US 2711520 A
Description (OCR text may contain errors)
June 21, 1955 K. c. KERNEN ET AL 2,711,520
CONNECTOR EOR USE ON RICE TENSION RESISTANCE CABLE Filed May l, 1951 C0 ADUC-VNF- Conoucwr NSULATNG n A com; @23g v/C aNnoc-rwe Comi 5,4% msOL/RTNG Cove R COVER limited States Patent O CNNECTOR FR USE N HIGH TENSION RESISTANCE CABLE Kenneth C. Kernen, Holly, and Ralph H. Mitchel and Raymond E. Schwyn, Flint, Mich., assignors to General Motors Corporation, Detroit, Mich., a corporation of Delaware Application May 1, 1951, Serial No. 223,972
3 Claims. (Cl. 339-100) This invention relates to electrical connectors and ductor, the conventional methods of soldering have been found to be unsatisfactory, as the heat associated with this form of operation has a destructive effect on the organic core material. Moreover, as the high resistance coatings on the fibers of such conductors are generally of a carbonaceous material, such as graphite, it $3;
has been found difficult to effect a suitable electrical or mechanical bond between the graphite and the metallic connector by the conventional methods of soldering.
Accordingly, it is a principal object of the present invention to provide a simple and highly improved terminal connector which is so constructed and arranged as to effect a mechanical bond of suitable electrical characteristics with fibrous cored conductors.
Another object is to provide a connector adapted to be forcibly inserted into a fibrous conductor and retained therein by the mechanical co-action between a gripping means on the connector and the fibers of the conductor.
A more specific object is to provide a connector having an elongated shank with a point at one end for 5 facilitating the insertion thereof into a fibrous conductor and projecting means on said shank for locking the said connector in assembled position by the gripping action of said projections with the fibers of said c011- ductor.
A further object is to provide a terminal connector having a shank adapted to be inserted into the core of a cable and gripping means on the shank adapted to engage and hold the shank securely in the cable thereby providing a rigid mechanical connection with desirable electrical characteristics between the conductor and the connector.
Other and further objects will become apparent as the description of the invention progresses.
For a better understanding of our invention reference may be had to the drawing in which, Fig. 1 is a view partly in cross-section and partly broken away of a conductor illustrating one form of a connector embodying the present invention; Fig. 2 is a View taken on the line 2 2 of Fig. 1; Fig. 3 is an enlarged perspective View, partly broken away, of the connector illustrated in Figs. l and 2; Fig. 4 is a View similar to ICC Fig. l illustrating another form of connector embodying the present invention; Fig. 5 is a sectional view taken on the line 5 5 of Fig. 4, and Fig. 6 is a perspective view of the connector illustrated in Figs. 4 and 5.
Referring now to the drawing and more particularly to Figs. 1 to 3 thereof the numeral 1 indicates generally a conductor consisting of an outer protective coating of insulating material 2, such as rubber, surrounding a conductive core of organic fibers 3 coated with an electrically conductive carbonaceous material such as graphite. The core 3 includes a central region of braided strands of coated bers 4 surrounded by a concentric sleeve 4 also consisting of woven strands of electrically conductively coated fibers. Conductors of this general type are shown and described in the co-pending applications of R. W. Buchanan, R. W. Smith and T. G. McDougal Serial No. 99,756, filed June 17, 1949, now abandoned and Serial No. 208,930, filed February l, 1951, Patent No. 2,703,356 and to which reference may be had for a more complete description thereof. The electrical connector associated with conductor l is designated generally as 5, and comprises an elongated shank 6 of metallic material having suitable electrical conductive characteristics. A cap or head member 7, constructed of a suitable electrically conductive material may be attached to one end of shank 6 .in order to provide a means for attaching lead wire 7. However, if it is found desirable the lead wire may be secured directly onto the shank 6. In such cases the cap or head member 7 may be dispensed with since the lead wires are adapted to be connected directly to the shank 6. The lead wires 7 of an electrical system are attached to head 7 by any suitable means, such as soldering. The other end of the shank 6 is tapered to a point as shown at 8, to facilitate insertion of the connector 5 into the core of the conductor. in order to secure the connector 5 in position within the conductor .l the shank 6 of the former is formed with a plurality of crcumfcrentially and axially spaced barbs 9. These barbs are integral with the shank 6 and may be formed with a suitable cutting tool which after the forming operation bends them outwardly of said shank as shown in Figs. l to 3. Connectors constructed in this fashion, it is seen, may be easily inserted in position within the conductor and when s0 assembled are effectively locked in position. Any movement tending to dislodge the connectors causes the barbs 9 to grip the fibers of the conductor and penetrate into the twisted and braided structure of the core sleeve, thus effectively preventing separation of the parts. lt is also seen that as the connector 5 is inserted into the core structure, the shank 6 thereof forces the surroundingr core against the yielding pressure of the rubber sleeve 2 thus forming a tight mechanical connection between the said connector and core structure. A good mechanical bond which assures efficient electrical conduction between the connector and core is thus provided.
