US2890267A - Shielded braid terminator - Google Patents

Description

June 9, 1959 E. w. FORNEY, JR

SHIELDED BRAID TERMINATOR Filed April 29, 1957 INVENTOR. idyar 14/, Forneq, 1/:

United States Patent:

2,890,267 "SHIELDED BRAID TERMINATOR Edgar W. Forney, Jr.', Harrisburg, 'Pa., as'signor to AMP Incorporated, Harrisburg, Pa.

Application April'29, 1957, Serial No. 655,709

2 Claims. (CRIN- 88) This application constitutes a continuation-in-part of my previous application, Serial No. 583,080, filed May 7, 1956, now abandoned.

. This invention relates to electrical connectors and electrical connections for use on shielded wire cable having a central conductor and a braided conductor surrounding it. A layer of electrical insulation separates thetwo. con-- ductors and a second layer of insulation sometimes covers the braided conductor. It is often necessary to connect the braided conductor to ground and it is with this problem that the present invention is concerned.

It is an object of this invention to provide an electrical connector for securing a grounding wire to the braided conductor.

It is an object of this invention to provide an electrical connector of this type which is easily and accurately applied, to form an inexpensive, compact and long lasting connection.

It is also an object of this invention to provide a connector of this type that may be insulated.

Other objects and attainments of the present invention will become apparent to those skilled in the art upon a reading of the following detailed description when taken in conjunction with the drawings in which there is shown and described an illustrative embodiment of the invention; it is to be understood, however, that this embodiment is not intended to be exhaustive nor limiting of the invention but is given for purposes of illustration in order that others skilled in the art may fully understand the invention and the principles thereof and the manner of applying it in practical use so that they may modify it in various forms, each as may be best suited to the conditions of a particular use.

In the drawings:

Figure 1 is a perspective view of a connector, embodying principles of the invention, a cable, and a grounding connector before assembly and crimping;

Figure 2 is a side elevation, partly in section, of the parts shown in Figure 1 after assembly but before crimp- 111g;

Figure 3 is a perspective view of the connection made by crimping the parts shown in Figures 1 and 2;

Figure 4 is a section on the line IVIV of Figure 3;

Figure 5 is a perspective view of another assembly of a connector, a cable and a grounding conductor;

Figure 6 is a perspective view of the connection made by crimping the assembly of Figure 5; and

Figure 7 is a perspective view of two connectors, a cable and a grounding conductor before assembly and crimping.

Referring first to Figures 1 to 4 a shielded cable A and a grounding conductor B are connected by a connector C. The cable A has a central conductor 10, surrounded by a layer of insulation 12, which in turn is surrounded by a braided conductor 14. The connector C consists of an outer metallic ferrule 20 and a coaxial inner metallic ferrule 22. This connector may be formed in one integral piece, e.g., by a tube-drawing operation, so that Ithe inner and outer ferrules may be joined by an annulus .to expose the insulation 12, the three parts A, B and -C are assembled bypushing'the connectorC onto the cable A, with theinner ferrule 22 under the braided conductor 14 and over the insulation 12. The connector is pushed on. until the conductor 14 abuts on the rear face of the annulus 26. 'The conductor B is then prepared by stripping off part of the insulation 30, and the prepared conductor. is inserted from the free end of the outer ferrule 20-radially in line with the hole 32. The free endofithe inner ferrule -22 is reduced to form a sharp edge 46 to assist in the insertion of the inner ferrule beneath the braided conductor 14. When the three .parts have been assembled, theassembly. is crimped to a substantially circular shape, 'as'shown' in Figures 3 and 4. Alternatively the connector may be partially crimped after it has been placed on the cable, but before the grounding conductor has been inserted. Crimping is then completed after the grounding conductor has been inserted. In any event the V-shaped slots 42 permit the outer ferrule to collapse with a minimum of effort and there is less excess metal to be absorbed in the crimp than would be present in the absence of the slots. The slots 42 become slits 43 after crimping.

In the resultant electrical connection the inner ferrule 22 lies on the inner side of the braided conductor 14 and the crimped outer ferrule 20 overlaps and is coaxial with the inner ferrule, being joined to it by the annulus 26. The grounding conductor '29 is held between the outer ferrule 20 and the braided conductor and is radially in line with the hole 32. The grounding conductor 29 should be visible through the hole 32 so that it is possible to see whether electrical connection has been established. The inner ferrule 22 holds the braided conductor 14 in place while the outer ferrule 20 is crimped, and provides a support for the braided conductor and the necessary resistance to the crimping force to obtain a good electrical and mechanical connection.

The connector may be covered with a sleeve of electrical insulation as shown in Figures 5 and 6. The sleeve 44 may be of, for example, polyvinyl chloride, and is stretched across the V-shaped slots 42. When the connector has been crimped the sleeve 44 is gripped in the slits 43 and holds the sleeve against displacement.

The connector of this invention is particularly suitable for connecting two or more shielded wire cables in series. This is illustrated in Figure 7. In this case the grounding wires are inserted through the holes in the annuli and one of the connectors C has a second hole 32' diametrically opposed to the first hole 32. The connector C is similar to that illustrated in Figures 1 to 4. A grounding conductor 28 connects the two connectors C and C, serving as grounding conductor for both.

Various modifications may be made to the connectors illustrated. For example, While we have shown two V- shaped slots disposed symmetrically on either side of the hole or holes they may be assymmetrical and there may be more or fewer slots. Again a rib can be formed longitudinally of the connector with the hole formed in the end of the rib. This rib will accommodate a grounding conductor of large diameter. Further, while we have shown the holes formed in the annuli, they can also be in the outer ferrule, and while it is only necessary to have as many holes as grounding conductors, more holes may be present.

Changes in construction will occur to those skilled in the art and various apparently different modifications and embodiments may be made without departing from the scope of the invention. The matter set forth in the foregoing description and accompanying drawings is offered by way of illustration only. The actual scope of the invention is intended to be defined in the following claims when viewed in their proper perspective against the prior art.

I claim:

1. An electrical connection comprising a shielded cable having an inner insulated conductor, a metallic ferrule surrounding the conductor in close relationship thereto, a second metallic ferrule integrally connected with the first ferrule at one end thereof, at least one open V- shaped slot in the second ferrule diverging toward the free end, a plastic insulating sleeve surrounding the second ferrule, a grounding conductor extending between the ferrules, one end of the grounding conductor being disposed between the ferrules, a metallic braid concentrically covering the inner insulated conductor, one

end of the braid being disposed between the ferrules and coextensive with the one end of the grounding References Cited in the file of this patent UNITED STATES PATENTS 2,536,003 Dupre Dec. 26, 1950 2,696,518 Rochmann et al Dec. 7, 1954 FOREIGN PATENTS l02,l37 Great Britain Nov. 13, 1916 OTHER REFERENCES Publication I: Grounding Shielded Cable," published in Electrical Manufacturing, December 1952, pages 128- 130 relied on. (Copy in the Scientific Library and Div. 69 Class 174-35c.)

Publication II: Uni-Ring," published in Electronic Design, vol. 5, No. 3, Feb. 1, 1957 (page 109 relied on). (Copy in the Scientific Library and Div. 69 Class 174- 75.2.)

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