Container having improved bellows closure and blank for making same

Claim 1

A container made of corrugated fiberboard comprising four interconnected side panels defined by parallel fold lines and arranged to define a tubular enclosure of rectangular cross section and four interconnected closure panels hinged along a line to aligned edges of said side panels, a first pair of said closure panels being hinged to opposed side panels and a second opposed pair of said closure panels being each divided only by a pair of converging diagonal score lines into a trapezoidal flap and a pair of flanking triangular fold-back flaps, said first closure panels serving as first closure flaps which are hinged to said fold-back triangular flaps, one of said first closure panels containing a pair of first score lines oriented at an angle between about 82* and 89* to said hinge line, said first score lines defining said first closure flap, and the angle between said first score lines and the adjacent diagonal score line being less than the angle between said diagonal score line and said hinge line, the width of said first pair of closure panels being greater than the width of said second pair of closure panels and said length of said closure panels being such that said first pair of closure flaps overlap each other in closed position, said first closure flaps being folded inward of said trapezoidal flaps and said first closure flap which contains said first score lines being folded inward after said other first closure flap whereby said closure becomes biased into its inward closed position upon folding of said closure flaps.