US Patent 9952589 Inventory system with swiveling vertically mobile drive units

Disclosed inventory systems, methods, and devices can be used to retrieve and transport resources from one location to another. Specifically, a vertically mobile drive unit including a vertical element retention mechanism can be controlled by a management component to retrieve a resource, transport the resource from one floor to a different floor in an inventory system, and deposit the resource at a destination. The vertically mobile drive unit can transit vertically along a vertically disposed element in an inventory system, such as a structural pole or column; and can rotate around the structural pole or column in order to set down on an upper level after ascending, or to clear the upper level prior to descending.