AU700334B2 - Feedthrough coaxial cable connector - Google Patents

Description

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AUSTRALIA

Patents Act 1 990

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT Invention Title: Feedthro~lgh Coaxial Cable Connector The following statement is a full description of this invention, including the best method of performing it known to us: 9 09** 9 9990 C. S a.

GH REF: P1O137MK/DGC~dr r lA FEEDTHROUGH COAXIAL CABLE CONNECTOR Field of the Invention !i The present invention relates to connectors for i coaxial cables. More particularly, the present invention relates to a very low cost, easily installable feedthrough connector for coaxial cable of the type typically used o 15 indoors for wideband RF signal distribution, for example.

a 0a S. Background of the Invention Coaxial cable is in widespread use for distributing wideband radio frequency information, such as television and radio signals. Coaxial cable typically provides two conductors, a central axial conductor and an °0.0 outer conductor which is substantially concentric with the S inner central conductor. The central conductor is 0: o. typically completely surrounded by the outer conductor, and S 25 a low-loss, high dielectric insulation material, such as o- plastic foam, .separates the two conductors. An outer insulating jacket is usually, although not necessarily, provided over the outer conductor to provide electrical insulation and physical protection to the cable. The outer conductor may be a single element, or it may be a composite' of several layered elements of conductive foil, wire braid, etc. One element of a composite outer conductor construction may be a conductive film or coating applied to the outside surface of the low-loss, high dielectric insulation material.

'--------3lpls~a4ar~llqlPII r, 2 A number of appliances require interconnection and connection to service cable outlet jack, typically mounted to and extending outwardly from a wall plate within the home or other interior location, etc. Connections may be needed 5 between the service jack and the jacks of a television set, a video cassette recorder and a stereo FM

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Small diameter (approximately one quarter inch or smaller), flexible coaxial cables are typically employed to accomplish the needed connections. These coaxial cables typically include a solid wire central conductor, a foam core, an outer composite conductor formed of an inner aluminum coating on the foam core, one or more layers of open-mesh aluminum wire braid and one or more layers of an aluminum foil. The outer composite conductor is typically covered by a plastic outer insulator jacket of one or several layers of insulating material in order to complete the coaxial cable construction. The dimensions of such coaxial* cables may vary, depending upon type and source thereof. Also, the properties of the cable may vary, depending on type and source, and also depending upon such factors as ambient te,&perature. When ambient temperature, is -low, the polymer cable materials become very stiff and difficult to manouver during connector installation procedures. Also, the foil coated inner insulating core may vary in diameter from about .140 inch to as much as about .200 inch.

:These small diameter cables have been made available ;:to the consumer in standard lengths with connectors installed at the factory. Also, connectors have been made -available f or installation, but installation of these **connecto rs to a prepared cable end has typically required a crimping tool for crimping a retaining ferrule, or a tool for spreading a retaining slip ring, or the tighening of a compression nut which retains the connector to the cable end, or the like.. Some connectors for indoor service provide and require compressive coaction between the face of the threaded jack and the connector bodyI which is achieved in practice by tightening a threaded nut of the connector over the outer threads of the jack.

The connectors for indoor service are known as "feedthrough" connectors, in the sense that ther~e is no separate central connector element of the connector I P1~SfZ~t~Ss~ i provided for connection, the center conductor of the cable providing this element of the conneclion mechanism. The center conductor is usually engaged by a receptacle element of a jack. Such element, sometimes referred to as a center seizure mechanism, when present, provides a positive mechanical engagement between the connector assembly and the center conductor of the coaxial cable.

In the case of the feedthrough connector, an exposed end portion of the solid wire central conductor of the coaxial cable is directly engaged by the center seizure mechanism of the jack when the feedthrough connector is mounted thereon. Since the central conductor of the coaxial cable is not maintained in mechanical engagement with the feedthrough connectors, and since those connectors function only to feed or connect the outer conductor to the jack and thereby to position the exposed central conductorfor engagement with the central gripping mechanism of the jack, the prior techniques for securing the connector to the cable have proven to have drawbacks related to installation and have proven not to be entirely satisfactory for ready installation and extended, reliable use within indoor use environments.

Irrespective of the particular approach followed by the prior art, hitherto there has not been a very low cost 25 feedthrough coaxial cable connector which may be easily assembled and attached to the cable with a simple manipulation by a user without special tools, or skills, and which provides a positive, superior engagement over S* time with the jack to which it is mated for use.

30 A wide variety of techniques are to be found in the coaxial cable connector art for attaching a feedthrough connector to a prepared cable end. One representative example is to be found in the Quackenbush U.S. Patent No.

3,781,762. Therein, a tubular connector body includes an 35 annular flare. The body is dimensioned to fit between the insulating core and outer conductor of the prepared cable end,' and it aligns and positions an exposed end section of I~BI 1b the central conductor. The annular flare of the tubular body v. iuses the outer conductor to become stretched over it as the body is pushed between the core and the outer conductor during installation. A cylindrical ferrule, such as a split ring or crimp ring, is then installed over the body inside of the annular flare. The Quackenbush arrangement is said to provide good electrical and mechanical connection of the cable outer conductor to the connector body. However, the Quackenbush connector cannot be easily installed on the prepared cable end without special tools needed for installation of the clamping ferrule.

As mentioned, another feedthrough connector relies upon *a compression engagement obtained by tightening a threaded nut to the jack. The tightened nut of the connector compresses the outer conductor against the connector body and thereby secures the cornector to the cable. One drawback of this approach is that when the nut is not tightened upon the threaded jack, or when the Z) connector end is not engaged with the jack, a slight tug or jerk on the connector may cause it undesirably to become S. separated from the cable.

Other more conventional approaches are to be found in the coaxial cable connector art which include means for 25 engaging the exposed end of the central conductor. For example, British Patent Specification 621,459 describes a tubular connector body for insertion between the insulation *core and the outer conductor of a coaxial cable. An annular flared or bulged region expands the outer conductor of the cable, and a longitudinally extending split ferrule tube is pushed over the coaxial cable end to surround the body at the bulged region so as to press the cable against the bulged region to improve electrical connection and mechanical attachment.- The ferrule includes fingers enabling it to be secured to the connector body after it is positioned in place.

An annular split ring is described in the Leeper.U.S.

Patent NO. 2,805,399 in order to retain an outer conductor of a coaxial cable along a narrow ring location immediately adjacent a bulged annular frustoconical clip portion of a *body which is slipped under the outer conductor Of the coaxial cable in order to provide very secure mechanical retention of the cable to the connector. Here, a special tool is needed in order to position and install the slip ring.

