US3374307A - Electrical connector - Google Patents

Description

March 19, 1968 T. .1. RAUEN ETAL ELECTRICAL CONNECTOR Filed Feb. 28, 1966 INVENT ORS THEODORE J. BAUEN saw/1v c. MYERS, JR. ARTHUR a; cao/(E MM 1?." 'Jasze-Nr A ATTORNEY United States Patent O 3,374,307 ELECTRICAL CONNECTOR Theodore J. Rauen, Suitland, Edwin Clarence Myers, Jr., Temple Hills, and Arthur B. Cooke, Silver Spring, Md., assignors to the United States of America as represented by the Secretary of the Navy Filed Feb. 28, 1966, Ser. No. 532,536 2 Claims. (Cl.` 174-89) ABSTRACT OF THE DlSCLOSURE An electrical connector for insuring a positive electrical contact between the shield of an electrical cable and a connector. Specially shaped concentric rings are so related to the shield that the shield is secured between the concentric rings. The concentric rings are then held in place by coupling nuts which secures the connector with a desired connection.

The present invention is directed to an electrical connector and more particularly to an electrical connector which connects a cable shield braid to a cable connector in such a way as to maintain the integrity of the shielding.

Heretofore, various methods have been used to connect the end of a shield braid with a connector. One commonly used method is to carry the shield through the connector on one of the connector pins. A wire connection is made between the mating pin in the chassis connector and the chassis with which the connector is used. Such a connec- .tion provides a circuit between the cable shield and the equipment chassis, however there are various shortcomings. These shortcomings exist wherein a gap exists in the shielding because of the opening between the connector body and the cable shield. Second, a finite length of wire must be used for the connection between the connector pin and the chassis, which further degrades the shielding effectiveness. Third, fabrication of the connector to the cable requires a fairly high level of skill to achieve a satisfactory installation with no damage to the cable. Another method previously used, is to install the cable in such a manner that a cable clamp at the rear of the connector clamps directly onto the cable shield braid. This has the disadvantage of applying pressure on the cable itself. In time, cold-flow of insulation may occur, possibly resulting in short circuits within the cable and loss of contact between the braid and the clamp. Stil another method very commonly used is to attach a short wire to the shield inthe connector and terminate this wire on the connector shield at a screw. This technique has the same disadvantages as pointed out above in the first mentioned example.

The present invention overcomes the disadvantages of 4the prior art electrical connectors by an arrangement in which the shieldbraid is secured between two bushings and which are in electrical contact with the connector. The electrical connection with the chassis to which the connector is secured is made through the electrical connector body which is directly secured to the chassis.

It is therefore an object of the present invention to provide a simple, foolproof, reliable, effective means of terminating cable shields in connectors for braid type cables.

Another object is to provide a termination for a shield braid type electrical conductor such that the shield braid, the shield termination, and the cable connector shall provide a total and continuous enclosure about the conductors of the cable, thereby maintaining the integrity of the shield.

Still another object is to provide a connector for a shield braid type electrical conductor in which a reliable ice electrical connection is made between the shield braid and the connector.

Yet another object is to provide an electrical connector for the end of a shield braid type conductor which may be made with unskilled personnel as well as skilled personnel.

While still another object is to provide an electrical connector in which the connection between the shield braid and the connector is continuous and that all electrical connections in the shield circuit are secure metal to metal contact.

Still another object is to provide an electrical connector in which it is almost impossible to incorrectly secure the connector to the braid type electrical conductor.

Other objects and advantages of the invention will r hereinafter become more fully apparent from the following description of the annexed drawings, in which:

FIG. 1 illustrates an exploded view of the various elements of the connector partially cut away to better illustrate the various features of the elements, and

FIG. 2 is an assembled connector partially cut away to illustrate the various parts and assembled positions relative to each other.

Now, referring to the drawings, there is shown by illustration a preferred embodiment of the present invention. In carrying out the teaching of the present invention a shield braid type conductor is secured to an electrical coup-ling 10 which is provided with an internally threaded coupling nut 11 that secures the electrical connector to a chassis, not shown, or some other electrical element and is provided also with an externally threaded end 12 opposite from 4the internally threaded coupling nut to which the means for securing the cable is attached. As shown, the electrical coupling 10 is provided with female conductors 13 to which t-he ends of the conductor wires within the braided cable 32 are secu-red. The terminal connection means is provided with a nut 14 having internal threads 15 on one end which secures to the end 12 of electrical coupling 10 and external threads 16 on the opposite end to which a second cylindrical internally threaded nut or sleeve 17 is secured. The shield braid is secured within the connector by use of two bushings 21 and 22. Bushing 21 has a cylindrical outer surface and a flange 23 at one end thereof which extends outwardly from the cylindrical surface normal to the axis thereof. The inner surface of the bushing 21 has sloping or tapered surfaces sloping from each of the outer ends thereof toward each other with decreasing radii. The sloping inner surface of bushing 21` of decreasing radii toward each other forms separate surfaces 24 and 25. The second bushing 22 has a cylindrical inner surface 26 which is slightly larger than the cable about which it is to be secured and a sloping outer surface 27 which slopes toward the axis of the Ibushing away from an end which is provided with a flange 28 thereon. The sloping outer surface of bushing 22 has the same angular slope as the surface 25 of the first bushing such that the bushing 22 with the sloping outer surface ts within the end of the bushing with the sloping inner surface 25. The diameter of the cylindrical surface of bushing 21 is such that the bushing will extend inwardly of the connector element or nut 14 such that the flange 23 on the end thereof will rest juxtaposed to the end 34 of the connector which is provided with the threads 16 on the outer surface thereof. The flange 28 on the bushing with the outer sloping surface 27 is of the same diameter as the flange on the bushing 21. The diameter of the flanges are such that they will pass within the internally threaded nut 17 having the threads on the inner surface thereof such that the threaded nut 17 will screw-thread onto thev outward threaded end portion of the coupling nut 14. The female electrical elements of the electrical coupling to which conductors within the cable are connected are provided with insulators 31 which are secured about the female con- 3 nectors and about `the wire conductors to provide insulation about the connection.

