Tray handling system and process

• US 20060124513A1
• Filed: 12/09/2004
• Published: 06/15/2006
• Est. Priority Date: 12/09/2004
• Status: Active Grant

• Current Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Original Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Inventors: Wisniewski, Michael A., Morikawa, Hajime, McLaughlin, Jason G.
• Granted Patent: US 7,669,706 B2
• Time in Patent Office: Days
• US Class Current: 209/584
• CPC Class Codes: B07C 3/02 Apparatus characterised by the means used for distribution
• CPC Class Codes: Y10S 209/90 Sorting flat-type mail

Abstract

A device and method for sequencing trays includes a tray receiving conveyor and a recirculating conveyor. Trays are placed on the recirculating conveyor and merged with ejected trays into a multiple of sequenced trays at one or more merge locations. The system can include more than one merge location, with one of the merge locations providing a merge of trays into a contiguous sequence of trays.

Claims

1. A device for sequencing trays, comprising:

a tray receiving conveyor which receives trays outputted from bin locations; and

a recirculating conveyor buffer system having one or more merge locations, and being configured to recirculate staged trays and coordinate merging of the staged trays with newly ejected trays received from the bin locations into a multiple of sequenced trays at the one or more merge locations.

2. The device of claim 1, wherein:

the one or more merge locations includes at least two merge locations; and

the recirculating conveyor buffer system is configured into a looped conveying configuration with sections connecting the at least two merge locations to the looped conveying configuration.

3. The device of claim 2, wherein the looped conveying configuration is a recirculating section.

4. The device of claim 1, wherein the one or more merging locations includes a first merging location and a second merging location, and the recirculating conveyor buffer system further includes a diverting section diverting trays away from the first merging location.

5. The device of claim 1, further comprising an inclined conveyor connected between the recirculating conveyor buffer system and a tray receiving conveyor.

6. The device of claim 1, wherein the bin locations include a working area for discharging product into a tray and at least one queued area for storing full trays.

7. The device of claim 1, wherein the one or more merge locations is a first merge location and a second merge location, the first merge location merges the staged trays with the newly ejected trays into the multiple of sequenced trays during a preliminary sweep operation and the second merge location merges the multiple of sequenced trays with remaining one or more trays ejected from the bin locations during a final sweep operation into a final, contiguously sequenced set of trays.

8. The device of claim 7, wherein:

the recirculating conveyor buffer system includes a first conveying portion and a second conveying portion;

the first conveying portion includes the first merge location; and

the second conveying portion includes at least two divert locations and the second merge location.

9. The device of claim 1, further comprising a diverting portion which diverts the sequenced trays away from at least one feeder and feeds the sequenced trays back to the recirculating conveyor buffer system or an output.

10. The device of claim 1, further comprising a controller which coordinates movement of the recirculating conveyor buffer system such that the staged trays are coordinated to merge with the with newly ejected trays into the multiple of sequenced trays at the one or more merge locations.

11. The device of claim 10, wherein:

a first merge location of the one or more merge locations merges the staged trays with the newly ejected trays into the multiple of sequenced trays during a preliminary sweep operation; and

a second merge location of the one or more merge locations merges the multiple of sequenced trays with remaining trays ejected from the bin locations into a final, contiguously sequenced set of trays during a final sweep operation.

12. The device of claim 1, further comprising:

a tray staging and output conveyor positioned to receive trays from and feed trays to the recirculating conveyor buffer system and also leading to an output;

a diverting location located between the tray staging and output conveyor and a portion of the recirculating conveyor buffer system; and

a controller controlling and coordinating movement of the staged trays at the tray staging and output conveyor, the one or more merge locations and the output.

13. The device of claim 1, wherein the recirculating conveyor buffer system includes a first conveying portion and a second conveying portion, wherein

the first conveying portion includes a first divert location, a second divert location and a first merge location of the one or more merge locations;

and

the second conveying portion includes a second merge location of the one or more merge locations and a diverting location.

