GB512319A - Improvements in or relating to apparatus adapted to radiate energy and reflectors therefor - Google Patents

Abstract

512,319. Electric room heaters. WHITAKER, A., STEVENSON. J. B., LOCKWOOD, P. W., and BARNES, N. Jan. 25, 1938, No. 2400. [Classes 39 (iii) and 126] [Also in Group XX] The reflecting surface, 1, for an electric resistance or other room heater has a configuration such that successive sections thereof in planes normal to the line ab, which is assumed to be horizontal, appear as concave curves relative to said line. A section of the reflecting surface in the median vertical plane appears as the concave curve 6, and the section by another vertical plane coincides with the left hand side of the reflector and is indicated by the line 7, whilst an intermediate vertical section is indicated at 8. The vertices of the curves comprising the vertical sections of the surface lie on the arc 2 which is in the median horizontal plane of the reflector. The focal lengths of successive sections of the reflecting surface increase as the distance from the median vertical plane increases, and the sections are so proportioned that their focal points lie on the straight line ab, which is therefore the focal line of the reflector. The reflector is of such shape as to be of concave curvature in one dimension and of convex curvature in another, and a curved back plate is fitted to the edges of the reflecting surface so as to form, together with said surface, a hollow body. A straight bar or rod-like heating element is supported with its axis disposed along or in proximity to the focal line of the reflector, and a plurality of arms is provided for this purpose, the said arms being mounted behind the reflecting surface and projecting outwardly and around the side edges thereof, and terminating in front of the surface at points intermediate the side edges. Various forms of reflecting surfaces according to the invention include one such that successive sections of the surface by planes radial with respect to a point behind it appear as parabolic curves, or the said planes may be normal to the heating element. The reflector may be other than of parabolic form. Specification 512,412 is referred to.