Article handling system with distributed storage

• US 5,228,820 A
• Filed: 04/03/1992
• Issued: 07/20/1993
• Est. Priority Date: 09/21/1990
• Status: Expired due to Fees

• Current Assignee: Advanced Technology and Research Corporation |
• Original Assignee: Advanced Technology and Research Corporation |
• Inventors: Koogle, Dwight R., Stansfield, Thomas J., Fitzgerald, M. L., Barbera, Anthony J.
• Primary Examiner(s): Werner, Frank E.
• Assistant Examiner(s): ELLER JR, JAMES
• Application Number:
  US07/863,459
• Time in Patent Office: 473 Days
• Field of Search: 414/266, 414/273, 414/274, 414/278, 414/285, 414/277, 414/281, 414/331, 414/286, 414/282, 414/593, 414/267, 414/279, 414/280, 414/283, 364/478
• US Class Current: 414/278
• CPC Class Codes: B65G 1/0407 using stacker cranes constructional features of stacker cranes B66F9/06

Abstract

An article handling system comprises closed loop pathways, movable carriers adapted to travel along the pathways, a plurality of article storage buffer stations located adjacent to the pathways, and a hierarchical control system for controlling the transfer of articles to or from a given one of the article storage buffer stations by a movable carrier. The buffer stations provide distributed article storage which allows the system to operate with enhanced speed and efficiency.

Claims

1. An article handling system comprising:

a closed loop pathway comprising a monorail;

a movable article carrier which travels on said monorail along said pathway, said movable article carrier comprising drive means therefor;

at least one article buffer station located adjacent to said pathway, comprising

vertically spaced shelves on which articles are stored,

a vertically movable elevator having elevator drive means for transporting at least one of said articles to and from selected ones of said shelves, and

a transfer device having transfer device drive means provided on at least one of said shelves for transferring said articles between said buffer station and said movable article carrier; and

control means for controlling said elevator, the transfer of at least one of said articles between said article storage buffer station and said movable article carrie by said transfer device, and the movement of said movable article carrier along said pathway,

whereby said article are transferrable from said movable article carrier to said one of said shelves having said transfer device, and from there transferrable to said elevator for subsequent transfer to said selected ones of said shelves.

2. An article handling system as claimed in claim 1, wherein said movable carrier is provided with a generally planar surface for accommodating at least one of said articles thereon and a pivotable retaining member coupled to said movable carrier, said pivotable retaining member being selectively configurable between an extended position for retaining said article on said surface, and a retracted position for permitting said article to be displaced to and from said movable carrier.

3. An article handling system as claimed in claim 1, wherein said elevator comprises at least one generally planar surface for accommodating at least one of said articles thereon and an elevator transfer device provided on said elevator for transferring said article between said surface and at least one of said shelves.

4. An article handling system as claimed in claim 3, wherein said elevator transfer device comprises a member which can be selectively displaced between extended and retracted positions to effect the movement of said article between said elevator and at least one of said shelves.

5. An article handling system as claimed in claim 1, wherein said transfer device comprises a member which can be selectively displaced between extended and retracted positions to effect the movement of at least one of said articles between said at least one of said shelves and said movable carrier.

6. An article handling system as claimed in claim 1, wherein said control means comprises a memory device for storing data relating to each of said articles, said movable carrier, and each of said shelves, said control means being operable to determine from said stored data the location of said articles with respect to said carrier, said buffer station and said pathway to substantially continuously monitor the location of each of said articles within said article handling system.

7. An article handling system as claimed in claim 1, wherein said control means comprises a loop controller coupled to said movable carrier for generating a carrier control signal to control the movement of said movable carrier along said pathway and a memory device, said loop controller comprising a first transceiver for transmitting said carrier control signal to said movable carrier.

8. An article handling system as claimed in claim 7, wherein said movable carrier comprises a second transceiver for receiving said carrier control signal, and a carrier controller for controlling the operation of said movable carrier in accordance with said carrier control signal, generating a carrier status signal, and transmitting said carrier status signal to said loop controller using said second transceiver.

9. An article handling system as claimed in claim 8, wherein said first transceiver and said second transceiver are operable to substantially continuously transmit and receive said carrier control signal and said carrier status signal, said loop controller being operable to determine the position of said movable carrier along said pathway using said carrier status signal and to store said position data in said memory device.

10. An article handling system as claimed in claim 1, further comprising:

a second closed loop pathway comprising a second monorail;

a second movable article carrier which travels on said second monorail along said second pathway, said second movable article carrier comprising drive means therefor;

a second article storage buffer station located adjacent to said second pathway, comprising

vertically spaced shelves on which articles are stored,

a vertically movable elevator having elevator drive means for transporting at least one of said articles to and from selected ones of said shelves, and

a transfer device having transfer device drive means provided on at least one of said shelves for transferring said articles between said second buffer station and said second movable article carrier; and

an interloop transfer device having interloop transfer device drive means located between said first and said second pathways for transferring said articles between said movable article carrier and said second movable article carrier.

11. An article handling system as claimed in claim 10, further comprising first and second buffer station controllers for controlling said elevators and said transfer devices corresponding to said buffer station and said second buffer station, respectively.

12. An article handling system as claimed in claim 10, wherein said buffer station and said second buffer station comprise an article receiving device for receiving articles originating from an article source that is external to said article handling system, said articles having corresponding identification codes and said articles receiving device comprising a sensor for sensing said identification codes.

13. An article handling system as claimed in claim 12, wherein said control means comprises a memory device for storing said identification codes, and first and second buffer station controllers for controlling corresponding said article receiving devices, said elevators and said transfer devices.

14. An article handling system as claimed in claim 10, wherein said control means comprises:

first and second loop controllers for controlling the movement of said movable carrier and said second movable carrier along said pathway and said second pathway, respectively;

first and second buffer station controllers coupled to said buffer station and said second buffer station, respectively, for controlling corresponding said elevators and said transfer devices;

a first system controller for controlling said first loop controller and said first buffer station controller;

a second system controller for controlling said second loop controller and said second buffer station controller;

an interloop transfer controller for controlling said interloop transfer device; and

a memory device coupled to said first and second system controllers and said interloop transfer device for storing data generated by said first and second loop controllers which relates to the positions of said movable carrier and said second movable carrier along said pathway and said second pathway, respectively, and for storing data generated by said first and second buffer station controllers and said interloop transfer controller which relates to the location of said articles therein.

15. An article handling system as claimed in claim 14, wherein said control means further comprises a supervisory processor coupled to said memory device and said first and second system controllers to control said first and second system controllers in accordance with said carrier position data and said article location data stored in said memory device.

16. An article handling system as claimed in claim 15, further comprising an operator interface device coupled to said supervisory processor for providing said supervisory processor with operator command signals for selectively controlling the operation of said first and second system controllers, said operator command signals being operable to specify at least one of a plurality of destination locations along said pathway and said second pathway and in said buffer station, said second buffer station and said interloop transfer device.