US3629488A

US3629488A - Corona-impeding connector device for high voltage utilities

Info

Publication number: US3629488A
Application number: US15150A
Authority: US
Inventors: James Lenhart Mixon Jr
Original assignee: AMP Inc
Current assignee: TE Connectivity Corp
Priority date: 1970-02-27
Filing date: 1970-02-27
Publication date: 1971-12-21
Anticipated expiration: 1988-12-21

Abstract

The disclosure relates to a connector device for impeding corona discharges in high voltage utility lines in the region of 230 Kv. which can be installed by the use of a hot stick and a hot stick applicator for holding the corona-impeding connector during application thereof to the line, the corona-impeding connector including a set of gripping jaws which lockingly grips upon the cable due to compression thereof by means of an explosive tool or the like which forces the jaw member along an inwardly tapered portion of the corona-impeding connector to place same in compression against the cable and make a locking fit therewith. The disclosure also relates to a hot stick applicator of conductive material and coated with a nonabrasive substance, at least in the areas which come in contact with the corona-impeding connector, to prevent the formation of burrs or the like which may cause corona discharge from the corona impeding connector itself during operation thereof.

Description

' United States Patent [72] Inventor James Lenhart Mixon, Jr.

Harrisburg, Pa.

[21] Appl. No. 115,150

[22] Filed Feb. 27, I970 [45] Patented Dec. 21, 1971 [73] Assignee AMP Incorporated Harrisburg, Pa.

[54] CORONA-IMPEDING CONNECTOR DEVICE FOR 74, 79, 84 R, 84 S, 90, 94 R, 94 8,127,135,140 CR, 144; 24/126 R, 126 C, 136 B; 287/1 14; 339/270 R, 273 R, 273 S FOREIGN PATENTS 856,533 3/1940 France 935,194 2/1948 France ABSTRACT: The disclosure relates to a connector device for impeding corona discharges in high voltage utility lines in the region of 230 Kv. which can be installed by theme of a hot stick and a hot stick applicator for holding the corona-impeding connector during application thereof to the line, the corona-impeding connector including a set of gripping jaws which lockingly grips upon the cable due to compression thereof by means of an explosive tool or the like which forces the jaw member along an inwardly tapered portion of the corona-impeding connector to place same in compression References Cited against the cable and make a locking fit therewith. The CllSClO- UNITED STATES PATENTS sure also relates to a hot stick applicator of conductive materi- 2,128,112 8/1938 Barlow 24/126R and coated with a nonabrasive substance at least in the 2,567,374 9/1951 Greco 24/126 R areas which come in Contact with the corona impeding com 2,648,883 8/1953 Dupre 287/114 nector, to prevent the formation of burrs or the like which 3l63904 l/l965 Ziolklwsk' 174/84 5 X may cause corona discharge from the corona impeding con- 35l5794 6/1970 et 17 1 X nectoritselfduring operation thereof.

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SHEET 4 BF 4 CORONA-IMIEDING CONNECTOR DEVICE FOR HIGH VOLTAGE UTILITIES This invention relates to electrical connectors of the type used in conjunction with very high voltage utility lines, and, more particularly, to corona-impeding devices for terminating the ends of high voltage utility lines.

In high voltage applications, such as in the region of 230 Kv., wherein a cable is connected to a strain clamp, corona problems exist, particularly where a short length of the end of the cable leaves the clamp. One method of solving the corona problem of this type is to secure a conductive mass to the end of the cable. This has presented a great problem when operating in the voltage ranges mentioned above, particularly since there are no good insulators which would allow personnel to come into close contact with the line. It has therefore been necessary to apply such connectors to a cable by the use of hot stick applicators. The application of connectors of this type, in accordance with the prior art, has presented a problem in that it is necessary to apply the conductive mass to the end of the cable without scarring the conductive mass since scarring thereof will create further sources for corona discharge. Further, the prior art has not provided adequate hot stick applicators which are capable of holding and later releasing a conductive mass connector without scarring same and which can be easily operated with hot sticks.

In accordance with the present invention, there is provided a corona-impeding connector device for high voltage utility lines which can be readily installed by means of a hot stick without danger to the operator and with minimal problems in scarring or burring of the connector element. Also, there is provided a hot stick applicator capable of retaining a coronaimpeding connector device in accordance with the present invention for use with hot sticks and capable of release from the connector without danger to the operator and which does not damage the connector device. Briefly, the above is provided by the use of a corona-impeding connector device having a properly shaped conductive exterior and having a hollow interior with a movable pair of jaws which are movable outwardly along an inward taper for compressing the jaws. There is also provided means at the other end of the connector for ramming the jaws outwardly over a cable to provide inward compression due to the taper and therefore a firm mechanical lock between the connector and the cable. There is also provided a hot stick applicator having means thereon for connection to a hot stick and also having a coating thereon for prevention of scarring or burring of the corona impeding connector device.

It is therefore an object of this invention to provide a corona impeding connector device which may be secured to high volt age cables and will substantially reduce corona damage to the cable or to clamps or connectors in close proximity thereto.

