US3751611A

US3751611A - Electrical switch assembly with tension-transmitting insulator

Info

Publication number: US3751611A
Application number: US00144060A
Authority: US
Inventors: C Kerr
Original assignee: Eltec Inc
Current assignee: Eltec Inc
Priority date: 1971-05-17
Filing date: 1971-05-17
Publication date: 1973-08-07
Anticipated expiration: 1990-08-07

Abstract

A switch assembly mounted on an upright pole for electrically connecting and disconnecting a pair of conductors, where one of these conductors extends under tension generally horizontally away from the pole, and the other conductor extends generally along the pole. The assembly includes a base fastened to the pole, and a pair of elongated diverging insulators anchored to the base which carry a switch adjacent their outer ends. One of the insulators is substantially axially aligned with the tensed conductor, and serves to transmit tension between this conductor and the pole.

Description

United States Patent Kerr, Jr.

Aug. 7, 1973 ELECTRICAL SWITCH ASSEMBLY WITH TENSlON-TRANSMITTING INSULATOR Inventor: Charles E. Kerr, J12, Hillsboro,

Oreg.

Assignee: Eltec, Inc., Portland, Oreg.

Filed: May 17,1971

Appl. No.1 144,060

US. Cl 200/48 R Int. Cl. 1. H0lh 31/00 Field of Search 337/186, 168, 187,

References Cited UNITED STATES PATENTS 3/1959 Ortwig 200/48 R 8/1964 Pahl 200/48 R 8/1964 Pahl 200/48 R 3,238,330 3/1966 Smith, Jr .1 337/186 X Primary Examinerl-lerman J. Hohauser At!0rneyKolisch, Hartwell & Dickinson [57] ABSTRACT A switch assembly mounted on an upright pole for electrically connecting and disconnecting a pair of conductors, where one of these conductors extends under tension generally horizontally away from the pole, and the other conductor extends generally along the pole. The assembly includes a base fastened to the pole, and a pair of elongated diverging insulators anchored to the base which carry a switch adjacent their outer ends. One of the insulators is substantially axially aligned with the tensed conductor, and serves to transmit tension between this conductor and the pole.

7 Claims, 2 Drawing Figures PATENTED AUG 7 I975 To fi ,,,VU@1. fm H up; m TIWIJH m m em w y Kw E M WW4 H I w l ELECTRICAL SWITCH ASSEMBLY WITH TENSION-TRANSMITTING INSULATOR BACKGROUND AND SUMMARY OF THE INVENTION This invention pertains to a switch assembly for electrically connecting and disconnecting a pair of conductors, where one of these conductors extends under tension away from a pole, and the other conductor extends generally along the pole.

Various switch assemblies for a purpose such as that just indicated have been proposed in the past, but have not been entirely satisfactory. These prior switch assemblies have typically involved the use of at least three insulators, one of which -a so-called string insulator separate from the switch assembly-is used to transmit tension between the tensed conductor and a pole, and the other two of which (in the switch assembly) are employed to support the parts in a switch. Such construction is relatively complicated, bulky, and costly.

A general object of the present invention, therefore, is to provide a novel switch assembly for use under circumstances such as those indicated which avoids the drawbacks of prior switch assemblies in a practical and satisfactory manner.

More specifically, an object of the invention is to provide such a switch assembly which requires only two insulators, one of which serves both to transmit tension between a tensed conductor and a pole, and also to carry a portion of a switch in the assembly.

According to a preferred embodiment of the invention, the proposed switch assembly includes a base adapted to be fastened to a pole, and a pair of elongated diverging insulators having one set of adjacent ends anchored to the base, and another set of spacedapart free ends remote from the base. The free ends of these insulators support the contacts and the movable blade in a switch mechanism. These contacts are each adapted to be connected electrically to a different one of the two conductors involved in an arrangement such as that mentioned earlier.

