GB535736A - Improvements in or relating to devices for sealing the ends of electric cables - Google Patents

Abstract

535,736. Cables. PYROTENAX, Ltd., and CLOTHIER, G. D. Oct. 16, 1939, No. 27984. [Class 36] A sealing device for the end of a cable, particularly one having pulverulent mineral insulation, comprises a clamping member B, for example of brass, formed as a threadcutting die B which is applied to the cable-end and rotated, so cutting a thread in the metal sheath C and securing the device to the cable. The thread may be such as to fit over the cable at its outer end B<3>, the diameter thereafter decreasing progressively or in steps. The member B may be integral with an insulating body portion or may be connected to the body portion by a screw-threaded collar, but as shown, it is separate from the body portion and spun, swaged, or riveted over to form an internal flange engaging a flange A<1> on the body A which may be of steatite. Flared apertures A<3> in the body receive the cores D which are provided with flexible tubes F to prevent kinking where they emerge from the fillet A<4> and shrouding tube E. The device as a whole may be located in a gland H. The threads may be cut in the member by a taper or parallel tap, the taper being produced in the latter case by reamering the crests of the thread. Before applying the device to the cable-end, hot or cold sealing compound is moulded over the latter or into the cavity G, and the surplus extruded through aperture B<4> in the member when screwing home. Cold sealing, with plastic compound, is done immediately after stripping the cable-end. A suitable compound for hot sealing incorporates solid fibre particles, for example as described in Specification 534,692. As sealing compound for extra high temperatures, a glazing flux or mixture may be poured into the cavity G in granular or plastic state. A steatite clamping member is referred to also.