14. The device of claim 13, further comprising a controller, wherein:

during a preliminary sweep operation, the controller coordinates one or more activities of;

the first conveying portion such that the newly ejected trays are directed to the first merge location;

the first divert location such that the staged trays are transported towards the first merge location;

the first merge location such that the staged trays are coordinated to merge with the newly ejected trays into the multitude of sequenced trays about the first merge location; and

during a final sweep operation, the controller coordinates one or more activities of;

the first divert location such that the sequenced trays are transported towards the second merge location;

the second divert location such that remaining trays within the bin locations are transported to the second merge location; and

the second merge location such that the remaining trays and the multitude of sequenced trays are merged into a final, contiguously sequenced set of trays.

15. The device of claim 13, wherein the controller, after a final sweep operation, controls the diverting location such that some trays of the contiguous sequence of trays are diverted to a tray staging and output conveyor.

16. The device of claim 1, wherein mail pieces are placed in trays.

19. The method of claim 18, further comprising placing product into the trays in the first location during the steps of claim 16.

17. A method of sequencing trays, comprising the steps of:

placing at least one tray into a flow path in response to a first triggering event;

recirculating the at least one tray to a merging location;

placing at least one other tray in the flow path in response to a second triggering event; and

merging the at least one tray and the at least one other tray into sequence as they pass the merging location.

18. The method of claim 17, further comprising filling trays in a first location and moving full trays to a queued, second location prior to the placing steps.

20. The method of claim 17, wherein:

the at least one tray is a first multitude of trays which are placed in sequence in the flow path in response to the first triggering event and a qualification;

the at least one other tray is a second multitude of trays which are placed in sequence in the flow path in response to the second triggering event and a qualification; and

the first and second multitude of trays are merged into the sequence.

21. The method of claim 20, wherein:

the second multitude of trays are remaining trays in a sort operation and the merging step places the first and second multitude of trays into a contiguous sequence; and

the first triggering event and the second triggering event are different.

22. The method of claim 20, further comprising:

placing remaining trays in a sort operation into the flow path based on a third triggering event; and

merging the first and second multitude of trays and the remaining trays into a contiguous, final sequence at a second merging location.

23. The method of claim 22, wherein the first and second triggering event are based on an amount of product within a tray located in a working area and a full tray in a queued area and the third triggering event is based on a final product being fed in the sort operation.

24. The method of claim 20, wherein the at least other one tray is at least a last remaining tray in a sort operation and the first triggering event is based on an amount of product within a tray located in a working area and a full tray in a queued area and the second triggering event is based on a final product being fed in the sort operation.

25. The method of claim 17, further comprising feeding the sequence of trays towards at least one feeder in order to provide a sequencing of product therein.

26. The method of claim 25, further comprising diverting some trays of the sequence of trays away from the at least one feeder until the at least one feeder has the throughput to process the product therein.

27. The method of claim 17, further comprising:

placing remaining trays into the flow path in response to a second triggering event;

recirculating the sequence of trays to a second merging location; and

merging the remaining trays into contiguous sequence with the sequence of trays as they pass the second merging location.

28. The method of claim 27, further comprising:

diverting the sequence of trays away from the first merging location and towards the second merging location; and

diverting the remaining trays away from the first merging location and towards the second merging location.

29. The method of claim 17, further comprising injecting mail pieces into the trays prior to the placing step.

30. The method of claim 29, further comprising injecting mail pieces into the trays during at least one of the recirculating step and the merging step.

31. A method of sequencing trays, comprising the steps of:

during at least one preliminary sweep operation;

directing newly ejected trays from queued bin locations to a first merge location;

diverting staged trays previously ejected from the queued bin locations towards the first merge location;

coordinating movements of the newly ejected trays and the staged trays such that the newly ejected trays are merged with the staged trays at the first merge location, into a sequenced set of trays; and

during a final sweep operation;

diverting the sequenced set of trays away from the first merge location and towards a second merge location;

ejecting remaining trays having product therein from working bin locations and the queued bin locations diverting the remaining trays towards the second merge location; and

sequencing, in contiguous sequence, the remaining trays and sequenced trays as they pass though the second merge location.

