US2983779A

US2983779A - Coaxial cable connector

Info

Publication number: US2983779A
Application number: US785025A
Authority: US
Inventors: Leo G Dumire; Edlen George; Haskell Boris
Original assignee: Phelps Dodge Copper Products Corp
Current assignee: Phelps Dodge Copper Products Corp
Priority date: 1959-01-05
Filing date: 1959-01-05
Publication date: 1961-05-09
Anticipated expiration: 1978-05-09

Description

y 1961 L. G. DUMIRE ET AL 2,983,779

COAXIAL CABLE CONNECTOR Filed Jan. 5, 1959 5 Sheets-Sheet 1 E1 3.3 if /fl /& l A? INVENTOR5 III/171170111] I 1 am y 4/; j Z/ flffasiiel BY fi ,W'i 16M ATTORNEYS May 9, 1961 G. DUMIRE ET AL 2,983,779

COAXIAL CABLE CONNECTOR Filed Jan. 5, 1959 3 Sheets-Sheet .2

INVENTOR5 Z.6.' fizz/mire 6 Zafilaa B. ffa/siell BY W M ATTORNEYS y 9, 1961 G. DUMIRE ET AL 2,983,779

COAXIAL CABLE CONNECTOR ATTORNEYS Unite States Patent F COAXIAL CABLE CONNECTOR Leo G. Dumire and George Edlen, Silver Spring, and Boris Haskell, Chevy Chase, Md., assignors, by mesne assignments, to Phelps Dodge Copper Products Corporation, New York, N.Y., a corporation of Delaware Filed Jan. 5, 1959, Ser. No. 785,025

4 Claims. (Cl. 174-75) The present invention relates primarily to electrical cable connectors and mountings, and particularly to con nectors and mountings for coaxial cable.

In the electrical transmission cable art there has been a considerable growth in the use of coaxial cables. These cables usually take the form of metal jacketed or braided cable. By metal jacketed cable herein is meant a cable comprising a tubular metal sheath or outer conductor, usually formed of copper or aluminum tubing, within which is housed a center or inner conductor, usually a copper wire or rod, the inner conductor being spaced or insulated from the outer tubing. In the specific case of coaxial cable, this inner conductor is centrally and coaxially spaced and supported from the outer tubing sheath, usually either by dielectric glass or plastic beads, a plastic spiral, a foamed plastic, or other insulating filler. In the case of braided cable, the above-mentioned sheath or outer conductor is a sleeve of braided wire filaments, and usually the braided sleeve is covered with a plastic sheath.

The advent and growth of coaxial cable and analogous shielded conductors has created special problems of installation. It is obviously desirable in the case of either field or bench installations, but particularly the former, that fittings for the cable be readily and easily applied with simple and conventional hand tools, and that mechanically and electrically reliable applications of fittings be attainable with a minimum of skill. Further, particularly in the instance of high frequency installations, it is of utmost importance that changes in the capacitive relationship between the inner and outer conductor be held to a minimum by the application of the fittings.

The present invention is accordingly primarily concerned with fittings for shielded electrical transmission cables, particularly coaxial cables, and with the mounting or fastening of such fittings on the cable. One aspect of the present invention relates to fastening a sleeve, nut, or the like to the exterior of the cable, by a procedure that is similar to but simpler than a threaded union. Broadly, the sleeve is formed with an internal helical groove or track. The internal diameter of this sleeve upon which the helical track is formed is slightly greater than the external diameter of the cable sheath to which it is to be applied so that it may telescope thereover. The end of a Wire having a diameter greater than the depth of the groove or track is introduced at the forward terminus of the groove, and the sleeve is then rotated over the cable. Rotation of the sleeve causes the Wire to embed in the cable tubing, and as rotation of the sleeve is continued, successive portions of the wire are thus embedded, and form the equivalent of a helical thread over which the groove or track in the sleeve advances, thus forming a union or fastening between the sleeve and cable tubing somewhat analogous to a threaded joint. Once the sleeve is thus anchored to the cable, it may provide the basis for an electrical end connector, an end coupling, a support, or the like, for the cable. In accordance with a further aspect of the present invention,

Patented May 9, 1961 means are provided for locking the aforementioned sleeve in position on the cable, and for providing separate electrical contact with the outer conductor and with the inner conductor when desired, as in the instance of providing a connector on the end of the cable.

It is accordingly one object of the present invention to provide a mechanical coupling between a cable and a sleeve applied thereover.

