GB363017A - Improvement in resistance device - Google Patents

Abstract

363,017. Wire resistances ; insulating conductors. VEGA LABORATORIES CORPORATION, 52, Vanderbilt Avenue, New York, U.S.A. Sept. 24, 1930, No. 28555. Convention date, April 4. [Classes 36 and 37.] An electric resistance conductor is insulated by a coating of refractory oxide formed by heating a mixture of a refractory oxide with a solution of a halogen compound coated on said wire, until the halogen compound is converted into a refractory oxide. The coating mixture is formed by adding finely-ground crystallized aluminium oxide to a 25 per cent solution of aluminium chloride and is contained in a cup through which the resistance wire is passed over a pulley after being cleaned. Current is passed through the wire which is heated, first at a low temperature and then at a high temperature, until the aluminium chloride is decomposed. The wire 4 is given about five such coatings and is then wound on porcelain base 2, the whole being finally heated in hydrogen at 1000‹ C. Aluminium fluoride or bromide can be used and oxides such as beryl, beryllium oxide and magnesium oxide &c. can be used with aluminium chloride as the halogen compound, and the metal of the halide may be the same as that of the refractory oxide. After winding the wire 4 on a former it may be dipped in, or sprayed with, an insulating material to form an integral cylindrical unit without the former.