US2409530A - Electric cable - Google Patents

Description

C. E.-BENNETT ELECTRIC CABLE Oct. 15, 1946.

Filed July 3, 1942 v INVENTOR M6,

ATTORNEY Patented Oct. 15, 1946 ELECTRIC CABLE Charles E. Bennett, Ridgewood, N. J assignor to The Okonite Company, Passaic, N. J., a corporation of New Jersey Application July 3, 1942, Serial No. 449,575

1 Claim. (Cl. 174-115) This invention relates to an improvement in electric cables, more particularly to cables for low tension work, and has for one of its objects the provision of such a cable which is of new and novel construction and is adapted for use in substitution of the usual BX cable.

In the accompanying drawing illustrating one embodiment of the invention:

Fig. 1 is a part sectional elevational view of a cable constructed in accordance with the invention; and

Fig. 2 is a section on the line 2-2 of Fig. 1.

Referring to the drawing in detail: 2 designates one of the conductors of the cable insulated with paper 4. The insulation 4 is in the form of a paper tape, applied spirally about the conductor. In the usual BX cable it is quite usual to employ rubber insulation which is built up to a wall thickness of as high as 31 mils. Owing to the improved construction of the cable of this invention, the wall thickness of the paper insulation 4 is only about 10 mils.

Extending along the cable on the outside of the insulation 4 is a bare copper conductor 6.

About the conductor assembly thus provided I apply an electrically insulating waterproof, non-metallic sheath 8. This sheath 8 may be composed of rubber or it may be composed of a rubber-like material such as polyethylene tetrasulfide, a synthetic material known commercially as Thiokol.

While the cable may be armored with metallic armor, such as commercial BX, I may employ an armor ID of paper. This paper is impregnated with heated terpin hydrate or an equivalent material which is capable of rendering the paper highly. moisture resistant. The addition of fortifiers such as cuprous stearate, zinc stearate, etc., to the terpin hydrate before impregnating the paper further enhances the Waterproofness of the armor. This treatment too increases the tensile strength, fiexural strength, compressional strength, etc, of the armor.

It will be appreciated from all of the foregoing that my cable, as above described, is of improved construction as compared with existing so-called BX cable. Owing to the fact that the insulated conductor 2 and naked conductor 6 are enclosed in the highly waterproof sheath 8, the cable is adapted for installation in wet areas where the ordinary BX cable is not permitted. It will be appreciated also that where treated paper armor is employed instead of metal BX I obtain a reduction in weight without sacrifice, however, of flexural and compressional strength.

It is to be understood that changes may be made in the details of construction and arrangement of parts herein illustrated and described without departing from the spirit and scope of my invention.

What I claim is:

An electric cable comprising in combination a paper insulated conductor, a bare conductor, an enclosing polyethylene tetrasulfide sheath, and an armor of paper impregnated with terpin hydrate.

CHARLES E. BENNETT.

Images