US3775732A

US3775732A - Shield termination device

Info

Publication number: US3775732A
Application number: US00225572A
Authority: US
Inventors: W Frogner
Original assignee: Hitemp Wires Inc
Current assignee: Hitemp Wires Inc
Priority date: 1972-02-11
Filing date: 1972-02-11
Publication date: 1973-11-27
Anticipated expiration: 1990-11-27

Abstract

For purposes of making an electrical connection between a braided metal shield on a signal or power cable and an adaptor connecting the cable to a cabinet chasis, a shield terminator is provided in the form of a separate sleeve of metal wires braided in a number of plies to be fitted around the cable shield at one end and around the adaptor at the other end.

Description

[4 1 Nov. 27, 1973 United States Patent [191' Frogner OTHER PUBLICATIONS SHIELD TERMINATION DEVICE Meier et al., IBM Tech. Disclosure Bulletin, January 1969, Vol. 11 No. 8 Page 956.

Feb. 1 1, 1972 Primary Examiner-Marvin A. Champion Assistant Examiner-Lawrence J. Staab Attorney-Dean S. Edmonds et a1.

[21] Appl. No.: 225,572

[51] Int. H01! 13/46 For purposes of makingan electrical connection between a braided metal shield on a s' lgnal or power [56] References Cited UNITED STATES PATENTS cable and an adaptor connecting the cable to a cabinet chasis, a shield terminator is provided in the form XXX RC 33 44M WWW 33 Skaer et a1. 4/1970 Phillips.........

of a separate sleeve of metal wires braided in a number of plies to be fitted around the cable shield at one 174/73 R end and around the adaptor at the other end.

2,108,635 2/1938 Aiken et al.

3,217,091 11/1965 Walker..............................

FOREIGN PATENTS OR APPLICATIONS 4 Claims, 1 Drawing Figure 239,349 12/1960 Austra1ia...........................174/73R lllllll "III I BACKGROUND OF THE INVENTION This invention relates to devices forconnecting electrical cable shields to adaptors into which the conductors of such cables are fitted. More particularly, it reto connect the cable conductors to the chasis. Adaptors of this sort are fitted coaxially'around an end portion of the cable from which the outer :braided shield has 7 been stripped away. In order to complete the shield circuit in such an assembly it is necessaryto make an electrical connection between the braided shield adaptor.

So-called pigtail connectorshave"beenused in the past to couple radio frequency braided shields'to adaptors securing the ends of the associated conductors. However, pigtail connectors are not .circumferentially complete since they do notsurround either the endof the shield or the adjacent adaptor.Inadditionthey are often inadvertently disconnected during use. Circumferentially complete braided connections have been disclosed in the prior art, such as in US. Pat. No. 3,248,778 wherein an extension .of the same braided shield surrounding the cable is broughtiforwardaround the adaptor as well and secured in place by soldering. Such assemblies have various disadvantages, among which is the necessity to cut the cable'back inside the braided shield and then attempt .to stretchtheshield around the larger diameter adaptor. In additiomspecial facilities are required in the field. to permitthe shield to be soldered in place.

SUMMARY OF THE INVENTION In broad terms,.the inventionis applicableto an electrical connector assembly wherein a portion of an electrical cable extendingbeyond a-surrounding outer metallic shield is held within an adaptor having a flange portion susbstantially coaxialwith the metalshield. The invention provides a shield termination device comprising a sleeve of metal wires braidedin'aplurality of plies from a first diameter end adapted'toifit around an end portion of the shield closest to'theadaptor'to a second diameter end adapted to fit around theiflange of the adaptor and back again at least onceitothe first diameter end. First circumferential securing means arcincluded for affixing the sleeve at i the t first diameter end thereof to the shield, Second circumferential securing and the means are provided for affixing the sleeve at the second diameter end thereof to the flange of the-adaptor.

DESCRIPTION OF PREFERRED EMBODIMENT Achievement :of these and other significant objects will be evidentin the following description of a preferred embodiment of the invention with reference to the accompanying drawing, which is a fragmentary side elevation, partly broken away, showinga shielded power cable connected to an adaptor by a shield termination device in accordance with'the' invention.

An installation in which the device of the invention is to be used may include an electrical power or signal cable 10. Such a cable may typically be employed in an aircraft electrical system. The outermost layer of the cable consists of a gross radio frequency shield 11 made up. of a multiplicity of braided metal wires. Tinned copper wires are frequently used for this purpose. Inside the shield 11 are conductors, layers of insulation and so on, designated generally in the drawing as the component 12.

In order to make an electrical connection between the cable 10 and a cabinet chasis or the like indicator at 13', an adaptor 14 of conventional construction is provided. The shield 11 of the cable 10 is cut back to the point 15 so that an exposed end portion of the conductors and other interior elements of the cable can be received coaxially within the interior of the adaptor 14. This connection of the conductors 12 to the adaptor l4 and the manner of securing the adaptor 14 to the cabinet'chasis 13 form no part of the present invention. The most common adaptor used for this purpose includes some type of flange portion 16 at the end of the adaptor immediately surrounding the cable conductors and a groove 17 is frequently defined between the flange portion 16 and the remaining body of the adaptor 14.

The flange portion 16 of the adaptor 14 is of greater diameter than and substantially coaxial with the metallic shield 11 on the cable 10 with which the adaptor is associated. It is the general object of the present invention to provide a shield termination device which makes an electrical connection between the braided shield 11 and the adaptor 14 in the region of its flange 16.'

