US1116090A - Flexible conductor. - Google Patents

Description

D. T. MAY. FLEXIBLE CONDUCTOR. APPLICATION FILED APR.27, 1912.

Patented Nov. 3, 1914.

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DA VID T. OF NEW YORK, N. Y., ASSIGNOR TO WESTERN ELECTRIC COMPANY, OF NEW YORK, N. Y., A CORPORATION OF ILLINOIS.

FLEXIBLE coNnUcroa.

Specification of Letters Patent.

Patented Nov. 3, 1914.

To all whom it may concern Be it known that I, DAVID. T. MAY, citizen of the United States, residing at New York, in the county of New York and State of New York, have invented a certain new and useful Improvement in Flexible Conductors, of which the following-is a full, clear, concise, and exact description. 7

This invention relates to flexible conductors, and particularly to flexible conductors for use in making telephone switchboard cords.

An object of this invention is the production of a cord which will have all the advantages ofthe tinselcord of ordinary type as regards flexibility, and all the advantagesof the steel cord as regards" durability without any of the disadvantages common to either. 7

This invention covers a conductor in which individual twists composing a strand are so laid together that the tape of each twist is tightened on the thread in the process of making the strand, and the strands are twisted together 'into a rope which has no central core, the whole construction resulting in a conductor of high efliciency.

In the drawing, the figure shows a section of cord constructed in accordance with ployed.

A thread 10, having a tape 11 of conduiztingmaterial wound thereon, forms a twist or a tinsel thread '9; 'A plurality of twists 9 are laid together, in a close spiral, with a right-hand lay; that is, in such a way that the tape 11 of each twist 9 is tightened on the thread 10 thereof. The laying together of the twists 9 results in a strand 12. Three strands 12 are then laid directly together with alefthand lay to form a conductor 8. In the completed conductor 8 the. relation between the lengthof lay (that is, the linear advance in making a complete turn) in each strand and the length of lay in-the whole conductor is such that there is no tendency for the conductor to kink or untwist. The conductor resulting from the laying together of the strands 12 is'then wrapped with two servingsv of insulation 13 and 14 wound tightly on the conductor in opposite directions, after which a braiding of cotton or silk 15 is placed thereon, as is usual. Three of these conductors are then taken and twisted together in thevform of a rope without any core being used; and after twisting, threads of ordinary cotton 16, 17 and 18, are used for the purpose of making a smooth finish on the outside of the. cord.

In twisting the three insulated conductors together, no attempt is made to form them to prevent separation of the conductors asthe resulting core is wrapped with a spaced serving of cotton 19, which accomplishes the same purpose. Over the resulting core is then braided a covering of glazed cotton 2-0, or other suitable material.

What is claimed is:

1. In a flexible conductor, a plurality of twists each comprising a thread and a conducting tape wound thereon, saidtwists forming a strand laid together in a direction to tighten the tape on each individual thread, and a plurality of such strands laid together in a direction opposite to that of each strand, the relation between the length of lay in each strand and the length of lay in the whole conductor being such that there is no tendency for the conductor to kink or untwist.

2. In a flexible conductor, a plurality of twists, each comprising a thread and a conducting tape wound thereon, said twists forming a strand laid together in a close spiral and in a direction to tighten the tape of each twist. and a plurality of such strands laid directly together in a close spiral and in a direction opposite to that of said twists, the" relation between the length of lay in each strand and thelength of lay in the Whole conductor being such that there is no tendency for the conductor to kinkor untwist.

v3. The method of making a flexible conductor, which consists in winding a conducting tape about a thread thereby forminga twist, laying togetherla plurality of such twists in a direction to tighten the tape of each twist thereby forming a strand, and laying together a plurality of such strandsin a direction opposite -to that of ing a twist, laying together a plurality of the whole conductor that there is no tendsuch twists in a direction to tighten the ency for the conductor to kink or untwlst. 10

tape on each twist thereby forming a strand, In witness whereof, I hereunto subscribe and laying a plurality of such strands dimy name this 25th day of April A. D., 1912. rectly together in a close spiral and in a DAVID T. MAY. direction opposite to that of the twists and Witnesses:

with such a relation between the length of F. TOOHEY,

lay in each strand and the length of lay in WALTER F. HOF MAN;

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