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A cable which is insulated by means of mineral insulation material and which comprises one or more hollow electric conductors, a mineral insulation material provided around the conductor(s) and a metal sheath, the ends of said cable being sealed in a moisture-tight manner and having a passage for th

A cable which is insulated by means of mineral insulation material and which comprises one or more hollow electric conductors, a mineral insulation material provided around the conductor(s) and a metal sheath, the ends of said cable being sealed in a moisture-tight manner and having a passage for the central conductor(s), as well as a method of manufacturing the cable.

대표청구항 ▼

A method of manufacturing a cable insulated with mineral insulation material and comprising a central electrical conductor unfilled hollow throughout its length, said mineral insulation material provided around said central conductor, a metal sheath surrounding said central electrical conductor and

A method of manufacturing a cable insulated with mineral insulation material and comprising a central electrical conductor unfilled hollow throughout its length, said mineral insulation material provided around said central conductor, a metal sheath surrounding said central electrical conductor and said insulation material, said central conductor extending along the length of said cable, and the ends of said cable being sealed in a moisture-tight manner by means of plugs through which said central conductor passes, said method comprising subjecting a hollow central conductor having a reducible diameter exceeding that of the desired conductor to a mechanical treatment for increasing the length of, and thereby reducing the diameter of said conductor having said reducible diameter while being periodically subjected to an annealing treatment characterized in that prior to commencement of said mechanical treatment said hollow conductor having said reducible diameter is filled with a material capable of withstanding the pressure of said mechanical treatment and the temperature of said annealing treatment and said material is removed from said conductor having said reducible diameter when said treatments are terminated and the diameter of said conductor having said reducible diameter has been reduced to the desired value.