This is achieved by forming a sleeve 18 of metal wires (perhaps 5 ends of tinned copper wire braided by from 24 to 64 carriers). This braiding is done to form a separate shield device tapering in diameter from one end to the other end, and of more than one ply. For example, a tapered form may be used in a standard braiding machine so that braiding commences at a small end 18a, then proceeds to a large end 18b, and finally is returned in a second braided ply to the small end 180. More than two such passes may be made on the form to produce additional plies depending upon the particular characteristics desired in the sleeve, such as wire density and shrinking properties. However, the standard form of sleeve contemplated by the invention consists of two plies formed from the small end to the large end and back again to'the small end.

During the course of fabrication of the braided sleeve 1 l8 andparticularly upon completion of the inner ply thereof. Then the braiding is resumed from the large end 18b back down to the small end 18a, thereby enclosing the draw wire 19 between the plies of the sleeve at the large end thereof.

In use, separate shield termination devices may be color-coded to indicate various sizes of large and small diameters and lengths. In a given installation, the properly selected sleeve is slipped over the shield 11 of the cable in such a manner that the small end 180 fits closely about the shield 11, as shown in the drawing. Tape or other circumferential securing means is applied about the small end 18a of the sleeve to hold it closely againstthe shield l I and also to cover any ragged wire ends onthe sleeve 18. The exposed conductors 12 of the cable are then inserted into the adaptor 13 in a conventional fashion and secured in place. The large end 18b of the sleeve 16 should be of a size such that it fits easily around the flange 16 of the adaptor 14. Merely by pulling the ends of the draw string 19 together, the large end 18b of the sleeve can be tightly secured to the adaptor within the groove 17. The ends of the draw wire 19 are then tied in place and a shield termination in accordance with the invention is complete.

I claim:

1. In an electrical connector assembly wherein a portion of an electrical cable extending beyond a surrounding outer braided metal shield is held within an annular adaptor having a flange portion of greater diameter than and substantially coaxial with said metallic shield, a shield terminator device comprising a. a sleeve of metal wires braided in a plurality of plies from a small diameter end fitted closely around an end portion of the shield closest to the tion of an electrical cable extending beyond a surrounding outer braided metal shield is held within an annular adaptor having a cylindrical flange portion of greater diameter than and substantially coaxial with said metallic shield, a shield terminator device comprismg a a. a sleeve of metal wires braided in two plies from I a small diameter end fitted closely around an end portion of the shield closest to the adaptor to a large diameter end fitted around the flange of the adaptor and back again to the small diameter end,

b. tape means affixing'the sleeve at the small diameter end thereof to the shield, and

c. a draw wire looped around the large diameter end of the sleeve between said'plies and brought out through the sleeve for affixing the sleeve at the large end thereof to the flange of the adaptor.

3. For use in an electrical connector assembly wherein a portion of an electrical cable extending beyond a surrounding outer metallic shield is held within,

an adaptor having a flange portion of greater diameter than and substantially coaxial with said metallic shield, a shield termination device comprising a. a sleeve of metal wires braided in two plies from a small diameter end adapted to fit around an end portion of the shield adjacent to the adaptor to a large diameter end adapted to fit around the flange of the adaptor and back again to the small diameter end;

b. first circumferential securing means for affixing the sleeve at the first diameter end thereof to the shield; and

c. second circumferential securing means for affixing the sleeve at the second diameter end thereof to the flange of the adaptor, the second circumferential securing means including a draw wire looped aroundthe large diameter end of the sleeve between the plies with the ends of, the draw wire brought out through the braided sleeve.

4. A shield termination device according to claim 3 wherein the first circumferential securing means is tape wrapped around the small diameter end of the sleeve.

Claims

1. In an electrical connector assembly wherein a portion of an electrical cable extending beyond a surrounding outer braided metal shield is held within an annular adaptor having a flange portion of greater diameter than and substantially coaxial with said metallic shield, a shield terminator device comprising a. a sleeve of metal wires braided in a plurality of plies from a small diameter end fitted closely around an end portion of the shield closest to the adaptor to a large diameter end fitted around the flange of the adaptor and back again at least once to the small diameter end, b. first circumferential securing means for affixing the sleeve at the small diameter end therof to the shield, and c. a draw wire looped around the large diameter end of the sleeve between said plies and brought out through the sleeve for affixing the sleeve at the large end thereof to the flange of the adaptor.

2. In an electrical connector assembly wherein a portion of an electrical cable extending beyond a surrounding outer braided metal shield is held within an annular adaptor having a cylindrical flange portion of greater diameter than and substantially coaxial with said metallic shield, a shield terminator device comprising a. a sleeve of metal wires braided in two plies from a small diameter end fitted closely around an end portion of the shield closest to the adaptor to a large diameter end fitted around the flange of the adaptor and back again to the small diameter end, b. tape means affixing the sleeve at the small diameter end thereof to the shield, and c. a draw wire looped around the large diameter end of the sleeve between said plies and brought out through the sleeve for affixing the sleeve at the large end thereof to the flange of the adaptor.

3. For use in an electrical connector assembly wherein a portion of an electrical cable extending beyond a surrounding outer metallic shield is held within an adaptor having a flange portion of greater diameter than and substantially coaxial with said metallic shield, a shield termination device comprising a. a sleeve of metal wires braided in two plies from a small diameter end adapted to fit around an end portion of the shield adjacent to the adaptor to a large diameter end adapted to fit around the flange of the adaptor and back again to the small diameter end; b. first circumferential securing means for affixing the sleeve at the first diameter end thereof to the shield; and c. second circumferential securing means for affixing the sleeve at the second diameter end thereof to the flange of the adaptor, the second circumferential securing means including a draw wire looped around the large diameter end of the sleeve between the plies with the ends of the draw wire brought out through the braided sleeve.