US Patent 7516587 Interlocking floor system

Multiple polymeric panels molded as a rigid integral body having a planar top surface and a bottom grid structure are interlocked together mechanically along side edges. Each side edge has alternating upwardly and downwardly facing steps with concave dimples on one and mating convex projections on the other for securely interlocking adjacent panels to each other. The steps of adjacent panels interlock with each other to form a complete floor system. The multiple polymeric panels can be molded to simulate flooring materials such as brick or overlaid with sections of linoleum, carpet, synthetic grass, tile or wood flooring. Alternately, the assembled panels can be covered with a sheet of decorative material.