US3701839A

US3701839A - Shield connector for multi-strand shielded cables

Info

Publication number: US3701839A
Application number: US168087A
Authority: US
Inventors: Donald J Smith
Original assignee: Smith-Schreyer and Assoc Inc
Current assignee: Smith-Schreyer and Assoc Inc
Priority date: 1971-08-02
Filing date: 1971-08-02
Publication date: 1972-10-31
Anticipated expiration: 1989-10-31

Abstract

A connector for use in splicing multi-strand shielded cables, particularly designed for interconnecting the shields thereof. Here the connector is provided with a protruding tang providing a secondary current path between the shield and the connecting strap.

Description

0 United States Patent 15] 3, Smith 1451 Oct. 31, 1972 [54] SHIELD CONNECTOR FOR MULTI- [56]- References Cited STRAND SHIELDED CABLES UNITED STATES PATENTS [72] Inventor: Donald J. Smith, Canoga Park,

Calif. 3,499,972 3/1970 Smith ..174/7s x 1731 A gn y m -d Primary Examiner-Mamie E. Askin 221 Filed: u 2, 1971 4" & 4" 21 Appl. No.1 168,087 i [57] ABSTRACT I I A connector for use in splicing multi-strand shielded 52 us. c1. ..174 78, 339/14 R, 339/95 R, cables, paniculafly designed f interconnecting the [51] Int CI p Bo "/1 shieldsthereof. Here the connector is provided with a r 'd' t 58 Field ofScarch....l74/78, as R; 339/14 R, 14L, protruding tang a secondary path 339/95 R, 263 R, 263 L between the shield and the connecting strap.

12 Claims, 6 Drawing Figures 1 I SHIELD CONNECTOR r'o'n MUL'II-STRAND v SHIELDED CABLES BACKGROUND OF THEINVEN'IION Telephone cables typically consist of a large number of conductors, surrounded by a Shield whichis of electrically conducting material, intheform of a tube having rather thinwalls, so that the resulting cable is flexible yet strong enough to prevent damage to the cable and to electrically isolate the interior conductors. The shield is then surrounded by insulatingsheath. Inmy previously issued patent entitled CONNECTOR AND CONNECTION, FOR SHEATH CABLE SHIELD US. Pat. No. 3,499,972, issued Mar. 10, I970, there is disclosed a connector suitable for interconnecting the shield of cables of this type. :The present disclosure constitutes an improvement over the invention shown in the aforesaid patent.

In the shield connector device shown in the previously issued patent, a tapered base section makes electrical contact with the cable shield, and the connector is securely fastened to the shield by means of a threaded stud and a bridge, whereupon a conductor strap is fastened to the threaded stud placingit in electrical contact with the bridge, and then the conductor is connected to another similarshield connector, which is similarly fastened to the other end of the cable to which the splicefis made. Current being carried by the shield is'then conducted through the threaded stud to the interconnecting strap. Normally, current carried in a shield is relatively small, but telephone cables are frequently mounted upon power poles in the vicinity of cables carrying very high currents for power purposes. If one of these cables breaks and comes into co'ntac't with the telephone cable, or should lightning strike the telephone cable, a very high current can be delivered to the shield. Because of its size, the threaded stud may be unable to handle this very high current in which case it can be burned through. The shields are grounded at various intervals, but if the, threaded stud is burned through, the current path to ground will be interrupted presenting a considerable hazard. I

SUMMARY OF THE INVENTION It is an object, therefore, of the present invention to provide an improved shield connector having another path for current in addition to the threaded stud, whereby highcurrents induced upon the shield will not cause an electrical failure in the shield connectors.

The foregoing'object is accomplished by the present invention, by providing the tapered base of the connector with an upraised tang, which extends through the cable shield, and the outer insulation sheath and makes electrical contact with the interconnecting strap.

Other objects and advantages of the present invention will become readily apparent upon reading the ensuing detailed description in conjunction with the accompanying drawings.

DESCRIPTION OF THE DRAWINGS FIGS. 1 and 2 are perspective views of a portion of shielded cable having the improved shield connector attached thereto.

FIG. 3 is an exploded perspective view of the im proved shield connector.

