Coordination of robot and conveyor

• US 3,958,682 A
• Filed: 06/09/1975
• Issued: 05/25/1976
• Est. Priority Date: 11/05/1973
• Status: Expired due to Term

• Current Assignee: Paul S. Martin
• Original Assignee: Paul S. Martin
• Inventors: Martin, Paul S.
• Primary Examiner(s): Blunk, Evon C.
• Assistant Examiner(s): Valenza, Joseph E.
• Application Number:
  US05/585,107
• Time in Patent Office: 351 Days
• Field of Search: 198/19, 198/40, 83/295, 72/31, 72/184, 214/1 PE, 214/1 CM, 214/1 BB, 214/1 BT, 408/32, 318/39, 219/79, 219/80, 219/124, 219/125 R
• US Class Current: 198/341.05
• CPC Class Codes: B25J 9/0093 co-operating with conveyor means
• CPC Class Codes: G05B 19/4182 manipulators and conveyor only
• CPC Class Codes: G05B 2219/45213 Integrated manufacturing system ims, transfer line, machining center
• CPC Class Codes: Y02P 90/02 Total factory control, e.g. smart factories, flexible manufacturing systems [FMS] or integrated manufacturing systems [IMS]
• CPC Class Codes: Y10T 408/365 Axes of tools moving with work during operation
• CPC Class Codes: Y10T 83/4682 With means controlling flying speed dependent on work speed

Abstract

An endless chain is caused to become locked to and driven by a work-carrier forming part of a conveyor. The chain drives a signal generator whose output represents the advance of the work-carrier past a robot and the generated signal is combined with program control signals of the robot to modify the operation of the robot so that the robot can operate on a moving work-piece whereas the robot'"'"'s program alone would cause robot operations on a work-piece that remains at-rest.

Claims

1. In combination, an industrial robot having a work head operable through a range of positions and having control means programmed for causing the work head to perform an automatic program of operations and three-dimensional motions relative to a work-piece at rest, a conveyor including a work carrier for transporting the work-piece along a path in the operative range of the work head, the work-piece and its work carrier forming a work unit, and means for modifying the control of the work head by the programmed control means in accordance with the travel of the work unit, said modifying means including means for providing corrective output having a starting condition, and means for operating said corrective output means out of said starting condition in synchronism with the travel of the work unit, said operating means including an endless chain, means for supporting said chain and for disposing a length thereof for movement along a chain-advance path adjacent and parallel to said path of the work carrier, said chain-supporting means including at least one sprocket and said chain being operable endlessly in one direction about said sprocket, transmission means for providing drive of said corrective output means by said sprocket, locking means for coupling said chain to said work unit to be driven thereby and for operating said corrective output means throughout the automatic program of the work head and for thereafter releasing the chain from the work unit, and means for restoring said corrective output means to its starting condition after completion of said automatic program while said chain is operated at any rate including zero in said one direction.

2. The combination in accordance with claim 1, wherein said coupling means includes a latch carried by said work carrier along said chain-advance path, the latch being complementary to and operable into locked engagement with any of numerous discrete portions of the chain, and means biasing said latch toward said engagement.

3. The combination in accordance with claim 1, wherein said transmission means includes means for decoupling said corrective output means from said sprocket during operation of said restoring means.

4. The combination in accordance with claim 1, wherein said chain supporting means includes an additional sprocket, said sprockets including first and second sprockets arranged to support said length of chain at the start and at the end of the chain-advance path, respectively, the sprockets having teeth that enter spaces in the chain, and wherein said releasable means comprises a latch carried by a work carrier along said chain-advance path and biased toward the chain and complementary to and operable into locked engagement with numerous discrete portions of said chain, said latch being adapted to enter the sprocket-tooth spaces of the chain, the teeth of said second sprocket being effective to push the latch out of locked engagement with said chain as said work carrier carries said latch past said second sprocket.

5. The combination in accordance with claim 4, wherein said corrective output means comprises encoding means, wherein said transmission between said sprocket and said corrective output means includes a clutch, and wherein said apparatus further includes a start control responsive to the work unit reaching a prescribed position for causing the clutch to couple said sprocket to said corrective output means.

6. The combination in accordance with claim 1, wherein said corrective output means is of a type wherein continued operation in one direction causes restoration thereof to said starting condition, and including means operable after release of said chain from the work unit for advancing said chain in said one direction until said corrective output means is restored.

7. The combination in accordance with claim 1, wherein said transmission provides continued coupling of said sprocket and said corrective output means during operation of said control modifying means and during operation of said restoring means.