It is a further object of this invention to provide a coronaimpeding connector device for high voltage utility lines capable of rapid and safe insertion by means of hot stick devices.

It is a yet further object of this invention to provide a hot stick applicator for use with the corona-impeding connector device of the present invention capable of use with hot sticks which substantially reduces the possibility of scarring or burring the connector device.

The above objects and still further objects of the invention will immediately become apparent to those skilled in the art after consideration of the following specific embodiments of the invention which are provided by way of example and not by way of limitation wherein:

FIG. I is a diagrammatic view showing a high voltage line secured to a strain clamp with a corona-impeding device attached to the wire where it leaves the clamp;

FIG. 2 is a perspective view of a corona-impeding connector in accordance with the present invention;

FIG. 3 is a view taken along the line 3-3 of FIG. 2;

FIG. 4 is a view taken along the line 44 of FIG. 2;

FIG. 5 is an exploded view of a one embodiment of the connector in accordance with the present invention;

FIG. 6 is a view similar to FIG. 4 but after termination;

FIG. 7 is a sectional view of a second embodiment of the connector of the present invention;

FIG. 8 is a perspective view of a hot stick applicator;

FIG. 9 is a sectional view of the hot stick applicator applied to a connector of the present invention; and

FIG. 10 is a diagrammatic view of a connector installation in accordance with the present invention.

Referring first to FIG. 1, there is shown a high voltage line 1 having a strain clamp 2 thereon and a terminated short length of cable which is terminated by the means of a corona-impeding connector 3 in accordance with the present invention.

The corona-impeding connector 3 in accordance with the first embodiment of the invention (FIGS. 2 to 6) includes a body 4 which may be cast from aluminum or other electrically conductive metal. The body member 4 has a tapered cavity 5 constituting the cable entry means in one end thereof and a threaded passageway 6 in the other end thereof. The end of body 4 having threaded passageway 6 is bulbed or enlarged as shown in the drawing. An insert member 8 is disposed in cavity 5. Insert 8 moves in cavity 5 and serves to close onto a cable end for a mechanical and electrical connection. Insert 8 may be a slotted unitary structure so that it will close onto a cable as it travels toward the small end of its tapered cavity 5 as shown in FIG. 9 or it can be as shown in detail in FIG. 5.

Referring now particularly to FIG. 5, there is shown an embodiment of the insert member 8 in exploded form. The insert member 8 includes a pusher plate 50 and four jaw segments 52 which are secured to the pusher plate by means of a set screw 54 and washer 56. The jaw segments 52 are positioned over the pusher plate 50 so that their triangular portions 58 are positioned in the triangular grooves 60 of the pusher plate. The washer 56 is then placed over the portions 58 and bolted to the pusher plate by setscrew 54. Each jaw member 52 has an inwardly tapered serrated gripping surface 62 for gripping a wire 1, each jaw member also having a weakened area 64 at which bending can take place due to compression of the jaw members during termination. Bending of the weakened area 64 due to such compression of the jaw members allows the jaw members to collapse radially inwardly as the jaws travel toward the small end of the tapered cavity 5.

The threaded passageway 6 can receive an explosive tool directly therein or it can receive a rotatable member 66 which can be rotated by a crank 68 for applying a compressive force to the jaw segments 52.

In use according to the first embodiment, the head of an explosive tool of well-known type can be threaded onto the passageway 6 whereafter the device 2 is pushed onto the cable. The explosive tool is then fired during which time the ram of the tool pushes the insert 8 outwardly in the direction of the taper. During its travel, insert 8 is inwardly compressed and closes onto the cable 1. The tool is then removed.

The result is a device of substantial mass on the end of a high voltage cable, the outside shape of which is suitably tapered and curved in order to shield and prevent corona discharge with no damage to the cable or the strain clamp. Alternately, as stated above, a setscrew may be placed into the passageway 6 to push the insert 8 toward the tapered portion of the body member of the body 4. In addition, a device of substantially the same outer shape with no threaded passageway 6 or with no insert 8 may be crimped or bolted onto a cable end, however this would be difficult under very high voltage applications.

In use, according to the second embodiment, a cable I is inserted into cavity 4 and bottomed against pusher plate 50. An explosive tool is threaded into the passageway 6 whereafter the tool is fired. The ram of the tool forces the pusher plate 50 and jaws to the right in tapered cavity 4. The jaws 52 compress inwardly onto the cable 1 for mechanical and electrical connection as shown in FIG. 6. The explosive tool is then removed and a closure plug (not shown) may be threaded into the passageway 6.

As stated above, a threaded plug with a ram on the end thereof may be turned into passageway 6 to effect the connection in which case an explosive tool would not be used. It should also be noted that terminals and connectors utilizing the principle of this invention may be used as shown in FIG. 6.

