Shielded Cable Connector

Abstract

Complementary male and female connectors for shielded cables such as audio cables. Each connector is in the nature of a male or female pin terminal, respectively, and each comprises a laminated metal structure consisting of two external, rather thin sheets of conductive, resilient metal with a sheet of plastic or the like insulating material in between. The opposite ends of each terminal are reversely bent and the terminals are so configured that each terminal can be crimped on to the end of a shielded cable simultaneously to grip both the inner conductor and the outer braid or the like shield while making electrical connection therewith, but with either conductor and the shield remaining electrically isolated. The male and female terminals then are simply telescopically associated in the normal manner to effect connection respectively between two inner connectors and two external shields.

Description

BACKGROUND OF THE INVENTION

Shielded cables are widely used in the audio field inasmuch as it is necessary to carry very low level electrical signals which must be amplified quite considerably. It is necessary to shield the inner signal carrying lead or conductor with a grounded outer shield to prevent stray hum and other signals from being picked up that would be amplified along with these signals in a highly undesirable fashion.

Terminals for interconnecting such shielded cables are widely used for separably connecting successive lengths of cable. The most common such terminals require unraveling a certain amount of the shield or braid for soldering to an external portion of a pin terminal with the center wire being inserted into a hollow pin terminal and soldered in place. A complementary jack likewise requires soldering. Soldering operations require considerable manual labor, and hence are quite expensive. Accordingly, efforts have been made to produce crimp-type terminals which do not require soldering. However, such connectors have been of a built up construction, comprising separate inner and outer conductor members interconnected by an insulating base of one sort or another. Such connectors are expensive to manufacture and thus save little or nothing in overall cost.

OBJECTS OF THE INVENTION

Accordingly, it is an object of the present invention to provide a crimp-type telescopic terminal for shielded cables which is simple and inexpensive to manufacture.

It is a further object of the present invention to provide a crimp-type connector for shielded cables which is of functionally one-piece construction.

Still more specifically, it is an object of the present invention to provide a pin-type terminal for shielded cables which is capable of production through minor modifications of sheet metal stamping and forming equipment and techniques but wherein a laminated stock or sheet material, comprising a "sandwich" of two relatively thin sheets of metal respectively on opposite sides of an insulating plastic sheet.

THE DISCLOSURE

Complementary male and female pin terminals of laminated construction are provided for crimping direct to the inner conductor and simultaneously to the outer shield of a shielded cable, which connectors are of a laminated construction as described in detail hereinafter with reference to the accompanying drawings wherein:

FIG. 1 is a perspective view of a male pin terminal constructed in accordance with the present invention;

FIG. 2 is a side view of the terminal of FIG. 1 on an enlarged scale;

FIG. 3 is a top view of the terminal of FIGS. 1 and 2;

FIG. 4 is an end view thereof as taken substantially along the line of 4--4 in FIG. 3;

FIG. 5 is an intermediate cross-sectional view as taken along the line 5--5 in FIG. 2;

FIG. 6 is a cross-sectional view as taken substantially along the line 6--6 in FIG. 2;

FIG. 7 is one-half of a longitudinal sectional view through the connector of FIG. 2 on a greatly enlarged scale, sections being broken away to permit foreshortening

FIG. 8 is a perspective view of a female terminal complementary to the male terminal of FIG. 1;

FIG. 9 is a top view of the female terminal of FIG. 8 on an enlarged scale;

FIG. 10 is a side view of the female terminal;

FIG. 11 is an intermediate cross-sectional view taken substantially along the line 11--11 in FIG. 10;

FIG. 12 is a cross-sectional view taken substantially along the line 12--12 in FIG. 10;

FIG. 13 is an end view from the right end of FIG. 10 as taken substantially along the line 13--13;

FIG. 14 is an enlarged longitudinal sectional view of the female terminal generally similar to FIG. 7;

FIG. 15 is a side view showing male and female terminals plugged into one another and connecting shielded cables;

FIG. 16 is a top view corresponding to FIG. 15;

FIG. 17 is a fragmentary view partially in longitudinal section and on an enlarged scale showing the interconnected male and female terminals;

FIG. 17a is a continuation of the right end of FIG. 17 showing the connection of the male terminal to the corresponding shielded cable; and

FIG. 18 is the cross-sectional view taken substantially along the line 18--18 in FIG. 17a.