On assembly, in securing the braided wire to an electrical coupling, the following steps are taken. The nut 17 having the screw-threads on the inner surface thereof is slipped over the wire and then followed by Ithe bushing with the sloping outer surface and the bushing with the cylindrical outer surface and the forward nut 14 having the external threads on one end and the internal threads on the forward end thereof. The ends of the conductors in cable 32 are cleared of insulation for a length which is equal to the length of the female electrical connectors on the electrical coupling to which the wires are to be connected. The shield braid is separated at the ends 33 for a small distance along the length of the wire and turned back along the outer su-rface of the braid shielded cable. The insulator elements are slid over the ends of the conductors and the conductors are secured to the female connectors of the electrical connector then the insulation is passed over the connected conductors. The forward nut 14 is then secured with the end having the inner threads thereon to the end 12 of the electrical coupling having the outward threads thereon. The bushing 21 having the tapered surfaces on the inner surface thereof is then passed over the loose portion of the braid extending back along the cable and extended into the connector nut 21 until the flange on the bushing with the tapered inner surface is against the end portion 34 of the connector nut having the threads on the outer surface thereof. Positioned in this position the loose ends of the braid will be alongside the tapered surface of the bushin-g and extending toward the flange on tapered surface bushing. The second bushing 22 having the tapered outer surface is then pushed forward such that the tapered outer surface is inwardly of the loose ends of the braid such that loose ends of the braid are between the inner tapered surface 25 of the forward bushing and the outer tapered surface of the second bushing. The rear nut 17 having the inward threads thereon is then slid forward and screwthreaded onto the connector nut 14 having the threads on the outer surface thereof. As the rear nut 17 is screwed onto the forward nut 14, the flange of the bushing having the outer tapered surface thereon is pressed forward pressing the tapered surface 27 in between the loose ends of the braid and the cable itself. Thus, as the rear nut 17 is tightened into position, the bushing with the tapered outer lsurface is pressed tightly forward securing the loose ends of the braid between the inner tapered portion of the forward bushing and the outer tapered portion of the rear bushing as shown more clearly in FIG. 2.

As can be seen by the assembled connector as shown in FIG. 2, the loose ends of the braid are secured between the tapered surfaces of the two bushings; there is no radial pressure against the braided cable or any pressure on the conductors within the cable. There is a positive electrical connection between the loose ends of the shield braid and the two bushings such that the forward nut of the terminal connector that secures to the end portion 12 of the electrical coupling 10 which is connected to a piece of equipment to provide a conductive path between the braid and the electrical coupling.

Such an assembly secures a braided electrical shield to an electrical connector without any undue pressure on the braid or any other portion of the wire cable. Thus, all electrical connections in the shield cable are secure metal to metal contacts over a considerable area and with substantial pressure applied. Since the braided end of the shield cable is secured between the two bushings,

it can be seen that the assembly of the present invention can 'be used for different sized cables insolong as the terminal elements are sufficiently large to pass over the cable.

Thus, the terminal element as shown can be used for a wide variety of connector sizes and the dimensions may be varied to fit a wide variety of connector types, and cable sizes.

The electrical coupling portion of the terminal to which the end connector is secured to the apparatus is not shown in cross-section since this may be any well known connector which may be of the female or male type.

Gbviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

The invention described herein may be manufactured and 1used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

What is claimed and desired to be secured by Letters Patent of the United States is:

1. An electrical connector for connecting a shield braid type cable to an electrical coupling which comprises:

a first nut including an internally threaded end and an externally threaded end,

a first bushing having a cylindrical outer diameter with an outer flange at one end thereof and an inner surface sloping from each end inwardly with decreasing radii and arranged to slide within said first nut,

a cylindrical second bushing having a flange on the outer surface at one end thereof and a cylindrical inner surface with the outer surface thereof sloping with a decreasing radii from the flange end -to the opposite end,

said second bushing arranged to slide into said flanged end of said first bushing with the outer sloping surface thereof matching the inwardly sloping surface of said first bushing and the flange thereon having the same outer diameter as the flange on said first bushing in order to secure an end of the braid of a cable between said inner surface of said first bushing and the outer sloping surface of said second bushing, and

a second nut including an internally threaded end having an inner diameter greater than the outer diameter of said flange on each of said first and second bushings arranged to slide over said bushings for securing said second nut to said externally threaded end of said first nut with said first and second bushings secured therebetween.

2. An electrical connector as claimed in claim 1 wherein:

said first bushing has an outer diameter which is less than the inner diameter of the externally threaded end of said first nut with the flange thereon having a diameter greater than the inner diameter of said first bushing, and

said second bushing has a sloping outer section with the same angular slope as the angular slope of the inner surface of said first bushing from the flange end inwardly thereof,

whereby said coupling lits around a braided cable and secures the electrical conductors within said cable to an electrical coupling while connecting said braid between said first and second bushings.

References Cited UNITED STATES PATENTS 2,785,384 3/1957 Wickesser 174--89 XR 2,936,440 5/1960 Mack et al. 174---89` XR 3,116,361 12/1963 Bentz et al. 174-89 XR DARRELL L. CLAY, Primary Examiner.

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