Patent ID: 8303233

Claim:
A storage and retrieval system, comprising: a frame having at least two columns adjacent to one another; a track disposed within each column, each track being generally parallel to one another; a plurality of storage units that reside and move within the tracks of each column; an actuator coupled to the frame for displacing one or more storage units in one or more of the columns; a first upper conveyor comprising a vertically hanging hook selectively movable for drop-hang engagement with a catch top-mounted to each storage unit for movement of at least one storage unit between a first position in one column and a first position in another column; and a second lower conveyor comprising a skid selectively movable between the at least two columns for supporting the bottom of at least one storage unit and carrying said storage unit in non-sliding relation between a second position in one column and a second position in another column; wherein sequential activation of the actuator, the first conveyor, and the second conveyor permits sequential clockwise or counterclockwise movement of the plurality of storage units within the frame.