Patent ID: 6964131

Claim:
A structural unit comprising a frame formed of molded synthetic polymeric/copolymeric plastic material, said frame being defined by a peripheral wall and relatively spaced inwardly projecting inner and outer walls terminating in respective terminal edges, said inner and outer wall terminal edges defining respective inner and outer openings, said inner opening being larger than said outer opening, an insert, said insert having a peripheral edge of a size to pass through said inner opening along a path substantially parallel to an axis of said inner opening but of a size too large to pass through said outer opening, said insert being located in a plane between said inner and outer walls, means for holding said insert in said frame, an access area through which said holding means is slid along a path of travel substantially normal to said inner opening axis into sandwiched relationship between said insert and said inwardly projecting inner wall, means for closing said access area, and means for pivotally mounting said frame relative to an opening of an associated structure.