US3549834A - Disconnect switch - Google Patents

Description

United States Patent Appl. No. Filed Patented Assignee DISCONNECT SWITCH 6 Claims, 4 Drawing Figs.

U.S. Cl. Int. Cl. Field of Search 200/48 ...H0lh 31/00 200/48; ,174/161,45,148,169,139, 177

References Cited UNITED STATES PATENTS Koppitz 200/48 Primary Examiner- Robert K. Schaefer Assistant Examiner-H. J. Hohauser Attorney- Spector & Alster ABSTRACT: A disconnect switch of the in-line type which includes a supporting strain insulator that is adapted to be placed in series in an electrical transmission line and wherein the opposite ends of the insulator support cooperating parts of a circuit interrupter which, in its closed position, electrically shunts the opposite ends of the insulator. The insulator is of the type that includes a tongue at one end and a clevis at the other end, and the circuit interrupter includes a pair of clips, one of which is mounted on the tongue of the insulator and the other on the clevis. Each clip isa unitary structure locked to the insulator by a single pin.

DISCONNECT SWITCH F This invention relates to improvements in disconnect switches of the type used in electric power transmission lines, as shown in Swedish Pat. 80825 of July 3, 1934 and US. Pat.

Nos, 1,821,167 and 3,300,599. Such switches include a strain insulator .the opposite ends of which support elements of a circuit-int'errupting device which when closed establishes a shunt acrossthe opposite ends of the insulator.

It is an object of this invention to provide a disconnect provide a switch of the type'stated which utilizes an insulator that has a tongue at one end and a clevis at the other end (which is a type of insulator termination that facilitates niechanicallyjoining of .such insulators in a string), and

wherein the circuit interrupter includes mounting clips, one of which has a socket for receivingthe tongue and the other is received in the clevis. Each clip is se cured to the insulator by a pin that passesthrough the tongue or clevis, as the case may v It is a still further object of this invention to provide a switch of the above-mentioned characterwherein the clip at each end of the insulator is a unitary one-piece structure of material of high electriccurrent conductivity and terminating at one end in a switch terminal. A circuit interrupter in the form of an electric switch blade is mounted on the terminal of one of the clips and is movable into and out of engagement with the switch terminal of the other clip.

The attainment of the above and further objects of this invention will be apparent from-the following description taken in conjunction with'the accompanying drawing forming a part thereof.

the drawing:

FIG. 1 is a side elevational view of a disconnect switch constructed in accordance with and embodying the present invention;

FIG. 2 is a bottom plan view thereof; and

, FIGS. 3 and 4 are fragmentary sectional views taken along lines 3-3 and 4-4 respectively, of FIG. 1.

Referring now in more detail to the drawing, 1 designates a disconnect switch comprising two unitary terminal clips 2,3 of metal of high electric conductivity, mounted on opposite ends of a strain insulator 5, which is a one-piece plastic dielectric material that is capable of withstanding the tension to which it will be subjected when the switch is installed in the power line. Thejinsulator 5 has at one end a metal cap 4 having a tongue 6 and .at the other end a metal cap 4 having a bifurcated portion or ,clevis7. The caps are permanently secured in place, as for instance in the molding operation, or otherwise. The clip 2 has a central socket 9 that receives the tongue 6. A pin 13 passes through the tongue 6 and thewalls of the clip 2 that define the sides of the socket, to lock the clip 2 to the insulator. The surface10 of the clip is flush against the adjacent surface 11 that is at the base of the tongue 6 to lock the clip against turning withlrespect to the insulator 5 The central portion 14 of the clip 3 is received in the clevis 7, with the full length of the clip surface 15 bearing against the adjacent surface at the base of the clevis 7. A pin 17 passes through the clip 3 and both tongues of the clevis 7, locking clipto the insulator 5. Both pins l3, l7 lie substantially at the longitudinal axis of the insulator 5. Each clip 2, 3 terminates in a lower portion that constitutes a switch terminal, and at its upperportion in a construction for making a current conductor connection therewith.

Rotatably mounted at the lower end of the clip 3 by a pin 18 is a switch blade 19 having opposed tines 20, 21 that embrace and Pbear against the switch terminal portion of the clip 3. When the switch is closed, the unpivoted ends of the tines 20, 2 1 lie on opposite sides of and engage switch terminal 22 which is the lower contact-forming end of the clip 2, to complete aucircuit between the clips 2, 3. Spring loaded bolt and nut assemblies 24-24 maintain the pressure of the ends of the tines against the clips 2, 3.

Attached to the clip 2 is a downwardly opening bladereceiving member or guide 25. A spring-biased latch book 26 is pivoted to the blade and has a pull ring 27 for engagement by a suitable tool so that upon pulling on the ring the latch hook 26 pivots to release the latch to allow the switch blade 19 to swing downwardly by continued pulling onthe ring. The construction and arrangement of theswitch blade and the guide 25 and spring-biased latchhook areconventional and are, therefore, not described in detailherefi'ri'.

Projecting respectively from the riiaih body portions of the clips 2,3 are supports 29, 30 for moiiriti the switch in a power line with the insulator 5 underten mliach support has a pin 31 that lies on the longitudinal axis ofthe insulator 5. Extension links 33, 34 are pivotally secured tothe clips2, 3 by the pins 31, 31 One of the supports 29 is bifurcated, as shown in FIG. 2, for receiving an eye of the extension link 33. The extension link 33 is clamped to and thus supported by a stationary power line insulator i that may be mounted on a power pole.

