US 3753203 A
A shielded electrical connector for a high voltage cable having a section of the cable insulation removed to expose a conductor, the connector including an electrically insulating member surrounding the cable insulation and conductor, and an electrically conductive shield surrounding said insulating member. The conductive shield is formed from a layer of electrically conductive material and a metallic mesh, the shield being bonded to the outer surface of the insulating member. A disconnect assembly can be provided for selectively connecting and disconnecting the shield to the cable.
Description (OCR text may contain errors)
gh voltage cable 11 removed to exg an electrig the cable insulatrically conductive yer of electrically c mesh, the shield the insulating Aug. 14, 1973.
3,390,331 6/1968 Brown et Primary Examiner-Marvin A. Champion Assistant Examiner-Robert A. Hafe Attorney-Ronald E. Barry et al.
 ABSTRACT A shielded electrical connector for a hi having a section of the cable insulatio pose a conductor, the connector includin 1y insulating member surroundin tion and conductor, and an elec ield surrounding said insulating member. The conuctive shield is formed from a la conductive material and a metalli eing bonded tothe outer surface of member. A disconnect assembly can be provided for selectively connecting and disconnecting the shield to mm QM fix a wwwm a I 1 Ill! 1114: ll! 9 1 tlitt ilMrID/O v r/l w n w W 5 Sankey.......
United States Patent [1 1 Link [ SHIELDED HIGH VOLTAGE CONNECTOR  Inventor: Edwin A. Link, Waukesha, Wis.  Assignee: RTE Corporation, Waukesha, Wis.
 Filed: June 30, 1971  App1.No.: 158,159
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UNITED STATES PATENTS 3,376,541 I 4/1968 2,522,072 9/1950 Tiemey.... 3,617,987 11/1971 3,585,568 6/1971 l SHIELDED HIGH VOLTAGE CONNECTOR BACKGROUND OF THE INVENTION An electrical connector or terminator of the type contemplated herein is shown in US. Pat. No. 3,376,541 entitled Safe Break Terminator. This connector includes a plug assembly having an insulating member surrounding the cable and a conductive shield on the outer surface of the insulating member, either coated thereon or formed as a separate layer which is then bonded to the insulator. The conductive shield is provided to protect the lineman from high voltages which may be present in the conductor. However, in the event of a fault, the high current present on the insulator tends to be grounded by the lineman rather than through the shield. This is due to the high resistance of the electrically conductive shield.
SUMMARY OF THE PRESENT INVENTION The electrical connector of the present invention includes an insulating member for the cable and a low resistance electrically conductive shield on the outer surface of the insulator. The conductive shield includes a metallic mesh to provide a low resistance path from the external conductive shield to the cable sheath. The shield can be connected to the semi-conductive sheath of the cable by a disconnectable type assembly provided on the conductive shield. The conductive shield can also be permanently connected to the sheath by an interference fit at the sheath end of the connector. If the shield is insulated from the grounded sheath, the shield can then be used as a means for detecting the presence of a voltage on the cable. This is due to the capacitive relationship of the conductive shield to the conductor in the cable.
Other objects and advantages of this invention will become apparent from the. following description when read in connection with the accompanying drawings.
THE DRAWINGS FIG. 1 is a side elevation view in section showing the connector of the present invention; i
FIG. 2 is an enlarged view of a portion of the stress cone of the connector showing the conductive shield permanently connected to the cable sheath;
FIG. 3is a view of a portion of the connector showing the connector shield connection to the cable concentric neutral; and
FIG. 4 is a view of an alternate form of disconnect assembly for disconnecting the cable sheath and concentric neutral to the conductive shield of the connector.
DESCRIPTION OF THE INVENTION The connector of the present invention is shown and described herein as an elbow connector for terminating a high voltage cable 12. It should be recognized, however, that the connector 10 can also be used to form a splice in a high voltage cable by providing similar connections to the cable sheath at each end of the connector as described hereinafter.
Referring to FIGS. 1 and 3 of the drawings, the electrical connector 10 of the present invention is shown as a terminator for a high voltage cable 12 of the type having a cable sheath 14 including a concentric neutral formed of a number of electrically conductive strands 15, a cable insulation 16, and a conductor 18. The cable 12 is normally prepared for termination by unwinding the strands 15 of the concentric neutral from the end of the cable and stripping the semi-conductive sheath 14 from the cable 12 to expose a portion of the cable insulation 16. A portion of the cable insulation 16 is then removed from the end of the cable 12 to expose a portion of the conductor 18.
As is generally well known, cable termination is made by securing or crimping a conductive member to the conductor 18 and inserting the end of the cable 12 with the conductive member 20 attached into the connector 10. The conductive member 20 includes a threaded opening 21 and is retained in the connector 10 by means of a conductive contact 22 which has a threaded section 24. The threaded section 24 is screwed into the threaded opening 21 provided in the conductive member 20. The conductive contact 22 extends outwardly into a recess 25 provided in the connector 10.
The electrical connector 10 is mounted on a receptacle 26 which has an outer surface 29 corresponding to the inner surface of the recess 25' and a conductive sleeve 28 positioned to receive the tubular contact 22. The receptacle 26 can be any form of high voltage contact such as used on a transformer, cable splice, etc. or another high voltage cable if the connector is used to form a splice.
The connector 10 generally includes an insulating member 30 and an electrically conductive shield 32. An electrically conductive insert or lining can be pro vided on the inner surface of the insulator to eliminate electrical stress on the void around the conductive member 20 and contact 22.
