Radiant heater

Claim 1

In a radiant heater, a trough-shaped outer shell having inwardly directed flanges along the lateral edges thereof, said outer shell also having a plurality of vent openings therethrough, a trough-shaped reflector having outwardly directed flanges along the lateral edges thereof, said reflector including said flanges being within the trough formed by said shell and the flanges on said reflector being overlapped by the flanges on said shell, the surfaces of said reflector being spaced from the surfaces of the outer shell to form an air space therebetween, said reflector being positioned in said outer shell so as to reflect radiation through the open face of the trough-shaped outer shell, means securing each reflector flange to its adjacent overlapping flange on the shell, said last means comprising fasteners spaced at intervals along the length of said flanges, each fastener including a spacer positioned between the confronting faces of said flanges to maintain same in spaced relation to form lateral air inlet passageways between the spacers whereby air may flow into the space between the outer shell and reflector and thence out through the vent openings in the outer shell, the innermost edges of the flanges on said shell being spaced laterally outward from the innermost edges of the flanges on said trough-shaped reflector, said reflector comprising a unitary metal sheet bent along laterally spaced parallel lines to form elongated planar reflecting surfaces joined edge to edge in such angular relation that said reflector is approximately parabolic in transverse cross section, and the planar reflecting surfaces immediately adjacent to the longitudinal center line of said sheet comprise a V-shaped rib projecting into said parabola in an approximate inversion of a vertex portion of said parabola, and an elongate heating element in said reflector located substantially at the focus of said parabolic section, said rib being arranged to reflect heat rays away from said heating element.