05/468041

12/02/1975

05/08/1974

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Hughes Aircraft Company (Culver City, CA)

439/585

H01R9/05; H01R11/08

339/6C,9C,91P,94C,142,143R,276R,177R

Lake, Roy

Desmond E. F.

Macallister, Sternfels Lewis W. H. B.

What is claimed is

1. A simultaneous double crimp coaxial cable and contact assembly comprising:

2. A coaxial electrical contact assembly having an axis comprising a housing of electrically conductive material having an inner surface, a contact therein having an outer surface, said inner and outer surfaces having substantially the same radial spacing therebetween along the axis, means for defining insulation of deformable plasticity between said housing and said contact, and means for imparting a plastic deformation of substantially uniform wall separation between said inner and outer surfaces, and for securing said insulation means between said housing and said contact, thereby for providing a stable, strong and interlocked assembly of said housing, said contact and said insulation means, and for establishing a substantially uniform dielectric constant along the axis.

3. A contact assembly as in claim 2 wherein said housing comprises a stamped and formed tube.

4. A contact assembly as in claim 2 wherein said housing comprises means for defining an enclosure formed from flat stock having edges in contacting relationship for forming a seam, and means for securing said edges together for preventing separation of said seam.

5. A contact assembly as in claim 4 wherein said securing means comprises at least one dovetailed joint.

6. A contact assembly as in claim 1 wherein said plastic deformation means includes means on said housing and on said contact for defining at least two substantially annular reliefs spaced at different radial distances from the axis.

7. A contact assembly as in claim 6 wherein said housing includes at least one radially inwardly formed portion and at least one radially outwardly formed portion for defining said annular relief means.

8. A contact assembly as in claim 7 wherein said contact includes a major diameter portion and a minor diameter portion of lesser dimension than said major diameter, said major and minor diameter portions being axially aligned and radially spaced respectively from said radially outwardly and inwardly formed housing portions for defining said annular relief means.

9. A contact assembly as in claim 8 wherein said plastic deformation means further includes radially inwardly and outwardly extending annular portions positioned and deformed in a plastic flow respectively between said major diameter portion and said radially outwardly formed portion and between said minor diameter portion and said radially inwardly formed portion.

10. A coaxial electrical contact assembly for terminating a coaxial cable having a specific dielectric constant including an inner conductor and an outer conductor surrounding inner conductor, comprising:

11. A coaxial electrical contact assembly as in claim 10 further including a ring positioned over said end of said outer contact means for electrically and mechanically securing the outer conductor thereto.

12. A coaxial electrical contact assembly as in claim 11 wherein said enclosure of said outer contact means includes protuberances at said end thereof for limiting axial engagement of said ring thereon.

13. A coaxial electrical contact assembly as in claim 10 wherein said enclosure of said outer contact means comprises a stamped and formed tube wherein said opening means comprises stamped out portions of said tube.

14. A simultaneous double crimp coaxial cable and contact assembly comprising:

15. An assembly as in claim 14 wherein:

16. An electrical contact assembly comprising:

17. A coaxial electrical contact assembly for terminating a coaxial cable including an inner conductor and an outer conductor surrounding said inner conductor, comprising:

18. A coaxial electrical contact assembly as in claim 17 wherein said enclosure of said outer contact means comprises formed flat stock having edges in contacting relationship to form a seam, and means for securing said edges together for preventing separation of said seam under bias of said insulating means and for maintaining the deformed and interlocked engagement of said insulating means.

19. A coaxial electrical contact assembly as in claim 17 further including a retaining clip mounted on said outer contact means and abuttable against said protuberance means thereof for enabling retention of said contact assembly within opening means in an insulation of a connector body.

20. A coaxial electrical assembly for terminating a coaxial cable including an inner conductor and an outer conductor surrounding said inner conductor, comprising:

21. A coaxial electrical contact assembly as in claim 20 wherein said insulating means includes a split end and wherein said socket entry stabilizer extends over said split end for deformation thereof into a recess in said inner contact means.

22. A coaxial electrical contact assembly as in claim 20 wherein said socket entry stabilizer includes a tip extending beyond the end of said outer contact means, said tip including an outwardly extending flange defining a shoulder abutting against an end opposite said outer conductor receiving end of said outer contact means and an internal recess for reception of a pin contact engageable with said socket means of said inner contact means.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to coaxial contacts for terminating electrical coaxial cables, and methods of assembly therefor.

