B65D 5/3685

Rigid or semi-rigid containers of polygonal cross-section, e.g. boxes, cartons or trays, formed by folding or erecting one or more blanks made of paper specially constructed to allow collapsing and re-erecting without disengagement of side or bottom connections {formed by folding or erecting a single blank by folding the blank to U-shape to form the base and opposite sides, the remaining sides being formed by extensions of these opposite sides}