A PROCESS FOR THE JOINING OF COAXIAL CABLES HAVING INTERMEDIATE INSULATION OF LOW MELTING POINT MATERIAL, IN PARTICULAR OF COAXIAL 'MICRO' CABLES HAVING INTERMEDIATE INSULATION OF EXPANDED PLASTICS MATERIAL, AND THE JOINY THUS OBTAINED

摘要

1278171 Joining coaxial cables S I R T I SOC ITALIANA RETI TELEFONICHE INTERURBANE SpA 23 Jan 1970 [18 Sept 1969] 3370/70 Heading H2E A process for the electrical interconnection of coaxial cables, each having an insulating sheath of low melting point material, between the coaxial conductors, comprising the previous substitution of the end portion of the sheath by a tube of high melting point insulating material so that when joining two such cables the sheath does not melt and allow said coaxial conductors to short to one another. The substitution is effected by heating said sheath to cause it to fuse and contract so enabling the tube to be inserted between the conductors (see Fig. 8). Each cable 1 has its layers of paper insulation 6, support tube of steel 5, conductive tube of copper 4 and polythene sheath 3 cut back successively, insulating tape 7 being preferably added after cutting the paper layer through, adding a wire pigtail 8 and welding it to the support 5 and conductive 4 tubes preferably before cutting the conductive tube the welding heat causing the insulating sheath 3 to fuse and contract inside the conductive tube. The high melting point tube is then added. The inner conductors 2, 2SP1/SP are welded together, after inserting them into a slotted tube 13, preferably using tin. A slotted plastics tube 15 is clipped over the join so formed, a thermosetting plastics tube 11 then being slid over this tube 15, heated to melting point and compressed by the tube 11 as it shrinks. The copper tube 10 is then slid over the join and welded to said pigtails, a plastics tube 12 being slid over the joint and bound in position to complete the joint insulation.