GB925083A - Improvements in the formation of an elastically extensible electric current conducting cable - Google Patents

Abstract

925,083. Extensible cables. T. G. GARCIA, J. A. M. GUNDIN, and J. L. ALVAREZ. July 17, 1959 [July 19, 1958], No. 24701/59. Class 36. An extensible cable comprises a core a of elastically extensible filaments 1 covered by a tubular sheath b of lesser extensibility and having a conductor c helically wound thereon, this conductor comprising at least one conducting filament 2 helically wound around a flexible dielectric core 3 and with an insulating cover 4. The assembly is provided with an overall sheath d which is also elastically extensible. The inner sheath b is preferably produced with helical corrugations 5 and the conductor c is provided with an additional braided covering e which fits loosely so that some of the loose material will fit into the helical corrugations to lessen any tendency of the conductor to slip upon the core when the cable is extended. The conductor core 3 may be of cotton or nylon thread, the sheath 4 of plastic and the braided coverings b, d and e of "stretch" " nylon thread. An alternative form of conductor (Fig. 6, not shown) comprises a plurality of nylon filaments each having a helical winding of tinsel thereon and laid up together with a binding of nylon thread around them. They are sheathed and covered as before. A method of making the cable consists (Fig. 7-9, not shown) in passing the core a in stretched condition through a braiding head; passing the stretched and braided core through a winding apparatus, which helically winds on the made-up conductor, whilst maintaining tension in the core by pulleys and, as the resultant cable emerges from the pulleys, releasing the tension and winding it on to a drum whilst twisting it about its axis to remove twists imparted to the core by the winding process. It is then passed under tension through a second braiding head where the outer sheath d is braided on under tension and the finished cable is allowed to relax as it emerges through the tensioning pulleys to be wound on to a storage drum.