摘要:
A POF cable line which comprises a steel pipe and three cable cores drawn in the steel pipe. At least one curved offset section is arranged on the steel pipe at a part spaced from a cable joint at a predetermined distance, with a straight portion of the steel pipe interposed therebetween. The curved offset section prevents the cable cores in the part of the steel pipe from snaking hard and consequently prevents the insulation paper in the part from making soft spots or creases. The snaking occurs easily in the offset section when the cable core thermally expands.
摘要:
A method is disclosed in which an insulating film of an oxide of metal, of which a stranded conductor (30) is made, is formed on the surface of all strands in a stranded conductor, while the stranded conductor is held in the stranded form. In a step of oxidation-treating the strands of an electric cable the pressure of an oxidation treatment solution at the outer portion of the stranded conductor immersed therein is made higher than the pressure in the inner portion of the stranded conductor (30), causing the oxidation treatment solution (48) to be adequately penetrated from the outer portion into the inner portion of the stranded conductor to permit a desired oxide film to be formed on the surface of all the strands in the stranded conductor. In order to more facilitate the penetration of the oxidation treatment solution (48) wholly into the interior of the stranded conductor (30) and the more facilitate an oxidation reaction, vibrations are, in addition to this method, imparted to the stranded conductor (30) in the oxidation treatment step (40) to cause the untwisting of the stranded conductor (30) to be effected to some extent, while the stranded conductor being heated is entered into this step.
摘要:
A laminated insulation paper of the type having two cellulose layers separated by a plastic layer is formed with through holes in the plastic layer such that the respective cellulose layers may contact one another through the through holes. The insulation paper is formed by pressing heated, rounded pins into one of the cellulose layers while backing the other layer until the two cellulose layers are contacted through the hole thus formed in the plastic layer.
摘要:
This invention provides an insulating paper sheet produced by mixing synthetic resin flakes with natural fibers to provide a composite paper mass. This insulating paper sheet is favorably accepted as an insulating member for covering the conductor of a power cable.
摘要:
In a method for manufacturing a stranded conductor for an electrical power cable comprising a process for forming cupric oxide films of from 0.3 .mu.m to 3 .mu.m in thickness by passing an uninsulated stranded conductor constituted by a plurality of stranded copper strands through oxidizing liquid, the stranded conductor passing through the liquid is curved in a wave to form gaps between the strands, and the oxidizing liquid is caused to penetrate between the strands through the gaps to form cupric oxide films of from 0.3 .mu.m to 3 .mu.m in thickness on the surfaces of the strands. Also disclosed is a stranded conductor for an electrical power cable constituted by a plurality of stranded copper strands, at least one of the copper strands being covered with a cupric oxide film free from exfoliation.
摘要:
Apparatus for continuously vulcanizing a covered material on a conductor comprises a feed device for feeding the conductor in one direction at a constant speed and an extruder for applying the covered material to the conductor fed from the feed means. A vulcanizing tube extends from the extruder, the cable passing through the vulcanizing tube. The vulcanizing tube has a curing section extending from its inlet to a location intermediate its inlet and outlet. A take-off device is disposed forwardly of the vulcanizing tube for hauling the cable. A load applying device is disposed between the extruder and the take-off device for applying a load to the traveling cable at a location forwardly of the curing section of the vulcanizing tube, so that a tension exerted on the cable in a direction opposite to the direction of travel of the cable is applied to the traveling cable.