The clips 2, 3 have contact pads 36, 36' at their upper ends through which bolt holes 37, 38, 39 extend. Conductors '41, 41', which are electrically the ends of portions of a conductor of a power transmission line, are each clamped at one end to 'the respective contact pads 36* or 36' in a conventional manner, as by a clamp or similar device that is held in place by two bolts passing through theholes 37, 38. or 38, 39. One side of the part of the line is mechanically terminated by being clamped to an eye 45 of the link 33 and may continue from there as part of the conductor 41 or be electrically connected at the eye 45 to the conductor 41. The opposite side'of the line is mechanically terminated at an eye 46 of the link 34 and is either electrically connected to theconductor 41 or the conductor. 41 constitutesa.continuation of the end of the line, that is mechanically terminated at the eye 46. The line is assumed to be pole-supported adjacent tothe left-hand side of the switch, the portion of the linethat extends to the right.

from the link 34 being supported at its far end by the next pole or tower. The switchis free to tilt to a limited degree in a vertical plane about the pivot pin 31 as a center. The required amount of tilting is very-slight and is determined by the angle of inclination to the horizontal of the end of the transmission line conductor that is connected to the link 34, due to the ordinary sag of the line.

The power line is mechanically connected to the free ends of the extension links. 33, 34 with the ends of the power line connected to the conductors 41, 41 respectively. The switch is in the power line. The insulator 5 is in tension. The insulator 5 rigidly joins the clips 2 and 3. The insulator constitutes a break in the electrical continuity of the: line when the switch 19 is open. When the switch is closed it reestablishes the electrical continuity of the line.

It is to be noted that the pin 31 passes through the longitudinal axis of the insulatortS (and the same is also true of the pin 31'). This permits the necessary turning of the entire unit about the pin 31 as a center, as may be necessary due to the small sag of the line that is connected to the line 34, all without subjecting the insulator 5 to bending stresses.

The precise constructions herein shown are illustrative of the principles of the invention.

Iclaim:

1. An electric disconnect switch for power transmission lines comprising spaced-apart contact clips each having a pad portion at which electrical contact may be made with a power line, a switch blade having contact means and being pivotally attached to one of the clips, the other clip having switch contact means for releasableengagement with the contact means of the switch blade, an insulator extending between the contact clips, said insulatonhavinga tongue at one end and a clevis at its other end, one of said clips having a socket for. receiving said tongue and the other of said clips having a portion thereof received in said clevis, means passing through the clevis and its associated clip for securing the insulator to that clip, and means passing through the tongue and its associated clip for securing the insulator to the last-mentioned clip, the

sides of the tongue and the sides of the arms of the clevis being parallel to one another and centered with respect to the longitudinal axis of the insulator, and said insulator having a longitudinal axis extending through said clips, and each of said clips has means parallel to one another and forming parallel axes separated from one anotherby the insulator and at which the switch may be pivotally supported with tensile forces applied at said mounting means to place said insulator in tension.

2. An electric disconnect switch for power transmission lines comprising spaced-apart contact clips each having a pad portion at which electrical contact may be made with a power line, a switch blade having contact means and being pivotally attached to one of the clips, the other clip having switch contact means for releasable engagement with the contact means of the switch blade, an insulator extending between the contact clips, said insulator having a tongue at one end and a clevis at its other end, one of said clips having a socket for receiving said tongue and the other of said clips having a portion thereof received in said clevis, means passing through the clevis and its associated clip for securing the insulator to that clip, and means passing through the tongue and its associated clip for securing the insulator to the last-mentioned clip, said insulator having a'longitudinal axis, and said means passing through said cleavis and said means passing through said tongue are pins at said longitudinal axis, and each clip has means at said longitudinal axis and spaced from the associated pin for forming a pivotal connection to support the switch.

3. A switch comprising a strain insulator, electrically conducting switch clips one on each end of the insulator, a pin securing each clip to the insulator, said pins being parallel to one another and at right angles to the longitudinal axis of the insulator, cooperating means between each clip and the insulator for locking the clip to the insulator against turning with respect to the insulator, each clip having a portion for receiving a line wire connection and having another portion constituting a switch terminal, which portions together are a onepiece structure, means for making a mechanical terminating connection of a part of an electric transmission line and the switch at one of the clips, and means for making a mechanical terminating connection of another part of the same line at the other clip whereby the insulator mechanically connects and electrically separates the two portions of the line, means for making electrical connections between the respective terminated parts of the line and the respective associated clips, and a switch blade movable into and out of a position electrically connecting the switch terminals.

4. A switch comprising a strain insulator, electrically conducting switch clips one on each end of the insulator, means securing each clip to the insulator, cooperating means between each clip and the insulator for locking the clip to the insulator against turning with respect to the insulator, each clip having a portion for receiving a line wire connection and having another portion constituting a switch terminal, means for making a mechanical terminating connection of a part of an electric transmission line and the switch at one of the clips, and means for making a mechanical terminating connection of another part of the same line at the other clip whereby the insulator mechanically connects and electrically separates the two portions of the line, means for making electrical connections between the respective terminated parts of the line and the respective associated clips, and a switch blade movable into and out of a position electrically connecting the switch terminals, each of said clips having a switch mounting portion, the respective switch mounting portions being at locations in line with the longitudinal axis of the strain insulator.

5. A switch according to claim 4 wherein separate switch mounting links are secured to the switch mounting portions of the respective clips.

6. A switch according to claim 5 wherein there is a line insulator supporting one of the links.

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