Automated handling system for container held material

Claim 1

In an automated material storage and retrieval system which includes a rack assembly, a frame movably mounted to said rack assembly for permitting horizontal movement thereof, a load bed vertically movable on the frame, the combined movements of the frame and load bed effecting displacement of the load bed to a preselected location on said rack assembly and load handling means mounted on the load bed for transferring loads relative to the load bed, further wherein drive means are provided to render the horizontal and vertical movements, a condition response apparatus for determining load bed location comprising: a control unit mounted on said frame; position indicator means mounted to the rack assembly for indicating horizontal and vertical position locations on the rack assembly; means mounted on said movable frame and operatively associated with said position indicator means for sensing horizontal and vertical movement of the frame and load bed relative to the rack assembly and generating a plurality of discrete signals as a result thereof to control said drive means; means connected to the sensing means for selecting and verifying preselected one of said signals generated therefrom to control said drive means to position said frame at a preselected location on said rack assembly; said control unit including means for entering a span count and for also preselecting a load transfer operation at a preselected storage location; comparison means with inputs connected to the entering means and the selecting and verifying means for energizing the drive means until the load bed arrives at the preselected location; means with an output for determining if the preselected transfer operation can be performed at the preselected locations; span means connected to the output of said determining means for actuating the drive means to effect movement of the load bed only to a predetermined number of successive immediate adjacent predetermined locations relative to said first preselected storage location in the event that the preselected transfer operation cannot be performed at the first preselected location; numerical counter means with an output connected to the span means for limiting and controlling, to the span count, the number of successive attempts made at said immediate adjacent predetermined locations by the span means in an effort to perform the first preselected load transfer operation.