US1680679A - High-tension underground cable - Google Patents

Description

- HAYMAN HIGH TENSION UNDERGROUND CABLE Filed Oct. 25, 1927 BELT [v.suLA T/ON.

Inventor: William C. I". ayman.

b M JfjZ y H is Attorney Patented Aug. 14, 1928.

- :nrurse qsr a.

WILLIAM c. HAYMAN; F SCHENECTADY,

NEW YORK, ASSIGNOR TO GENERAL ELEC- TRIG- COItFEANY, -A -'COR-PORATION OF NEW YORK.

: The; present invention relates to multiple .conductor hightension underground cable .and has for its object to provide fillers therefor ,of. improved construction to, the end that gas-.ma y be, excludeclflifromithe. interior of m che claims appended .theretO- e: ebl es omp etyis ib s ib ei- I a i e ider 'e pfi atl li e be novel; and inyention, attention ;is dit e he eq pa y es es r ptiee a Iri a t sts?!d ewie ski l ie fi i estiatir set; my eve t ni show n ere-asse i oe-a reee esli t tb etle a ,I Qe he pi rp 's I t i s sa i e ly u r t- 4 e y er smi Irhere ai we- .nection with af25 QQO u three;conducter cable but it 'is not to; understood as limited 7 thereto or to I the, man ing shape fof \thefconductors altl ioughthe arrangement of the latter is particularlyadvantageous"in ,acablelofthiseharacter i Each fofa central conductor mernber' l whic'h is segmental in cross section, and snugly surrounding it is a plurality of sniallenconductors 2 which are laid up in any suitable way so that the conductor as a whole is self-supporting. Surrounding each of the conductors thus formed are numerous layers of insulation 3, said layers being composed for example of relatively narrow, tightly-wound strips or ribbons of tough paper, the joint between adjacent strips in one layer being covered by other strips both above and below it. The conductors are assembled in a we lknown manner to form a body in which they are spaced 120 apart. Surrounding the conductors and their individual lnSlll l tions is an annular covering or belt of insulation 4 which may also be formed of paper and wound on in the manner described for the individual conductors. Outside of the belt insulation is a lead sheath 5.

Between the conductors thus assembled both at the center and adjacent the belt insulation are spaces 6 in which are located fillers. It is to the construction of these fillers that my invention is specifically directed. The commonly accepted arrange ment is to make these fillers wholly of jute in the form of relatively hard twisted cords or to make them wholly of paper. Both of these are objectionable because the material does not properly pack. Owing to the fact that the places where the insulating HIGH-TENSION UNDERGROUND C ABLE.

' ,Ap uifio'n filed October 25, 1527., serial No. 228,646.

covering and' the belt insulation contact wedge-shapedspaces or openings are formed and to the fact that the jute cords are round and of considerable size they do not prop- .erlyz fillj the spaces and as a result. small. voids are'formed in which gas can and does collect witli itheresult that ionization takes place 'in' these regions. When paper alone is uujsedf'it also fails completely fill the s'paces between; the conductor coverings due wholly orii large part to the lack of resil ien ey;o 't hefpape'rf I fovercom e'the: objection above noted by using a, filler which is composed of three distinctfelement-s instead of one. The sides .of each filler .where the space. between the beltjand conductor cove 'ings contracts to the proportions of a knife edge as indicated at 7, areiee'mposedhof paper strios 8 and for purposcl have found kraft paper to be .sat1sfactory. The. paper is cut into relative ly wid n 'trips and is passed through a suitmachine.whichcrumples it and at the iisamejtime' gives to it a wedge-like formation 11i crpss-sectionand of any, sui able length.

The paper may take the form of a paper cord or twine and be given the wedge-like formation as the conductors are passe through a forming or sizing die in the cable assembling operation. Between two of these wedge-like strips is located a suflicient number of jute cords 9, to fill the remainder of the space. The number of these cords and the size thereof will vary for different size cable as will be readily appreciatei'l. Since the jute cords are somewhat elastic they serve to firmly press the side. paper members laterally into the wedge-like openings with the result of completely filling the spaces between conductor coverings and the belt insulation. For the central space between the conductors I also employ a filler of crumpled kraft paper 10 which in the assembling operation made to completely fill the central region between them. For this purpose it is preferable to use a number of pieces of paper cord or twine which extend lengthwise of the cable and the pressure of the sizing or forming die squeezes the paper to the shape indicated.

F or simplicity of description, I have referred to the fillers in the positions they occupy aft-er the cable parts are assembled. In making the cable each of the conductors is first insulated, then they are laid up or asscmbled with,.the central tiller between them, and the paper and'jute fillers in the outer spaces. The conductors and the fillers are then passed through a sizing die-which compresses them, after 11Whi0h the belt insulaton is tightly wound thereon. The cable is then thoroughly impregnated With-asuit able compound, as heayy oil, ,for example,

in any suitable manner, after which thelead sheath is applied. Due to the elasticity of the jute the'paper wedges or members are forced laterally, which action is in part due to the sizing die and the .wound-on'belt insulatlon and the paper, and completely fill the wedge-like portions of the filler spaces. Any iuinu te spaces} or voids are filled with the compound or fiuidwith which the paper insulation and the fillers are impregnated.

What I claim as new and desire to secure by Letters Patent of the United States, is; 1. In a cable, the combination of a number of separately-insulated conductors, a belt of insulation which surrounds the conductors and bindsl them together,'and fillers for the 1 spaces between the conductor coverings and the belt insulation, each of which comprises side members'which are made of paper and a central member located between the side members and which is made of jute.

2. In a cable, the combination of a number of separately-insulated conductors," a wrapping of paper whichforms:the be1t insulation and binds the conductors together, and fillers for the spaces between the conductors and the belt insulation, each of which comprises two side members which are made of kraft paper and are wedgeshaped in cross-section and a central member located between the side members which 'lation and'fillers, and a fluid-tight metallic sheath which encloses the belt insulation.

4. In a cable, the combination of a number of separately-insulated conductors, a body of paper located within the space defined by the contacting surfaces of the conductorwinsulations and filling the same, a belt of insulation which surrounds the conductors and binds them together, and fillers for the spaces defined by the conductor insulations and the belt insulation, each of said fillers comprising wedge-shaped side members madeof paper and a member centrally located between the side members and made of jute, said jute exerting side-wise pressure on the paper members.

In witness whereof, I have hereunto set my hand this 24th day of October, 1927.

WILLIAM C. HAYlVLAN

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