US Patent 10131111 Structural weld pattern

A blow molded structure and having ribs formed therein, the ribs defined by a recess in one wall of the blow molded structure that defines two sidewalls on either side of a joint, the joint being a weld between the two opposing walls of the blow molded structure. The ribs are arranged in intersecting paths and a passage is defined in the interior cavity of the blow molded structure at the intersection of two ribs such that fluid flows through the passage during molding.