Frost resistant window sash

Claim 1

A frame construction for insulating and holding double-pane glass panels used as insulation between a cold space and a warm space, said frame construction comprising b. a unitary, extruded metal frame member having a glass engaging strip portion shaped to extend against and in contact with a substantial area of the cold side of an enclosed doubleglass pane adjacent an edge thereof, and an edge-retaining frame element extending generally at right angles to said strip portion for engaging the edge of such glass pane, c. a unitary extruded rigid plastic frame member having a glassengaging strip portion for extending against the warm side of an enclosed glass pane opposite to the side engaged by said metal frame member so that a double-pane glass panel will be held between said members near the edge thereof, said plastic member having an edge portion extending at right angles to said strip portion and overlying the outermost portion of the edgeengaging metal frame member, d. means for fastening said metal frame member and said plastic frame member together comprising a bottom slot extending from the outermost side of the edge-engaging element of the metal member perpendicular to the plane of the edge of the glass pane, and a mating locking strip integral with said plastic member and engaged in said slot, said locking strip having a barb at one end thereof, and said slot having a ridged surface engagable by said barb to retain the locking strip in the slot, with a portion of the said metal frame element engaged between said locking strip and the glass-engaging strip portion of the plastic frame member to thereby hold said plastic frame member and said metal frame member together.