METHOD AND APPARATUS FOR MANUFACTURING A FULLY-FILLED ELECTRIC CABLE
1394629 Filled stranded cables INDUSTRIE PIRELLI SPA 31 July 1973 [2 Aug 1972] 36404/73 Heading D1T [Also in Division H1] An electric cable is made by passing a plurality of individually insulated conductors 8, Fig 1, to a stranding device 9 immersed in an electrically insulating water-impervious medium 2 heated to a temperature at which it is in a liquid state, the stranded conductor 10 being then passed to a cooling station 14 where the insulating medium is cooled to an ambient temperature at which it assumes a viscous state. The electrically insulating medium 2 is continually fed into a bath 1 via a trough 3 and thence through an overflow 4 to ensure that the bath 1 is always full. Any medium 2 escaping through a lay plate 6 collects in a container 16 and is fed back via a duct 17 to the trough 3. The cooling station 14 may be a waterjacket through which a tube 13 for the stranded conductor passes, the tube 13 has an internal diameter approximately equal to that of the strand 10, preferably exceeding the diameter of the latter by 2 mm at the most. Fig 2 (not shown) shows apparatus similar to that of Fig 1 except that the bath 1 contains a plurality of stranding dies and lay plates so that a strand of the multi-layer concentric type can be formed. Fig 3 (not shown) shows a plurality of devices similar to that of Fig 1, the insulated strands passing out of these devices being fed into a common further similar device where these strands are stranded into a single conductor. The medium in the bath 1 is preferably maintained at a temperature at least 5C higher than its dropping point and the medium in the stranded conductor 10 is preferably cooled in the cooling station 14 to at least 5C lower than said dropping point.