Cable molding method

Abstract

A method and apparatus for forming cured polyethylene insulation about high voltage cables by applying uncured polyethylene around a core of the cable. The polyethylene is heated, cured and then cooled to room temperature in a pressurized nitrogen gas atmosphere. In one form the molding apparatus comprises first and second mold forms which define a cavity and which include means for heating the mold halves to the polyethylene curing temperature. Means is also provided to introduce the pressurized nitrogen into the cavity and for subjecting cable portions that extend beyond the mold to pressurized nitrogen until such cable portions are sufficiently cooled to prevent their deformation under pressure, to prevent the oxidation of polyethylene and/or to prevent the formation of voids or enclosures. In another embodiment, the apparatus includes cooling openings for receiving a coolant preselectedly along the molding apparatus, a number of spaced-apart temperature gauges for indicating temperature at various locations along the apparatus, a pressure gauge for indicating pressure in the mold cavity, a heat source and a nitrogen source. At each end of the apparatus are recesses in which soft resilient strips are located. During the molding process, the ends of the molding apparatus are kept at a reduced temperature and the pressure in the mold cavity is varied, the nitrogen being used to pressurize the mold cavity during curing. This method insures a quality repair or splice without detracting from the quality of the cable.

Dependencies are inferred from the claim text.