US2379755A - Method of handling strands - Google Patents

Description

METHOD 6F HANDLING STRANDS Filed Aug. 14, 1941 FIGJ INVENTO R -J. N. SE1. V16

ATTORNEY Patented July 3, 1945 HANDLING s'ra Nns JdhiifN. Selvi g, Westfield, J., assigns to Western Electric Company, Incorporated, New York, N. Y., a corporation of New York A Application August 14, 1941, Serial No. 406,853

This invention relates to a method of handling strands, and more particularly to a method of making an insulatingsheath on an electrical conductor strand.

In. some instances electricalpconductor wires have of recent years come to be insulated by forming directly on the wire a'continuous seamless sheath of pulpous insulating material, e. g.

paper pulp fibres of cellulose-felted -or intermatted together. cellent electrical characteristics for many uses because the sheath of felted fibres contains a highproportion of its volume as air entrapped -Wires thus insulated have exwithin and between its fibres; and, for 'many uses, the higher the proportion of air thus held within the gross surface'of .the sheath, the

greater the usefulness'of the insulation. i i. i

An object ofthe present invention is -to provide a method of making an improved sheath of pulpous material as described containing a materially increased proportion of entrapped air within the grosssurface of the sheath.

With the above and other objects in view, the invention may be embodied in a method of insulating electrical conductor strand comprising steps of forming a ribbon or tape of wet pulpous material, applying a wire to the partially formed tape to be enclosed therein by the complete forming thereof, compressing spaced longitudinal strips of the tape to render the same relatively thin,-dense and tough while leaving the corresheath as electrical wire, and folding and felting the tape into a seamless sheathabout thewireare old and-form nopart of the present invention. Hence these are not disclosed here. Suitable procedure-and apparatus for these purposes are disclosedand described in detail in U. S. Patent *1,61,5,;394of January 25, 1927, to J .S. Little, to which "refer ence may-be had, ifdesired, for these features. InFig. 1 hereinis showna 'pair of rolls l0 and II to receive. a plurality of flat ribbons or tapes 2!] of wet paper pulp each having a metal wire 2| embedded and contained within it. Thelower roll I0 is provided with a surface of hard:material, metal, hard rubberyhard fibre; artificial resinor other suitable substance, and is formed with parallel peripheral grooves 12 and 13 of two kinds distributed in repeated duplications of one set or pattern I l for each wire bearingta pe 20;

For clarity, only one tape is shown, but in practise there will usually be a plurality of tapes, The middle groove 13 of each set or pattern 14 of groovesis deeperand widerthananyother groove of the set and receives and gives passage to that part of the tape 20 which contains the wire 2|. Oneither side of the groove [3 isa plurality of parallel grooves I! all preferably alike and equally spaced apart. The roll II is smooth on its surface and is made to have its "outer surface relatively soft and elastically yieldsponding intercalated strips, thick and fluffy, and

the material into a seamless sheath.

Other objects and features of the invention will appear from the following detailed descrip tion of one embodiment thereof taken in connection with the accompanying drawing in which the same reference numerals are applied to identical par-ts in the several figures and in which Fig. 1 is a broken diagrammatic view. in eleva tion of a pair of rollers for squeezing a tape of wet paper pulp having a wire embedded therein;

Fig. 2 is aplan view of a portion of such tape after squeezing;

Fig. 3 is a section on the line 3-3 of Fig. 2; and i Fig, 4 is a view similar to Fig; 3 showing the tape formed into a cylindrical sheath about the wire. i The general procedure and apparatus for creating a tape of wet pulpous material such as paper pulp, applying a wire to the partially formed tape, completingthe tape to contain the ing, e. g. by making the body of the roll through-. out of suitablematerial or by providing a hard] cored. roll with a surface layer or sheath l5 of j i suitable material, e. g. soft vulcanized rubber,

vulcanized corn oil, or the like.

the wire 2|, strongly compressed by the roll ll where the tape lies on the lands l6 while [the portions betweenthese compressed parts are merely pressed down into the grooves I2 by the roll ll without any material compression of the substance of the tape in these portions. Hence the tape emerges from the rolls I!) and H sub-x stantially in the state disclosed in Figs. 2 and 3.

The longitudinal strip portions H6 which were pressed by the lands l6 of the roll l0 are thin, dense and tough while the intercalated longitudinal strip portions 2 or the tape which were a kept free of pressure by the grooves [20f the A tapezu with its wire 2! in passing over the roll ID, has its lateral portions at each side of i of the structure so made, is the presence in the sheath 220 of longitudinally extending passages 222 created by the wrapping of the longitudinally ridged tape I20; It is the presence of these longitudinal voids, passages or ducts 222 within the body of the sheath 220 in the finished product that notably increases the value of the sheath as an insulator. Another feature of importance is the presence within the sheath of the longitudinally extending, thin, hard pressed, tough strips 2l6 corresponding to the elements H6 in Figs. 2 and 3. Paper pulp and fluffy paper at best have no great tensile strength, and when the sheathed wire is subjected to more or less severe bending or pulling or friction in subsequent manipulation or use there may be danger of rupture of the sheath, especially transversely of the wire. In the wire shown in Fig. 4 the longitudinal strips 216 integrally parts of the sheath have a-tensile strength which may be several times that of any partof a sheath of undifferentiated structure, and so tend to support and save the sheath 220 as a whole where an ordinary pulp sheath might well be ruptured.

. The embodiment of the invention herein disclosed is illustrative and may be variously modified and .departed from without departing from the spirit and scope of the invention as pointed out in and limited only by the appended claims.

What is claimed is:

. 1. Ina method of insulating an electrical conductor and which method includes a step of creating a tape of pulpous material containing awire therein anda step of wrappingthe tape about the Wire to form a substantially seamless sheath about the wire, a step following the step of creating the tape and preceding the step of aplurality of mutually laterally spaced longitudinal portions of the tape to create in the tape longitudinal strips which are thin, dense and tough intercalated with strips which are thick and fluffy.

2. In a method of insulating an electrical conductor and which method includes a step of 4 creating a continuously advancing tape of pulpous material containing a wire therein and a step of wrapping the tapeabout the wire to form a substantially seamless sheath about the wire, a step following the step of creating the tape and preceding the step of wrapping the tape which step consists in supporting a transverse portion only of the advancing tape on one side thereof, and a step simultaneous therewith of exerting pressure at a fixedlocation on a transverse portion only of the advancing tape on the other side thereof and only over a plurality of mutually laterally spaced longitudinal portions of the tape to create in the tape longitudinal strips which are thin, dense and tough intercalated withstrips which are thick and 3. Ina method of insulating an electrical conductor and which method includes a step er creating a continuouslyadvancing tape of pulpous material containing a wire therein and a step .of wrapping the tape about the wire to form a substantially seamless sheath aboutthe wire, astep following the step of creating the tape and preceding the step of Wrapping the tape which step consists in supporting a transverse portion only of the advancing tape on one side thereof on a roller, and a step simultaneous therewith of exerting rolling pressure on the transverse portion of the tape'onxthe roller thereof and only oyer a plurality of mutually laterally spaced longitudinal portions of the tape. to create in the tape longitudinal strips which are thin, dense and tough intercalated with strips which are thick and flufiy.

JOHN N. SELVIG.

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