STACKER CRANE POSITION CONTROL SYSTEM WITH AN AUXILLARY VERIFYING MEANS

• US 3,581,915 A
• Filed: 09/19/1968
• Issued: 06/01/1971
• Est. Priority Date: 09/19/1968
• Status: Expired due to Term

• Current Assignee: Saul Sanford
• Original Assignee: Saul Sanford
• Inventors: SAUL SANFORD
• Application Number:
  US04/760,873
• Time in Patent Office: 985 Days
• US Class Current: 414/273
• CPC Class Codes: B65G 1/0421 with control for stacker crane operations

Abstract

An automatic warehousing system comprising a storage structure defining a plurality of load-handling locations, and an automatic load carrier for delivering loads to and picking up loads from the load-handling locations, with the control system for the load carrier including command-receiving and movement-determining means for controlling the movement of the load carrier to a selected load-handling location, and with verifying means coacting with the control means for verifying the accuracy of the positioning of the load carrier at selected load-handling locations prior to final handling of loads by the load carrier at the selected storage locations.

Claims

1. In an automatic warehousing system having a storage structure and a load-handling carrier for delivering and picking up loads at a plurality of load storage locations in said storage structure, control means for said load carrier for controlling actuation of the latter to the selected load storage locations, and means coacting with said control means for verifying the position of said load carrier as indicated by said control means for the selected load storage location, said control means and said verifying means both including separate and independent signal-Producing means for respectively signalling the position of said load carrier in said storage structure, a common output means to which said signal-producing means are operatively coupled, and means responsive to said output means to prevent actuation of said load carrier to handle a load at the then confronting storage location if the load carrier position as indicated by said control means fails to match the corresponding position as indicated by said verifying means.

2. A system in accordance with claim 1 wherein said control means includes selector means and counting means comprising said signal-producing means of said control means coacting with said selector means for controlling the movement of said load carrier to the selected load storage location, and said verifying means includes duplicate counting means comprising said signal-producing means of said verifying means in circuit with the first-mentioned counting means, and control elements in circuit with said counting means and said output means for permitting actuation of said load carrier to pick up or deposit a load at a selected load storage location only when said counting means are in synchronism with one another.

3. A system in accordance with claim 1 wherein said control means includes selector means and counting means comprising said signal-producing means of said control means coacting with said selector means for controlling the movement of said load carrier to the selected load storage location, and said verifying means includes sensor means comprising said signal-producing means of said verifying means operable to sense the position of said load carrier and in conjunction with said output means and said responsive means operable to permit actuation of said load carrier to pick up or deposit a load only in the event that the position of said load carrier as indicated by said sensor means corresponds to the position of said load carrier as indicated by said selector means.

4. A system in accordance with claim 3 wherein said sensor means comprises mechanically responsive switch means actuated into conductive condition by movement of said load carrier to said selected storage location to cause checking of said load carrier position.

5. A system in accordance with claim 3 wherein said sensor means comprises light-responsive switch means actuated into conductive condition by movement of said load carrier to said selected storage location to cause checking of said load carrier position.

6. A system in accordance with claim 3 wherein said sensor means comprises magnetically responsive switch means actuated into conductive condition by movement of said load carrier to said selected storage location to cause checking of said load carrier position.

7. A system in accordance with claim 1 wherein said storage structure includes a pickup and discharge station from which said load carrier commences its movement to deposit a load into or withdraw a load from a selected load storage location, and wherein said control means includes means operable to cause said load carrier to return to said pickup and discharge station in the event that the position of the load carrier as indicated by said verifying means does not correspond to the position of the load carrier as indicated by said control means.

8. A system in accordance with claim 1 wherein said control means includes selector means comprising switch means for each of said storage locations in said storage structure, and being adapted to be selectively actuated to define one or more load-handling storage locations to which said load carrier is adapted to move during a load-handling cycle, and said signal-producing means of said verifying means including means for checking the position of said load carrier as designated by said selector means for each of said storage locations.

9. A system in accordance with claim 1 wherein said control means includes selector means comprising switch means for each of said storage locations in said storagE structure, and being adapted to be selectively actuated to define one or more load-handling storage locations to which said load carrier is adapted to move during a load-handling cycle, and said signal-producing means of said verifying means including means for checking the position of said load carrier as designated by only certain of said selector means for the storage locations, the last-mentioned checking means being responsive to movement of said load carrier to certain of said storage locations corresponding to said certain selector means for causing energization of said means preventing actuation of said load carrier to deliver a load or pick up a load from the selected storage location in the event that the position of the load carrier as indicated by said verifying means does not correspond to the position of said load carrier as indicated by said control means.

10. A system in accordance with claim 1 wherein said load carrier is movable horizontally and vertically to a selected load storage location and laterally into and out of the storage structure to deposit and to pick up loads, motor power means for actuating said load carrier, said control means being connected to said power means, said control means including selector means for selecting to which of said load storage locations said load carrier will move upon actuation thereof and said verifying means verifying the accuracy of the positioning of the load carrier at a selected load storage location as indicated by said selector means prior to said lateral movement of said load carrier to handle a load at the selected storage location.

11. A system in accordance with claim 1 wherein said load carrier comprises a generally horizontally movable conveyor portion, an elevator portion movable generally vertically on said conveyor portion, and an extractor portion mounted on said elevator portion and adapted for lateral movement with respect thereto to deposit and pickup loads at selected storage locations in said storage structure, said verifying means including means operative to verify both the horizontal and vertical positioning movements of said load carrier in said storage structure.

12. In an automatic warehousing system having a storage structure and a load-handling carrier for delivering and picking up loads at a plurality of load storage locations in said storage structure, control means for said load carrier for controlling the actuation of the latter to the selected load storage locations, and means coacting with said control means for verifying the position of said load carrier as indicated by said control means for the selected storage location, said load carrier comprising a generally horizontally movable conveyor portion, an elevator portion movable generally vertically on said conveyor portion and an extractor portion mounted on said elevator portion adapted for lateral movement with respect thereto to deposit and pick up loads at selected storage locations in said storage structure, motor power means for actuating said load carrier, said control means being operably coupled to said power means, said control means including selector means for selecting to which of said load storage locations said load carrier will move upon actuation thereof, sensor means for sensing the horizontal and vertical movements of said load carrier and means for receiving commands and determining movements of said load carrier to the selected load storage locations via actuation of said power means, said verifying means coacting with said command-receiving and movement-determining means for verifying the accuracy of the positioning of the load carrier at a selected load storage location as indicated by said selector means prior to said lateral movement of said extractor portion of said load carrier to handle a load at the selected load storage location, and wherein said command-receiving and movement-determining means includes first stepping switch means adapted to be actuated in step fashion by said sensor meanS as said load carrier moves to a selected load storage location effective to actuate said control means and deenergize said motor power means to stop movement of said load carrier at a selected load-handling storage location, and said verifying means including other sensor means and second stepping switch means, said other sensor means being adapted to sense the horizontal and vertical movements of said load carrier independently of the first-mentioned sensor means and to actuate said second stepping switch means in step fashion as said load carrier moves to the selected storage location, and a common output means in circuit with said stepping switch means and responsive to the latter, and reject means responsive to said output means to prevent actuation of said extractor portion to handle a load at the then confronting load storage location, if the load carrier position as indicated by said control means fails to match the load carrier position indicated by said verifying means.