The insulating member 30 is generally molded from a dielectric material and includes the tapered recess 25 and a cable passage or opening 36. The insulating member 30 is shielded by means of the electrically conductive shield 32 which includes a coating or layer 38 of electrically conductive material secured to the outer surface of the insulating member 30. The coating or layer 38 is insulated from the cable 12 by means of small sections 40 and 42 of the insulating member which extend beyond the end of the shield 32.
. The insulating member 30, the shield 32, and the lining 34 are all formed of an elastomer or rubber. A conductive material such as lampblack, graphite or carbon black is combined with the elastomer or rubber used for the shield 32 and lining 34. The member 30, shield 32 and lining 34 are molded to the desired shape as is generally understood in the art.
In accordance with the invention, means are provided in the connector 10 to provide a low resistance current path to ground. Such means is in the form of a metallic material which is shown embedded in the conductive layer 38. It should be noted, however, that the metallic material 50 can be embedded in the outer surface of the insulating member 30 in the space between the insulating member 30 and the layer of conductive elastomer 38 or within the layer 38 as shown. The metallic material in the preferred form shown in the drawing is in the form of a metallic mesh. Metallic material in the form of strands of metal or metallic chips can also be used. A high conductive metal such as copper should be used to provide the low resistance path for any fault currents which may occur in the connector.
Means are provided for connecting the shield 32 to the semi-conductive sheath 14 of the cable 12. Such means is in the form of a disconnect assembly 52 which is partially embedded in the shield 32. In this regard, the assembly 52 includes a sleeve 54 having a threaded opening 56 and a flange 58 at the inner end. The flange 58 and a portion of the sleeve 54 are embedded within the conductive layer 38, with the open end of the sleeve 54 extending outward from the outer surface of the shield 32. A hot stick type screw 60 having a threaded section 62 is threadedly received in the sleeve 54 and a number of strands of the concentric neutral are connected to the screw 60. In the event of a fault current occurring in the conductor 18, the low resistance metallic material will provide a low resistance path through the assembly 52 and cable sheath 14 to ground.
The conductive shield 32 can be permanently connected to the cable sheath by means of an interference fit as shown in FIG. 2. In this embodiment, the section 40 has been removed from the insulating member 30 and the diameter of the opening at the end 31 of the insulating member has been made slightly smaller than the diameter of the cable sheath 14. An interference fit is thereby provided which assures electrical contact between the conductive shield 32 and the cable sheath. The strands of the concentric neutral can be wrapped around the end 31 of the insulating member.
The conductive shield 32 can be used to detect the absence or presence of a voltage on the cable by disconnecting the conductive shield 32 from the cable sheath 14. This is accomplished by means of the disconnect assembly 52. In this regard, on removal of screw 60 and strands 15 from the sleeve 54', the conductive shield will be insulated from the cable sheath 14 by the small sections 40 and 42 of the insulating member 30. The layer of conductive material 38 will then provide a capacitive reaction to any voltage present in conductor 18. Contacting the conductive shield 32 with a voltage sensing device will then provide an indication of the absence or presence of voltage on the cable.
In the alternate form of the means for connecting the shield 32 to the sheath 14 in FIG. 4, a disconnect assembly 69 having an electrically conductive collar 70 and a conductive contact 74 is mounted on the cable 12. The collar 70 is formed of an electrically conductive material as described above in connection with conductive layer 38 and includes a conical section 72. The collar 70 is connected to the semi-conductive sheath 14 by means of the electrically conductive contact 74 which is provided on a metal ring 76 mounted on the collar 70 and is connected to the strands 15 of the concentric neutral. After cable termination has been completed, the collar 70 is pushed upward into engagement with the connector 10 with the conical section 72 in engagement with the shield 32 on the connector 10. A low resistance connection is then provided from the shield 32 through the collar 70'and the connector 74 to the sheath 14. When it is desired to disconnect the conductive shield 32 from ground, the conical section 72 is turned back as shown in phantom line in FIG. 4. 1
The elbow connector 10 can be disconnected from the bushing 26 by means of an eye provided in the conductive shield 32. The eye 80 can be reinforced by providing a metallic insert or plate 82 having an opening 84 within the conductive material. The inserts 82 should extend around a portion of the outer surface of the insulating member 30 to anchor the insert firmly into the conductive material.
RESUME The connector 10 of this invention protects the lineman from possible electrical shocks due to high currents which may be present on the connector. This is accomplished by incorporating a metallic material in the conductive shield of the connector to provide a low resistance current path to ground. The low resistance current path should have a resistance less than the resistance path through the body of a man to assure that high currents will be grounded through the connector. The incorporation of the metallic mesh in a semiconductive resilient shield allows the connector to be forced onto a bushing without adversely affecting the conductive shield. The conductive shield can also be used to detect voltage by disconnecting the conductive shield from the cable sheath.
1. A cable connector for a high voltage cable having a cable sheath, said connector comprising,
an electrically insulating member adapted to be mounted on the cable and having an interference fit therein,
an electrically conductive shield on the outer surface of said insulating member,
said shield being formed from an electrically conductive low resistance metallic mesh and a layer of electrically conductive high resistance resilient material,
and electrically conductive means for grounding said shield and metallic mesh to the cable sheath whereby high fault currents present in the cable are grounded through the cable sheath.
I 2. The connector according to claim 1 wherein said metallic material is embedded in said layer of electrically conductive resilient mesh.
3. The connector according to claim 1 wherein said metallic mesh is mounted in tight engagement with the outer surface of said insulating member and said resilient layer completely covers the mesh and the outer surface of said insulating member.
4. The connector according to claim 1 wherein said grounding means comprises a conductive disconnect assembly partially embedded in said shield in direct contact with said mesh and adapted to be connected to the semi-conductive sheath of the cable.