.in Figs. 4, 5 and 6 there is illustrated another form of connector embodying our invention which is generally designated as lli. Connector 10 is assembled with a conductor l, similar to the conductor 1 shown in Figs. l and 2, and comprises a cylindrical shank 11. This shank may be equipped with a cap or head member 12, one end thereof having a transverse or annular aperture adapted to receive one end of a helical spring 13 for coupling the connector onto an electrical terminal (not shown). However, if it is found more convenient, the shank 11 may be fastened directly to the terminal. The head 12, in such cases is unnecessary and may be dispensed with. The shank 11 of connector 10 is formed with relatively deep helical threads 14 which terminate in a pyramidal end portion 15. The threads 14 are formed on the shank 11 by twisting a rod which has a polygonal cross section about its axis until the threads acquire the desired pitch. The drawing discloses the use of a rod having a diamond cross section, but itshould be understoodV that other cross sectional shapes may be used. By a proper choice of.v a cross sectionalV shape the threads can be given the depth required for optimum gripping. In assembling the parts, as shown in Fig. 4, the pyramidal end 15 of connector Il@ is first inserted into the core structure of conductor 1 and the shank 11 is then screwed into the core until the cap or head member 12 abuts the end of said conductor. As wit-h the connector 5, the insertion of connector 16 into the conductive region of the conductor 1, causes expansionpof'the core structure against the yielding pressure of the rubber covering 2. By thisv action, the threads 1Sl intimately engage the braided and twisted strands of the conductor, thus firmly securing the parts in assembled position. that a mechanical bondl isz provided between the core and connector having highly efficient electrical conductive characteristics. The cap or head member 12, like cap member 5, may befsecured to the shank 1 1 by soldering or by any other suitable means. The helical spring 13 especially adapts the connector 11) for varied uses, such for example, as in connecting conductors to shielded spark plugs (not shown). ln such cases the conductor 1 is inserted into a recess in the spark plug andl the spring13 resiliently engages the central electrode thereof.
The connectors have been shown and described herein as being associated with conductors having central strands coated with electrically conductive material surrounded. by a sleeve also of electrically conductive material which in turn is surrounded by a sleeve of insulating material. conductors shown herein may be associated with other types of conductors without departing from the invention, as for example, conductors comprising a single electrical conductive member or strand with or without an outer coating or sleeve of insulating material.
From the foregoing description it is seen that simplified and highly improved connectors have been provided which insure proper control with fibrous cored conductors under all conditions. By this construction resonant electrical conditions in automotive vehicle systems can be effectively suppressed, especially those which in any manner interfere with audio and video reception.
While the embodiments herein disclosed constitute preferred' forms of our invention, it will be apparent to those skilled in the art that the invention may be embodied in other forms. 1t therefore is to be understood that it is not intended to limit the invention to said embodiments but only by the scope of the claims which follow.
What we claim as new and desire to secure by Letters Patent of the UnitedStates is:
1. A connector adapted to be inserted longitudinally through the end ofr an electrical conductor having` an electrically non-conductive outer layer of elastic material into the electrically conductive core of bers of a non-metallic material which is disposed inside of said outer layer and compressed radially inwardly thereby, said connector comprising an elongated cylindrical shank of electrically conductive material, a tapered point on one end of said shank, said point being adapted' to be forced into said conductive central fibers of said conductor so as to spread said fibers for the entrance of said shank, an enlarged head secured to theopposite end of said shank to limit the extent of movement of 1t therefore will be observed It is apparent, however, that the U said shank into said conductor, said head being adapted to be connected to electrically conductive means, and gripper means on said shank comprising a plurality of barbs, said barbs projecting radially outwardly from said shank and being axially inclined toward said head to thereby position said barbs for spreading said conductive fibersV apart when said shank is inserted` into said conductor and to embed' themselves in said bers and prevent the withdrawal of said shank from said conductor, said barbs being' axially and' circumferentially staggered' around' the outer surface of said shank to embedA atV least aportion of said barbs in circumferentially different portions of said fibers.
2. The combination of any electrically conductive cable 1, having a central non-metallic fibrous core coated with an electrically conductive carbonaceous material encompassed by an electrically insulating outer cover of radially inwardly contractingr elastic material for compressing said fibers radiallytogether, a connector having a shank extending axially inwardly from one end of said cable and being disposed in said central fibrous core in intimate contact with said electrically conductive coating, the inner end of said shank being tapered to spread said fibers to facilitate inserting said connector axially into said cable,` the opposite end of said shank having, an enlarged head for abutting said end of said cable and being adapted to receive electrically conductive means, said shank including a plurality of gripping means, said gripping means being disposed axially along said shank andv projecting radially from said shank into said fibers, said elastic cover compressing said fibers radially inwardly against said grippers for causing said grippers to be embedded in said fibers.
3, The combination of an electrically conductive cable having a central non-metallic fibrous core coated with an electrically conductive carbonaceous material encompassed by an electrically insulating outer cover of radially inwardly contracting elastic material for compressing said fibers together, a connector having a shank extending axially inwardly fromone end ofsaid cable and being disposed in said central fibrous core in intimate Contact with saidV electrically conductive coating, the inner end of said shank being tapered for spreading said fibers to facilitate inserting* said connector axially f into said cable and the other end of said shank having an enlarged head for abuttingv saidV end of said cable and being adapted to receive electrically conductive means, said shank including a plurality of barbs projecting radially outwardly from said shank into said fibers, said barbs being circumferentially and axially staggered on said shank and axially inclined towards said head for spreadingA said fibers apart when said shank is inserted axially into said conductor, said outer cover compressing said fibers radially inwardly for embedding said barbs therein.
References Citedr in the file of this patent UNITED STATES PATENTS 1,175,343 Conrad Mar. 14', 1916 1,218,571V Lawton Mar. 6, 19-17 1,420,657 Kelly JuneV 27, 1922 1,425,384 euy Aug. s, 1922 1,484,202 Baker Feb. 19, 1924 1,532,882 Carpenter Apr. 7, 1925 1,909,248 Benkelman May 16, 1933 2,192,760 Thorson Mar. 5, 1940 FOREIGN PATENTS 214,525 Great Britain Apr. 24, 1924 162,606 Great Britain May 5, 1921