A further object of the present invention is to provide such a coupling having a partially self-forming union between the cable and sleeve.

Another object of the present invention is to provide an electrical connector employing the foreging coupling as the basis of union between the connector elements and an electric cable.

Still a further object of the present invention is to provide an electrical cable end mounting to an electrical instrument housing employing the sleeve and cable union as the basis for anchoring the cable.

Still another object of the present invention is to provide a mechanical anchor on the exterior of a metal jacketed cable and a separate electrical connecting element for the cable supported by the anchor, in a manner to provide both a firm and reliable electrical connection with the cable and a tight and strong mechanical union between the anchor and cable.

Other objects and advantages of the present invention will become apparent to those skilled in the art from a consideration of the following exemplary detailed description of preferred specific embodiments of the invention, this description being had in conjunction with the accompanying drawings in which like numerals refer to like or corresponding parts, and wherein:

Fig. 1 is longitudinal sectional view of a coaxial cable connector embodying the principles of the present invention, applied to the end of a metal jacketed coaxial cable;

Fig. 2 is an exploded view of the connector and cable shown in Fig. 1;

Fig. 3 is an enlarged and partially cut-away isometric view of a sleeve anchored to a metal jacketed coaxial cable in accordance with the present invention;

Fig. 4 is a longitudinal section of the sleeve shown in Figs. 1-3;

Figs. 5A-D are views of the sleeve being anchored to a metal jacketed coaxial cable, shown in successive steps of application;

Fig. 6 is a sectional and isometric view of an embodiment of the present invention for mounting the end of a metal jacketed coaxial cable on an electrical instrument housing;

Fig. 7 is an isometric view of one element employed in the embodiment of Fig. 6;

Fig. 8 is a modification of the embodiment of the invention shown in Fig. 1;

Fig. 9 is a modification of the embodiment of the invention shown in Fig. 6;

Fig. 9A is a modification of the embodiment of the invention shown in Fig. 8;

Fig. 10 is a further modification of the embodiment shown in Fig. 6;

Fig. 11 is an elevation view of the sleeve employed in the present invention embodying an additional feature of the invention;

Fig. 12 is a view of the sleeve of Fig. 11 applied to a pipe, rod, hose, or cable;

Figs. 13 and 14 are cross-sectional views taken on lines 13-13 and 14-44 respectively of Fig. 11;

Fig. 15 is an elevational and partially cut away view of a sleeve as shown in Fig. 11, and embodying a further feature of the invention;

Fig. 16 is a longitudinal sectional view of a connector applied to a braided coaxial cable;

Fig. 17 is an elevational view of a braided cable prepared for application of the connector as shown in Fi 16;

i ig. 18 is a longitudinal sectional view of a modification of the connector shown in Fig. 16;

Fig. 19 is a longitudinal sectional view of a further modification of the connector shown in Fig. 16.

Fig. 20 is a longitudinal sectional view of still another modification of the connector shown in Fig. 16;

and

Figs. 21 and 22 are transverse sectional views of sleeves employed in the present invention taken along the'line of the first convolution of the helical groove in the sleeve, with a wire, as employed in the present invention inserted therein.

One important aspect of the present invention resides in the manner of and means for anchoring the sleeve to a cable, or the like. This is best shown in Figs. 3, 4, and SA-D. There is here shown a section of coaxial cable 10 having a metal tubing outer conductor or jacket 11, which may for example be of aluminum or other malleable metal. A center conductor 13 is coaxially spaced and insulated from the metal tubing or sheath 11 by a foamed plastic dielectric filler 12, for example. The sleeve 15 to be anchored to the cable 10 may be formed of aluminum, if aluminum jacketed cable is used. It has a tubular section 16, and may have a flange 17 at one end for subsequently described coupling purposes. The flange 17 is conveniently provided with flats 18 to facilitate turning the sleeve with a conventional wrench or like tool, as will subsequently become apparent. Obviously the flats 18 could be formed on the sleeve portion if desired. A helical groove or track 19 is formed on the inner surface of sleeve 15, and the tubular end may be cut back or notched at 20 defining one end or terminus of the groove 19. The other end of this helical groove may terminate blind in the sleeve. The inner diameter of the tubular sleeve is chosen to telescope over the cable 19. With the sleeve 15 partially telescoped over the end of the cable 11], as shown in Fig. A, the end of a length of wire 21 is fed into the open end of groove 19, and the sleeve is then rotated to advance the groove over the wire. Wire 21 is chosen of a diameter somewhat greater than the depth of the groove 19, and is formed of a material harder than that forming the jacket 11 of the cable, for example, stainless steel. Consequently, as the sleeve 15 is rotated, a portion of the diameter of the wire 21 embeds in the cable jacket 11 (see Fig. 1), and the helical groove 1% causes the sleeve 15 to thread over the embedded portions of the wire as the leading portion of the groove causes successive portions of the wire to embed in the cable jacket,

