US1606165A - Electrical conductor - Google Patents

Description

H. H. GLENN ELECTRICAL CONDUCTOR Filed Sept. 22, 1921 Lit) Patented Nov. 9, 1926.

UNITED STATES HOWARD H. GLENN, OF WESTFIELD, NEW JERSEY, ASSIGNOR TO WESTERN ELECTRIC 1,666,166 PATENT OFFICE.

COMPANY, INCORPORATED, OF NEW YORK, N. Y., A CORPORATION OF NEW YORK.

ELECTRICAL CONDUCTOR.

Application led September 22, 1921. Serial No. 502,423.

This invention relates in general to electric conductors and particularly to a flexible shielded conductor.

In view of the increasing use of electrical currents of high frequency there is an increasing necessity for shielding conductors in such a manner as to prevent interference from extraneous magnetic fields. In apparatus used under such conditions it has been the common practice to shield the conductors by placing them within a lead tube or sheathing which may be easily bent to conform with the desired path of the conductor. The apparatus is, Where possible, provided with metallic shields which are grounded so as to drain ofi' any potentials induced therein. However, in the case of flexible conductors, such as receiver cords for example. it has heretofore been difficult to provide the desired degree of shielding and it is an object of the present invention to provide such a shielding means.

Other objects will hereinafter appear.

In accordance with the invention there is provided a shield or braiding of tinsel thread which is woven about the conductor but insulated therefrom. Furthermore this tinsel braiding is closely wound at the point where the conductors are brought out through the braiding to provide a conducting strand which may be grounded or connected to the metallic parts of the apparatus and which may also serve as a stay-cord to prevent any undue strain being placed upon the conductor itself.

In the drawings:

Fig. 1 discloses a receiver cord embodying the invention.

Fig. 2 is an enlarged view of a cord with parts broken away to show the construction thereof.

The receiver cord as shown in Fig. 2 comprises conductors 3. 4 surrounded' by a flexible shield over which is placed a protective braiding. Each conductor consists of a plurality of conducting strands 5-5 of tinsel thread. each tinsel thread consisting of a textile core 6 about which is helically wound a metallic tape 7.y The strands 5 are twisted together asshovvn and are then served with two layers 8 -8 of floss or a similar insulating material, these layers being laid with the direction of Winding reversed. Over the servings 8-8 is placed an insulating coatance of the cord a textile braiding 14 is y placed over the shield 11.

In the case of a receiver cord as shown in Fig. 1, the two conductorsv 3 and 4 are separated the desired distance and an additional insulated conductor 17 of suitable length to ,connect the two receivers together is provided as shown, the braidings 11 and 14 being continued over the separate branches of the cord. By means of terminals. 18-18 the various conductors are connected to the windings of the receivers in such a manner that the two windings are joined in series. The braid`14 is discontinued a short distance fromthe end of the conductors as at 20 and the conductors are brought out from the shielding braiding 11, this braid being continued for a short distance and closely wound so as to form a conducting strand 21 which may be connected to the metallic parts of the receiver by means of an eye member 22, thus permitting the apparatus to be grounded. By making the length of the strand-21 slightly less than the length of the adjacent portions of the conductors, any 'strain placed upon the cord is taken up by means of the strand 21, thus preventing damage to the insulated conductors or the loosening of the connections. l

At the opposite end of the cord (not shown) the shielding braiding l1 is also arranged to provide a closely wound conducting strand to form a ground connection and which may also be used, .if desired, as a stay-cord.

By means of the flexible shielding described above, it is possible to overcome a diiiculty heretofore experienced in properly shielding certain types of apparatus. The construction described has the further advantage of removing all strain from the conductors themselves and by serving to connect' all metallic parts to ground it provides protection from all static disturbances.

What is claimed is:

1. A flexible shielded electrical conductor for attachment to pieces of electrical apparatus, comprising a plurality of mutually insulated conducting strands, and a uni-potential braided conducting shield surrounding said conducting strands, said shield terminating in elongated portions adapted to connect to portions of the electrical apparatus to relieve mechanical strain on the conducting strands and to equalize the electrical potential of said pieces of apparatus.

2. A Shielded electrical conductor coinprising an insulated conductor, a braiding ofilexible conducting material surrounding said insulated conductor and extending beyond the endthereof to provide a stay cord an an electrical connection between said shield and apparatus connected with said conductor.

3. In combination, a telephone receiver` a metallic casing therefor, a pair of flexible insulated conductors connected to the receiver, and flexible means to shield said conductors, said shield consisting of a grounded braiding of tinsel strands surrounding said cond-uctors throughout the greater part of their length but having one end closely wound and attached to said casing to provide a stay cord for the conductors and a ground for the casing.

4. A telephone headset, comprising in combination a pair of electromagnetic sound reproducing devices, an insulated conductor connecting said devices, a flexible braided shield surrounding said conductor, said shield consisting of Woven tinsel conductors and a protecting'braid about said shield.

5. A telephone headset, comprising in combination a pair of electromagnetic sound reproducing devices, an insulatedconductor connecting said devices, a flexible braided shield surrounding said conductor, said shield consisting of closely Woven metallic conductors terminating in stay cords at each end for preventing any undue strain being placed upon said insulated conductors.

6. A telephone headset, comprising in combination a pair of electromagnetic sound reproducing devices, an insulated conductor connecting said devices, a flexible braided shield surrounding said conductor, said shield continuing beyond the ends of said insulated conductor to provide stay cords at the telephone receiver ends of said insulated conductor,.and a tie cord formed by said shield at the opposite ends of said insulated conductor opposite said telephone receiver end.

7. A receiver cord comprising a plurality of insulated conductors, a iexible electrical metallic Shield surrounding said insulated conductors, said shield continuing beyond the ends of said conductors to provide stay cords, and a textile protective. braiding about said shield.

8. A telephone headset, comprising in combination a pair of electromagnetic sound reproducing devices, an insulated conductor connecting said devices, an electrostatic shield completely surrounding said insulated conductor, said shield comprisin a plurality of iexible braided tinsel conc uctors and serving as a connection separate from said lirst mentioned connection between said devices.

In Witness whereof, I hereunto subscribe my name this 20th day of September A. D.,

HOVARD H. GLENN.

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