Apparatus for molding stress control cones insitu on the terminations of insulated high voltage power cables

摘要

This invention relates to stress control cones for terminations of high-voltage power transmission cables. Such cones are used beyond the end of the cable insulation shielding, and for the purpose of providing thicker insulation for reducing the stress at and beyond the unshielded insulation on a high-voltage power cable. This invention builds up greater thickness of insulation beyond the end of the cable insulation shield, preferably by wrapping the cable with layers of insulating tapes that are then heated and fused to one another and to the outside surface of the cable insulation. The hot build-up of additional insulation is fused, or brought to incipient fusion, to merge the build-up to the cable insulation and the build-up layers to one another, instead of using preformed stress relief cones which are unsuitable for very high voltage. The build-up material is shaped to the most effective contour by the application of force from hydraulically-operated molding shapes made of metal and forced against the build-up by hydraulic motors attached to portable shaping apparatus.