STRUCTURAL ELEMENT WITH INTERLOCKING RIBBING

摘要

A structural element comprising opposed first and second, laterally and longitudinally extended, generally planar surface structures each having a closed figure pattern of ribbing projecting therefrom toward the opposite surface structure, a third structure disposed between the first and second surface structures in ribbing-engaging relation therewith, the opposed ribbing being interlocked across the third structure in registered, mating relation.