GB1018707A - Flexible electric heating device - Google Patents

Abstract

1,018,707. Electric heating cables. SINGER CO. Nov. 20, 1963 [Nov. 30, 1962], No. 45836/63. Heading H5H. [Also in Division H1] A flexible electric heating cable comprises a core 20 of fibreglass or asbestos fibre material in which is embedded a low resistance wire 26 and on which is helically wound a high resistance heating wire 22, the wires being joined at 28 and the whole assembly being coated by a layer 24 of thermoplastic insulating material. The wire 22 is wound with Variably-spaced convolutions to produce relatively cold, hot or warm sections 40, 42, 44, a completely cold section or sections being produced if desired by the insertion of one or more wire shunts 50 of appropriate length. Terminal connections 30, 32 are made to wires 26, 22, the connection to the latter wire being through a shunt 34. The cable may be wound or otherwise secured in its heating position, Figs. 1 and 2 (not shown), and its heating effect may be increased by making the wire 26 of a high resistance type. If the wire 26 is of low resistance, the cable is manufactured by forming the core 20 in long lengths with the wire 26 position therein and then winding on the heating wire 22 with shunts 34 positioned at spaced intervals along its length. The coating 24 is next applied and the cable cut into sections of desired length at a shunt 34, wires 22, 26 being joined at 28 and the cable ends being sealed with insulating material. Alternatively the cable may be manufactured in sections of the desired length in which case wires 22, 26 may comprise one continuous element.