Patent ID: 6668512
Filing Date: 2003-12-30
Classification: E04B,E04C

Abstract:
Tubular lightweight and extruded plastic structural members for use in constructing ribbed concrete roof and mid-level floor/ceiling slabs comprising,An elongate tubular member, the member being generally rectilinear in cross-section, having four longitudinal walls, comprising a pair of side walls, a floor, and a top, there being substantially centrally located a horizontal wall substantially parallel to the top and the floor, and extending between the side walls to form upper and lower hollow conduit sections of the interior of the member, there being a vertical wall substantially parallel to the side walls, and extending from the horizontal wall at a central intersection to the floor substantially centrally thereof, there also being a first and a second sloped wall each extending downwardly and outwardly at approximately the same angle from the central intersection with opposite ends thereof joined to a bottom right and left intersection of a side wall and the floor, the bottom surface of the floor extending beyond the side walls on each side of the member, but lying in substantially the same plane, and serving as the flat bottom or wing-like longitudinal projections on each side of the member, the outer longitudinal edge of each wing including cooperating alignment means arranged to align each member with a next adjacent wing edge in a moisture resistant relationship when a plurality of the members are interconnected to form a concrete form, wherein said sidewalls, bottom wall and wings are gradually tapered from a thickest portion at the bottom left and right intersections to a thinnest portion to increase the stiffness of said wings.