Referring now to FIG. 7, there is shown a second embodiment of a connector in accordance with the present invention. This embodiment is similar to the embodiment of FIG. 2 to 5 and operates in the same manner. The differences are in shape and the possibility of operation thereon by attaching a hot stick through the aperture 70 thereon. Otherwise, elements the same as those of the embodiment of FIGS. 2 to 6 are provided with the same character reference.

Referring now to FIGS. 8 through 10, there is shown a hot stick applicator for use with the corona-impeding connector device of FIG. 1 through 6.

The hot stick applicator 40 is of cylindrical shape having a hollow interior portion which is greater in cross section than is the cross section of the corona-impeding connector device to be used therewith. The applicator 40 includes a cutout region 42 therein and a retaining member 44 which is secured to a threaded extension 46 which passes through a threaded portion in the applicator and includes at its outside end a circular portion 80 for use with a hot stick. The entire applicator or just those regions which would come in contact with a coronaimpeding connector device will be coated with a soft material to prevent burring or scraping of the connector device. The connector device 3 is secured within the applicator 40 by placing one portion of the thicker region thereof into the aperture 42 and tightening the securing portion 44 at the other end thereof by means of the threaded member 46 to secure the connector device into the applicator as shown in FIG. 9. The applicator also includes a hot stick securing device 82 to which hot sticks 84 are applied after placement of the connector device into the applicator. By means of the hot sticks, the applicator 40 with connector device 3 therein is positioned whereby the open end 4 of the connector is placed over a cable 1 to be terminated as shown in FIG. 10. An explosive device 66 or the like is then threaded into the apertures 6 by means of a hot stick and operated to move the jaws 52 over cable 1 whereby secure mechanical and electrical connection is made between the connector device and the cable. The explosive device or the like is then removed by means of a hot stick and the threaded member is also then rotated whereby the connector device can then be removed from the hot stick applicator. The applicator 40 can then be removed by means of the hot sticks 84 with the cable 1 now being terminated by means of the corona-impeding connector device 3 in accordance with the present invention.

It can be seen that the corona-impeding connector device in accordance with the present invention can be quickly and easily installed by means of hot sticks and by means of a relatively simple hot stick applicator in accordance with the present invention with the provision of relatively minimal scarring or burring of the connector device and with minimal danger to the operator.

Though the invention has been described with respect to a specific preferred embodiment thereof, many variations and modifications thereof will immediately become apparent to those skilled in the art. It is therefore the intention that the amended claims be interpreted as broadly as possible in view of the prior art to include all such variations and modifications.

What is claimed is:

1. In a connector for an electrical cable, the combination comprising: a tapered cavity in one end of said connector and adapted to receive an electrical cable end, a passageway in said connector and communicating with said cavity, an insert mounted for movement within and toward the narrow end of said tapered cavity, said insert including a plurality of jaws adapted to receive the cable ends there between, each of said jaws being fixedly mounted on said insert in radial spaced relationship, each of said jaws including a weakened portion along its length thereof allowing each of said jaws to be bent individually along its length in cantilever fashion about said weakened portion and radially inward m gripping relationshlp on said cable end, means communicating with said passageway for forcefully moving said insert toward the narrow end of said tapered cavity, wherein said insert further includes a pusher plate connected to each of said jaws and in alignment with said passageway, said means forcefully reacting against said pusher plate for moving said insert toward the narrow end of said tapered cavity, and wherein said insert further includes a washer overlying a portion of each of said jaws and secured to said pusher plate.

2. The structure as recited in claim 1, and further including: a setscrew securing said washer to said pusher plate.

3. The structure as recited in claim 2, wherein, said weakened portion of each jaw is circumferentially spaced from an adjacent jaw, and said washer is located between all of said jaws and adapted to receive the cable end in abutting relationship therewith.

5. The structure as recited in claim 1, and further including: positioning means secured to said jaw members to position said jaw members in the shape of a frustum of a cone, said frustum of a cone having substantially the same shape as said tapered cavity, and said jaw members being spaced from each other to allow radially inward compression thereof.

4. The structure as recited in claim 3, wherein, said connector includes at one end thereof a bulbed configuration.

6. The structure as recited in claim 5, wherein, the interior surfaces of said jaws include serrations thereon.

$ i i i

Claims

1. In a connector for an electrical cable, the combination comprising: a tapered cavity in one end of said connector and adapted to receive an electrical cable end, a passageway in said connector and communicating with said cavity, an insert mounted for movement within and toward the narrow end of said tapered cavity, said insert including a plurality of jaws adapted to receive the cable ends there between, each of said jaws being fixedly mounted on said insert in radial spaced relationship, each of said jaws including a weakened portion along its length thereof allowing each of said jaws to be bent individually along its length in cantilever fashion about said weakened portion and radially inward in gripping relationship on said cable end, means communicating with said passageway for forcefully moving said insert toward the narrow end of said tapered cavity, wherein said insert further includes a pusher plate connected to each of said jaws and in alignment with said passageway, said means forcefully reacting against said pusher plate for moving said insert toward the narrow end of said tapered cavity, and wherein said insert further includes a washer overlying a portion of each of said jaws and secured to said pusher plate.