Abstract: A floor grating assembly is disclosed, which comprises tread rails arranged in closely spaced parallel relation and held by spacer bars. The spacer bars, which are notched, are inserted in alignment openings of preferably triangular shape in the tread rails. After insertion, the spacer bars are rotationally reoriented to a position securing the tread rails in spaced apart relation. Flange means extending along the lower edges of the spacer bars are locally deformable into locking notches formed in the alignment openings. The spacer bars are thus locked against rotation out of their operative positions. Manufacturing economies and structural improvements are realized.

Abstract: A connecting structure for sections of floor coverings such as of floor covering use in public walking areas, the connecting structure having longitudinal transversely spaced upstanding T members adapted to be retained in accomodating side vertical openings of the adjacent edge portions of floor covering sections for connection of the sections and being sufficiently flexible to bend along a longitudinal axis for a roll up of adjacent sections.

Abstract: A door bottom weather sealing structure carried as a surface mounting at the inside bottom portion of a door comprising a channel member extending the width of a door having disposed therein an extensible and retractable sealing member, the sealing member having an outward projection thereof engaging the door jamb upon the closing of the door for an automatic extension of the sealing member into floor engagement and an automatic retraction of the sealing member upon the opening of the door, the structure providing a precise adjustment of the extension of the sealing member.