Method and apparatus for palletizing and depalletizing layers of

Abstract

A palletizer/depalletizer system includes a palletizer assembly and depalletizer assembly stacked one beneath the other on a common frame assembly. Both assemblies are adapted to handle layers of articles and stacks of pallets. The palletizer loads articles on stacks of empty pallets by transferring layers of articles one at a time onto the uppermost pallet until the pallet is fully loaded, conveying the loaded pallet away from the system using a conventional automated storage and retrieval (ASR) machine, and then loading the next pallet on the stack. The depalletizer creates stacks of empty pallets by repeatedly unloading layers of articles from a pallet to empty the pallet and then accepting a loaded pallet on top of the recently-emptied pallet. The palletizer and the depalletizer each include a separate article transfer assembly preferably taking the form of a pair of independently-operated sweep arms which act in conjunction with one another to transfer articles horizontally in a staging plane between 1) a hoisting zone in which is vertically movable a hoist supporting the pallets and 2) a staging area in which is disposed a staging conveyor which conveys articles to or from the system. A stackable pallet suitable for use in a palletizer/depalletizer system of this type and for handling by a conventional SRM without shifting either laterally or longitudinally also is provided.