US Patent 7850413 System and method for transporting inventory items

An apparatus for transporting inventory items includes a housing, a drive module, a docking module, an elevating shaft, and a rotation module. The drive module is capable of propelling the apparatus in at least a first direction. The docking head is capable of coupling to or supporting an inventory holder. The rotation module is capable of inducing rotation in the housing relative to the elevating shaft. The elevating shaft connects to the docking head and is capable of raising the docking head when the housing is rotated relative to the elevating shaft.