A In the Pugner U.S. Patent No. 4,053,200, a connector A 10 body has two radially raised portions. A plural-fingered, elongated brass ferrule slides over the cable and the outer radially raised portion in order to seat or nest between the two raised portions of the body and press the outer conductor of the. cable against the connector body. While the elongated brass ferrule provides a radial band of circumferential compression force to press the cable outerconductor against the tubular body, similar to the manner described in the Quackenbush reference discussed above, no engagement is provided between the elongated ferrule or other structure of the connector and the cable behind the outer raised portion of the connector body. Apparently, to aid requisite securement of the cable to the connector, the Pugner reference teaches a central connector structure 1:::,which is crimped or otherwise secured to an exposed end section of the central conductor of the cable.

1.**Without the further retention means by the central connector structure as shown in the Pugner patent, tugging and pulling stresses upon the coaxial cable will tend to caus it o beomedisconnected from the connector as described by Pugner, especially if the connector is threaded onto the jack at the time. Also, any flexures of the cable, particularly within an indoor environment such as the home, will tend to cause the outer conductor to 0 06stretch and possibly to los~e effective electrical contact with the ridge of the outer raised portion and/or provide an unwanted signal leakage path at the connector.

The Schwartz U.S. Patent No. 3,264,602 provides a C- la d-_a I_ Ilb 7 connector body for a coaxial cable which has a rearwardly tapered, ringed frustoconical surface which is slipped under the outer conductor of the coaxial cable. An outer member snap-locks over the cable in a manner which compresses the S outer conductor against the frustoconical surface in order to lock the cable to the connector and to provide a positive electrical connection between the inner surface of the outside conductor of the cable and the facing frustoconical ringed surface of the conductive connector body.

The Lee U.S. Patent No. 4,789,355 provides a coaxial cable connector plug which has tines or leaves which slide over the threaded end of the jack. An outer annular sleeve may then be pushed forward over the tines in order to compress them against the threaded jack and lock the connector plug against the jack in the manner of a compression collet, even though the plug is not threaded to mate with the threads of the jack.

what the inventor calls a "snap-n-seal" coaxial cable connector for a prepared end of a coaxial cable. This four-part connector assembly includes a mandrel body which has a ramped contour 39 diverging from the rear end thereof, so that the body 30 may be press fit between the dielectric core and the shielding braid. As seen in Fig.

2B and as best seen in Fig. 4, the ramped contour 39 :appears to flatten out and ends at a step inwardly forming a right angle with the flattened region. A plastic compression sleeve 60 is pushed over the body 30 and the cable end. The. compression sleeve snap-locks into a metal 2 collar member 20 and is said thereby to lock the cable end to the connector assembly. Since the ramped contour 39 appears to end at a flattened region, the body 30 fails to provide a knife edge for effectively cutting into the braid or aluminum sheet forming the outer conductor of the coaxial cable.

The Ito et al. U.S. Patent No. 4,249,790 describes a n I I 1 I' 1 Im 8 push-on type connector plug for a coaxial cable end. In pertinent part, the connector plug includes a slotted shield casing forming a plurality of resilient fingers which engage the outer cylindrical surface of a connector receptacle as the connector plug is pushed onto the receptacle. The fingers appear to be contoured to cooperate with an outer band structure in order to provide a spring bias force which pushes the fingers against the outer cylindrical surface of the receptacle and thereby provide a good electrical and mechanical push-on, pull-off attachment.

The Morello Jr. U.S. Patent No. 3,196,382 describes a crimp type coaxial cable connector 12 which includes a mandrel body having an integrally threaded mating cap for mating with a receptor connector 14. The Morello Jr..

connector device is not a push-on feedthrough connector.

While the foregoing approaches recognize the problem of providing effective contact and positive mechanical attachment of the prepared cable end and the cable connector, none of the foregoing approaches achieve a simplified, easily installed, positively acting feedthrough coaxial cable connector intended primarily for ready installation by the untrained user or consumer or by the trained technician, and for reliable use typically within o. an indoor environment over an extended time period.

a I -9- 1" SUMMARY OF THE INVENTION The present invention provides a feedthrough coaxial cable connector for connecting to a prepared end of a coaxial i cable having an exposed solid-wire centre conductor and a cable splice or tap port jack receptacle, the connector comprising: a split tubular radial walled portion forming a receptacle engagement member which surrounds the cable splice or tap port receptacle and is coaxially disposed about the exposed centre conductor and dimensioned to slide onto and contact in close fitting friction engagement an outer surface of the cable splice or tap port receptacle with which the connector mates in use, and a resiliently deformable elastomeric radial compression member to snugly fit over the 15 split tubular wall portion and provide compression on the Ssplit tubular member and hoop strength thereto and to protect the split tubular radial walled portion while holding the split tubular radial walled portion on the cable splice or tap port receptacle, the resiliently deformable elastomeric radial compression member sliding along the cable to fit over the split tubular radial wall portion and the prepared end of the coaxial cable so as to also assist in retaining the cable on the cable connector.

The present invention further provides a method of gripping a cable splice or tap port receptacle comprising: positioning a split tubular radial walled member over the receptacle; and sliding a resiliently deformable elastomeric radial compression member along a coaxial cable mated to the receptacle and over the split tubular radial walled member to compress the split tubular radial walled member into friction fitting engagement on the receptacle.

Ai. advantage of at least a preferred embodiment of the present invention is to provide a feedthrough coaxial cable connector for indoor use which may be installed by a user with exertion of but moderate finger -o^L y bR -ur ,C 10 strength and without any special tools or skills being required.

A further advantage of at least a preferred embodiment of the present invention is to provide a feedthrough coaxial cable connector which achieves improved flexural strain rrlief against rearward e e

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11 pulling force thereby to prevent the cable from beinc disconnected from the connector in response to tugging or pulling forces whether or not the connector.is culled free of the jack. That is to say, a preferred embodiment of the present invention provides a feedthrough coaxial cable connector which preferentially releases from a jack with which it is mated, rather than becoming damaged and inoperative by separation of the connector and the coaxial cable end.

A further advantage of at least a preferred embodiment of the present invention is to provide a kit of a few co-acting parts which may be assembled and installed by the consumer as a connector on an easily prepared end of an indoor coaxial cable by hand without special tools and without special training or.

skills.

A further advantage of at least a preferred embodiment of the present.

invention is to provide a retenton ring having a resiliently deformable portion of elastomeric material which coaczs with an annular or helical blade edge forming an annular or helical barb of a mandrel body underlying the outer conductor, so that once locked in place, the resiliently deformable portion of the retention ring effectively locks the cable onto the connector and impedes rearward tugging forces from causing the cable end to be detached from the 25 connector.

