Patent ID: 7922417

Claim:
An elongated structural element for an enclosure comprising: a first flange, a second flange attached to said first flange at a substantially right angle, a first interlocking protrusion located on the outer surface of said first flange, said first interlocking protrusion comprising a neck portion and a head portion, the width of said head portion being approximately twice the width of said neck portion, said head portion being offset from said neck portion such that one side of said first interlocking protrusion is essentially flat, the direction of said offset of said head portion being toward said second flange, the height of said first interlocking protrusion being approximately equal to the width of said head portion of said first interlocking protrusion, a second interlocking protrusion, said second protrusion being substantially identical in size, shape, and orientation to said first interlocking protrusion, said second interlocking protrusion being located on the outer surface of said first flange, the distance between said first interlocking protrusion and said second interlocking protrusion being approximately equal to the width of the neck portion of said first interlocking protrusion, a third interlocking protrusion comprising a neck portion and a head portion, said third protrusion being substantially identical in size and shape to said first interlocking protrusion, said third interlocking protrusion being located on the outer surface of said second flange, the direction of the offset of the head of said third interlocking protrusion being away from said first flange, a fourth interlocking protrusion comprising a neck portion and a head portion, said fourth protrusion being substantially identical in size, shape and orientation to said third interlocking protrusion, said fourth interlocking protrusion being located on the outer surface of said second flange, the distance between said fourth interlocking protrusion and said third interlocking protrusion being approximately equal to the width of the neck portion of said first interlocking protrusion, wherein said first and second interlocking protrusions can interlock to said third and fourth interlocking protrusions without intermediary components.