acsa'rre as illustrated by the successive stages of application of V the sleeve in Figs. 5A-D, embracing one and one half complete turns of the sleeve. The force required for this operation is substantial, and accordingly the flats 18 facilitate the use of a wrench, or like tool. When the sleeve has been fully applied to the cable, it will be retained thereon by a desired number of convolutions of the wire 21 whose cross section is partially housed in the convolutions of groove 19 and partially embedded in the cable sheath 11, as shown in Figs. 1 and 3.

Having thus provided for securing the sleeve 15 to the cable 10, an electrical end connector can be applied to the cable, with the sleeve 15 functioning as an anchor therefor. For this purpose, before the sleeve is applied, a length of outer conductor 11 and insulation 12 are removed from the cable, leaving a corresponding length of center conductor 13 protruding from the trimmed end of the cable. The sleeve 15 and wire 21 are then applied to the cable as aforedescribed. An annular wedge 25, preferably formed of aluminum for aluminum jacketed cables, having a frusto-conical surface portion 26 is carried in recess 22,forrned in the flanged end of sleeve 15. Recess 22 has an annular shoulder 23 which may also be frusto-conical and may have a taper mating with that of surface 26 on wedge 25. The inner diameter of wedge 25 is substantially the same as or slightly less than the inner diameter of outer conductor 11, so that when the wedge 25 is driven home in recess 22 against the end of conductor or tubing 11, the end of the tubing is flared or flanged by the wedge and is caught and worked between surface 25 of the wedge and surface 23 of recess 22. Wedge 25 thus provides a means for locking sleeve 15 against further rotation on the cable 10, as well as providing a well defined contact ring for the outer conductor 11.

Wedge 25 is locked in place, and the center conductor is supported, by an adapter 30, shown for example as a splice adapter for uniting the ends of two identical or similar cables. Adapter 30 is basically a tubular body, preferably of aluminum for aluminum jacketed cables, affording a mechanical completion of the connector, and an electrical extension of the cable. In order to center the adapter accurately relative to the cable 111, the adapter is recessed at 31 to receive and mate with the outer circumference of the flange 17 on sleeve 15. Adapter 31) is also externally threaded at 32 to engage with an internally threaded shouldered nut 33 formed to abut flange 17 on the sleeve. Tightening of nut 33 on adapter 30 drives flange 17 into adapter recess 31, and causes recessed surface 34 of the adapter to drive wedge 25 home and thus flare and work the end of outer conductor11. As shown in Fig. 1, the parts are oriented and related so that surface 34 of adapter 30 and surface 26 of wedge 25 remain axially spaced from the opposite and corresponding faces of the sleeve 16. Because of this relationship, and since as further shown in Fig. l, the internal diameter of Wedge ring 25 is less than the internal diameter of sleeve 16 and associated wire 19, a force contact is thus effected, by the tightening nut 33, between the inner portion of wedge surface 25 and that part of the end portion of outer conductor 11 which is located radially inwardly of the sleeve and wire. The force of this contact provides a bearing point transmitting an axial thrust along cable 11 relative to the sleeve 16 and wire 19. The force of this relative thrust in turn pulls the sleeve up tight on the wire and the wire up tight on the outer conductor or tubing 11, taking up all mechanical tolerances and providing a virtually play free mechanical junction between the sleeve and the cable, as well as a firm and reliable electrical contact between the outer conductor 11 and the contact Wedge 25. Adapter 31} also mounts a center contact 36 Within its bore 35, by means of a molded plastic button 37 which seats in recess 38 in the bore of adapter 31 and recess 39 in the center contact 36. The plastic button 37 and recesses 38 and 39 are appropriately designed to provide the connector with a matching impedance for the cable 10. The center contact 36 is formed preferably of copper for cable having a copper center conductor, and with female or tubular ends 40, 41 to receive the protruding ends of the center conductors 13 from the ends of two cable sections, while the central portion 42 thereof is solid to provide a continuance of the character of the center conductor 13. In the case of a splice, the connection to the other end of the adapter 30 would of course be identical to that already described, and need not be further described or illustrated.