FIG. 4 is a partial sectional view of the improved shield connector attached to a portion of shielded cable. FIG. 5 is a top plan view of the improved shield connector. v I

FIG. 6 is a bottom'plan view of the improved shield connector. I r

DETAILED DESCRIPTION or THE PREFERRED EMBODIMENT The shield connector comprises a tapered base portion 12, having a broad end '14,, and a narrow end 16. The base portion 12 is curved so as to generally conform to the curvature of a cable. A threaded stud 18 is affixed to the base 12 and projects upwardly from the convex part thereof. The base 12 is provided with one or more friction tangs 20, the purpose of-which will be more readily apparent following the description of its method of attaching to a cable. v i a The connectornext comprises abridge 22, having a web portion 24, and depending legs 26. It will be seen that the depending legs form a recess'28, which is curved to generally conform to the curved outer shape of acableaNea'r one end of the web 24 there is provided a'passageway'3i0, adapted to receive therein the threaded stud 18. A nut32 is provided for'threading onto the stud 1.8 j I v The tapered base member 12 is provided at the broad end 14 thereof with an upraised conductor tang 34. This tang 34 projects upwar'dly in the approximately same direction as the threaded stud 18, and is of greater length than the friction tangs 20. Conductor tang 34 is situated generally along the longitudinal axis of the base 12, substantially in alignment with the position of the stud 18. I

FIGS. 1 2 and 4 illustrate a preferred manner of connecting the shield connector to a cable. The cable 36 has a plurality of conductors 38 formed ina bundle in the interior thereof. These conductors 38 are surrounded by a thin insulating layer 39, then a conductive shield 40, which is in turn surrounded by an outer insulating sheath '42. The shield 40, and the insulating sheath 42, are cut or slit as shown at 44 in FIG. 1. The

tapered base portion 12 of the connector is then in-- serted with the small end 16 first between the shield 40, and the insulating layer39, so that the stud 18 and the tang 34 are in the slit 44 and projecting through the sheath 42. In this manner, the base 12 is in electrical contact with the shield 40. An interconnecting strap 46, which is typically of the woven or braided conductor type, is next positioned over stud l8 and then the bridge 22 is installed by inserting the stud 18 through the passageway 30, whereupon the nut 32 is threaded onto the stud and firmly afiixed. In this manner, electrical contact is established between the shield 40, through the base 12, then through the threaded stud 18, to the web 24 of the bridge 22 through the depending legs 26 to the interconnecting strap 46. In addition,

electrical contact is established through the current conducting tang to strap 46. The other end of strap 46 will be connected to another cable, to which a splice is made and the manner of connecting'thestrap thereto will be substantially identical.

It will thus be seen that the tang 34 provides a secondary current path over and above that provided by the 3 stud 18. Although tang 34 is aligned along thelongitudinal axis with the stud 18, it is not parallel therewith in the lateral axis as seen in FIG. '4, but is bent slightly away from the stud. This tang is located, when the parts areassembled, so that it is not under the bridge,- but extends upward near the end of the bridge. When attached to a cable as previously described, the angled configuration of the tang working in close proximity to v the bridge operates to gather and compress a portion of the strap, as shown in FIG. ,4, assuring a tight electrical connection.

It has been found that in the absence of tang 34 high currents in the neighborhood of 1,200 to 1,500 amps will burn throughthe stud 18, thereby interrupting the continuous connection between the shields at the location of the splice, so that the shield is no longer grounded. On the contrary, with the tang 34, currents of up to 2,000 amps can be sustained for alonger period of time withoutfailure. I

While a particular embodiment of the invention has been shown and described, it is contemplated that changes and modifications consistent with the objects and advantages of this invention are within the scope thereof.

lclaim:

1. As an article of manufacture, a shield connector comprising:

a base of conductive material, said base being tapered so that one end is narrower than the other end and curved so that the edges curve downwardly, said base having one or more upwardly directed friction tangs and an upwardly directed electrically conducting tang having a dimension substantially greater than said friction tang, said conducting tang being located at the broader endof said base;

an upwardly directed screw threaded stud mounted on said base;

a bridge having a first end and a second end, the first end having two spaced-apart legs defining a first recess, the second end having two spaced-apart legs defining a second recess, a passageway in said bridge receiving said stud; and

screw threaded fastening means engaging said stud fastening said base, said bridge and said stud together.

2. A combination of a cable and a shield connector,

said combination comprising:

an electrical cable having an outer protective sheath and a conductive shield inside of said sheath;

a base positioned at least partially under said protective sheath in electrical contact with said shield, said base being curved to conform to the inner surface of said shield;

an upstanding electrically conducting tang secured to said base, said tang passing through said shield and said sheath; 7

an upstanding screw threaded stud mounted on said base, said stud passing through said shield and said sheath;

a bridge positioned over said sheath above said base, said bridge including means curved to conform to I the outer surface of said sheath, said bridge having a assa ewa erein receivin said st dme s; scre thr eade fastening mean engagi ng sal d stud means fastening said bridge to said 'baseland clamping said shield therebetween; and

, an electrical conductor fastened to said stud and electrically contacted by said conducting tang.