2. Description of the Prior Art

Coaxial contact assemblies for terminating coaxial electrical cables comprise inner and outer contacts and one or more insulators which are generally fabricated on screw machines in which material is machined from the inside and outside of solid round stock. Several problems result from such construction, relating to cost, contact configuration, and cable-to-contact assembly. Any transverse holes required in any of those components must be formed in a machining, milling or drilling operation separate from work by the screw machine, leading not only to increased costs of capital equipment but also of the required labor. The configuration of the contact components, in particular to their internal configurations, is limited to simple stepped holes or recesses of increasing diameter within and facing the end openings, unless very expensive and specialized tooling is utilized.

With respect to assembly operations in terminating coaxial cables to prior art coaxial contact assemblies, several crimp operations are generally required, one for each connection of each coaxial cable conductor to its assigned connecting point in the contact assembly. Usually several crimp tools or repeated use of a single tool is required. Furthermore, the prior art coaxial contact assemblies must be shipped to the user as several loose components and the user must make a multistage connection of the cable conductors to the contact components. Thus, use of prior art coaxial contacts and their assembly to coaxial cables involves considerable cost in time, labor and assembly techniques.

SUMMARY OF THE INVENTION

The present invention overcomes these and other problems by utilizing a coaxial contact assembly having a unique progressively stamped and formed outer housing contact having dovetails on its seam for strength. The housing is configured in such a manner that when an inner plastic dielectric component, previously assembled onto an inner pin or socket contact, is forced within the housing, the dielectric material flows into reliefs between the housing and the inner contact to provide a stable and strong assembly. Specially designed windows or ports in the outer housing enables crimping of the cable inner conductor to the inner contact of the coaxial contact. As a result of this design, the coaxial contact assembly may be shipped to the user fully assembled except for one separate crimp ring, so that the user need only strip the cable, slide its conductors into place respectively into the inner contact and over the housing, slip the crimp ring over the outer cable conductor, and simultaneously crimp the cable outer and inner conductors to the coaxial contact assembly in a single operation.

It is, therefore, an object of the invention to provide a coaxial contact assembly of inexpensive construction and of low cost.

Another object is to provide such a contact assembly which is capable of being shipped to a customer as fully assembled as in practicable.

Another object of the present invention is to provide a stable and strong contact assembly.

Another object of the present invention is to provide a controlled dielectric constant between the coaxial electrical components of the contact assembly.

Another object of the present invention is to provide such a contact assembly with a dielectric constant which is capable of matching, as nearly as possible, the dielectric constant of the coaxial cable to which it is to be coupled.

Other aims and objects as well as a more complete understanding of the present invention will appear from the following explanation of exemplary embodiments and the accompanying drawings thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts one embodiment of the present invention in partial cross-section configured as a male coaxial contact assembly;

FIGS. 1a through 1d depict several components of the male coaxial contact assembly illustrated in FIG. 1 respectively including its inner socket contact, its housing contact, its socket insulator, and its socket entry stabilizer;

FIG. 2 depicts another embodiment of the present invention in partial cross-section configured as a female coaxial contact assembly;

FIGS. 2a through 2c respectively depict several components of the female contact assembly of FIG. 2 including its inner pin contact, its housing contact, and its pin insulator;

FIGS. 3a through 3g depict several steps for securing a coaxial cable to either of the coaxial contact assemblies of FIGS. 1 and 2;

FIG. 4 depicts a coaxial cable affixed to a coaxial contact assembly; and

FIG. 5 is a cross-sectional view of FIG. 4 taken along lines 5--5 thereof.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Accordingly, referring to FIG. 1, a male coaxial contact assembly 10 comprises a socket inner contact 12 coaxially housed within a male housing 14 with a socket insulator 16 and a socket entry stabilizer 18 secured between inner contact 12 and housing 14.

Socket inner contact 12, see also FIG. 1a, comprises a bifurcated socket 20 for reception of an inner pin contact on a female coaxial contact assembly (shown in FIG. 2) and a wire-receiving end 22 for receipt of an inner conductor of a coaxial cable. It is to be understood that socket 20 need not be bifurcated, only that it incorporate means to enable secure electrical coupling with the mating pin contact. Between bifurcated socket 20 and wire-receiving end 22, socket inner contact 12 includes a major diameter portion 24 bounded on either side by a pair of recesses 26 and 28, major diameter portion 24 having sloping connecting portions 30 adjoining the recesses.

Housing 14, see also FIG. 1b, comprises an enclosure formed from flat stock having opposed edges in contacting relationship to form a seam 32, with dovetail joints 34 locking the edges together for strength and to prevent the separation of the housing at its seam. Housing 14 is provided with a pair of diametrically opposed ports or openings 36, one of which is formed by notching out or otherwise removing material at the edges of seam 32 from the housing stock. During forming of the housing, a plurality of protuberances, indentations and bumps are formed therein, comprising a pair of annular protuberances 38 and 40, an annular indentation 42, and a plurality of bumps 44, preferably three in number. The housing terminates at an end 45.