8. The combination in accordance with claim 1, wherein said corrective output means includes an impulse counter and impulse means operable by said transmission means for supplying impulses to the counter, and wherein said restoring means is arranged to restore said counter to its starting condition, whereby restoration of the corrective output means to its starting condition is independent of the chain.

9. The combination in accordance with claim 1, wherein said corrective output means includes a digital encoder operable by said transmission means, a storage register, and means for deriving the difference between the output of the encoder and that of the storage register for thereby providing the desired corrective output, said restoring means including means responsive to arrival of the work unit at a prescribed position for entering the output of the encoder into the storage register for thereby establishing said starting condition, whereby restoration of the corrective output means to its starting condition is independent of the chain.

10. The combination in accordance with claim 1, wherein said coupling means includes discrete devices on said work carrier and on said chain cooperable to form a drive coupling, and wherein said corrective output means comprises an encoder operated by said transmission means, and wherein said control modifying means further includes drive means for resetting the encoder to zero following completion of the automatic program of the robot and for concurrently advancing a said discrete device on the chain into starting position.

11. The combination in accordance with claim 1, wherein said corrective output means comprises an electromechanical digital encoder, and wherein said transmission means includes a clutch between said sprocket and said encoder, and wherein said restoring means includes drive means for resetting the encoder to zero, further including control means for activating said encoder-resetting drive means following completion of the program-controlled operation of the robot on the work carried by the work carrier, said control means causing disengagement of the clutch during resetting of the encoder.

12. The combination in accordance with claim 1, wherein said coupling means includes driving and driven devices of the article carrier and the endless chain, respectively, the devices of said coupling means being cooperable in interlocked relationship and the device carried by the chain being disposed in the path of advance of the driving device of the work carrier for establishing said interlocked relationship and for thereby operating said corrective output means.

13. The combination in accordance with claim 1, wherein said coupling means comprises latching means carried by a work carrier and operable to engage and become locked to any of numerous portions of the chain distributed along the length thereof, and wherein said corrective output means comprises a digital encoder, said apparatus further including a start control responsive to the arrival of the work unit at a position along said path following establishment of locking engagement of said latch to said chain for concurrently initiating operation of the programmed control means of the robot and for initiating the advance of said encoder.

14. The combination in accordance with claim 1, wherein part of the coupling means is carried by the work carrier and includes a pivoted latch biased toward the chain for cooperation with any of numerous portions thereof distributed along the length thereof and effective, when in coupled relationship to the chain, to enforce fore-and-aft motion of the chain in the event of fore-and-aft jerking of the article carrier.

15. In combination, an industrial robot having a work head operable through a range of positions and having control means programmed for causing the work head to perform an automatic program of operations and three-dimensional motions relative to a work-piece at rest, a conveyor including a work carrier for transporting the work-piece along a path in the operative range of the work head, the work-piece and its work carrier forming a work unit, and means for modifying the control of the work head by the programmed control means in accordance with the travel of the work unit, said modifying means including means for providing corrective output having a starting condition, and means for operating said corrective output means out of said starting condition in synchronism with the travel of the work unit, drive means for said corrective output means, locking drive coupling means for initiating, maintaining and terminating coupling of said drive means to said work unit for operation in synchronism therewith during travel of the work unit along said path, and means operative after coupling of said drive means to said work carrier has been established for initiating the automatic program of the robot and for rendering said control modifying means effective to modify the automatic operations of the robot pursuant to its programmed control means.

16. The combination in accordance with claim 15, wherein said corrective output means includes an electromechanical digital encoder continuously coupled to said sprocket by said transmission means, a storage register, and means responsive to said register and said encoder for deriving values representing the advance of the encoder, and said restoring means including start control means responsive to the arrival of the work unit at a starting position for entering into the storage register the value represented by the encoder at that time.

17. The combination in accordance with claim 15, wherein said corrective control output means includes an electromechanical encoder, and wherein said drive means includes clutch means activated by said means responsive to the arrival of the work unit at a start position for initiating operation of the encoder, and wherein said restoring means includes reset means for said encoder, and further including control means for said clutch and said reset means operative after the robot has completed its program for discontinuing operation of the encoder by the drive means and for causing reset of the encoder by the reset means.

18. The combination in accordance with claim 15, wherein said corrective output means includes a pulse generator operated by said drive means and a counter rendered responsive to said pulse generator by said means responsive to the arrival of the work unit at the start position.