3. The combination of claim 2 wherein said base is positioned under said shield, said shield and said sheath both being cutaway permittingthe passage of said stud means and said conducting tang therethrough.

4. The combination of claim 3 wherein said base has one or more upwardly projecting tangs frictionally engaging said shield and in electrical contact therewith.

5. The combination of claim 2 wherein said curved means of said bridge are downwardly depending legs joined by a web of material forming a curved lower surface.

6. The combination 'of claim 2 wherein said base is tapered so that the end of the. base positioned the furthest under said sheath is narrower than the other end, said conducting tang being positioned at said other end.

7. As an article of manufacture, a connector for making electrical contact to the shield of an electrical cable having a protective sheath overlying said shield and an insulating layer underlying said shield, comprising:

a base of conductive material adapted to be brought into engagement with said shield, said base being curved to conform to the inner surface of said shield; I

screw threaded stud means mounted on said base and extending upwardly therefrom; I

an electrically conducting tang secured to saidbase and extending upwardly therefrom; said tang having a major dimension such that it is adapted to extend through said shield and said sheath when said base is brought into engagement with said shield; and

. a bridge adapted to be brought into engagement with said protective sheath, said bridge including means curved to conform to the outer surface of said sheath, said bridge having a passageway receiving said stud means, a nut engaging said stud means fastening said bridge to said base.

8. The connector of claim 7 wherein said curved means of said bridge comprises downwardly depending legs joined by a strip of material having a curved lower surface.

9. The connector of claim 7 wherein said base is tapered to provide a narrow end and a broad end.

10. The connector of claim 9 wherein said tang is positioned upon said base near the broad end thereof.

11. The connector of claim 7 wherein said base is further provided with at least one upwardly-projecting friction tang of smaller dimension than said conducting tang.

12. The connector of claim 11 wherein said conduct-t. ing tang is positioned upon said base near the broad end thereof and said friction tang is positioned upon said base near the narrow end thereof.

Claims

1. As an article of manufacture, a shield connector comprising: a base of conductive material, said base being tapered so that one end is narrower than the other end and curved so that the edges curve downwardly, said base having one or more upwardly directed friction tangs and an upwardly directed electrically conducting tang having a dimension substantially greater than said friction tang, said conducting tang being located at the broader end of said base; an upwardly directed screw threaded stud mounted on said base; a bridge having a first end and a second end, the first end having two spaced-apart legs defining a first recess, the second end having two spaced-apart legs defining a second recess, a passageway in said bridge receiving said stud; and screw threaded fastening means engaging said stud fastening said base, said bridge and said stud together.

2. A combination of a cable and a shield connector, said combination comprising: an electrical cable having an outer protective sheath and a conductive shield inside of said sheath; a base positioned at least partially under said protective sheath in electrical contact with said shield, said base being curved to conform to the inner surface of said shield; an upstanding electrically conducting tang secured to said base, said tang passing through said shield and said sheath; an upstanding screw threaded stud mounted on said base, said stud passing through said shield and said sheath; a bridge positioned over said sheath above said base, said bridge including means curved to conform to the outer surface of said sheath, said bridge having a passageway therein receiving said stud means; screw threaded fastening means engaging said stud means fastening said bridge to said base and clamping said shield therebetween; and an electrical conductor fastened to said stud and electrically contacted by said conducting tang.

3. The combination of claim 2 wherein said base is positioned under said shield, said shield and said sheath both being cutaway permitting the passage of said stud means and said conducting tang therethrough.

6. The combination of claim 2 wherein said base is tapered so that the end of the base positioned the furthest under said sheath is narrower than the other end, said conducting tang being positioned at said other end.

7. As an article of manufacture, a connector for making electrical contact to the shield of an electrical cable having a protective sheath overlying said shield and an insulating layer underlying said shield, comprising: a base of conductive material adapted to be brought into engagement with said shield, said base being curved to conform to the inner surface of said shield; screw threaded stud means mounted on said base and extending upwardly therefrom; an electrically conducting tang secured to said base and extending upwardly therefrom; said tang having a major dimension such that it is adapted to extend through said shield and said sheath when said base is brought into engagement with said shield; and a bridge adapted to be brought into engagement with said protective sheath, said bridge including means curved to conform to the outer surface of said sheath, said bridge having a passageway receiving said stud means, a nut engaging said stud means fastening said bridge to said base.

12. The connector of claim 11 wherein said conducting tang is positioned upon said base near the broad end thereof and said friction tang is positioned upon said base near the narrow end thereof.