Socket insulator 16, see also FIG. 1c, comprises a dielectric plastic material capable of plastic deformation and flow. The socket insulator includes a through bore 46 of generally constant diameter from each end for reception of socket inner contact 12, with an inner annular ring 48 of lesser diameter than that of bores 46. Insulator 16 also is provided with an entry port 51 and with an outer annular portion 52 of slightly greater dimension than that of the periphery of the insulator. At its end opposite from its entry port 51, socket insulator 16 terminates in a preferably bifurcated lipped portion 54.

Socket entry stabilizer 18, see also FIG. 1d, comprises a dielectric plastic material of general tubular form having a nose section 56 of greater diameter than that of the remainder of the stabilizer so as to form a rearwardly facing shoulder 58. The outer diameter 59 of nose section 56 is substantially equal to the outer diameter of end 45 of housing 14. At its other end the stabilizer is provided with a bevelled opening 60 which is adapted to cooperate with bifurcated lipped portion 54 of socket insulator 16. Socket entry stabilizer 18 is also bevelled at opening 62 to serve as a guide for entry of the inner pin contact 80 of the female coaxial contact (FIG. 2) into socket 20.

When male coaxial contact 10 is assembled by the manufacturer, major diameter portion 24 of socket inner contact 12 forces inner annular ring 48 of socket insulator 16 and the material surrounding ring 48 into the space formed by protuberance 38 of housing 14. In a similar manner, indentation 42 of housing 14 forces outer annular part 50 of socket insulator 16 and the material below part 50 within recess 26 of socket inner contact 12. As a consequence of these undulating features of both the housing and the socket inner contact, socket insulator 16 is flowed into place into the reliefs formed to secure coaxial contact assembly 10 togetheer thus providing a stable and strong assembly thereof. Furthermore, the interior of the housing is configured approximately to conform to that of the socket inner contact, insofar as it is possible, to maintain an equal spacing between the two electrical pin and housing contacts so as to maintain, with socket insulator 16, a particular dielectric constant which is made as nearly equal as possible to that of the coaxial cable which is to be terminated in the coaxial contact assembly.

As a further feature of the present invention, the spacing between protuberances 38 and 40 on housing 14 provides a site for a retention clip 64, which enables latching of male coaxial contact assembly 10 within an insulation body of a connector.

Socket entry stabilizer 18 fits within housing 14 so that rearwardly facing shoulder 58 abuts against end 45 of the housing, while bevelled opening 60 fits over bifurcated lipped portion 54 of insulator 16 to force portion 54 within recess 28 of socket inner contact 12. Socket entry stabilizer 18 may be secured to the housing by any suitable adhesive.

A female coaxial contact assembly 70, which is adapted to mate with male coaxial contact assembly 10, is depicted in FIG. 2. It is formed similar to male contact assembly 10 and includes a pin inner contact 72 coaxially surrounded by a female housing 74 with a pin insulator 76 of dielectric material separating and insulating contact 72 from housing 74. There is no element in the female coaxial contact assembly comparable to socket entry stabilizer 18 of male coaxial contact assembly 10.

Pin inner contact 72, see also FIG. 2a, includes a pin 80 which is adapted to slide and reside within bifurcated socket 20 of the male coaxial contact. The pin inner contact also includes a wire-receiving end 82 which is adapted to receive an inner conductor of a coaxial cable. Between pin 80 and end 82 is a major diameter portion 84 with a pair of connecting stepped recesses 86 and 88 defined by two diameters disposed between portion 84 and wire-receiving end 82. A sloping connecting portion 90 joins portion 84 with recess 86.

Female housing 74, see also FIG. 2b, like male housing 14 of male coaxial contact assembly 10, is formed from stamped and formed stock to form an enclosure whose edges abut at a seam 92 which is secured and locked together by a pair of dovetail joints 94. A pair of diametrically opposed openings or ports 96 stamped from the stock extend through the housing. A pair of protuberances 98 and 100 with an indentation 102 therebetween and preferably three bumps 104 are also stamped into the stock. Housing 74 is deformed inwardly at 105 to insure electrical contact with housing 14 of the male coaxial contact assembly when the male and female coaxial contact assemblies are engaged.