A furthei advantage of at least a preferred embodiment of the present invention is to provide a mandrel body for a coaxial cable connector which has an annular or helical blade edge formniug a sharply' contoured surface projecting ottwardly from a 30 substantially tubular.. mandrel body portion, and to use an elastomeric retention ring to cause an aluminum foil and braded wire portion of an outer conductor of the coaxial cable to be contacted by the blade edge in-a way which fosters positive long term connection to the foil and 35 braded wire conductor elements without formation of insulating oxides and without actually shearing the fine wires of the outer conductor braid, so that the connector 4-.

12 will operate reliably throughout wide ranging temperature cycles of the anbient surroundings and without impairment resulting from occasional movement and tugs on the cable.

A further advantage of at least a preferred embodiment of the present invention is to provide, most preferably by die casting, a mandrel body including a tubular portion defining an annular or helical blade edge forming a sharply contoured surface projecting outwardly from the tubular portion. The tubular portion may be formed to act as a collet in order to engage differently dimensioned coaxial cables ,within a predetermined dimensional range.. Preferably, ramping is effectively promoted with the aid of an expendable conically shaped guide for providing a ramp between the different cable diameters.

A further advantage of at least a preferred embodiment of the present invention is to provide a nesting tool for containing a kit of parts comprising the elements of the cable connector in a manner which facilitates proper and ready assembly of the elements into an installed feedthrough connector at the prepared end of a coaxial cable.

In a preferred embodiment of the present invention a feedthrough coaxial cable connector is provided for connecting to a prepared end cf a coaxial cable having an exposed solid-wire central conductor. In accordance with the principles of the present invention, the connector includes 25 a tubular mandrul body of conductive material such as yellow brass which has been plated with a suitable metal or alloy, such as tin, in order to improve lubricity, for ezample. The tubular mandrel body is dimensioned to be pressed beiteen a foil-bonded dielectric core and other elements of an outer..conductor of the prepared end of the f" cable.

In one presently preferred embodiment, the mandrel body preferably includes a rearvardly converging, generally frustoconical surface portion defining a shallow angle with respect to the cable, a fitst radial wall portion defining a knife edge with the frustoconical surface portion, a tubular shank portion extending from the first radial wail 13 portion to a second radial wall portion, and a jack engagement portion coaxial about the exposed central conductor and dimensioned to fit on and contact an outer surface of a jack with which the connector mates in use.

The jack engagement portion is preferably adapted to diverge radially from the second radial wall portion thereby enabling an initial slide-on engagement with the outer surface of the jack. A tight friction fit is desireably achieved between the jack engagement portion and the outer surface of the jack. In one preferred form, the jack engagement portion defines an inside compression collet structure. Preferably, the mandrel body is formed by die casting, in preference to machining.

In another embodiment the mandrel body preferably includes a helical b5rbed thread extending radially outwardly therefrom in the nature of a shallow, spaced apart continuous turead of controlled sharpness to enable the mandrel body to be rotatably inserted onto the prepared cable end by threading into the underside of the outer conductor, thereby to establish a positive electrical connection, as well as a positive mechanical connection, but without actually shearing the fine wires typically forming .0 at least a part of the outer conductor.

e *A radial compression providing structure, which 25 preferably may include a flanged or splined snap-ring, Sincludes a resiliently deformable elasomeric portion which is shaped-and dimensioned to cause'an inside surface region of the outer conductor to bear directly against and bend over the knife edge barb formed by the first radial wall 30 portion at the inside- end of the frustoconical portion of the mandrel body.

Preferably, a slideable shell is disposed over at least the jack engagement portion of the mandrel body. The shell is slideably positionable generally away from a 35 connector end facing the outer surface of the jack to enable the jack engagement portion of the connector to slide over the outer surface of the jack, and is slideably 14 positionable toward the connector end so as to radially compress the radially diverging jack engagement portion against the outer surface of the jack to enable the the connector to be securely connected thereto in a positive friction fit.

In one embodiment of the present invention, the slideable shell further defines a radial portion for compressing a region of the coaxial cable outer conductor against the frustoconical surface portion of the mandrel body when the slideable shell is slideably positioned toward the connector end.

The jack engagement portion may be slotted longitudinally to form a slip ring for slideable engagement over the outer surface of the jack.

The jack engagement portion may include plural slots, and it functions as a compression collet to lock onto the outer surface of the plug as the slideable shell is positioned toward the connector end. .facing the jack.

In one embodiment of the present invention, the snap ring includes a cap portion for fitting snugly over the jack engagement portion of the mandrel body thereby to provide initial additional strength to resist hoop stresses that may 25 develop in the jack engagement portion before the slideable shell means is positioned toward the connector end facing the jack.

The slideable shall may be adapted to guide the snap ring into position over the coaxial cable end and adjacently against i "i the first radial wall region of mandrel body during 'installation of the connector onto the prepared end of the coaxial cable.

e* The radial compression member may be reformed as a retention or snap-ring, and an outer sh(-l is preferably included, which cooperates with and co-acts with the snap-ring to position it during assembly and installation and further to compress the jack engagement portion against the jack when the assembled connector is in use in its intended manner. A "throw-away" installation tool which enables the connector assembly to be provided in kit of parts, nested for delivery to the user and which facilitates ready and easy assembly and installation of the connector onto a prepared end of the coaxial cable is yet another aspect and advantage of the present invention. The tool may also provide a visual gauge for installation, and it may also be adapted to self-release, once the connector elements are properly installed on the prepared cable end.

Features and advantages will be more fully understood and appreciated upon consideration of the following detailed description of preferred embodiments, presented in conjunction with the accompanying drawings.

a* 00 100 *oo 16 Brief Description of the Drawings In the Drawings: Fig. 1 is a greatly enlarged partial view in elevation and longitudinal section along a central .xis.of a portion of a coaxial cable connector incorporating principles of the present invention.

Fig. 2A is a greatiy enlarged diagrammatic view in elevation and longitudinal section of a portion of a resiliently elastomeric snap ring element of the Fig. 1 connector. Fig. 2B is an end view in elevation of the inside collet structure of the mandrel body of the Fig. 1 connector. Fig. 2C is a view in elevation and partial section of the mandrel body of the Fig. 1 connector modified to define an inside helical thread within the collet structure portion thereof. Fig. 2D is an end view in elevation of the inside collet structure in which the fingers thereof are formed by parallel saws. Fig. 2E is a view in elevation and partial section of the Fig. 2D f ft oft ft t on ~c 17 mandrel body. Fig. 2F is a view in front elevation of an outer shell of the Fig. 1 connector. Fig. 2G is a view in partial section and side elevation of the Fig. 2F outer shell.

