GB312945A - Improvements in electric heating more particularly intended for use with mercury vapour lamps - Google Patents

Abstract

312,945. Reynolds, F., and Sample, L. Dec. 2, 1927. Electric stoves.-An apparatus for use in electrically heating tubes, rods, &c., particularly the preliminary heating of mercury vapour lamps, consists of a series of parallel steatite &c. insulating-tubes 1 through which a resistance wire or ribbon 2 is threaded, the tubes, when bound together, forming a self-contained flexible mat which will wrap round the object to be heated. The binding material may take the form of a thin metal strip 3 to which the tubes are secured by a thin wire or thread 4, the thread being burnt on the first passage of the current. When m position round the tube 5, the ends of the strip are secured by a clip 3a and bent outwards. Alternatively, the thread may be looped round the curved portions of the wire 2. In other modifications, the tubes are secured together by a strip of adhesive paper over which a clip is placed when the device is in position, or a fine metal wire may be interlaced between the tubes; or twin holes may be formed in the tubes, one set carrying the heating wire and the other the binding wire. When the tubes are even in number, one of the end tubes may be made longer or shorter than the remainder to avoid the risk of a short circuit when the device is wrapped round the object to be heated. Specification 9375/04 is referred to.