In using the connector aforedescribed, wedge 25 may be press fitted into aperture 22 of sleeve 15. Nut 33 is slipped over cable 10, then the assembled sleeve 15 and wedge 25 are applied to the cable with wire 21, in the manner illustrated in Figs. SA-D. The sleeve is rotated over the cable and wire until the end of the cable sheath '11 abuts the wedge, and then the sleeve is rotated a little further to unseat the Wedge partially and cause it to protrude somewhat from the mouth of recess 22. Nut 33 is then brought up on shoulder 17 and threaded onto adapter 30. The nut 33 thus draws the adapter over flange 17, and surface 34 of the adapter bears against the wedge. Further tightening of the nut forces the wedge to flare the end of sheath 11 and to grip, compress, and work the flare between frusto-

conical surfaces

26 and 23. During this assembly operation, the extending end of the center conductor 13 is of course fitted into the hollow portion 40 of the center contact 36.

Various aids can be employed to facilitate starting the reception of wire 21 into the leading end of groove 19. For example, the leading end of the groove can be flared, and/or the end of the wire can be tapered and barbed to afiord a grip on the cable sheath and to start the travel of the sleeve over the wire. Although the wire 21 shown in the drawing is circular in cross section, it is understood that the invention is not limited thereto, and wires of other cross sectional configuration can be employed, as for example oval, triangular, diamond, and rectangular. Also, as is apparent to those skilled in the art, adapters of various types and purposes can be employed in connection with the present invention, and it is not intended to imply that the invention is restricted to a splice adapter as illustrated.

Another form of the present invention is shown in Fig. 6, wherein the principles of the present invention are utilized to mount a metal jacketed cable on an electrical instrument housing, and introduce the cable into the housing. In many respects the present mounting is similar to the connector above-described, and such corresponding elements need only be briefly indicated.

Sleeve '52 of the mounting is essentially the same as sleeve 15, and is aflixed to metal jacketed cable 50 by means of a wire in the same manner as previously described. Support 53 is designed to bear against the back of the sleeve flange, in the same manner as nut 33, but instead of being threaded to engage the adapter 33, sup port 53 is formed with a flange 54, appropriately tapped to receive bolts 55, and by this means be secured to the instrument housing 56. The annular wedge element 60, shown in enlarged perspective in Fig. 7, has a frustoconical surface 61, similar to, and functioning in the same manner as surface 26 on wedge 25, to flare work, and grip the abutting end of the outer conductor of cable 50. Wedge 60 further has a flange 62, designed to be interposed between the sleeve 52 and the surface of housing '56 and to be partially received in recess 70 in the leading surface of sleeve 52. A sealing gasket ring 71 may also be interposed between the leading surface of sleeve 52 and the surface of housing 56, circumscribing flange 62 of the wedge. Wedge 60 terminates with a protruding sleeve 63 which extends into housing 56 through the opening 57 therein. The end of sleeve 63 may have an apertured plastic dielectric cap 64 threaded thereto for centrally supporting the protruding end 51 of the center conductor of cable 50 relative to protruding sleeve 63. Thus, wedge 60 functions as an extension of the outer conductor of cable 50, and with the projecting end of the inner conductor provides a coaxial cable extension into the housing 56.

In using the present mounting, a portion of the outer conductor and insulation of the cable is removed, leaving a section of center conductor projecting therefrom. After the mounting member 53 is slipped over the end of cable 50, sleeve 52 with wedge 60 assembled thereto, as by being press fitted in recess 70, is united to the end of the cable by means of a wire, in the manner aforedescribed, and the protruding end '51 of the center conductor is fed through wedge bore 65 and cap 63. The sleeve 52 is fed onto the end of cable 50 until the end of the outer conductor of cable 50 abuts the wedge, then the sleeve is turned a little farther to unseat the wedge partially. Gasket 71 is put in place, mounting member 53 is brought up to engage the flange on sleeve 52, the protruding center conductor and sleeve 63 of the wedge are passed through the opening 57 in the housing, and the mounting member is bolted to the housing. As the mounting member is tightened down on the housing, the flange 62 of the wedge abuts the housing and is driven home thereby, imparting a flare to and Working the end of the outer conductor of cable 50 to anchor the sleeve against rotaion, and to compress and to grip the flare between the frusto-conical surfaces of wedge 60 and sleeve 52 establishing good electrical contact between the wedge and the end of the cable outer conductor. The cable 50 is thus mounted to the housing, and an extension thereof is introduced into the housing for electrical coupling to the components contained therewithin.