With the base properly mounted on a pole, one of the insulators, which might be thought of as the upper insulator, extends away from the pole, substantially in axial alignment with the tensed conductor. Means is provided adjacent the free end of this upper insulator accommodating attachment of the adjacent end of the tensed conductor in a manner permitting the transmission of tension through the insulator between the conductor and the pole. The other insulator, which might be thought of as the lower insulator, inclines downwardly from the base.

Such construction results in a simple and compact switch assembly which adequately serves its intended purposes. Contributing to such compactness and simplicity is the fact that the insulator employed to transmit tension between a tensed cable and a pole is also employed to support a portion of the switch in the assembly. As an important consequence of this arrangement, one of the insulators heretofore believed necessary is eliminated, without losing its function. Also contributing to compactness in the assembly is the diverging configuration proposed for the insulators.

DESCRIPTION OF THE DRAWINGS These and other objects and advantages attained by the invention will become more fully apparent as the description which follows is read in conjunction with the accompanying drawings, wherein:

FIG. 1 is a simplified fragmentary side elevation illustrating a portion of an electrical power distribution system employing a switch assembly as contemplated herein; and

FIG. 2 is an enlarged fragmentary side view illustrating details of the switch assembly employed in the system of FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION Turning now to the drawings, and referring first to FIG. 1, indicated generally at 10 is a portion of an electrical power distribution system which employs a switch assembly, indicated at 12, constructed according to the present invention. System 10 includes a plurality of spaced-apart generally upright poles, such as the two poles shown at 14, 16. These poles are conventional in construction, each including an upright post, such as posts 14a, 16a, and crossbars, such as those shown at 14b, 16b. Switch assembly 12 is mounted in a manner which will be more fully explained on crossbar 1412.

Extending between poles l4, 16 is a conventional elongated electrical power conductor 18. The right end of this conductor in FIG. 1 is supported on pole 16 through a conventional insulator 20 which is mounted on crossbar 16b. The left end of conductor 18 in the figure is connected, as will be more fully described, to switch assembly 12. Conductor 18 is under tension, with the level of such tension being about 12,000 pounds.

The right end of conductor 18 in FIG. 1 is suitably connected electrically to other parts (not illustrated) of system 10. The left end of this conductor in the figure is intended to be coupled through switch assembly 12 to another conductor, shown partially at 22, which extends downwardly along and adjacent post 14a in pole l4. Conductor 22 might typically be a jumper for carrying current between conductor 18 and some electrical apparatus or system (also not illustrated) adjacent the base of pole 14.

Turning now to FIG. 2 which illustrates details of switch assembly 12, the switch assembly includes a base 24, a pair of

elongated insulators

26, 28, and a switch 30.

Base 24 comprises a body 32 on which are mounted a pair of axially aligned laterally outwardly projecting pins, such as pin 34 (showing on the near side of the body), and a pair of substantially

planar decks

36, 38. Deck 36 occupies a substantially vertical plane herein, and is disposed at an angle of about l20 to deck 38. The various parts making up the base preferably are formed of a material such as steel. The base is securely fastened to crossbar-14b by means of a pair of conventional fasteners, such as fastener 40, which extend through suitable accommodating bores in the crossbar and about pins 34, as indicated.

Insulators

26, 28 are formed from axial stacks of conventional ceramic insulator dishes, such as dishes 42. The insulators are substantially the same in size. Insulator 26, which might be thought of as the upper insulator herein, has its left end in FIG. 2 suitably anchored to deck 36, with the insulator extending substantially horizontally to the right of the deck in the figure. Insulator 28, which might be thought of as the lower insulator,

has its upper end in FIG. 2 suitably anchored to deck 38.

Insulators

26, 28 occupy a substantially common vertical plane, and diverge from one another progressing outwardly from base 24, with their longitudinal axes disposed at an angle of about 60 to each other. Insulator 26 is disposed with its longitudinal axis substantially axially aligned with the longitudinal axis of tensed conductor 18. Further, these two axes, along with pins 34 and fasteners 40, occupy a substantially common plane indicated at 43. The importance of this relationship will become more fully apparent shortly.

