Making insulated conductors

摘要

A conductive element is covered with an insulating material which is cooled within a predetermined temperature range, and preferably near or at ambient, by moving the conductor first through a cooling trough and then in a plurality of convolutions about spaced grooveless rollers which comprise a capstan. The length of the cooling trough is such that the insulation is not deformed as it engages the capstan and the number of convolutions wrapped about the capstan which is subjected to a cooling medium are determined to insure that the temperature of the conductor exiting from the capstan is at or near ambient. Unlike conventional grooved capstans, the capability of the grooveless capstan to provide for a variable number of convolutions compensates for temperature differences caused by different conductor designs and/or manufacturing parameters such as line speed and thereby insures that coaxial capacitance measurements taken at the exit end of the capstan are made with the conductor temperature being substantially constant.