Patent ID: 8888434

Claim:
A buffer storage add-on for a workpiece stocker, comprising a storage chamber comprising a plurality of storage compartments for storing a plurality of containers, the storage compartments arranged in an x-y array with transport pathways between the storage compartments, wherein the storage chamber comprises a first outside side, wherein the first outside side is configured to be coupled to a second outside side of the workpiece stocker, wherein the second outside side of the workpiece stocker is different than a front side of the workpiece stocker, wherein the x-y array defines an x-y plane, wherein the storage compartments have at least one side facing a transport pathway of the transport pathways, wherein the transport pathways are sufficiently large to accommodate movements of a container of the plurality of containers, wherein the transport pathways are connected to enable the container to travel to any storage compartment of the plurality of storage compartments; an x-y mechanism coupled to the storage chamber; a robot arm comprising an end handle for supporting the container, the robot arm comprising an extension mechanism for extending the end handle in a z-direction, wherein the z-direction is a direction not in the x-y plane, wherein the end handle is configured to be extended beyond the first outside side, passing the second outside side to an inside of the workpiece stocker, wherein the robot arm is extended for picking or for placing the container at a station of the workpiece stocker, wherein the robot arm is coupled to the x-y mechanism to move the container along the transport pathways, to a storage compartment of the plurality of storage compartments.