One piece folded and glued container with tabbed columns

Abstract

A container is made in a collapsed configuration with bellows fold corners for self-erection and has spaced-panel end walls encompassing hollow columns for vertical reinforcement. An outer end wall panel is joined to the container bottom, leading to a ledge panel that is horizontal when the container is erected, and an inner end wall panel folds over and down to lock via tabs into openings in the bottom. The hollow columns reside under the ledge panel and are provided by column-forming panels folded inwardly and glued to the inner end wall panels. Score or fold lines define the corners of the hollow column and are placed to bear against inner sides of the front and back walls, which holds the hollow columns open when the container is erected. The column-forming panels have protruding tabs backed by corresponding tabs on a ledge panel between inner and outer panels of the end walls. These tabs form a two thickness registration tab that engages a corresponding opening in the container bottom for stacking. The registration tab is barb shaped, having laterally opposite stepped edges dimensioned such that edges of the top panel flaps pass and are locked down by the stepped edges when the top panel flaps are folded downwardly to engage the registration tab. The container can be made entirely automatically in a knocked-down-flat state by application of glue and folding at the appropriate lines, and is erected in a single motion.