Fig. 3 is a longitudinally exploded view of the Fig.

1 connector about to be installed on a prepared cable end of a coaxial cable with the aid of one form of expendable plastic assembly tool or jig.

Fig. 4 shows the Fig. 3 assembly nested within the assembly jig incident to installation of the Fig. 1 connector onto the coaxial cable end.

Fig. 5 shows the Fig. 4 assembly with the coaxial cable installed thereon.

Fig. 6 snows the installed connector assembly with S* 15 the outer shell element slid back to a position enabling the 9 connector to be installed on a receptacle or jack.

Fig. 7 shows the installed connector assembly mounted on a receptacle or jack with the outer shell pushed forward to lock the connector in place on the receptacle.

S 20 Fig. 8A illustrates in front view and axial section a tined, resiliently elastomeric portion of a snap-ring in accordance with the principles of the present invention.

Fig. SB illustrates the Fig. 8A tined snap-ring in rear elevation.

25 Fig. 9 shows in exploded view an alternative embodiment of connector in accordance with the principles of I he present invention.

Fig. 10 shows the Fig. 9 manirel element positioned onto the prepared cable end.

Fig. 11 shows the completed assembly of the Fig. 9 embodiment.

Fig. 12 shows the Fig. 9 embodiment engaging a connection receptacle.

Fig. 13 shows yet another embodiment of the present invention in unassembled, axially exploded view.

Fig. 14 shows placement of the Fig. 13 mandrel onto the prepared end of a coaxial cable.

Fig. 15 shows placement -of a snarl member over the mandrel-cable assembly' depicted, in Fig. 14 Fig. 16 shows the fully assembled Fig. 13 embodiment in electrical and mechanical attachment with a connection receptacle or jackc.

F ig. 17 illustrates yet another embodiment of a connector assembly in accordance with the present invention in unassembled, axially exploded view in elevation and partial section.

Fig. 18 shows 'the Fig. 17 embodiment nested in initial, unassembled arrangement incident to installation upon a prepared coaxial cable end. An expendable insertion tool provides a nest or container for holding and aligning :i the uninstalled component parts of the Fig. 17 connector assembly in axial. alignment to facilitate assembly onto the prepared end of the coaxial cable.

Fig. 19 illustrates installation by rotation of the Fig. 17 container and nested connector assembly elements onto the prepared coaxial cable cable end.

Fig. 20 illustrates the Fig. 17 connector assembly after the installation procedure of Fig. 19 has been completed.

Fig. 21 illustrates the assembled 17 connector assembly in electrical and mechanical connection with a receptacle or jack.

o .Fig.22 comprises a cable end view in elevation of an embodiment of a colleting mandrel body which is radially expansive thereby to adapt and be used with coaxial cables having insulating. cores of varying diameters within a predetermined range in accordance with principles of the present invention.

Fig. 23 is a side view in elevation and section of the Fig. 22 mandrel body, taken along the line 28 in Fi4.

22.

Fig. 24 is a somewhat diagrammatic view in side elevation of the Fig. 23 mandrel body and an expenda-le F ft (t 4 o elevation of the Fig. 23 mandrel body and an expenda le conical, ramp-shamed colleting guide member enabling installation of the Fig. 23 mandrel body onto two cables having inner cores of di',fering diameters.

Fig. 25 is a view in partial section and axial explosion of the Fig. 17 coaxial cable connector embodiment showing a modified container/ nesting tool.

Fig. 26 illustrates placement of the coaxial cable connector elements within the container tool and threading of the assembly and tool over the prepared end of the coaxial cable.

Fig. 27 illustrates initial engagement of the dielectric core of the cable with the plug end of the container tool.

i~ as Fig. 28 illustrates the final position of the Fig. when the dielectric core of the cable has pushed the container tool to a point of disengagement between the' teeth thereof and the slots of the mandrel cap.

Detailed Description of Preferred Embodiments With reference to Fig. 1 a coaxial cable 10 includes a central longitudinal conductor 12 which is concentrically surrounded by a high dielectric, insulator material 14, such 0as plastic foam for example. A thin metal conductive foil *00or coating 16, typically formed of aluminum alloy, is banded to the outer surface of and thereby contains the .foam core 14 and embedded central conductor 12. An open mesh wire braid or wrap IS is wrapped or placed immediately outside of the outer metal coating 16 to provide mechnrical strength to the cable and yet, to permit the cable 10 to flex quite fzaely -without damage. Additional layers of 44 aluminum foil and wire braid may be included as part of a composite outer conductor. Together, these -composite elements 16, IS fotr, an .outer electrical conductor and shield which is substantia~lly concentric with, and spaced (by the dielectric core material 14) away from the center conductor 12.

An outer insulator coating 20 of a suitable 21 thermoplastic resin material covers the outer electrical conductor to seal the cable from the ambient, to isolate the outer conductor electrically from the ambient and to provide some additional stiffness and mechanical protection to the cable The cable 10 may be type RG-6 having a nominal overall diameter of about .275 inch, or a type RG-59 having a nominal overall diameter of about .240 inch. The diameter of the inner core material 14 of the RG-6 cable is about .185 inch, whereas the diameter of the inner core material 14 of the RG-59 cable is about .145 inch, thereby illustrating a core diameter variance range of about .040 inch between two very popular indoor cables.

As shown in Fig. 1, the end of the cable 10 has been prepared by cutting back the outer conductor 20, outer braid 18, outer foil jacket 16 and dielectric core 14 for a short' distance to a location referred to by the lead line associated with the reference numeral 22 in Fig. 1, so as to expose a short segment of the central conductor 12. The exposed segment of the central conductor 12 is engaged by a central conductor receptacle within a conventional jack typically having a threaded outer cylindrical surface. The jack may be a standard threaded port connector having a nominal outer diameter of about .375 inches although this diameter is known to vary somewhat in practice.

As shown ii. Figs. 1 and 2A through 2G, a 'preferred embodiment 24 of a connector incorporating the principles of the present invention includes a mandrel body 26 formed of a suitable conductive material, such as yellow brass, for *0 a 30 example. Preferably,-the mandrel body 26 is die cast with a two-part mold that separates along the longitudinal axis of the mandrel body 26. As formed by die -casting, for example, the mandrel body 26 is formed with suitable reliefs and edge contours, so that it cooperates as intended with 35 the other structural elements of the connector without scratching or unwanted interferences. By employing a die casting operation, rather than machining, eac mandrel body o o° 22 26 may be formed in less than one second, leading to substantial economies in manufacturing. Preferably, the mandrel body 26 is plated with a suitable metal or alloy, such as tin, in order to improve its lubricity characteristics.

