US1856676A - Telephone cable - Google Patents

Description

May 3, 1932.

W. K. WESTON TELEPHONE CABLE Filed Feb. 9, 1929 INVEN TOP W K. Wes 101v ATTORNEY Patented May 3, 1932 UNITED STATES PATENT; oFFmE WILLIAM KIRBY WESTON,

OF SANDERSTEAD, SURREY, ENGLAND, ASSIGNOR TO WESTERN ELECTRIC COMPANY, INCORPORATED, OF YORK, N. Y., A CORPORA- 'IION OF NEW YORK TELEPHONE CABLE Application filed February a, 1929, Serial No. 388,709,

In the manufacture of cables for telephone communication it is usual to select certain conductors for particular circuits and to assemble them into corresponding groups which may be pairs, quads or larger order m pedients are in groups. In such anarrangement proper balan'ce of electrical characteristics in each,

group is essential to high quality transmission and to attain such balance various exuse. It is also necessary to for distinguishing any conductor, pair or sub-group from others in any particular group in the cable. T his is usually done by applying an identifying color or mark to the paper insulation of the conductors.

The present invention provides an improved electric cable in which all the insulated conductors of one group or in any individprovide a means so ual group are marked or identified by the of either of the pairs.

same color or are marked sothat the coloring material both as regards quality from an electrical standpoint, and quantity per unit area on each conductor insulation, is as nearly as possible the same., By this means any electrical unbalance due to difierence of electrical characteristics of the coloring or marking of conductors in each group may be appreciably reduced.

The invention will be described by way of example with reference to a quadded cable as represented in the accompanying drawg The cable comprises a plurality of quads 1 arranged in layers which are shielded bv a metallic screen 2 in known manner. The quads each contain four conductors insulated from each other by a paper insulation applied for example in the form of a ribbon. The four conductors of each quad are arranged in pairs. The two conductors of each pair are twisted together. .The number of twists per unit of length of one pair preferably difiers from that of the other pair in the same quad. The pairs are twisted together to form the quad and the length of lay of the quadded twist is different from that Each conductor is in sulated by a paper ri bon of a neutral color or of a natural color printed with identificaand in Great Britain February 14, 1928.

tion marks. The color or colors of the insulation employed for all the conductors in one quad are all the same. The four papers for one quad may preferably be chosen from adjacent positions in the paper roll, these four papers being imprinted with the same amount of ink on each paper, the. ink being also of the same color or composition. The identification of either pair in any quad is permitted by using different markings on the pairs, taking care that in giving this different marking the same amount of coloring material is present on all the conductors of the quad. This is shown in the figure in which conductors A, B, form one pair, while conductors G, D form the other pair of a quad 4:, The identification in this case may be, for example, by means of black marks upon a natural color ground and the conductors C, D would have narrow stripes for identification purposes, but the total amount of color per unit of surface of any of the conductors, A, B, C or D is the same. If desired,'or' course, the conductors of each pair may also be identified in a similar manner provided the said precaution is taken. The identification between the conductors of difierent quads may be made by using different colors for different quads, for example quad 5 may comprise conductors which are insulated by means of paper having a red stripe on a natural colored round, the identification between the pairs of quad 5 being permitted by arranging different width stripes on the insulation as in the case of quad 4.

By so marking the insulation of the conductors in the cable it is found that capacity unbalances are not introduced through nonuniformity of the insulation surrounding the conductors of each quad, and in order further to ensure this it is preferable that the disposition of the ink upon each of the papers of a quad is made substantially in similar manner for all four conductors in order that the qualities of the paper may not be differently afl'ected.

The identification marks shown in the drawing are in the form of stripes at right angles to the length of the conductors. This is obtained by marking the ribbon with ferent angle oblique stripes so that after wrapping around the conductor the angle of application of the ribbon produces the right angle direction of the stripe. If desired the stripes may be marked on the paper in such a way in the finished cable that they may appear at a difon the insulation and in some cases a difi'erence in the angle may be used for giving the identification between difierent conductors of a quad or between the conductors of different quads.

A lead sheath or the like 3 is provided in the usual manner to complete the cable.

In an actual cable the quads would be much closer then shown on the drawing which is intended to illustrate the principles of the invention with most clearness.

It should be understood that it is within the scope of the invention to other insulating materials than aper as described above and that the insulation, eve: case of paper, may be applied in other iorms than that of a ribbon; coloring matter furthermore may be ap, lied to the insulation alter the latter has been placed upon the (acnductor. Thus, the

conductor may be insulated with papier miich the identification color applied been formed the papiecmdch the conductor drier t is claimed is l; i i telephone c conductors, pap r i r a tors, a coloring substance per insulation in such am its the capacities "fictive such formation as to sci, marks on said conduct A telephone cable a p pairs of conductors, paper insu conductors, coloring subs said paper in such amounts t o of conductors of diiierand in such configur conductors may be ideir led thereby, 8. A cable comprisin. nsulated conductors i aving colored ident cation apto the outer surface of the aper wherein the ground color for the marlicg the same for at least two oi the conduc ors in one group and the identification ing is composed of such coloring matter and has such configuration that said conductor" have substantially the same dielectric char acteristics and the markings on said con ductors are substantially difi'erent,

l. A cable comp-rising a plurality of paper insulated conductors arranged in groups and having colored identification markings ap plied to the insulating paper wherein for at least two of the conductors of any one group the ground color for the marking is the same, and the coloring matter 01 the marking is the same and is applied in the same amount per unit area of paper insulation and wherein the coloring matter being the same for said 0011- ductors, the marking matter on the paper of one conductor of the pair being disposed differently from the marking matter on the other conductor of said pair,

In witness whereof, I hereby subscribe my name this twenty-ninth dav of January,

WlliLlrlll/l lWESTOl-l,

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