Patent attributes
A blow-molded unitary structure includes a panel having first and second panel walls and a generally hollow interior between the first and second panel walls. The structure also includes a plurality of depressions, or at least one ridge, or both the depressions and ridge to enhance the strength of the structure. The plurality of depressions is monolithically formed with the panel, recessing from the second panel wall toward the first panel wall. A depression has a side wall composed of first and second segments. Cross-sectional-wise, the first and second segments have different widths and thus collectively forms a step between the first and second segments. A ridge is also monolithically formed with the panel and includes a section, at which the width of the ridge varies along the height direction of the ridge.
