Sealing cable sheaths

986,648. Insulating cable and wire joints and terminals. STANDARD TELEPHONES & CABLES Ltd. June 14, 1963 [June 19, 1962], No. 23509/62. Heading H2E. An insulating thermoplastic cable sheath is sealed by placing a preformed thermoplastic member 13 over an unsheathed portion of the cable 6 (which may be a joint) and heating a surface of the member and an adjacent surface of the cable sheath, or of a further thermoplastic member 7 sealed to the sheath, and pressing the two surfaces together so that they fuse and unite. The parts being sealed may be relativelyrotated to ensure thorough mixing of the melted surfaces. The disc 8 may first be fused to the end faces of the sheath 3 at 15, and the collar 11 at 16, by fitting between the disc and the said faces and around the cable core 6, a two-part heating plate, removing this plate when it has melted the faces in contact with it, and pushing these faces together. Similarly collar 11 and sleeve 13 are sealed to a ring 7, the collar 11 being supported on a wooden mandrel 14 until it is sealed in position. Similar methods are used to seal a spur joint (Fig. 2, not shown) and an end cap to a cable end (Fig. 4, not shown) while the sleeve 13 may be formed from two tubes, or from a tube having a longitudinal slit which is subsequently sealed. A joint between two circumferential faces (Fig. 5, not shown) is described in Specification 986,649. A valve coated partly with thermoplastic material may be heated and forced into a sealing fit with any of these sleeves.