Power cable for portable machines

Claim 1

A flat, flexible, three-phase power cable suitable for use on portable mining machines comprising: A. a core assembly comprising: a. three equal-gage-size insulated power conductors in parallel alignment, the central of said insulated conductors comprising a plurality of stranded copper wires and rectangular encasement of polychloroprene insulation surrounding said wires, and each of the other of said conductors comprising a plurality of stranded wires and a D-shaped encasement of polychloroprene insulation surrounding said wires, said Dshaped encasement having substantially flat surfaces facing said central conductor, b. A flexible flattened copper grounding strand comprising a copper area at least 50 percent of the area of the wires in one of said conductors, said grounding strand being positioned between the central insulated conductors and a first of said conductors comprising said D-shaped encasement, c. a flexible copper ground-check strand comprising a copper area no greater than two-thirds the area of said grounding strand, said ground-check strand being positioned between said central conductor and the second of said conductors comprising said D-shaped encasement, and d. a rectangular encasement of polymeric insulation surrounding said ground-check strand, said encasement having sufficient thickness and stiffness whereby the flex endurance of said ground-check strand exceeds the flex endurance of said grounding strand and said conductor wires, B. an open web fibrous binding surrounding said core, anD C. a tough polychloroprene jacket surrounding said binding overall.