GB577772A - Improvements in the manufacture of electric cables - Google Patents

Abstract

577,772. Cables &c. BEAVER, C. J., DAVEY, E. L., and GLOVER & CO., Ltd., W. T. Nov. 24, 1944, No. 23481. [Class 36] In a high-pressure gas-filled cable, the core, comprising stranded conductors 1, Fig. 1, pre-impregnated paper tapes 2, a conductive screen 3 and copper woven fabric 4 incorporating fine copper wire warps 4a, is enclosed in an envelope 5, folded round to fit the core and leave two flanges 6, which are soldered together. Over this is a layer 8 of copper woven fabric tape, metal tape 9, such as hard brass, steel, phosphor bronze, or cadmium copper tape, applied helically with a short lay, and a protective sheath 10. The envelope is applied by passing the core over a roll above which is a reel carrying a coil of metal tape, such as copper or brass tape. The tape 15 is drawn off the coil and passed under a cylindrical roller with a U- shaped groove so that it lies over the cable core 11 as shown in Fig. 5. The core and tape then pass through another set of rolls, one roll holding the tape 15 in contact with the top of the cable core 11 and side rolls bending the sides into engagement with the lower half of the core, leaving flanges 6 as shown in Fig. 6. The flanges, whose inner surfaces are tinned before the tape is applied to the core, are passed through a bath containing a non-corrosive flux, such as a mixture of colophony and resin oil, and then through a bath of molten solder, whose melting point is above 200‹C., such as one consisting of 56 per cent. tin and 44 per cent. lead. On leaving the solder bath, the core and tape are passed through three more sets of rolls, one pressing the flanges together, the second bending them through 45 degrees, and the third pressing them so that they lie alongside the surface of the envelope. Specification 393,694 is referred to.