US3539709A - Sealing crimp ring for coaxial connector - Google Patents

Description

NOV. l0, 1970 s. T. BRANcALE'oNE SEALING CRIMP RING FOR COAXIAL CONNECTOR Filed Nov. 4. 1968 I L t' l* I @gmx wil/ll l INVENTOR BY HMI/i? mmm United States Patent O U.S. Cl. 174-75 4 Claims ABSTRACT OF THE DISCLOSURE The invention comprises a sealing crimp ring for attachment to an end of a coaxial cable. The sealing crimp ring comprises a tubular body having front and rear ends and an intermediate section with the end of the cable being receivable within the tubular body from the rear. A cylindrical rubber seal is mounted within the body, the tubular body being deformable inwardly around the rubber seal to form an environmental seal between the coaxial cable and the tubular body. The tubular body may form an integral part of the electrical connector. Further, a rubber seal may be used at the front end of the tubular body as well as at the rear end.

The invention relates in general to sealing crimp rings and, more particularly to a crimp connector having an environmental seal mounted externally of the connector assembly.

BACKGROUND OF THE INVENTION In conventional coaxial cable electrical connectors, it has been found advantageous to electrically and mechanically couple the cable shield or braid to the body or outer conductor of the connector member by depositing the braid radially between an inside relatively rigid ferrule and an outside crimp ring, and crimping the outside ring radially inwardly to effect the connection. When designing such a crimp connector, the designer must choose between a crimped but nonenvironmental connector or a crimp connector having an environmental seal containing additional size and parts which increase cost while simultaneously decreasing reliability.

As is well known, the technique of crimping is the compression of a soft metal ring around the connector ferrule with the cable bread sandwiched therebetween. This crimping is accomplished with a crimp tool whose jaws reduce the crimp ring to the tool internal configurations and dimensions. Further, when humidity sealing is required, the crimped cable and connector combination must be contained within the housing which is usually integral with the connector body. Integral with the housing and external to the crimp ring are various types of ramps, seal glands, washers, and clamp nuts to effect an adequate humidity seal. In certain cases, boots and shrink tubes have been used but these do not provide an adequate humidity seal where a true environmental connector is required.

The present invention utilizes a sealing crimp ring combining the high reliability and the simple assembly advantages of the crimped connector with the compression sealing advantages of a threaded clamping mechanism. This sealing crimp ring is as simple to assemble as a conventional crimp conector. Further, it is possible to accomplish an environmental seal in a crimp connector without burying the crimp termination inside of a more complex connector assembly. The sealing crimp ring can be used on any shielded connector where sealing and crimping is desired.

3,539,709 Patented Nov. 10, 1970 SUMMARY oF THE INVENTION More particularly, the invention comprises a sealing crimp ring for attachment to an end of a coaxial cable. The sealing crimp ring comprises a tubular body having front and rear ends and an intermediate section with the end of the cable being receivable within the tubular body from the rear. A cylindrical rubber seal is mounted within the body, the tubular body being deformable inwardly around the rubber seal to form an environmental seal between the coaxial cable and the tubular body. The tubular body may form an integral part of the electrical connector. Further, a rubber seal may be used at the front end of the tubular body as well as at the rear end.

The advantages of this invention, both as to its construction and mode of operation, will be readily appreciated as the same becomes better understood by references to the following detailed description when considered in connection with the accompanying drawing in which like reference numerals designate like parts throughout the figures.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 depicts a connector member, partly in section, embodying a novel sealing assembly in accordance with the invention;

FIG. 2 depicts the connector member of FIG. l with sealing assembly secured within the connector member prior to completion of assembly of the device.

FIG. 3 is a rear view, partly in section, of the assembled connector, taken along the line 3-3 of FIG. l.

FIG. 4 depicts an alternative arrangement for utilizing the sealing assembly;

FIG. 5 depicts the sealing assembly of FIG. 4 after completion of the sealing assembly; and

FIG. 6 depicts an alternative arrangement of a portion of the sealing assembly.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the drawing, there is shown in FIG. 1 a connector member 12 depicted as a plug connector member, although the invention is equally applicable to a receptacle connector member adapted to be connected with the plug connector member 12, or may be embodied in other types of connector members. The connector member 12 includes a tubular body or shell 14. The bore 16 of tubular body 14 includes an enlarged rear portion 18. Rearwardly opening slots 22 formed by fingers 24 are provided on the rearward section of the tubular body 14. The bore 16 is of annular configuration where the rear portion 18 meets intermediate constricted bore portion 26 so as to dene a rearwardly facing shoulder 28 and an angular section 32.

The bore 16 further contains an enlarged forward bore portion 34, a forwardly facing shoulder 36 and a rearwardly facing shoulder 38 where the forward bore portion 34 and intermediate bore portion 26 adjoin each other. A shallow counterbore 42 is provided at the front end of the body 14 for receiving an annular sealing gasket 44, the gasket being adapted to provide a seal between a forward end of body 14 and the forward end of the body of a mating connector member (not shown).

A coupling nut 46 is rotatably mounted about the front portion of the body 14, and extends forwardly from the front end of the body 14 for connecting the member 12 with a mating connector member. Coupling nut 46 is rotatably retained on body 14 by provision of an internal annular groove y48 in nut 46 which receives a retainer ring 52, the ring extending radially inwardly into an annular groove 54 in the outer surface of body 14.