32. The method of claim 31, further comprising providing a triggering event, to eject at different times, respectively, the newly ejected trays, the staged trays and the remaining trays into a flow path prior to the first merge location.

33. The method of claim 32, wherein the triggering event for ejecting the newly ejected trays and the staged trays is different than for ejecting the remaining trays.

34. The method of claim 31, further comprising the step of diverting some of the trays of the contiguous sequenced trays away from a feeder when the feeder is unable to process product with other trays of the contiguous sequenced trays and then leading the trays back to the feeder when the feeder regains the processing ability to process the product therein.

35. The method of claim 31, further comprising repeating the steps of claim 31 for a sequencing operation, and diverting the contiguous sequenced trays to an output.

36. The method of claim 31, further comprising placing product within the newly ejected trays and the staged trays.

37. The method of claim 36, wherein the product is mail pieces.

38. A mail sorting system, comprising:

at least one mail feeder feeding mail to trays located in bin locations comprising a working area and at least one queued area;

a tray receiving conveyor which receives the trays ejected from the at least one queued area in response to a triggering and qualification event;

a recirculating conveyor buffer system, including;

at least two merge locations;

at least two diverting locations downstream from the at least two merge locations, respectively, and

a conveying system leading to the at least one mail feeder or an output; and

a controller coordinating controlled movement of the trays ejected during different processing operations from the at least one queued area as they pass through the at least two merge locations and the at least two diverting locations in order to sequence the trays into a sequence at a second of the at least two merge locations.

39. The mail sorting system of claim 38, wherein the trays ejected during different processing operations include staged trays and newly ejected trays, and the controller coordinates controlled movement of the staged trays and the newly ejected trays such that the staged trays are coordinated to merge with the with newly ejected trays at either a first or the second of the at least two merge locations.

40. The mail sorting system of claim 38, wherein the recirculating conveyor buffer system is configured into a looped conveying configuration with sections connecting the at least two merge locations and the at least two diverting locations.

41. The mail sorting system of claim 38, wherein the at least two or more merge locations are a first merge location and a second merge location, the first merge location merges staged trays with newly ejected trays into the sequence during a preliminary sweep operation and the second merge location merges the sequenced trays with remaining one or more trays ejected from the at least one queued area during a final sweep operation into a final, contiguously sequenced set of trays, as coordinated by the controller.

42. The mail sorting system of claim 38, further comprising:

a tray staging and output conveyor positioned in tray flow communication with the recirculating conveyor buffer system and the output; and

a diverting location located between the tray staging and output conveyor and a portion of the recirculating conveyor buffer system.

43. The mail sorting system of claim 38, wherein:

the recirculating conveyor buffer system includes a first conveying portion and a second conveying portion;

the first conveying portion includes a first divert location and a second divert location of the least two diverting locations, and a first merge location of the at least two merge locations; and

the second conveying portion includes a second merge location of the at least two merge locations and a diverting location of the least two diverting locations.

44. The mail sorting system of claim 43, wherein the controller:

during a preliminary sweep operation coordinates one or more activities of;

the first conveying portion such that newly ejected trays from the at least one queued area are directed to the first merge location;

the first divert location such that staged trays previously ejected from the at least one queued area are transported towards the first merge location;

the first merge location such that the staged trays are coordinated to merge with the newly ejected trays into the sequence; and

during a final sweep operation coordinates one or more activities of;

the first divert location such that the sequenced trays are transported towards the second merge location;

the second divert location such that remaining trays within the bin locations are transported to the second merge location; and

the second merge location such that the remaining trays and the sequenced trays are merged in a contiguous sequence of trays after passing though the second merge location.

45. A machine readable medium containing code for merging, in sequence, trays, comprising at least one module for:

placing at least one tray into a flow path in response to a triggering event;

recirculating the at least one tray to a merging location;

placing at least one other tray in the flow path in response to the triggering event; and

merging the at least one tray and the at least one other tray into sequence as they pass the merging location.