Considering now the construction of switch 30, this switch includes a pair of

contacts

44, 46 suitably anchored to the spaced-apart ends of

insulators

26, 28, respectively, and an elongated blade 48. The contacts are suitably formed, as by casting, to have the respective shapes indicated from a suitable high electrical conductivity metal, such as copper. Contact 44 includes a terminal pad 44a, an embossment 44b (whose purpose will by explained shortly), a foot 440, and a catch 44d. Embossment 44b has a generally cylindrical configuration, and includes an axial bore 50 (which extends normal to the plane of FIG. 2). The embossment is disposed in plane 43. Contact 46 includes a terminal pad 46a and a leg 46b.

Switch blade 48 is conventional in construction, and is mounted on leg 46b of contact 46 by means of a pivot pin 54. The blade and pivot pin are also formed of a suitable high electrical conductivity metal, such as copper. The blade is shown in a position making an electrical connection between

contacts

44, 46, with a conventional contact member (concealed) which is carried adjacent the upper end of the blade in FIG. 2 seating against foot 44c of contact 44. Blade 48 may be swung clockwise in FIG. 2 about pin 54 to break the connection between the contacts.

Mounted on blade 48 is a conventional hookoperated latch mechanism 56 including the usual gearconnected hook ring 58 and spring-biased latch member 60. Latch member 60 operates in conjunction with catch 44d, and also in conjunction with a conventional guide and bearing member 62 suitably mounted on contact 44. As is well understood by those skilled in the art, the latch member may be released from catch 44d, and blade 48 may be swung downwardly to break a connection between

contacts

44, 46, by pulling downwardly on ring 58 with a hook-such a hook typically being mounted on an end of an elongated rod which may be manipulated from the ground.

An important feature of the present invention is that tension in conductor 18 is transmitted through insulator 26 to pole ,l4this insulator also being employed as one of the insulators supporting switch 30. Accordingly, the left end of conductor 18 in FIG. 2 is attached to the insulator through contact 44. More specifically, anchored to the left end of conductor 18 is a conventional clevis 64 which fits about embossment 44b, and is secured thereto by means of a nut and bolt assembly 66. The bolt in assembly 66 extends through bore 50.

With the axes of insulator 26 and conductor 18 aligned as mentioned, and with these axes occupying plane 43 along with pins 34, fasteners 40, and embossment 44b (and hence clevis 64 and assembly 66), insulator 26 readily transmits tension along its axis between conductor 18 and pole 14. Such tension is transmitted without any tendency of the insulator or base to twist or rock away from crossbar 14b.

A suitable electrical connection between conductor 18 and contact 44 is established through a jumper 68 having its lower end in FIG. 2 suitably attached at 70 to conductor 18, and its upper end in the figure suitably attached through a conventional connector 72 to terminal pad 44a. The upper end of conductor 22 in FIG. 2 is connected electrically to contact 46 through a connector 74 which is fastened to terminal pad 46a. Connector 74 is substantially the same in construction as connector 72.

It will thus be apparent that the proposed switch assembly avoids the drawbacks mentioned earlier which characterize prior switch assemblies intended for similar purposes. By utilizing insulator 26 both as a medium for transmitting tension between conductor 18 and pole 14, and as a means for supporting parts in switch 30, only two insulators are required in the switch assembly. The resulting assembly is, therefore, much simpler and more compact in construction than that characterizing prior switch assemblies. Further adding to compactness in assembly 12 is the fact that

insulators

26, 28 are mounted in a diverging configuration, with their ends which are anchored to base 24 disposed closely adjacent one another.

Obviously, an assembly such as assembly 12 may be constructed with various dimensions to suit different applications.

