GB752890A - Process for the production of electrically heated articles - Google Patents

Abstract

752,890. Embedded electric heating resistors. ERNST, W. G. Jan. 14, 1954 [Jan. 15, 1953], No. 1140/54. Class 39(3). [Also in Group V] A heating resistance wire 2 is embedded in a mouldable synthetic material, especially polythene, polyvinyl chloride, polyamide or " Terylene " (Registered Trade Mark), by producing a base body 1 of the material by injection in a mould, winding a resistance wire 2 on the body and temporarily securing it thereto, and then applying a second layer 7 of the synthetic material over the wire by injection in a finishing mould. A handle or steering wheel covering or a rigid or flexible pipe for a gas or liquid e.g. a fuel pipe or a wall or part of a wall of a holder may be thus formed. The wire is secured to the base body 1 by fusion, e.g. by passage of current, or is secured at spaced points 3 by local overheating or by a molten adhesive mass of the plastic or by a solvent, so that the wire is embedded at these points. The wire is thus secured on the outer surface of an injection-moulded plastic tube 1, and an outer plastic layer 7 is moulded by injection on the tube. One end of the wire may pass through the inner tube and be attached to a leaf spring 5 forming an earth terminal, or the leaf spring may be placed over the end of the tube, and another terminal 6 may be embedded at the opposite end in the outer covering 7. The tube 1 may be placed over a metal handle of a machine, or may form a covering for a steering wheel, in which the current leads pass along the spokes to a switch. Alternatively, the inner core may be solid and may be pressed on to a metal handle.