Patent ID: 7178647

Claim:
A system for absorbing an impact, said system comprising: a blow molded thermoplastic energy absorbing member comprising; opposing first and second walls defining a hollow space; a plurality of fused pairs of recessed ribs, each said fused pair of recessed ribs comprising first and second recessed ribs; said first recessed rib is integrally molded from said first wall and having a first recessed rib end; said second recessed rib is integrally molded from said second wall and having a second recessed rib end; said first and second recessed ribs being integrally fused at a welded surface disposed between said first and second recessed rib ends; an average distance from said first wall to said welded surface is about approximately 15.0 to 45.0 mm; an average distance from said second wall to said welded surface is about approximately 15.0 to 45.0 mm; said hollow space having an average height between said first wall and said second wall of about approximately 30.0 to 90.0 mm; and a interlocking rib integrally coupled to at least two of said fused pairs of recessed ribs, said interlocking rib extending no further than a distance equal to the square root of twice said average height of said hollow space between said first and second walls.