The conductive mandrel body 26 includes a thinned tubular region 28 with a slight, axially converging chamfer 29 at the end of the body 26. A frustoconical region forms a frustoconical outer surface region 31. Preferably, the .frustoconical outer surface region 31 forms an acute angle (less than 90 degrees) with a central longiudinal axis of the mandrel body 24 (which is generally in alignment with the central conductor 12 of the coaxial cable 10). Preferably, the angle formed by the surface region 31 with the longitudinal axis is between about degrees and about 5 degrees, and it is preferably degrees, plus or minus one degree.

A first, radially extending annular wall 32 extends outwardly to converge the inner end of the frustoconical surface 31 thereby to form an annular. knife-edge projection or barb 33. The barb edge 33 is designed to be a cutting surface which cuts or bites slightly into an inside ring portion of the outer metal braid and foil layers 18 without actually shearing them, thereby to cut through any oxide or S" 25 other insulating formations or deposits on the inside surface of the metal foil 16 so as to achieve and maintain a positive, very low resistance electrical connection between the mandrel body 26 and the outer conductor foil and braid 18. As seen in Fig. 1, the frustoconical I 30 surface 31 forms an acute angle with the annular wall 32, most preferably about 30 degrees.

A thinned tubular region 34 extends away from the base of the first radial wall portion 32 and meets a thickened second radial wall portion 36. The second wall portion 36 extends radially outwardly to the location of a Scollet structure 37 at which fingers or leaves 38 extend.

The fingers 38 define the inside collet structure 37 and 23 provide an inside cylindrical engagement surface suitable for engaging the outer threaded surface of a jack with which the connector 10 is intended for use, such as an "F" jack, for example. The inside surface of the collet structure 37 may be smooth, as shown in Fig. 1, or it may be provided with a shallow-cut helical groove or thread 39 as shown in Fig. 2C. A radially diverging ch'-mfer or bevel edge 40 at the entrance of the collet structure of fingers 38 facilitates slidable engagement of the leaves or fingers 38 upon the threaded surface of the jack. The pitch of the groove 39 is set to correspond with the thread pitch of the jack. If the groove 39 is present, a more positive attachment is achieved with the threaded jack than if the thread 39 is not provided, should such a characteristic be desired.

Preferably, each finger 38 is formed with a thickened' region 42 adjacent to the chamfer 40 and becomes gradually thinned at a region 44 adjacent to the second, thickened radial wall portion 36. The inside geometry of the connector 24 is generally cylindrical when in an unstressed, uncompre-sed state. In this relaxed state which enables the connector 24 to be slid over the outer surface of the jack, the outer surfaces of the fingers 38 define a slightly curved or frustoconical geometry.

Preferably, there are four fingers 38 provided by the mandrel body 26. There may be more or fewer fingers; however, four fingers 38, each defining a quadrant of a cylinder and separated by longitudinal slots 46 from adjacent fingers, cooperate to provide a very effective compression collet closure structure for positive engagement over the outer surface of the jack, when a hoop, band, slip ring, or other circumferentially compressing member is slidably positioned over the thickened regions 42 0 of the fingers 38. The fingers 38 may be formed by cross-sawing across the collet structure 37 at right angles, as shown in Fig. 2B, for example. Alternatively, and preferably for mass production, the fingers 38 are 24 formed by a single machining operation of two parallel saws which move in one direction across the collet structure 37, as shown in Figs. 2D and 2E.

The connector 24 further includes a resiliently deformable elastomeric cap 50 which is preferably formed by injection molding of a suitable thermoplastic resin material. The cap 50 includes a deformable flange region 52 which becomes thinned and tapered into a rearwardly flaired, knife-like annular edge 54. When the cap 50 is properly positioned over the mandrel body 26 and cable a cap region 56 snugly fits over the fingers 38 and provides some additio;tal hoop strength and protection to the fingers 38 from overbending due to proper insertion into the jack.

As shown in Fig. 2A, the cap 50 is dimensioned such that the flange region 52 snap-locks into a recess formed adjacent to the first radial wall 32 of the mandrel body 26.

Since the flange region 52 is initially flaired outwardly, the thinned annular edge 54 curls up around the outer plastic insulation 20 and tends to stretch or pull it down over the knife edge 33 of the mandrel body 26. When positioned against the outer insulator 20 of the cable the flaired edge 54 of the cap 50 actually presses the cable 10 against the first radial wall portion 32, causing the outer conductor braid and foil layers 18 to become sharply creased at the knife edge 33. This resultant "2 crease not only prevents aluminum oxide from impeding a very low resistance, high conductance contact between the outer conductor and the conductive mandrel body 26, it also effectively prevents rearward displacement of the cable relative to the connector 24. In effect, tugging forces applied to the cable 10 will cause the connector to become STdisconnected from the jack, rather than result in separation w.o of the cable end from the conductor, given the acute angle of the knife edge 33 of the mandrel body 26 and the compressive action of the flaired edge 54 of the elastomeric cap 113_ ICeqll~----~B-e I Preferably, an outer shell 58 is provided which further cooperates with and strengthens the connector 24.

The shell is formed by injection molding of a hard plastic material, such as 6/6 nylon. As diagrammed in Fig. 1, the shell 58 has a forward cylindrical portion 60 which is dimensioned to compress the mandrel fingers 38 against the outer surface of the jack when the portion 60 is slid forward along an axial locus denoted by the arrow 61. An inside edge regicn 62 of the portion 60 bears against the cap region 56 which in turn presses inwardly against and compresses the fingers 38 toward the outer surface of the jack in the manner of a compression collet.

At the same time, a rear, frustoconical portion 64 of the shell 58 positions an inside surface 66 against a region of the outer plastic insulator 20 adjacent to the frustoconical surface 31 of the mandrel body 26. The inside surface 66 thereby clamps the insulator and outer conductor jacket against the surface 31, thereby preventing relative movement of the cable 10 relative to the connector 24 and particularly relative to the knife edge 33, and further accentuating the creasing action of the outer conductor jacket over the mandrel knife edge 33 and preventing rearward movement relative to the connector 24.

