US Patent 7819269 Bulk container

A stackable collapsible container for flowable materials. The container has a flexible outer skin and rigid support, having a top frame and bottom frame connected by poles. The top frame and bottom frame are designed for mating engagement when the containers are stacked, as well as for mating engagement when the containers are broken down for transport. The top frame and bottom frame are provided with similar perimeters to prevent undesired movement and contact between adjacent top frame when the containers are filled and transported.