It has been previously suggested herein that the assembly between the wedge 25 and sleeve 16 of Fig. 1, and the wedge 60 and sleeve 52 of Fig. 6, may be by press fit. If a more secure assembly therebetween is desired, a positive retaining or captivating structure may be provided as shown in Figs. 8 and 9. In Fig. 8, the Fig. 1 embodiment has been modified so that wedge 25a is provided with flange 80, and the sleeve 16a is formed with a complementary recess 82. When the wedge 25a has been seated in recess 82 of sleeve 16a, the end 81 of the sleeve is swaged or turned inwardly to form a retaining collar, and thus positively retain or captivate the wedge 25a in the recess 82. Enough space is provided in the recess 82 to accommodate limited axial movement of wedge 25a therein, to permit the same operations as aforedescribed in applying the sleeve 16a to a cable.

For this embodiment, the adapter 30a is also somewhat modified, in that the recess 31a is annular to accommodate the swaged or turned end 81 of the sleeve, and permit the surface 34a to bear against the wedge, when the shouldered nut 33 (not shown in Fig. 8) is used to draw the adapter 30a to the sleeve 16a.

Fig. 9 is a modification of the embodiment of Fig. 6. Here, the wedge 60a and sleeve 52a are similar to parts 60 and 52 of Fig. 6, except they are retained in assembled relationship by a split ring 92, instead of a press fit as utilized in Fig. 6. For this purpose, recess 70a has an annular groove 91 for housing the ring 92, and the flange 62a of wedge 60a also has an annular groove 90 for receiving the ring when the wedge is inserted in the recess 73a. Groove 90 has an axial dimension substantially exceeding the thickness of the ring 90 to permit limited axial movement of the wedge relative to sleeve 52a during application of the fitting to a cable, as aforedescribed, the wedge nevertheless being positively retained or captivated in assembled relation with the sleeve by ring 92.

A further modification for retaining the wedge and sleeve in assembled relationship is shown in Fig. 9A. Here the wedge 25b having a flange a is brought into juxtaposed relationship with the wedge end of sleeve 16b, and the two parts are adhered together in spaced relation by means of an annular spongy or elastomeric adhesive 83. In this instance, the bearing face 34b of adapter 30b may be flat for abutting engagement with wedge 25b when the shouldered nut 33 (not shown in Fig. 9A) is brought up to the flange of the sleeve 16]) and is threaded onto the adapter 30b. When the sleeve 16b is affixed to a cable as aforedescribed, the cable sheath end is brought into abutment with the wedge 2512. Thereafter, when the nut 33 (not shown) draws the adapter 30b against the wedge, the annular spacer and adhesive 83 is compressed, and wedge 25b flares and works the end of the cable sheath as with the previously described embodiment.

The connector shown in Fig. 10 is in many respects a simplification of that shown in Fig. 6. Again it is the object of the present embodiment to anchor a cable to an instrument housing or chassis, and introduce the end of the cable therein. For this purpose a simple flanged sleeve 69b is telescoped a desired distance over the end of the cable 50, and then wired onto the cable outer sheath in the manner illustrated in Figs. SA-D. A shouldered support element 53 adapted to cooperate with the flange on sleeve 60b, having been previously applied over the cable 50, is brought up into engagement with the flange on sleeve 60b, the protruding end of the cable isfed through hole 57 in the wall of housing '56, and support element 53 is then bolted to the wall of the housing by means of bolts 55, thus drawing the sleeve 60b tight up against the housing. If desired, appropriate sealing gaskets or rings may be employed to seal the opening 57. Thus, an end of cable 50, including its outer conductor'or sheath and center conductor, is introduced into and mounted upon the housing 56, to be connected to electrical components within the housing, as desired.

In the foregoing embodiments of Figs. 1-9A, the wire upon which the sleeve is threaded functions to anchor the sleeve axially to the cable. The sleeve is then anchored against rotation by the jamming action of the wedge on the end of the outer sheath of the cable or the like. In some instances, however, the sleeve may not be applied to the end of the cable, or otherwise it may not be desired to deform the end thereof. In such instance, the wire itself may be usedto lock the sleeve against rotational movement as well as against axial movement, which feature of the invention is shown in Figs. 11-14.