The outer shell 58 must have a sufficiently high 25 modulus of elasticity and resilience to stretching so that it effectively closes the fingers 38 of the collet structure 37 as the shell 58 slides forward over the mandrel body 26. Since jacks are found in practice to range in diameter over about an .015" range, the sizing of 30 the inside diameter.. of the edge region 62 should be such that when the front edge of the outer shell portion 60 is slid about halfway over t-e collet structure 37, a secure grip is thereby achieved between the structure 37 ind a jack of nominal diameter, e.g. .375 inches. In thisJ 35 manner, smaller and larger diameter jacks of the type, for example, may be securely engaged by the connector 24, particularly if the inside surface of the collet structure .o *.e 9 S o

S..

0 9090 *69 *09&a 060 2 rr~-~ 26 37 is provided with the shallow thread 39, as shown in Fig.

2C. A modulus of elasticity of at least 100,000 pounds per square inch, and a resiliency enabling stretching up to about four percent of nominal are presently preferred characteristics for the outer shell 58.

An oxide-formation preventing gel may be coated onto the mandrel body 26 on the radial wall portion 32 adjacent to the knife-edge 33, or on the frustoconical surface 31, or at both locations as desired. The gel may have lubricating properties and may facilitate insertion of the mandrel body 26 between the dielectric core 14 and the outer conductor foil jacket 16. Gels under compression, such as.disclosed in commonly assigned U.S. Patents Nos.

4,634,.207; 4,643,924; 4,721,832; and, 4,701,574, the disclosures of which are he:eby incorporated by reference, are suitable for use with the embodiments of the present invention disclosed herein.

Also, with the connector 24, a space 53 is provided between the thickened radial portion 36 of the mandrel body 26 and the flaired region 52 of the deformable elastomeric cap 58. This space 53 enables excess outer cable material to be curled up and accomodated, fur.ther relaxing the tolerance requirements for preparation of the end of the cable 10 for installation of the conductor 24.

25 Turning to Figs. 3-7, an assembly sequence of a kit of parts which will eventually comprise the connector 24 is illustrated. Therein, a molded plastic assembly tool or jig I 70 is shown in axial alignment with the other components previously discussed in conjunction with Figs. 1 and 2. In 30 Fig. 3, an end 11 of the cable 10 is prepared as shown, so that the foam core 14 and exposed outer coating 16 extend a small distance beyond the outer insulator 20, and braid and aluminum foil layers-18. The braid and foil layers 18 are folded up and radially outwardly away from the 35 longitudinal axis of the cable 10. The cable end 11 may be prepared with a special tool, or simply by using a sharp knife or single edge razor blade. The stubby wires of the 1'A 27 braid and foil layers 2.8 are folded back by the installer's finger after the ring of outer insulator coating has been cut away.

In Fig. 4, the mandrel body 26, cap So and outer shell 58 are nested into the assembly tool 70 in P-1eparation for receiving the prepared cable end 11 as shown therein.

A annular ring portion 71 of the tool 70 provides a A convenient grip location for the user's fingers. The cable is gripped in one hand, and the assembly tool 70 containing the body 26, cap 50 and outer shell 58 is gripped in the other hand. Thent, the cable is pushed toward the tool and into and through the the outer shell and cap 50. When the cable engages the mandrel body 26, it pushes the body forward and away from the cap 50 and outer shell 58, as shown- in Fig. In Fig. 5, the cable end 11 is shown inserted into the tool 70 and the end has pushed the mandrel body 26 to the forward end of the tool 70, passing over and leaving behind the cap 50 and the shell 58. If the tool 70 is foarmed of a transparent plastic material, then it is possible for the :_nstaller to see that the cable end 11 has passed over the frustoconical region 30 and the thinned tubular region 34 and is butted up against the outside of the second rad, al wall portion 36. In this manner the transparent tool 70 acts as ;i gage for aiding proper installation. When the cable has reached the desired position, as shown in Fig. 5, the cable 10 is then pulled o. away from the tool 70, with the installer grasping the 2 outer shell 58.

As the cable 10 and mandrel body 26 are drawn rearwardly, the outer shell 58 retains the cap 50 and causes it to slip over the cable 10 and over the annular bulge therein now formed by thd outer jack~et elements lying upon the surface 31. Continuing to pull the cable 10 relative to the shell 58 causes the cap 50 to be moved into its final locki~ng position' over the thinned tubular region 34 in front of the first wall portion 33, as shown in Fig. 1.

-U L~Cs I ii The cap 50 is thus snap-locked against the outer insulator at the vicinity of the radial wall 32 and prevents rearward movement of the cable 10 by coaction with the knife edge barb 33 of the mandrel body 26.

It will be appreciated that the tool or jig 70 forms a convenient package for containing a kit of parts including the mandrel body 26, snap-lock cap 50 and outer shell 58.

A "blister-pack" package may include the tool and parts and be formed onto a cardboard substrate for convenient distribution to the householder or other installer/user of the connector 24. The substrate may conveniently provide printed instructions and illustrations for assembly and use of the connector 24.

In Fig. 6, the connector assembly 24 has been withdrawn from the tool 70 (which may now be discarded as spent, or retained for installation of another connector' assembly 24). Then, with the outer shell in the slid back position as shown in Fig. 6, the connector 24 may be pushed onto a jack 72, as shown in Fig. 7. The exemplary jack 72, typically an jack, may define an outer threaded surface 74 against which the fingers 38 of the mandrel body 26 come into contact. The shallow thread 39 (if present on the S" inside surface of the collet structure 37) is pitched to mate with the threaded surface of the jack. The outer shell 58 is then slid forward to a position shown in Fig.

7 which simultaneously locks the fingers 38 against the threaded surface 74 and the outer jacket elements against the frustoconical surface 31 of the mandrel body 26. The connector 24 is now securely, yet removably, attached to the connector. Any tugging on the cable 10 will result in the connector 24 becoming dislodged from the jack 72 in o8 preference to an unwanted separation of the connector 24 and the prepared eable end 11.

To remove the connector 24 from the jack 72, the outer shell 58 may be grasped between the fingers and rotated to facilitate loostening the connector from the jack. The shell 58 is then slid rearwardly, thereby 29 *releasing the fingers 38 arnd enabling ready removal of the connector assembly 24. An outer annular ring or a pair of opposed flanges 59 (Figs. 2F and 2G) formed on the shell 58 provides a suitable thumb-finger gripping mechanism to enable rotatable and slideable movement of the shell 58 relative to the mandrel 26, cap 50 and cable 10 for installation and removal of the connector 24 to and from the jack 72.

