Interlocking wooden mat

Claim 1

A laminated wooden mat section of at least three ply construction adapted to be secured in interlocking relation to other like mat sections for supporting heavy equipment and vehicles around or leading to oil field drilling sites or the like, said mat section comprising; a lower layer of substantially parallel and closely spaced longitudinally extending wooden planks of substantially equal length with the ends thereof aligned to define a square or rectangular configuration, an intermediate layer of substantially parallel and closely spaced planks overlying said lower layer and extending transversely thereto, said intermediate layer planks being of substantially equal length and extending transversely from one edge to the other of said lower layer with substantially all of the ends aligned in said square or rectangular configuration, an upper layer of substantially parallel and closely spaced longitudinally extending wooden planks overlying said intermediate layer in parallel relation to said lower layer, said upper layer planks being of substantially equal length with substantially all of the ends aligned with the ends of said lower layer in said square or rectangular configuration, at least one plank of said upper layer being longitudinally offset to provide a male extension at only one end and a female recess only at the other end of said upper layer, at least one plank of said intermediate layer being laterally offset to provide a male extension at only one edge and a female recess only at the other edge of said intermediate layer, said upper layer having one less plank than said lower layer at one edge of thereof to expose the ends of said transversely extending planks of said intermediate layer and to expose said female recesses along one edge of said mat section to permit an adjacent mat male extension to be lowered thereinto during assembly, said layers being securely attached together at common overlapping intersections, and said upper layer male extensions being adapted to fit and be removably secured in said upper layer female recesses on an adjacent mat and said intermediate layer male extensions being adapted to fit and be removably secured in said intermediate layer female recesses on an adjacent may by being lowered into position for assembly in an edge to edge, and end to end configuration with the edges and ends, respectively, of adjacent mats being in a straight line.