Turning now to the drawings in greater particularity and first to FIGS. 1-7, there will be seen a male terminal 20 constructed in accordance with the principles of the present invention. This terminal is of the pin terminal type with a plurality thereof designed to be housed in bores in a plastic or the like housing. Terminals of generally this type and a housing therefore known in the prior art, for example, see John H. Krehbiel U.S. Pat. No. 3,178,673 and John H. Krehbiel U.S. Pat. No. 3,465,279. The male terminal 20 is of sheet material (predominently metal as will be disclosed hereinafter) construction and includes a tubular body 22 of predetermined diameter tapering at the left as seen in FIGS. 2 and 3 in a frustoconical section 24 to a front or entering end 26. The front or entering end 26 includes an intermediate barrel 28 of predetermined intermediate outside diameter somewhat less than that of the body 22. The barrel tapers at 30 into a restricted neck 32, and at the extreme entering end there is a tip 34 of somewhat less outside diameter than the barrel 28.

The body 22 has open portions 36 along the sides, and rearwardly, diagonally outwardly directed lances or legs 38 of a resilient nature are formed from the material of the body in the area 36 and extend diagonally outwardly and rearwardly from the rear of the barrel 28. As will be understood by those skilled in the present art, when the terminal is inserted front end first into a housing, the lances 38 will snap over shoulders in the housing to latch the terminal against undesired or unauthorized withdrawal. A longitudinal seam 40 runs the length of the front or entering end 26, of the intermediate frustoconical portion 24 and of the body 22, lending enhanced resiliency to the terminal.

Rearwardly of the cylindrical body 22 is a terminal-retaining section 42 including oppositely extending wings or flanges 44 lying substantially in a common diametrical plane at right angles to the diametrical plane of the lances 38. As will be seen, the distance across the wings 44 is greater than the diameter of body 22 whereby the wings may engage upon entering movement against shoulders to limit inserting of the terminal into a housing.

Rearwardly of the terminal-retaining section or portion 42 is a wire-gripping section 46 of generally V-shaped cross section as may be seen in FIG. 6, including a bight 48 and upwardly and diagonally outwardly diverging flanges 50. A suitable tool or machine crimps the flanges 50 down against a wire inserted in the wire-gripping section 46, and more will be said about this later.

Finally, rearwardly of the wire-gripping section there is provided a shield-gripping section 52 of greater diameter and having a bight 54 and upwardly and outwardly diverging legs 56 designed for crimping about the braid or other shield of a shielded cable or wire, as will be disclosed hereinafter.

The male pin terminal as just described is of sheet material construction of a resilient nature. As may be seen particularly with reference to FIG. 7, and also with reference to FIGS. 5 and 6, and to some extent with reference to FIGS. 2 and 3, the sheet material construction comprises an outer metal sheet A and an inner metal sheet B laminated on opposite sides of an intermediate plastic sheet C. The plastic material may be a polyester such as Mylar, or it may be a highly plasticized polyvinyl chloride formulation. A plastic sheet thickness on the order of 0.005 inch is contemplated, and the metal sheets may be of the same or slightly greater thickness, preferably being material that has both resiliency and good electrical contact characteristics. Brass, beryllium, copper, or phosphor bronze are preferred examples, but other metals are satisfactory. The metal may be heat bonded to the plastic inner layer, or they may be adhesively secured thereto. Certain advantages may be obtained as will be set forth hereinafter by using a sheet of plastic with adhesive on each side, with the lamination of the metal to the plastic occurring just before forming.

Attention should be directed to the tip 34 where it will be seen that the laminated sheet material is turned outwardly and back upon itself, whereby the inner sheet B is at the outer surface of the tip 34 and provides a generally cylindrical contacting surface Y. The surface Y engages a complementary portion of the female terminal to be described shortly hereinafter. The barrel 28 has an external cylindrical contacting surface X which comprises the outer metal sheet A, as opposed to the inner metal sheet B forming the contacting surface Y.

As will be seen at the extremity of the folded over portion, the sheet A extends a greater distance back upon itself as indicated at 58 than does the sheet B as indicated at 60, the plastic sheet extending an intermediate distance 62 all as effected by the different radii of bend of the three respective sheets. As will be apparent, a certain amount of slippage in the bend area among the three sheets is necessary to effect this result, and this readily can be effected by adhering the metal sheets to fresh adhesive surfaces on opposite sides of the plastic sheet immediately before forming of the terminal, whereby the adhesive has not yet set and will allow the slippage. Alternatively, with a highly plasticized vinyl or other plastic sheet, there will be a controlled cold flow of the plastic sheet.