Fig. 8 shows a cap 50a which is provided with a plurality of spllg.ss 55 in lieu of the continuous resilient portion 54. The operation of the cap 50a is similar, with that described for the cap 50. However, the splines 55 dig 9into the outer plastic insulation 20 of the cable 10 to 5create a series of stress points or barbs which coaact to retain and lock the braid and foil layers 18 against the knife- edge barb 33. In practice, the pointed tips of the splines 55 actually dig into the outer plastic coating Figs. 9-12 illustrate an alternative embodiment 24a 20 of a connector embodying the principles of the present invention. In these figures, the same reference numerals are applied to the elements diiscussed in conjunction with Figs. 1- 7. A modified cap 50b includes a thickened radial portion 52a leading to the deformable annular edge 54. A disk 58a provides the finger closure function provided by the region 60 of the shell 58, previously described. The advantage of this embodiment 24a is that it provides a very flat and compact connector assembly. Also, there is very little drawback from stress relaxation of the thick disk, a problem sometimes encountered with the thinner outer shell 58 of the earlier described embodiments. one disadvantage with the connector 24a is that without the portion 64 of the outer.-shell, there is no additional reinforcement or support provided to the cable end at the vicinity of the frustoconical portion 30 of the mandrel body 26.

The connector 24e shown in Figs. 13-16 reveals yet another combination of cap 50e and outer shell 58c for use with the originally described mandrel body 26. In this embodiment of connector 24e, the cap 50e includes an elongated tail section 53 which is dimensioned and configured to overly the knife edge 33 of the mandrel body 26. When assembled and installed on the jack 72, the outer shell 58 is pushed to its forward position by grasping the outer flange 59. This action locks the fingers 38 onto the threaded outer surface 74 of the jack 72. A tapered 15 annular edge 63 cooperates with the cap 50e to provide further compression to the cable jacket at the vicinity of the knife edge 33, as shown in Fig. 16.

The connector 24f, shown in Figs. 17-21-, includes a mandrel body 26c in which the frustoconical knife-blade edge 33 of the prior embodiments is replaced by a knife-blade helical thread or edge 33a projecting radially outwardly from the thinned tubular region 28. In one practical example, the thinned tubular region may be slightly frustoconical and have an average outside diameter of about .180 inch. The helical knife blade edge 33a has an apex I which is approximately .210 inch and is formed as an acutely angled projection extending from the tubular region 28. The helical knife blade 33a is so shaped as to bite sufficiently into the fine aluminum strands of the outer conductor braid or a.luminum foil to obtain a positive electrical contact with the foil and also to provide a positive metuhanical securement therewith, without causing the strands to shear or break off.

An effective compromise between sharpness and dullness of the knife edge is to make it flat across for about two to three mils. A one mil flat is too sharp and will result in shearing the fine wire braid, while an eight mil radius at 7 C the edge has been found to be too dull with resultant slippage of the braid under tension. Ideally, the knife blade 33a should subject the braid wires to shear stresses without actually resulting in shearing them off. In practice the compromise is reached by considering sharpness of the knife edge 33a and the hardness of the material of which it is made.

The jig or tool 70a is modified to include teeth which are sized and positioned to engage the slots 82 defined between the fingers 38 of the collet structure 37.

An outer end portion 84 of the tool 70 may be provided with S* radial spokes or projections to facilitate gripping and :o impartation of rotational torque to the tool 70 to enable insertion of the threading mandrel 26c onto the prepared 15 end of the cable 10. Rotational installation of the mandrel 26c onto the prepared cable end is illustrated diagrammatically in Fig. 19 by the arrow 84. The use of a helical knife-blade edge 33a on the mandrel 26c has been found to be particularly advantageous in order to 20 facilitate ready installation of the assembly 24f onto the coaxial cable 10 at low ambient temperatures which cause substantial stiffness of the outer elastomer jacket thereof. When the outer jacket 20 has stiffened due to .o lower ambient temperatures, it aids in causing the helical knife-blade edge 33a to bite into and positively engage the outer conductor braid/foil of the coaxial cable Otherwise, the assembly of the connector assembly 24f is the same as described hereinabove for the assemby 24.

4' The mandrel body 26d, illustrated in Figs. 22-24, P Cbl"c 32 solves a problem otherwise associated with coaxial cables having different diameter foam cores within a predetermined size range. For example, an RG-59 cable 10a may have a diameter of about .145 inch for the core 16a, whereas an RG-6 cable 10b may have a diameter of about .185 for its core 16b. Both cables may be effectively terminated by aI connector assembly including the mandrel body 26d. The body 26d, otherwise identical to the body 26, is formed to define e.g. four longitudinal slots 86. The slots 86 are very narrow, e.g. .010 inch, for example; and they extend f rom the cable end to the wall 36. An inside diameter, denoted by reference numieral 88, at the cable end :0 corresponds generally to the outside diameter of the smallest cable core l6a within the size range to be 00 15 accomodated, while an inside diameter, denoted by reference numeral 90, of the central bore of the tubular portion 34 of the mandrel body 26d is sized to accomodate the outside diameter of the largest cable core 16b within to. the predetermined size range. The frustoconical portion S 20 30a of the mandrel body 26d is tapered toward the cable end diameter 88 on both the inside and outside thereof.

An expendable ramping tool 92 is provided for use in attaching the mandrel body 26d to the prepared cable end.

*.Go The ramping tool 92, when positioned axially over the 25 exposed cent al :ondu .ctor 12' of the cable 10 to abut the core 16 causes the fingers formed by the slots 86 to expand radially as the mandrel body 26d is pushed toward the core 16. This radial expansion of the cable end of the mandrel body 26d positions it so that it will properly come into overlying engagement with the cable core, whether it be of a smaller diameter such as the core 16a, or of a larger diameter such as the corei 16b. After the outside of the core 16 is engaged, the ramping tool is forced axially all the way through the tubular portion and into the region enclosed by the collet structure 37 where it may be readily removed and discarded by the installer.

While the frustoconical knife-blade edge 33 i -RYAL0.1L L h_ 33.

illustrated in the Fig. 22-24 embodiment, it is clear that a helical knife blade edge 33a may also be used with equally successful results in this .embodiment.

Referring now to Figs. 25-28, the connector 24f depicted in Figs. 17-21 and discussed in conjunction with those figures is again depicted. However, in Figs. 25-28, a modified tool 70b illustrated in combination with the elements of the connector 24f and the cable 10. The tool has a significant advantage in that it automatically prevents over-installation of the connector mandrel 26c onto the prepared cable end.

In certain locations, low light levels make it most difficult or even impossible to gage whether the connector mandrel body 26c has been rotated onto the prepared cable 15 end sufficiently. The consequence in practice has been that the mandrel body 26c has been threaded onto the cable end too far, with the result that the outer conductor braid and shield has become bunched up, leading to poor electrical and mechanical connection of the connector onto the cable end.

The tool 70b is configured to prevent the mandrel body 26c from being rotated too far onto the prepared cable end.

