Variable pitch storage shelves

Abstract

The present invention generally comprises a container storage system for efficiently storing large capacity and small capacity containers or FOUPs. In one embodiment, each storage location within the stocker comprises a pair of spaced apart supports. A large capacity container or a small capacity container may be seated in any storage location. The storage locations are arranged within the stocker to minimize the amount of empty space between the supports of a storage location and a container seated in an adjacent storage location. In one embodiment, the vertical pitch between supports of adjacent storage locations is less than the height of a large capacity FOUP container shell. Thus, when a FOUP is seated in a storage location, its container shell extends between the supports of the storage location located directly above.

1 . A container storage device for storing large capacity workpiece containers and small capacity workpiece containers, each small capacity workpiece container and large capacity workpiece container includes a container shell and a flange, the container storage device comprising:
 a first storage location for supporting a workpiece container by its flange, said first storage location having a first support spaced apart from a second support by a predetermined distance that is greater than the width of a container shell of a large capacity workpiece container; and   a second storage location for supporting the flange of a workpiece container, located above said first storage location, including a first support spaced apart from a second support by a predetermined distance that is greater than the width of a container shell of a large capacity workpiece container;   wherein the vertical pitch between said first and second supports of said first storage location and said first and second supports of said second storage location is less than the height of the container shell of a large capacity workpiece container.   
     
     
         2 . The container storage device as recited in  claim 1 , wherein said first support and said second support of said first storage location each include a registration feature for engaging the flange of either a large capacity workpiece container or the flange of a small capacity workpiece container. 
     
     
         3 . The container storage device as recited in  claim 1 , wherein said first support and said second support of said second storage location each include a registration feature for engaging the flange of either a large capacity workpiece container or the flange of a small capacity workpiece container. 
     
     
         4 . The container storage device as recited in  claim 1 , wherein said first support and said second support of said first storage location restrict the lateral movement of a workpiece container seated on said first and second supports of said first storage location. 
     
     
         5 . The container storage device as recited in  claim 1 , wherein said first support and said second support of said second storage location restrict the lateral movement of a workpiece container seated on said first and second supports of said second storage location. 
     
     
         6 . The container storage device as recited in  claim 1 , wherein said first storage location includes a sensor to determine whether a workpiece container is located in said first storage location. 
     
     
         7 . The container storage device as recited in  claim 1 , wherein said second storage location includes a sensor to determine whether a workpiece container is located in said second storage location. 
     
     
         8 . A container storage device for storing large capacity workpiece containers and small capacity workpiece containers, each small capacity and large capacity workpiece container including a container shell and a flange, the container storage device comprising:
 a first storage location including a first support and a second support horizontally spaced apart from each other by a predetermined distance, said predetermined distance being greater than the width of a container shell of a large capacity workpiece container yet able to support a workpiece container by its flange;   a second storage location, located above said first storage location, including a first support and a second support horizontally spaced apart from each other by a predetermined distance, said predetermined distance being greater than the width of a container shell of a large capacity workpiece container yet able to support a workpiece container by its flange;   wherein when a large capacity workpiece container is located in said first storage location, the container shell of the large capacity workpiece container extends between said first support and said second support of said second storage location.   
     
     
         9 . The container storage device as recited in  claim 8 , wherein said first support and said second support of said first storage location each include a registration feature for engaging the flange of either the large capacity workpiece container or the flange of the small capacity workpiece container. 
     
     
         10 . The container storage device as recited in  claim 8 , wherein said first support and said second support of said second storage shelf each include a registration feature for engaging the flange of either the large capacity workpiece container or the flange of the small capacity workpiece container. 
     
     
         11 . The container storage device as recited in  claim 8 , wherein said first support and said second support of said first storage location restrict the lateral movement of a workpiece container seated in said first storage location. 
     
     
         12 . The container storage device as recited in  claim 8 , wherein said first support and said second support of said second storage location restrict the lateral movement of a workpiece container seated in said second storage location. 
     
     
         13 . The container storage device as recited in  claim 8 , wherein said first storage location includes a sensor to determine whether a workpiece container is seated in said first storage location. 
     
     
         14 . The container storage device as recited in  claim 8 , wherein said second storage location includes a sensor to determine whether a workpiece container is seated in said second storage location.