby firmly embrace the blade-engaging portion 58 of the jaw assembly.

FIG. 3 shows the distribution switch in the closed position. In this position, it can be seen that the hook-shaped arm 91, provided as an integral part of latch member 80, has its bearing surface 92 positioned immediately beneath the underside of blade-negaging portion 58. In this position (without manipulating pull ring assembly 75) the distribution switch is latched in the closed position. In order to open the distribution switch, the hook-shaped end of a hook stick (not shown) is inserted into eyelet 83 to rotate the pull ring assembly 75 clockwise relative to FIG. 3 as shown by arrow 94. It should be noted that, with the distribution switch in the closed position, the tortion spring 77 prohibits any relative movement between the pull ring assembly 75 and the latching member 80. By rotating pull ring assembly 75 in the clockwise direction as shown by arrow 94, its lower end projection 84 bears against arm ill and acts against the force of tortion spring 77 to urge latching member 80 counterclockwise about itsmounting pin 86 as shown by arrow 95. This causes the bearing portion 92 to be rotated away from the underside of blade-engaging portion 58 enabling the distribution switch to be moved to the fully opened position. Tortion spring 77 assures that the latching member 80 and handle assembly 75 will be retained in their relative positions so as to prevent the projection 84 from moving out of engagement with the unerside of arm 81.

The terminal pad 57 which forms an integral part of the jaw assembly of the distribution switch is further provided with a pair of removable loadbuster attachment hooks 96 and 97 which are shown best in FIGS. 3 and 3b and which are provided for use of the switch with a loadbuster device.

Terminal pads 57 and 60 are further provided with openings 98 and 99 for mechanical anchorage of incoming lines without use of suspension insulators now required on conventional switches (plain parallel connector could be of the type shown in FIG. 1), while connecting cable extensions of the type shown in FIG. 1 directly to the terminal pads 57 and 60 through suitable terminal clamps (not shown) which are fastened by means of fastening members (not shown) and bolt holes 56 and 61 respectively to clamp the cable extensions thereto in applications where this becomes necessary.

FIG. 4 shows an alternative embodiment for a distribution switch assembly in which like elements have been designated with like but primed numerals. In the embodiment of FIG. 4, the insulator and base assembly is comprised of insulators 42' and 43' which are integrally molded in a single operation with base portion 41'. The base portion is of a different configuration from that shown in FIG. 3 and is provided with openings 101 and 102 which cooperate with the side openings 44a and 440' along one edge of base portion 41 (see FIG. 4a) to receive the clamping assemblies 48' and 49

' having bolts

50 and 51 respectively, forjoining the unitary assembly to a supporting surface in the same manner as was previously described. The insulators 42' and 43 are each angularly aligned relative to the plane of the bottom edge of base portion 41'. Typical cross-sectional configurations of the unit 43 are shown in FIGS. 4b and 4c.

The upper ends of the insulators 42 and 43 are mounted to end caps 54' and 59' in a manner similar to that shown in FIG. 3. The disconnect switch assembly is substantially similar to that shown in FIG. 3 except that the terminal pads 57' and 60' are substantially coplanar with the plane of the base portion 41'. The disconnect switch assembly in operation is also substantially similar to that shown in FIG. 3. However, the increased supporting strength and the high resistance to cantilever forces which the assembly of FIG. 4 is able to withstand, totally eliminates the need for suspension insulators as has been described hereinabove.

It can therefore be seen from the foregoing description that the present invention provides a novel combined insulator and base supporting assembly for use in mounting and supporting disconnect switches in which the angular orientation of the insulator members in outdoor mounting provides under effect of rain self cleaning removal of contamination and offers high resistance to cantilever forces and a smaller overall size while retaining all of the advantages of conventional disconnect switch insulator support assemblies.

Although there has been described a preferred embodiment of this novel invention, many variations and modifications will now be apparent to those skilled in the art. Therefore, this invention is to be limited, not by the specific disclosure herein, but only by the appending claims.

We claim:

I. An integral one-piece insulation support assembly for distribution switches and the like comprising a base portion having a substantially planar mounting surface;

fastening means embracing said base portion forjoining said assembly to a supporting surface;

first and second elongated insulators having their first ends integrally joined to and supported by said base portion on the side opposite said mounting surface and extending radially outward from said base portion, said insulators being diagonally aligned relative to said mounting surface, said base and said insulators being formed as an integral molded unit and being comprised of the same insulating material.

2. The assembly of claim 1 wherein the angular alignment of the insulators is substantially a right angle.

3. The assembly of claim 1 wherein said insulators and base portion are formed of an insulating material, said material bein orcelain, epox or combination of both. I

4. e assembly 0 claim 1 further comprising a switch assembly having a blade and ajaw portion;

said jaw portion including an end cap mounted on the second end of one of said insulators;

said blade portion including an end cap mounted on the second end of the remaining one of said insulators;

a blade;

mounting means for pivotally mounting one end of said blade to said blade portion end cap whereby said blade is adapted to have its opposite end engage said jaw portion when said blade is pivoted to the closed position.

5. The assembly of claim I wherein each of said insulators is provided with skirts aligned transverse to the mounting sur face to provide for self-cleaning of contamination deposits thereon.

6 The assembly of claim 4 further comprising first and second terminal pads electrically connected to said jaw and blade portion end caps respectively;

means for mechanically securing and electrically connecting cable terminals to said pads for coupling said switch into an electrical circuit.

7. The assembly of claim 4 further comprising pull ring operated latch means pivotally mounted to said blade and engaging said jaw portion for latching said blade in said closed position and being movable in a first direction for unlatching said blade from said jaw portion.

Claims

1. An integral one-piece insulation support assembly for distribution switches and the like comprising a base portion having a substantially planar mounting surface; fastening means embracing said base portion for joining said assembly to a supporting surface; first and second elongated insulators having their first ends integrally joined to and supported by said base portion on the side opposite said mounting surface and extending radially outward from said base portion, said insulators being diagonally aligned relative to said mounting surface, said base and said insulators being formed as an integral molded unit and being comprised of the same insulating material.

3. The assembly of claim 1 wherein said insulators and base portion are formed of an insulating material, said material being porcelain, epoxy or combination of both.

4. The assembly of claim 1 further comprising a switch assembly having a blade and a jaw portion; said jaw portion including an end cap mounted on the second end of one of said insulators; said blade portion including an end cap mounted on the second end of the remaining one of said insulators; a blade; mounting means for pivotally mounting one end of said blade to said blade portion end cap whereby said blade is adapted to have its opposite end engage said jaw portion when said blade is pivoted to the closed position.

5. The assembly of claim 1 wherein each of said insulators is provided with skirts aligned transverse to the mounting surface to provide for self-cleaning of contamination deposits thereon.

6. The assembly of claim 4 further comprising first and second terminal pads electrically connected to said jaw and blade portion end caps respectively; means for mechanically securing and electrically connecting cable terminals to said pads for coupling said switch into an electrical circuit.