A tubular outer contact 56 is mounted in the constricted forward bore portion 34 of body 14, extending forwardly through the gasket 44 and having a forward contacting portion comprising a plurality of spring contactingfingers 58. The rear end of the outer contact 56 is aligned with the forwardly facing shoulder 36. The tubular outer contact 56 has a rearwardly facing annular shoulder 62 therein and serves to limit the forward position of an insulator 64 which is insertable into the tubular contact 56 from the rear. Insulator 64 has an axial bore 66 extending therethrough, with a relatively large forward counterbore 68 and a relatively small rearward counterbore 72 therein. The rear end 74 of the insulator 64 is approximately aligned with the forwardly facing shoulder 36 of bore 16.

Insulator -64 may be composed of Teflon or other suitable dielectric material having su'icient structural rigidity to support a center contact member 76 within the insulator bore 72. Center contact member 76 includes a forward contacting portion 78 that is exposed within the insulator forward counterbore 68 so as to be accessible to a mating contact member from the front of the connector member. The center contact member has an axial recess 82 therein which opens to the rear of the contact member so as to receive the bored forward end of the center conductor of a coaxial cable.

The coaxial cable 84 which is engaged with the connector member 12 includes a center conductor 86, a dielectric layer 88 surrounding the center conductor 86, a braided tubular outer conductor 92 surrounding the dielectric layer 88, and a cable jacket 94 of insulation material which surrounds the braidedouter conductor 92.

The dielectric layer 88 is trimmed back from the end of the coaxial cable 84 so as to leave an exposed forward end portion of the center conductor 86 which is inserted into the axial recess 82 of center contact member 76 and secured thereto by soldering or crimping.

The structure in the connector member to which the tubular outer conductor 92 of the cable is crimpel coml reduced diameter central bore 124 and an enlarged diameter forward bore 126, and an enlarged diameter rear bore 128. The forward section of the member 122 contains forward opening slots 132 formed between lingers 134, and rearward opening, slots 136 formed between fingers 138. An annular notch 142 is formed in the member 122 adjacent the bore 124 and a forwardly facing shoulder 144 is formed adjacent the rear end of forward bore 126. Further, an annular notch 146 is formed in the member 122 adjacent the bore 124 and a rearwardly facing shoulder 148 is formed adjacent the forward end of rear bore 128. j

The connector body 143 is made integral with a rearwardly extending cylindrical ferrule 152 whose bore v 162, 164 is compressed thus forming the desired environmental seal. Further, the central reduced section 122 may be crimped to the braid 154 simultaneously'. The connector assembly of FIGS. 4 and 5 is similar to that of FIGS. 1 and 2 with the exception of body member 143 and, therefore, the connector assembly has not been described in detail.-

Referring now toFIG.' 6', there is shown an alternative embodiment of the foldable members of FIGS. 1 and 4. In FIG. 6, the foldable member is shaped as a triangular v piece of metal 170 prior to compression. Thus, on comprises a ferrule 96 having an enlarged rearward portion f 98 which is slidably engaged over the cable jacket and a constricted forward portion 102 slidably engaged over the braided tubular outer conductor 92. The rearward portion 98 and rforward portion 102 of ferrule 96 are interconnected by an annular portion 104 adjacent the angular section 32 of tubular body 14, the cable jacket being terminated at the junction of the rearward portion 98 and the angular portion 104 of the ferrule 96.

The braided tubular outer conductor engages the inner surface of the forward portion 102 of ferrule 96 and then overlaps the end thereof adjacent the rearwardly facing shoulder 38 and is interposed between the outer surface of forward portion 102 and the constricted intermediate bore portion 26 to provide electrical contact between outer conductor 92 and outer contact 56 through the tubular body 14.

A cylindrical rubber seal 112 which is slidably inserted over the cable jacket has its outer surface adjacent the enlarged rear bore portion 18 of the body 14. The front surface 114 of the seal abuts the rear end of the rearward portion of the ferrule 96, thereby forming an air gap between the remainder of the front surface 114 and the rearwardly facing shoulder 28. The rear surface 116 of the seal terminates short of the end of the fingers 24.

By applying a crimp tool to the members 24, the rubber member 112 is compressed, with the final angle of the members 24 determining the amount of compression transferred throughout the resilient material. Of course, a crimp tool could be designed which could fold over members 24 to the desired anglewhile simultaneously crimping the center region of the assembly to the braid 92.

Referring now to FIGS. 4 and 5, there is depicted an alternative embodiment of the sealing assembly of FIG. 1 wherein the ferrule is an integral part of the body of the connector assembly. The sealing mechanism comprises a generally cylindrical ring member 122 having a pression, each of the triangular members are almost in contact with each other vat their edge surface, thus entirely enclosing the rubber packing material within the seal.

What is claimed is:

1. In a cable connector having a coaxial cable end, means coupling the cable end to a cable connector, an outer sleeve in contact with the outer conductor of said cable end, and extending axially along said cable,

said sleeve having an end portion surrounding a portion of said cable and spaced therefrom, a resilient memj ber inserted in the area between said sleeve and said cable, the ends of said sleeve being bent inwardly so as to form an acute angle with the axis of said sleeve, the inward bending of the end of said sleeve compressing said resilient member, the end angle being directly related to the amount of compression transferred to said resilient material.

2. A cable connector in accordance with claim 1 wherein a resilient member is provided at both ends of said sleeve and each of said ends are bent inwardly at said acute angle.

3. A cable connector in accordance with claim 1 wherein said end portion is formed of a plurality of fingers each of said fingers being bent at said acute angle with respect to the axis of said cable. y

4. A cable assembly in accordance with claim 3 wherein said lingers are triangular in shape and wherein upon compression said resilient material is thus almost entirely enclosed by said sleeve.

References Cited UNITED STATES PATENTS 3,221,290 11/1965 Stark et al. 174-75 XR 3,238,494 3/1966 Bentley 174-75 XR 3,428,739 2/ 1969 Jackson.

DARRELL L. CLAY, Primary Examiner U.S. Cl. X.R.

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