US1642515A - Cable-joint structure - Google Patents

Description

D. M. SIMONS CABLE JOINT STRUCTURE pt; 13, 1927. I 1,642,515

Filed Janfl3, 1926 //v vw'rok WITNESSES Q fimmmm ziw wz g. a??

Patented Sept. 13, 1927.

UNITED STATES PATENT. OFFICE.

DONALD m. smons, or OSBORNE, rniwsnvmm, Assrcmor. TO s rmnnn UNDER- eaoonn cum: comm, or. rrrrsnonen, rnnnsxnvmm, A conrom'rrorr or PENNSYLVANIA.

CABLE-JOINT STRUCTURE.

In Letters Patent of the United States N 0. 1,585,124, granted on my application May 18, 1926, I have described a joint for electric cables intended for high-tension service.

The 'oint includes a body of insulating materiai formed of a single sheet of paper or like material, Wrapped in a single continuous spiral around the united conductors and upon the adjacent endsof the bodies of ma- 1 chine-laid insulation, previously cut away to admit of electrical union of the conductors. The sheet of material carries at or near its edge metal strips which converge in the length of the sheet one toward another.

the finished article these strips constitute screens electrically continuous with the cable sheath and flaring within the joint casing,

and these screens are stress-l1Iniiting-elements, rehevlng the spaces and the spacefilling substances within the joint casing and external to the screens of all electrical stress.

In an application filed August 5, 1925, Se-

rial No. 48,301, I have described such a wrap within a cable joint, formed of a single sheet of paper-or other insulating material, filling the space between the cut-away ends of machine-laid insulation, and building out the body at the point of union, to the normal diameter of the insulated conductor. And I have further shown in this second application that the sheet may be of such length and proportions that it may in continuous wrap constitute not merely a building-out and a replacement of the machine-laid insulation,

mit of union between the bared conductor ends but it may constitute also the body of insu ation within the joint casing, external to the normal diameter of the insulated cable I conductor, and carrying at its ends the flarmg screens of the application first above where the latter had been cut away to ad-" My invention is illustrated in the accompany ng drawin in which the figure is a yiew in longitu joint in the building of which my invention is practiced.

Referring to the drawing, here are shown two cable-ends from which the lead sheath 1 has been cut away, exposing the envelopes 2- of machine-laid insulation, and from which the envelopes of insulation in turn have been cut away,exposing the conductors lnal and axial section of a- 3. The insulation is cut away in opposite that it may be formed of low-fusion metal,

cast to place, and it knows that it ma .be preformed and sweated to place and to electric union upon the conductor ends. When the unitingbody 4 has been applied, its exposed cylindrical surface 41 is continuous with the cylindrical surface .21 of the lowest step of insulation 2. V

I have discovered that by wrapping upon the union so effected the web of insulating material which I have described in m earlier applications and alluded to above obtain a joint of hitherto unattained excellence.

The sheet is a web of such widthas to extend between the next pair of steps, from riser 22 to opposite riser, so that as it is wrapped on in one continuous spiral itfills all the space between the steps. The sheet itself is of increasing width correspondingly stepped, so as to fillall the space between the opposite cut-away ends of machine-laid insulation. Thus a body 8 is built up which, filling all the interval, restores the original diameter of the insulated conductor throughout the extent. of the joint. The sheet of wrapped-on material may be continuous in length throughout all the spiral extent, or

it may be pieced in a succession of lengths; roll but in width it extends without break soj Olen face to face of the cut-away bodies of insulation.

The material of which the' sheet is composed will ordinarily be paper; muslin may be used, or other equivalent material. It will ordinarily (at the time of application be already filled with oil, varnish, or'other suitable filling material. The wrapping may be done under oil. I have, however, discovered an alternative method, well suited to the conditions-of field installation, and which afl'ords a satisfactory result. It is this: As wrapping progresses the advancing line of contact with the surface to which application is made is flushed with oil or equivalent inaterial, ourediupon it. Eventually the otherwise finished joint will be 'flushed with ,oil or equivalent material. y

When the web has beenapplied and the interval between the bodies 20f insulation has been filled in the manner described, the

joint may be completed as desired. The

whole is enclosed in the usual joint casing 5, secured at its ends to the cable sheath 1. At

any suitable time before completion, the .joint structure may be flushed and filled with oil, or'othe'r insulation in liquid condi tion. And in the finished joint I prefer that the jointcasing 5 shall carry a reservoir'full of liqluid insulation, in the form of .a closed of sylphon tube .50 communicating wit the chamber within the casing. This in the manner and for the purposes known to the art.

The 'wra ping which I have described may built e body 8 and no more. Preferably, however, I continue the wrap beyond the point where the original diameter of the cable insulation is restored, and in continued wrap I similarly fill, first the space between the cut-away ends of the cable sheath, and then: I similarly and in continuous wrap (with the possibility of piecing longitudinally, as already explained) build up an,

overlying and envelop body-9, which body 9, in vconsequence o metallization of the web of paper adjacent'its opposite edges,

carries flaring metallic'screens 10, intimately contacting with the substance of body 9,-

electrically united with the ends of the cable sheath '1, limiting the region .of electrical strain, and relieving the spaces and materials within the joint casing and external'to the screens of such strain. It will be under-' stood that-in order to build the body 9 having the characteristics described, the web of paper will be suitably proportioned, its width being increased at the proper points and to the proper extent, and the metalliza-. tion will be efiected in suitable manner and over suitably disposed areas;

it will be understood that cable joints must ordinarily be made in the field, and the fact will be appreciated by those acquainted with the industry, that my invention is -adapted to field conditions, that it may be advantageously and successfully practiced.

I-claim as my invention:

In a joint structure for an electric cable two meeting cable-ends including each a conductor, an enveloping body of machinelaid'insulation, and a. sheath, the body of machinelaid insulation being cut back in a stepped out and leaving the conductor-end unenveloped, the insulation adjacent the conductor-end being recessed with a re-entrant-vconical recess, a body of conducting material uniting'the conductor-ends, filling the re-entrant recesses in the ends of the bodies of machine-laid insulation, and presenting a continuous surface with the lowest step of the cut-away ends of machine-laid insulation, and a wrapped-on body of sheet insulation-overlying the continuous surfaces of machine-laid insulation and of the unit- 'of the original diameter of machineelaid insulation and in such continued portion carrying strips of metal whichwhen wrapping is completed constitute flaring screens of 'ing body, and all the space external to the v insulation, said metal electrically continuous with the ends of the cable sheathand borne in intimate: funion .upon the wrappedon body ofinsulation.

In testimony whereof I have hereunto set my hand. DONALD M. SIMQNSP

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