In accordance with an aspect of the present invention, the tool 70 is formed with a hollow cylindrical plug region The plug region 83 is concentric with the connector elements and with the prepared cable end. The plug region S83 defines an inner wall 85 which butts up against the mandrel body., as shown in Fig. 26. A central opening 87 is defined through the inner wall 85. Since the center conductor wire 12 has a diameter which typically ranges between 32 mils and 40 mils, the central opening 87 is I sized to be about twice the largest wire diameter, or about mils in diameter. This diameter is selected for two very important reasons: first, it is sufficiently smaller than the diameter of the dielectric core 16 of the cable so that an end wall 17 thereof will come into contact with the' inner wall 85 and thereafter dislodge the tool Secondly, the small diameter opening 87 serves as a gage to

L

i:1 1.

44

C

I Ja 34 be sure that the center conductor 12 which is exposed at the prepared cable end is not bent. (If the exposed end of the inner conductor 12 is bent, damage will likely ensue to the center contact within a receptacle with which the assembed conductor and cable end will be used).

As shown in Fig. 26 the cable 10 is just entering engagement with the mandrel body 26c. As the tool 70b is rotated, the teeth 80 thereof engage the slots 82 between the leaves 38 of the outer cap portion 37 of the mandrel 10 body 26c and cause it to rotate with the rotation of the tool 70b. Fig. 27 illustrates a position at which the mandrel body 26c has been screwed onto the prepared end of the cable 10 to a position at which the endwall 17 of the dielectric has butted up against the inner wall 85 of the tool.

As shown in Fig. 28, continued rotation of the tool 70b causes the mandrel body 26c to move rearwardly along the prepared cable end, and results in the dielectric core 26 projecting slightly beyond the end of the inner wall of the mandrel body. At this position, the inner wall 85 of the tool 70b is pushed away from the mandrel, causing the teeth of the tool to become disengaged with the slots 82 between the cap fingers 38. At the point shown in Fig. 28, further rotation of the tool 70b does not cause any further rotation of the mandrel body 26c and thereby prevents it from becoming -installed too far along the prepared cable end. Thus, with the tool 70b, the installer may rotate it relative to the cable 10 until automatic disengagement occurs, at which point the mandrel body 26c is properly installed to a correct length along the prepared cable end.

While the same concept may be employed with a push-on tool and annular barb 33, discussed previously, it is particularly advantageous to use the concept with the mandrel body 26c having the helical thread barb 33a.

Statement of Industrial AlD1icability The present invention realizes a three-part feedthrough connector assembly for a coaxial cable which may be readily installed upon a prepared end of a coaxial cable, and which efficiently and effectively clamps onto the prepared cable end to provide a secure electrical and mechanical securement to the outer conductor. A locking mechanism for locking the connector onto a jack or receptacle, and an installation tool, provide important aspects of the present invention.

While the instant invention has been described by reference to what is presently considered to be the most practical of embodiments and the best mode of practice on thereof, it is to be understood that the invention may embody other widely varying forms without departing from oB the spirit of the invention. For example, the outwardly So,,o 15 diverging shape of the inside compression collet 37 may be curved as opposed to frustoconical thereby to enable.

overstroke to account for the range in diametral tolerances of various jacks within a type with which the connector may 0 0 be used. Also, alternatively, the outwardly divergent 0 20 shape may be provided by the cap member 50. The presently o" preferred embodiments are presented herein by way of °illustration only and should not be construed as limiting S the present invention,. the scope of which is more particularly set forth in the following claims.

29 What is claimed is:

Claims (6)

1. 3. A feedthrough coaxial cable connector according to claim 2 wherein the shell means includes an internal 37 frustoconical surface designed for compressing an outer conductor region of the coaxial cable against an external frustoconical surface of a mandrel body when the shell means is slidably positioned over the mandrel body whilst locking the connector onto the receptacle, the external frustoconical surface forming a rearward extension of the split tubular radial walled portion and being located inside the outer conductor region.
2. 4. A feedthrough coaxial cable connector according to claim 3 wherein the split tubular radial walled portion includes at least two slits to create at least two fingers in the split radial walled portion. A feedthrough coaxial cable connector according to claim 4 wherein the split radial walled portion includes at least four fingers.
3. 6. A feedthrough coaxial cable connector according to claim 5 wherein the elastomeric compression member is a resiliently deformable elastomeric cap dimensioned such that the cap snap locks against an annular wall of the mandrel body, the annular wall forming part of a large diameter end of the external frustoconical surface.
4. 7. A feedthrough coaxial cable connector according to claim 6 wherein the cap member provides hoop strength and protection to the fingers of the radial walled portion.
5. 8. A feedthrough coaxial cable connector according to claim 6 wherein the shell means is an outer shell being slidable in the forward direction along a longitudinal axis of the cable to provide locking of the fingers on the receptacle and additional hoop stress round the fingers, such that the fingers, the elastomeric compression member and the outer shell together form a compression collet.
6. 9. A method of gripping a cable splice or tap port receptacle comprising: positioning a split tubular radial walled member over the receptacle; and IF- I r JC~ _L 1 38 sliding a resiliently deformable elastomeric radial compression member along a coaxial cable mated to the receptacle and over the split tubular radial walled member to compress the split tubular radial walled member into friction fitting engagement on the receptacle. Ii Dated this 2 6 t h day of May 1998 RAYCHEM CORPORATION oo By their Patent Attorneys Sa.. a Saooo o e O So o a o a o*on W o Abstract of the Disclosure A feedthrough .coaxial cable connector includes a tubular mandrel body dimensioned to be pressed between a foil-bonded dielectric core and other elements of an outer conductor of the prepared end of the cable. The body has cable engagement surface which defines a knife edge projection therearound for engaging an outer conductor of the cable by creating shear stresses therein without actually shearing the outer conductor. A tubular shank portion extends from the cable engagement surface portion to a radial wall portion, and a jack engagement portion is coaxial about the exposed central conductor. The jack engagement portion achieves a tight friction fit upon a jack and may be formed as an inside compression collet. A radial compression providing structure causes an inside surface region of the outer conductor to bear directly- against and bend over the knife edge. portion. Preferably, a slideable shell is slideably positionable generally away from a connector end facing the outer surface of the jack to enable the jack engagement portion of the connector to slide over the outer surface of the jack, and slideably positionable toward the connector end so as to radially ocompress the radially diverging jack engagement portion Sagainst the outer surface of the jack to secure the connector thereto. A kit of parts including an expendable installation tool enables proper assembly of the cable *i6o connector without special skills or tools. '0 00 /-r