Reference now should be made to the right or rear end of the terminal, and particularly in FIG. 7, where there again will be seen a folded over construction, but this time with the material folded to the inside, whereby the outer sheet A is on the inside, providing a shield-gripping section or surface S. The wire-gripping section or portion 46 has a smaller diameter wire-gripping surface W which comprises the inner metal sheet B as opposed to the outer metal sheet A forming the shield-gripping surface. The edges of the three sheets are again offset as indicated respectively at 64, 66 and 68. As will be understood, the offset at either end insures against electrical short circuiting in their respective areas.

Turning now to FIGS. 8-9, there will be seen a female terminal 70 complementary to the male terminal 20 and of a similar, laminated, resilient construction, as will be brought out in detail hereinafter. The female terminal 70 includes a body 72 of generally cylindrical construction tapering at 74 in frustoconical fashion to a restricted neck 76 which opens up at a second frustoconical section 78 to an entering or receiving end 80, the construction of which will be set forth hereinafter in greater detail. The body 72 is provided with open spaces 82 with rearwardly and outwardly directed resilient lances 84 for retaining the terminal in a housing, in the same manner as the male terminal.

As in the male terminal, there is a longitudinal seam 86 through the parts of the terminal just described, providing enhanced resiliency.

Rearwardly of the body 72 the female terminal 70 reduces in diameter in a tapered or frustoconical section 88 to a terminal mounting section 90 having diametrically outwardly extending flanges or wings 92 for limiting insertion of the terminal. Further rearwardly of the terminal mounting section 90 is a wire-gripping portion 94 having upwardly and outwardly diverging flanges 96 designed to be crimped against a bare wire.

Rearwardly of the wire-gripping section 94 there is a shield-gripping section 98 of greater transverse dimension and likewise having upwardly and outwardly diverging flanges 100 to be crimped against the external shield of a shielded cable.

Turning now to FIG. 14, the female terminal will be seen to be of laminated construction similar to the male terminal. Thus, there is an outer metal sheet A and an inner metal sheet B bonded to an intermediate plastic sheet or layer C. The receiving end 80 is folded inwardly upon itself, whereby the outer sheet A becomes the inner sheet in this area, providing a cylindrical contacting surface X of the same diameter and physically and electrically engageable with the outer contacting surface X of the male terminal. Similarly, and inwardly from the entering end 80 at the restricted neck 76, there is an inner contacting surface Y of the same diameter and physically and electrically engageable with the contacting surface Y of the male terminal. It will be observed that the contacting surface Y of the female surface comprises the inner sheet B, while the contacting surface X comprises the outer sheet A.

Turning now to the left end, it will be seen that in the wire-gripping portion 94 the inner sheet B provides a wire-gripping surface W, while at the shield-gripping portion the folded in outer sheet A provides a shield-gripping surface S. Insulation at the edges adjacent the folded-over portion at either end is insured by the spacing of the respective edges, in the same manner as discussed with regard to the male terminal.

Reference should now be made to FIGS. 15-18 for a showing of the male and female terminals attached to shielded cables and telescopically associated with one another. As will be seen particularly in FIGS. 17 and 17a each wire or cable 102 comprises a central metallic conductor 104 illustrated as a solid wire, but which can be stranded. A central conductor is received against the wire-gripping surface W and the adjacent portions of the terminal are crimped about the wire 104 in known fashion.

Insulation 106, preferably of a plastic material, overlies the central conductor 104, and is stripped back somewhat therefrom to expose the end of the central conductor received in the wire-gripping section W. A shield 108, conventionally a braid, overlies the insulation 106, and an outer insulating jacket 110 covers the shield. The outer insulating jacket 110 is stripped back somewhat from the extremity of the shield, whereby the shield 108 is gripped by the shield-gripping section S, the latter being crimped in place by known techniques. Thus, the terminal, either male or female, is quickly attached to the corresponding shielded cable by a simple crimping operation. Crimping is made to the center conductor and to the shield simultaneously at a great savings in time and expense.