Pin insulator 76, see also FIG. 2c, comprises dielectric material capable of being plastically deformed. The pin insulator is provided with a through bore 106 of substantially uniform diameter, with an inner annular ring 108 of lesser diameter. An outer annular portion of two diameters 110 and 111 is formed on the exterior of the pin insulator and terminates at one end in an entry port 112.

In a manner similar to that described with respect to the male coaxial contact assembly of FIG. 1, the female coaxial contact assembly is coupled together in a stable strong assembly by outward extrusion of inner annular ring 108 and surrounding material of pin insulator 76 by recess 86 of pin inner contact 72 into protuberance 98 of housing 74. In a similar manner, indentation 102 of housing 74 forces outer annular part 111 and internal material of pin insulator 76 within recess 88 of pin inner contact 72. The spacing between protuberances 98 and 100 form a recess for a retention clip 114 to enable latching of the female coaxial contact assembly within an insulation body of a connector.

Just as with male coaxial contact assembly 10, female coaxial contact assembly 70 is constructed so that the spacing between the interior surface of housing 74 and the outer surface of pin inner contact 72 is as nearly equal as possible to obtain, with pin insulator 76, as nearly equal a dielectric constant as is possible.

As shown in FIGS. 1 and 2, both coaxial contact assemblies are prepared in readiness for connection to a coaxial cable by the user; therefore, both contacts are provided with separate crimp rings 116 and 118 respectively on the male and female coaxial contact assemblies. In addition, both coaxial contact assemblies are provided with separate dielectric spacers 120 and 122 which are furnished as optional equipment in the event that the inner conductor insulation of the coaxial cable needs to be build up in thickness to provide for proper alignment, support, and other mechanical and electrical stability. As a consequence, spacers 120 and 122 enable attachment of a variety of coaxial cables to the contacts.

The assembly of a coaxial cable to either a male or female coaxial contact assembly is depicted in FIGS. 3a through 3g inclusive. In FIG. 3a is shown a coaxial cable 124 comprising an inner conductor 126, an inner conductor insulation jacket 128, a braided outer conductor 130, and an outer conductor insulation jacket 132.

In operation, crimp ring 116 or 118 is slid over the coaxial cable and in back of the area to be stripped. The cable is then stripped as shown in FIG. 3b so that inner conductor insulation jacket 128 is stripped back from inner conductor 126, braided conductor 130 is cut back from inner conductor insulation jacket 128, and outer insulation jacket 132 is stripped back from braided conductor 130. Outer braided conductor 130 is then flared as shown in FIGS. 3c and 3d preferably by use of an appropriate flaring tool. Flaring of conductor 130 must be sufficient to accept an end barrel portion 134 of the respective coaxial contact.

As shown in FIG. 3e, inner conductor 126 of coaxial cable 124 is aligned with preassembled coaxial contact assembly 10 or 70, and the prestripped coaxial cable is then slid into position so that inner conductor 126 is received within wire-receiving end 22 or 82 and outer braided conductor 130 passes over end barrel 134. The installer may observe that inner conductor 126 of cable 124 is penetrating wire-receiving end 22 or 82 by viewing through the inner conductor crimp port or opening 36 or 96. In this operation, it is important that coaxial cable braid conductor 130 envelop the outside diameter of end barrel 134 and that individual strands of a braid not penetrate the inside diameter of the crimp barrel to avoid electrical short circuitry. Furthermore, of course, it is important that conductor 126 likewise not make an electrical short-circuit to housing 14 or 74.

As shown in FIG. 3f, crimp ring 116 or 118 is then slid forwardly over braid 130 until it abuts bumps 44 or 104. The assembly is now ready for simultaneous crimp, as shown in FIG. 3g.

As shown in FIG. 3g, a portion of a crimp tool 136 includes a pair of diametrically opposed inner conductor crimp indentors 138 and a pair of crimp ring indentors 140. Closure of indentors 138 and 140 in the direction of arrows 142 permits simultaneous crimping of crimp ring 116 or 118 about outer braided conductor 130 and end barrel 134 while, at the same time, inner conductor crimp indentors 138 pass through inner conductor crimp ports 36 or 96 to crimp wire receiving ends 22 or 82 about inner conductor 126. The result of this simultaneous crimping operation is shown in FIGS. 4 and 5, wherein the coaxial contact assembly is now in readiness for insertion within an insulation body of a connector along with other coaxial contacts.

It is to be understood that, although preferred stamping, forming, etc., constructions are described, other suitable manufacturing processes may be employed. Furthermore, although the invention has been described with reference to particular embodiments thereof, it should be realized that various changes in modifications may be made therein without departing from the spirit and scope of the invention.