Abstract: A storage and retrieval crane system that includes a tower having a pair of spaced columns and a tower drive mechanism for moving the tower horizontally along a floor between storage racks. A carriage is coupled to a carriage drive mechanism for vertical movement between the columns, and a shuttle is coupled to a shuttle drive mechanism on the carriage for moving the shuttle horizontally from the carriage in directions lateral to direction of movement of the tower along the floor. At least one of the drive mechanisms, and preferably all of the drive mechanisms, include primary and secondary drive arrangements, and facility for selectively alternately connecting one or the other of the primary and secondary drive arrangements to drive the tower, carriage or shuttle.

Abstract: In a storage installation, a load carrier drive for propelling a load carrier longitudinally in the aisles between storage frames includes a rotating coupling member driven by the drive for contacting and driving the drive of a transfer car when the load carrier is positioned for transfer by the transfer car, whereby the transfer car is propelled by the load carrier drive.