| 摘要 |
585,861. Cables. STANDARD TELEPHONES & CABLES, Ltd., and WEBB, J. K. Dec. 22, 1944,No. 25756. [Class 36] An electric conductor is insulated with thermoplastic material, the voids in which are reduced by heating the insulated conductor under pressure, the pressure being maintained during cooling. The temperature should be only a little below the melting point of the material, and the pressure should be about 2 tons per square inch. The insulated conductor may be placed in vacuo prior to the application of heat and pressure or between two such applications. The material may be polyethylene or, according to. the Provisional Specification, polyvinyl chloride or ethyl cellulose. To apply the heat and pressure the cable is drawn into a steel tube in sections 8 with end pieces 9 and then evacuated of air and filled with water. Steam under pressure is circulated through the jacket 10 which has inlet and outlet pipes 11, 12. When the water has been heated, its pressure is increased by a pump 13. |
