Abstract: An octagonal container closure in which the bottom closure flaps are held in place while the structural integrity of the flaps is maintained. Locking apertures are placed in opposed side closure flaps. The apertures remove as little material as possible from the side closure flaps and maintain the rectangular shape of the flaps. The apertures are shaped and located to allow the corners of the opposed end closure flaps to protrude through the apertures and to lock behind the side closure flaps. The shape of the apertures provides a two-way lock on each corner of an end closure flap, holding it both in the length and width direction. This provides a firmer closure than has been previously achieved.

Abstract: An octagonal container closure in which the bottom closure flaps are held in place by slots formed in opposed side closure flaps. The slots are located and of a length to allow the corner and end closure flaps to extend through the slots and lock behind the side closure flaps.