.As in the previous embodiments, the sleeve 16 is provided with the helical groove 19, except as shown in Figs. 11-14, each end of the groove terminates in an aperture to the outside of the sleeve. The leading end of the groove 19 terminates in aperture 101 which enters into the groove 19 at a somewhat tangential angle with respect to the sleeve circumference, and similarly, the terminating end of the groove has egress aperture 102 which exits also somewhat tangentially from this end of the groove. Thus, with the sleeve 16 telescoped over a cable, or the like 10, a wire 21 is fed into the leading end of the groove 19 through aperture 101, and the sleeve is rotated to embed the wire and advance over the embedded wire in the same manner as in Figs. SA-D. However, when the leading end of the wire reaches the end of the groove 19, it is scooped up by aperture 102 and fed up out of the sleeve 19. The leading end of the wire 21 may be tapered or beveled to facilitate the scoop operation of aperture102, if desired. With the wire 21 now protruding from both

apertures

101 and 102, its ends may be trimmed and reversely bent as shown in Fig. 12, to lock the sleeve 16 against rotation relative to pipe or cable 10, as well as against axial movement provided by the wire convolutions.

A1ternatively, if a more secure lock against rotation is desired, the ends of the wire protruding from

apertures

101 and 102 may be spliced together in any conventional fashion.

The double apertured form of sleeve shown in Figs. 11-14 additionally afiords the means for a further feature of the present invention shown in Fig. 15, wherein the wire and sleeve may be preassembled for application to the end of a cable, pipe, or hose. As shown in Fig. 15, a length of wire 21 may be preassembledto sleeve 16 prior to application to a cable, etc, by being fed into the aperture 101, along the convolutionsof groove 19, and out of the aperture 102. A substantial length of wire is retained extending outwardly from aperture 101. Thus assembled, the sleeve and wire can be applied to the end of a, cable, etc., and rotated. The portion of the wire in the groove 19 immediately adjacent leading aperture 101 grabs the outer surface of the cable, or the like, and continued rotation of the sleeve advances the sleeve over the helix of wire as the trailing end of the wire protruding from aperture 102 feeds out therefrom. This or initial grab, in the present embodiment, the depth of the groove 19 for a desired length, say one convolution, back from aperture 101, should be tapered to a depth greater than the remaining groove convolutions, with the maximum depth immediately adjacent the aperture 101. This tapered leading. end of groove 19 aflords a. corresponding taper to the projection of the wire inwardly in this portion of the sleeve, in order that the preassembled wire can become wedged over the outer surface of the cable, or the like, when the leading end of the sleeve 16 is first applied over the end of the cable, and thus efiect the initial grab.

The foregoing embodiments of the present invention have been primarily concerned with the application of the invention to metal jacketed electrical cable, such as metal jacketed coaxial cable. In contrast to the metal jacketed cable, the following embodiments shown in Figs. 16-20 are primarily concerned with the application of the present invention to braided cable.

In Figs. 16-20, a connector is shown applied to one form of conventional braided coaxial cable. Coaxial cable is shown as comprising an outer layer 111 of protective and insulating material, which is usually an insulating plastic, and may be formed of other materials, such as an insulating rubber, or the like. Immediately inside the outer layer 111 is the braid 112, usually of copper filaments, and which functions as a shield or outer conductor for the cable. A solid dielectric plasitc filler 113 encases the center conductor or wire 114, insulating the same and locating it coaxially relative to the braid 112. To prepare the end of the cable for application of an end connector, for example, a desired length of the outer cable layer 111 is removed from the end of the connector, exposing a length of braid thereunder. The exposed length of braid is then debraided and the braid filaments bent back over the outside of the remaining covering layer 111. The exposed dielectric filler 113 is then trimmed from the cable to leave an exposed length of inner conductor 114. The cable is now in the condition illustrated in Fig. 17, and is ready for application of the connector thereto.

The connector itself comprises a sleeve 115 having a flange 116 at one end, and a helical groove essentially the same as the sleeve 16 in Figs. 3 and 4, or the sleeve 16 in Figs. 11-15. The internal diameter of sleeve 115, as in the preceding embodiments, is chosen to be slightly larger than the external diameter of the cable and folded braid depicted in Fig. 17, so as to be able to be telescoped thereover. Sleeve 115 is intended to be fed over the cable and folded braid with the insertion into the leading end of the groove of a wire 118, of larger diameter than the depth of the helical groove, in exactly the same manner as described above in connection with Figs. SA-D. In so doing, the wire 118 is partially housed in the helical groove and compresses the folded braid into the outer cable layer 111, to partially embed the braid strands and wire 118 therein, as shown in Fig. 16.