While a preferred embodiment of the invention has thus been described herein, it is appreciated that variations and modifications may be made without departing from the spirit of the invention.

It is claimed and desired to Secure by Letters patent:

1. In combination with a pair of electrical conductors, where one extends under tension substantially horizontally away from a generally upright pole, and the other extends generally along said pole, a switch assembly comprising a base mounted on said pole,

a pair of elongated spaced-apart insulators rigidly anchored against movement to said base, one of said insulators extending generally horizontally and substantially in axial alignment with said one conductor, said one insulator being mechanically interposed between said one conductor and said pole whereby it transmits tension between the two, and

a switch including a pair of spaced-apart contacts, each mounted on a different one of said insulators, and an elongated blade mounted for movement relative to said insulators between positions making and breaking an electrical connection between said contacts, one of said contacts being electrically connected to said one conductor and the other contact being electrically connected to said other conductor.

2. The switch assembly of claim 1, wherein said insulators have a fixed, nonmovable relationship relative to one another, and diverge from one another progressing therealong away from said base.

3. The combination comprising a generally upright pole,

a first electrical conductor extending under tension generally horizontally away from said pole,

a second electrical conductor extending generally along and adjacent said pole,

a pair of elongated spaced-apart insulators having one set of ends secured rigidly to said pole and another set of free ends remote from the pole, one of said insulators extending substantially in axial alignment with said first conductor, and said two insulators having a fixed, nonmovable relationship relative to each other,

means mechanically interconnecting said first conductor and said free end of said one insulator whereby said one insulator transmits tension between said first conductor and said pole,

a pair of electrical contacts each mounted adjacent the free end of a different one of said insulators, and each electrically connected to a different one of said conductors, and

an elongated movable switch blade mounted for movement relative to said insulators between positions making and breaking an electrical connection between said contacts.

4. A switch assembly for connecting and disconnecting a pair of conductors, where one conductor extends under tension substantially horizontally away from an upright pole, and the other conductor extends generally along and adjacent said pole, said switch assembly comprising a base adapted to be mounted on said pole,

a first elongated insulator having one end anchored to said base and another end remote therefrom, said first insulator extending generally horizontally and in axial alignment with said one conductor with said base mounted on said pole, and being fixed against movement relative to said base,

means mounted on said other end of said first insulator accommodating attachment of an end of said one conductor in a manner permitting the transmission of tension through said first insulator between said one conductor and said pole,

a second elongated insulator spaced from said first insulator having one end anchored to said base and another end remote therefrom, and also being fixed against movement relative to said base, and

a switch including a pair of spaced-apart contacts and an elongated blade which is movable relative to said insulators between positions making and breaking an electrical connection between said contacts, one of said contacts being mounted on said other end of said first insulator and accommo- 5 ing a pair of conductors, where one conductor extends under tension away from a pole, and the other conductor extends generally along the pole, said switch assembly comprising a base adapted to be mounted on said pole,

a pair of elongated spaced-apart insulators having one set of ends anchored to said base and another set of free ends remote from the base, said insulators being fixed on said base against movement relative to one another and against movement relative to said base,

one of said insulators being adapted to transmit ten sion between said one conductor and said pole with said base mounted on said pole, and

a switch including a pair of spaced-apart contacts each mounted adjacent the free end of a different one of said insulators and each adapted to be connected electrically to a different one of said condoctors, and an elongated blade mounted for movement relative to said insulators between positions making and breaking an electrical connection between said contacts.

6. The switch assembly of claim 5, wherein said insulators diverge from one another progressing therealong from their anchored ends toward their free ends.

said one conductor, and said other contact being 7. A switch assembly for electrically connecting and disconnecting a pair of conductors, where one of such conductors extends under tension away from a pole, said assembly comprising a switch mechanism having a pair of contacts each electrically connected to a different one of said conductors,

a pair of spaced-apart, fixed-position insulators adapted to be secured against movement to said pole, each supporting a different one of said contacts, and

means accomodating a mechanical interconnection between said one conductor and one of said insulators whereby said one insulator transmits tension between said one conductor and said pole.

