Closure for refrigerated housing

Claim 1

A planar door for a refrigerated housing and the like comprising, a lower member having a bottom wall and vertical walls extending upwardly therefrom, a planar upper member extending over and spanning said lower member, insulation carried in said lower member below said planar upper member, outwardly extending flanges integral with the top of said vertical walls, said planar upper member having downwardly and inwardly turned edges which extend around said outwardly extending flanges in a loosely fitting relation so as to permit expansion between said upper member and said lower member, said inwardly turned edges being guiding surfaces upon which said door is supported when used in a refrigerated housing, fastening means attaching said planar upper member to said lower member adjacent a central portion thereof so as to allow said upper member and said lower member to expand freely from said fastening means with a minimum of buckling in said planar door, and a smooth surface member interposed between said insulation and said planar upper membeR so as to permit said planar upper member to expand relative to said lower member without engaging said insulation.