Adjacent its flanged end, sleeve 115 is provided with an annular groove 130, in which is supported a dielectric button 119, which may be formed of dielectric plastic and molded in position during fabrication of the sleeve 115. Button 119 is intended to support a tubular metal center contact element 120 centrally thereof, designed to receive therein or therethrough the exposed protruding end of the center conductor 114. Center contact 120 may be mounted centrally on button 119 by any conventional expedient, such as by crimping the center contact at 120a into an aperture in the button.

Thus, as depicted in Fig. 16, the sleeve 115 carrying the center contact 120 may be assembled with the end of the cable 110 by means of wire118, as aforedescribed; and in so doing, the protruding end of center conductor 114 is received in center contact 120. An internally shouldered nut 117 cooperating with the flange 116 on sleeve 115 is provided, to threadingly engage a compleof the cable.

9 mentary fitting (not shown) for receiving the center ,contact 120, and making electrical contact with the cable outer conductor or braid 112 through flange 1-16, sleeve 115, and wire 118 engaging the folded portion of the braid.

If electrical contact with the outer braid 112 is not required, the folded braid may be omitted and trimmed with the insulation and dielectric material, andthe sleeve may be wire threaded directly onto the outside of the cable covering layer 111. The various features above described with respect to locking the sleeve against rotation, and using a preassembled wire'and-sleeve, as shown in Figs. 11-15, may of course be resorted to as desired.

Figs. 18-20 show modifications of theFig. 16 embodiment, like parts being designated by like numerals need not be further described. However, in the Fig. 18 embodiment, a ferrule 121 is inserted between the folded portion of the braid and the outer protective layer 111 With ferrule 121 thus inserted, the wire threading of sleeve 115 onto the'end of the cable causes the wire 118 and braid to be embedded in the ferrule rather than in the outer cable layer 111.

The connector may be still further modified, as shown in Fig. 19, by providing an additional ferrule 122. Here, ferrule 121 is again provided between the folded braid and the outer protective layer 111. In addition, a second ferrule 122 is positioned over the folded braid. When the sleeve 115 is wire threaded over this assembly, wire 118 deforms or crimps outer ferrule 122, which in turn transmits the compression forces to the folded braid section and the inner ferrule 121. The wire 118, ferrule 122, and the folded braid section may therefore be considered as all embedded in ferrule 121.

The embodiment of Fig. 19 can be further modified as shown in Fig. 20 by mounting button 119 on the end of ferrule 122 by an appropriate annular crimp 122a, instead of being carried by sleeve 115. In such instance it may be desired, for better electrical contact and characteristics, to effect contact between the braid and the complementary fittings through the end 122a of ferrule 122, instead of through the sleeve 115. To this end, when the sleeve 115 is wire threaded onto the cable end, it is threaded down past the end 122a of ferrule 122, as shown in Fig. 20. This leaves end 122a of ferrule 122 exposed to make contact when the nut 117 draws the fitting into engagement with the complementary fitting.

In all the foregoing embodiments, as has been indicated, it is preferred that some expedient be provided for starting the embodiment of the wire on the pipe, hose or cable to which the sleeve is to be anchored. Two such expedients have been suggested; one being to flare the leading end of the helical groove in the sleeve, i.e. gradually to increase at least the depth of the first groove convolution toward the wire feed in end so that the wire gradually emerges from the groove proceeding down the convolution; and the other being to taper the end of the wire first inserted into the groove through the feed in aperture. The former expedient is applicable to all forms of the invention illustrated, while it is apparent that the latter expedient may be employed advantageously primarily with those forms of the invention in which only the end of the wire is inserted in the groove when the sleeve is first applied to the hose, cable, or pipe. Both of these expedients are illustrated in Figs. 21 and 22, which are each sectional views of a sleeve as cut along the line of the first groove convolution, with the wire inserted.

