US1037883A - Waterproof cable. - Google Patents

Description

H. W.'IISHER. WATERPROOF CABLE. APPLICATION FILED 311129, 1912.

'1 ,O37,883, Patented Sept. 10, 1912.

WITNESSES: INVENTOR 1M m v I atfiwrQL gw-s BEST AVAILABLE COP UNITED STATES PATENT OFFICE.

HENRY W. FISHER, 0F PITTSBURGH, PENNSYLVANIA, ASSIGNOR 'IO STANDARD UNDERGROUND CABLE COMPANY, OF PITTSBURGH, PENNSYLVANIA, A CORPO- RATION OF PENNSYLVANIA.-

WATERPRDOF CABLE. I

Specification of Letters Patent.

To all whom it may concern:

Be it known that I, HENRY W. FISHER, residing at Pittsburgh, in the county of Allegheny and State of Pennsylvania, a citizen of the United States, have invented or discovered certain new and useful Improvem'ents in Waterproof Cables, of whichunprovement the followin is a specification.

The use of a layer 0% asphaltum, surrounding an electrical conductor, has been variously suggested both for insulating purposes and as a water-proofing layer. It

as been found that, in order to render the asphaltum layer in and of itself effective to resist electrical discharge, the layer must be of such thickness that the conductor, owing to the manipulation of the cable in service, s liable to become so eccentrically dis osecl within the said layer that oints of wea ess may develop. Hence, sue a use of asphaltum in electrical conductors has been unsatisfactory. When asphaltum has been used as a water-proofing layer, in cables as heretofore constructed, it has been surrounded by braid or other material which absorbs the asphaltum' and, extending into and through the body thereof, afiords paths for the mss of moisture into the insulating coverings of the cable to their evident detriment.

'. As a water-proofing agent, as well as an acid-resisting agent, it is well known that asphaltum has certain properties which are desirable in the construction of electrical cables; and these properties have not been fully obtained in such cables as they have been constructed heretofore.

It is the object of my invention, which re lates to electrical cables, to combine, with their several coverings, a layer ofasphaltum in such a manner that the layer will be fully efl'ective to resist the encroachment of water and acid to the insulating portions of the cable. To such an end I have found that a relatively thin layer of asphaltum may be held in an unbroken and continuous film, which will be impervious to water and which will resist the action of acid, by incasing the said layer between layers of nonabsorbent materials; 'My invention consists, therefore, in adding to an insulated electrical conductor a layer of asphaltum incased between such (material. I

, While I do not wish to limit myself to any Patented Sept. 10,1912.

nish, whereby the surface of the cloth is rendered smooth and impervious, and its fibers protected so that they cannot absorb substances with which they may come in contact.

It will be readily understood that my invention is capable of various embodiments in order to meet the requirements of service.

Therefore, as a part of my specification, I show on the accompanying drawing several cross-sectional views of cables illustrating different constructions.

In the several figures like numerals are used to designate like parts.

In Figure 1. which illustrates the simplest construction of my improved cable, the conductor 1 is surrounded successively by a body of insulation 2, a layer of asphaltum 3, and a wrapp ng of varnished cloth 4. The conductor may be of any desired form that is, it may be a single wire or a strande conductor. The insulation may also be of any desired form, such as several wrappingsof tape saturated with insulating compound, or

it may consist of a body of rubber. But, whatever the insulation may be, it is'desirable to have its exteriorsurface of such a character that it will notabsorb the superimposed layer of asphaltum 3. It will be observed that the asphaltum layer will be incased between two non-absorbent layers,

and that, in "iew of such particular disposi- The cable illustrated in Fig. 3 difl'ers from that shown in Fig. 1 in that the core 1 consists of a plurahty of separably insulated BEST AVAILABLE COP electrical conductors. As in Fig. 1, the insulation, being rendered non-absorbent, is surrounded by a layer of asphaltuni around which is a wrapping of varnished cloth.

I have found the electrical cables, thus far described, to be particularly well adapted for use in mines or like places, wherein the cables are usually subjected to the action of water which may have a quantity of acid intermingled with it. And when so used such cables have certain advantages over the heretofore used lead-sheath cables, in that they combine cheapness and lightness in weight with effectiveness to resist water and acid. However, under some conditions of service, it is desirable to cover my cables with a lead sheath as an additional safeguard against water and acid, or as a mechanical protection. Such a cable is illus trated in Fig. lwherein the conductor 1 is surrounded by successive layers of insulation 2, varnished cloth 4, asphaltum 3, varnished cloth 4, braid 5, and lead sheath 6. It will be observed of this construction that, in case the lead sheath breaks down, the layer of asphaltum will protect the cable from injury by water and acid.

In another and limited aspect, my invention may be described as consisting of a wrapping of varnished cloth about a layer of asphaltum. \Vhen so viewed, the asphaltum, in addition to forming a continuous layer around the insulation, forms a seal for the well known spiral opening between the superimposed helical wrapping of the varnished cloth, which in and of itself is, to a marked degree, water-proof and acidresisting.

By the term asphaltum, as used throughout this specification and claims, I mean to include the residue of petroleum distillation as well as native asphaltum, the two substances being substantially identical in characteristics and properties. I also mean to include, under the term asphaltum, certain compositions which contain a large proportion (approximately 80%) of unmodified asphaltum; for I have found that, while the unmodified asphaltum is effective to accomplish the resultheretofore described, by combining certain ingredients with it, better results may be had. The pure asphaltum may be compounded with softening substances such as petroleum or vaselinc. I may also employ a small quantity of i'osin. The proportion of ingredients in the material may be varied, it being essential only that the compound contain such a quantity of pure asphaltum as will render it pervious to water and acid.

I do not wish to limit myself to cables shown herein, for ,obviously many other forms may be made without departing from the spirit of my invention, as set forth in the appended claims.

I clalm as my invention 1. An electrical cable, consisting of a conductor surrounded successively by a body of non-absorbent insulating material, a layer of asphaltum, and a covering of non-absorbent material, substantially as described.

2. An electrical cable,.consisting of a conductor surrounded successively by a body of insulating material, a wrapping of varnished cloth. a layer of asphaltum, and a wrapping of varnished cloth, substantially as described.

3. In an electrical cable, the combination with a conductor. of a layer of asphaltum inc-ased between wrappings of varnished cloth and surrounding said conductor, substantially as described.

4. An electrical cable, consisting of a conductor surrounded successively by a body of insulation having a non-absorbent exlt'llul' surface, a layer of asphaltum, and a wrapping of varnished clot substantially as described.

In a cable construction, the combination of an electrical conductor, a body of non-absorbent insulation adequate in and of itself to protect a current flowing in said conductor, a layer of asphaltum and a wrapping of varnished cloth, substantially as described.

In testimony whereof I have hereunto set my hand.

HENRY W. FISHER.

WVitnesses:

E. J. VVARING, TRACY D. WA

It is hereby certified that in Letters Patent No. 1,037,883, granted Septemuer 10 1912, upon the application of Henry W. Fisher, of Pittsburgh, Pennsylvania, for an improvement in Waterproof Cables, an error appears in the printed specification requiring correction as follows: Page 2, line 60, for the word pervious read impen'm'mw; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Oflice.

Signed and sealed this 26th day of November, A. of, 1912.

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