Claims

1. In combination with a pair of electrical conductors, where one extends under tension substantially horizontally away from a generally upright pole, and the other extends generally along said pole, a switch assembly comprising a base mounted on said pole, a pair of elongated spaced-apart insulators rigidly anchored against movement to said base, one of said insulators extending generally horizontally and substantially in axial alignment with said one conductor, said one insulator being mechanically interposed between said one conductor and said pole whereby it transmits tension between the two, and a switch including a pair of spaced-apart contacts, each mounted on a different one of said insulators, and an elongated blade mounted for movement relative to said insulators between positions making and breaking an electrical connection between said contacts, one of said contacts being electrically connected to said one conductor and the other contact being electrically connected to said other conductor.

3. The combination comprising a generally upright pole, a first electrical conductor extending under tension generally horizontally away from said pole, a second electrical conductor extending generally along and adjacent said pole, a pair of elongated spaced-apart insulators having one set of ends secured rigidly to said pole and another set of free ends remote from the pole, one of said insulators extending substantially in axial alignment with said first conductor, and said two insulators having a fixed, nonmovable relationship relative to each other, means mechanically interconnecting said first conductor and said free end of said one insulator whereby said one insulator transmits tension between said first conductor and said pole, a pair of electrical contacts each mounted adjacent the free end of a different one of said insulators, and each electrically connected to a different one of said conductors, and an elongated movable switch blade mounted for movement relative to said insulators between positions making and breaking an electrical connection between said contacts.

4. A switch assembly for connecting and disconnecting a pair of conductors, where one conductor extends under tension substantially horizontally away from an upright pole, and the other conductor extends generally along and adjacent said pole, said switch assembly comprising a base adapted to be mounted on said pole, a first elongated insulator having one end anchored to said base and another end remote therefrom, said first insulator extending generally horizontally and in axial alignment with said one conductor with said base mounted on said pole, and being fixed against movement relative to said base, means mounted on said other end of said first insulator accommodating attachment of an end of said one conductor in a manner permitting the transmission of tension through said first insulator between said one conductor and said pole, a seconD elongated insulator spaced from said first insulator having one end anchored to said base and another end remote therefrom, and also being fixed against movement relative to said base, and a switch including a pair of spaced-apart contacts and an elongated blade which is movable relative to said insulators between positions making and breaking an electrical connection between said contacts, one of said contacts being mounted on said other end of said first insulator and accommodating an electrical connection with said end of said one conductor, and said other contact being mounted on said other end of said second insulator and accommodating an electrical connection with said end of said other conductor.

5. A switch assembly for connecting and disconnecting a pair of conductors, where one conductor extends under tension away from a pole, and the other conductor extends generally along the pole, said switch assembly comprising a base adapted to be mounted on said pole, a pair of elongated spaced-apart insulators having one set of ends anchored to said base and another set of free ends remote from the base, said insulators being fixed on said base against movement relative to one another and against movement relative to said base, one of said insulators being adapted to transmit tension between said one conductor and said pole with said base mounted on said pole, and a switch including a pair of spaced-apart contacts each mounted adjacent the free end of a different one of said insulators and each adapted to be connected electrically to a different one of said conductors, and an elongated blade mounted for movement relative to said insulators between positions making and breaking an electrical connection between said contacts.

7. A switch assembly for electrically connecting and disconnecting a pair of conductors, where one of such conductors extends under tension away from a pole, said assembly comprising a switch mechanism having a pair of contacts each electrically connected to a different one of said conductors, a pair of spaced-apart, fixed-position insulators adapted to be secured against movement to said pole, each supporting a different one of said contacts, and means accomodating a mechanical interconnection between said one conductor and one of said insulators whereby said one insulator transmits tension between said one conductor and said pole.