Fig. 21 illustrates the form of the sleeve groove in which the first convolution is spiralled, that is, starting with the feed in aperture 130, the groove 131 in the sleeve 132 has a depth greater than the diameter of the wire 133. Proceeding down the groove, its depth is tapered to a lesser and lesser dimension, until the wire diameter is greater than the depth of the groove and the V 10 wire protrudes therefrom so that it can be embedded in the tube, 'or the like, to which the sleeve is being applied. It can thus be seen, whether one is using the preassembled wire and sleeve form of the invention, or the form in which the end ofthe wire is inserted during the application of the sleeve to the tube or rod, this helical convolution provides an opportunity for the wire to wedge between the sleeve and tube or rod, to grab, and thus facilitate the embedding operation which results from further rotation of the sleeve.

Fig. 22 illustrates the form of the sleeve groove in which the end of the wire is tapered. Here, the first convolution of the groove 141 in sleeve 142, starting with the wire feed inaperture 140, may be of uniform depth,

and may also have the same depth as the remaining convolutions of the sleeve. The lead in end of the wire 143 is tapered, so that when the sleeve 142 is first partially telescoped over the end of a tube or rod, or the like, the

tapered end of wire 143 can be inserted through feed in aperture 140, and into the first convolution of groove 141 for at least a portion of the convolution. By this means, when the tapered end of the wire is inserted in the groove 141, the projection of the wire from the groove is tapered, near the leading end of the wire, so that the wire will wedge and grab against the tube or rod to which the sleeve is being anchored when the sleeve is rotated to embed the wire in the tube or rod. This tapered wire expedient would obviously be primarily useful in connection with the form of the invention in which the end of the wire is first inserted into the groove of the sleeve at the time that the sleeve is applied to the tube or rod to which it is to be anchored. This expedient could also be employed with a preassembled wire and sleeve, where the wire is preinserted in the groove only substantially to the extent of the taper on the wire. In this instance it would be desirable to provide a breakable bond between the preinserted wire portion and the groove. Of course, the features of tapered Wire and spiralled groove could be combined where desired.

Having thus described several specific embodiments of the present invention, it is understood that the scope of the invention is not limited thereto. The features of the present invention can be used in connection with numerous types of connector adapters, and for other cable mounting embodiments and environments. Further, the wire thread fastening means here disclosed may be used in environments other than electrical cable fittings. Accordingly, such changes, modifications and variations of the present invention as are embraced by the spirit and scope of the appended claims are contemplated as within the purview of the invention.

What is claimed is:

1. In combination, an electrical cable having a first conductor, a second conductor surrounding said first conductor, said second conductor being a solid walled tube formed of a malleable metal and having substantial resistance to compressive forces, and insulation means supporting said first conductor in spaced relation to said second conductor interiorly thereof, and an end connector for said cable comprising, a sleeve telescoped over an end portion of said second conductor and having a substantially helical groove defined on the interior surface thereof, a Wire having a cross-sectional dimension greater than the depth of at least a portion of said groove partially housed in said groove and partially embedded in said second conductor to anchor said sleeve to said second conductor, an annular contact means having an end face located in opposed relation to said end of said second conductor and the corresponding end of said sleeve, a portion of said end face being located radially inwardly of said sleeve and Wire and in axial thrust engagement with said end portion of said second conductor in an area located radially inwardly of said sleeve and wire in force transmissive relation to said second conductor axially thereof, said end face being axially spaced from said end of said sleeve, a second contact means in electrical contact with said first conductor, means supporting said second contact means in spaced relation to said annular contact means, and means engaging both said sleeve and said annular contact means forcing said sleeve and annular contact means toward each other and placingsaid end portion of said second conductor in an area radially inward of said sleeve and wire under axial compression against said portion of said end face and thereby providing a bearing placing the union between said sleeve and second conductor under axial tension in response to transmission axially along said second conductor of the compressional force between said end portion of said second conductor and said portion of said end face, said two contact means being further formed to provide electrical contact with an electrical conducting device, whereby said two contact means may provide an electrical connection between an end of said cable and said conducting device.

2. In the combination set forth in claim 1, said annular contact means including a wedge surface engaging said end portion of said second conductor to flare said end portion outwardly.

12 3. In the combination as set forth in claim 2, said sleeve having a tapered surface corresponding substantially to said wedge surface and juxtaposed thereto for sandwiching the flare formed on said end portion of said second conductor between said tapered and wedge surfaces.

4. In the combination as set forth in claim 1, said sleeve and annular contact means engaging means comprising an inwardly shouldered nut engaging one of said sleeve and annular contact means by said shoulder and the other by a threaded union. 7

References Cited in the file of this patent UNITED STATES PATENTS Salisbury Mar. 23, 1954