When a male terminal 20 is plugged into a female terminal 70 the corresponding surfaces X and the corresponding surfaces Y come into face-to-face engagement, respectively, whereby continuous electrical connection is made from one central conductor 104 to the next, while connection is simultaneously made from one shield to the next.

The specific example of the invention as herein shown and described will be understood as being used for illustrative purposes only. As will be understood, the terminal could be constructed without necessarily bonding both metal sheets to the plastic inasmuch as the folding over of the ends provides a mechanical interlock. Various additional changes in structure will no doubt occur to those skilled in the art and will be understood as coming within the ambit of the present invention insofar as they fall within the spirit and scope of the appended claims.

Claims

The invention is claimed as follows:

1. A tubular sheet metal electric connector having a longitudinal seam and comprising two sheets of conductive material sandwiched with an intermediate sheet of insulating material, the seam being substantially a butt seam and extending through the two conductive sheets and the insulating material, and the insulating material being laminated with at least one of the conductive sheets throughout the extent of the seam.

2. A connector as set forth in claim 1 wherein the sheets of conductive material comprise sheet metal.

3. A connector as set forth in claim 2 wherein the insulating material comprises a sheet of plastic.

4. A tubular sheet metal electric connector having a longitudinal seam and comprising two sheets of conductive material sandwiched with an intermediate sheet of insulating material, the seam extending through the two conductive sheets and the insulating material, and at least one end of said connector being turned back upon itself.

5. A connector as set forth in claim 4 wherein both ends of the connector are turned back upon themselves.

6. A tubular sheet metal electric connector having a longitudinal seam and comprising two sheets of conductive material sandwiched with an intermediate sheet of insulating material, said connector having an entering end that is turned out providing a predetermined outside diameter, and wherein a rearward part of said connector has a greater outside diameter.

7. A tubular sheet metal electric connector having a longitudinal seam and comprising two sheets of conductive material sandwiched with an intermediate sheet of insulating material, said connector having an entering end that is turned in and provides a predetermined inside diameter of conductive material that is exposed at said turn-in, and wherein a rearward part of said connector has a lesser inside diameter.

8. A connector as set forth in claim 1 wherein one end of the connector is turned in and back upon itself forming a crimp connection of predetermined transverse dimension, said crimp connection having a conductive material inwardly exposed for crimping to the shield on a shielded cable, said connector forwardly thereof having a portion of lesser transverse dimension forming a crimp connection for an internal connector of said shielded cable.

9. A tubular sheet metal electric connector having a longitudinal seam and comprising two sheets of conductive material sandwiched with an intermediate sheet of insulating material, said connector having a rear end that is turned in and back upon itself forming a crimp connection of predetermined transverse dimension for the shield on a shielded cable, said connector forwardly thereof having a crimp portion of lesser transverse dimension forming a crimp connection for an internal connector of said shielded cable, said connector also having an entering end that is turned out and back upon itself providing a contact area of predetermined outside diameter, and wherein said connector rearwardly thereof has a contact portion of greater outside diameter.

10. A connector as set forth in claim 8 wherein the other end of the connector is turned in and forms a contact area of predetermined diameter and wherein said connector rearwardly thereof has a contact area of less internal diameter.

11. A tubular sheet metal electric connector for shielded cables comprising first inner and second outer metal sheets sandwiched on opposite sides of an insulating sheet, the sandwiched sheets being formed into a hollow cylinder having a longitudinal seam, said terminal having front and rear ends, the rear end being folded in and back upon itself whereby the second sheet is on the inside, forming a shield-gripping crimp portion of predetermined transverse dimension, said terminal forwardly of said rear end having a wire-gripping crimp portion of lesser transverse dimension, the front end being turned back upon itself and having a first contact surface of first predetermined diameter, said terminal rearwardly of said front end having a second contact surface of a second predetermined diameter.

12. A connector as set forth in claim 11 wherein the connector is a male terminal and the front end is turned out and back and the first predetermined diameter is an outside diameter, the second predetermined diameter being an outside diameter greater than the first.

13. A connector as set forth in claim 11 wherein the connector is a female terminal and the front end is turned in and back and the first predetermined diameter is an inside diameter, the second predetermined diameter being an inside diameter less than the first inside diameter.

14. A connector according to claim 4 in which at least part of the seam extends through one turned back end.