Robotic containerization system

• US 6,201,203 B1
• Filed: 05/12/1999
• Issued: 03/13/2001
• Est. Priority Date: 05/12/1999
• Status: Expired due to Term

• Current Assignee: Northrop Grumman Systems Corporation (Northrop Grumman Corporation)
• Original Assignee: Northrop Grumman Corporation
• Inventors: Tilles, David J.
• Primary Examiner(s): Matecki, Katherine A.
• Application Number:
  US09/310,222
• Time in Patent Office: 671 Days
• Field of Search: 209/540, 209/541, 209/542, 209/545, 209/559, 209/563, 209/564, 209/583, 209/584, 209/587, 209/922, 209/933
• US Class Current: 209/584
• CPC Class Codes: B07C 3/008 Means for collecting objects, e.g. containers for sorted mail items pile receivers in general B65H31/00
• CPC Class Codes: B65G 1/1375 the orders being assembled on a commissioning stacker-crane or truck
• CPC Class Codes: B65G 47/54 at least one of which is a roller-way
• CPC Class Codes: B65G 57/24 the layers being transferred as a whole, e.g. on pallets
• CPC Class Codes: B65G 65/00 Loading or unloading of vehicles B65G67/00
• CPC Class Codes: Y10S 209/922 Miscellaneous feed conveyors
• CPC Class Codes: Y10S 209/933 Accumulation receiving separated items

Abstract

In a method and system for automatically forming a plurality of packages of groups of articles, the articles move along a conveying path in a substantially continuous motion. The selected articles are transferred to selected buffer storage assemblies in response to selection control signals from a central processing unit. The central processing unit generates the control signals according to predetermined packaging criteria. The groups of articles are stored in the buffer assemblies in a layer corresponding to one layer of a plurality of layers to be assembled in one of the plurality of packages. The entire layer in the buffer assembly is then transferred into an associated package at one time after assembly of that layer is completed from the accumulation of individual articles transferred from the conveying path. The articles are selectively oriented in the conveying path upstream of the buffer assemblies so that individual articles within each group may be oriented according to the predetermined packaging criteria. In the first embodiment, the buffer assemblies transfer selected articles from the conveying path into elevated positions above the conveyor until a complete layer is assembled. Articles moving to other destinations are able to pass under the buffered articles in a substantially continuous motion.

Claims

1. Apparatus for automatically forming a plurality of packages of groups of articles comprising:

transport conveyor means for moving a plurality of the articles along a conveying path in a substantially continuous motion;

a plurality of buffer storage assemblies disposed in spaced positions along the conveying path, each buffer storage assembly being capable of receiving articles from the transport conveyor while other articles thereon sustain substantially continuous movement;

transfer means for selectively moving selected articles from the transport conveyor to selected ones of the buffer storage assemblies in response to selection control signals; and

control means for generating the selection control signals according to predetermined packaging criteria for each package of the plurality of groups of articles to be formed at each of the respective buffer storage assemblies.

2. The apparatus of claim 1 wherein, said transfer means comprises elevator assemblies for selectively lifting the articles from the transport conveyor into buffer positions associated with the buffer storage assemblies.

3. The apparatus of claim 2 wherein, said elevator assemblies include a plurality of support fingers vertically movable between the transport conveyor and the buffer storage assemblies, said fingers engaging and lifting the groups of articles to the buffer positions.

4. The apparatus of claim 3 wherein, the transport conveyor includes a plurality of spaced rollers and the fingers are vertically movable between the rollers.

5. Apparatus of claim 2 wherein the buffer positions are disposed above the transport conveyor at a height which is sufficient to permit articles moving on the transport conveyor to other destinations to pass beneath articles stored in the buffer positions.

6. Apparatus of claim 5 wherein each elevator assembly includes a plurality of in-line shelves disposed longitudinally of the transport conveyor, each shelf being separately movable between the transport conveyor and buffer storage positions in response to the selection control signals.

7. Apparatus of claim 6, wherein the shelves are arranged in pairs, the respective shelves of each pair extending transversely of the transport conveyor from opposite sides of the transport conveyor.

8. Apparatus of claim 7 wherein each shelf includes a plurality of parallel conveyor belts.

9. Apparatus of claim 6 wherein each shelf includes a plurality of parallel conveyor belts.

10. Apparatus of claim 5, wherein the buffer storage assemblies are disposed on both left and right sides of the transport conveyor, and there is further provided a loading manipulator disposed below the transport conveyor for selective alignment with a chosen buffer assembly on the right or left sides when the control means signals that a transferable layer of articles in that buffer assembly is ready for transfer, and buffer elevator mechanisms for each buffer storage assembly for lowering that buffer assembly into lateral alignment with the loading manipulator and returning the buffer assembly to a plane of the conveying path of the transport conveyor once the layer of articles is transferred from the buffer assembly to the loading manipulator.

11. Apparatus of claim 10 further including a stop plate on one edge of each buffer assembly having a linear surface orthogonal to the longitudinal axis of the transport conveyor, a movable compression plate disposed on an opposite edge of the buffer assembly, said movable compression plate having a linear compression surface parallel to the linear surface of the stop plate, and a compression actuator for moving said compression plate toward said stop plate to edge justify the layer of articles in the buffer assembly against the stop plate prior to transfer of the layer to the loading manipulator.

12. Apparatus of claim 11 wherein the elevator mechanism comprises a scissors support device and a hydraulic actuator for moving the scissors to lower or raise the buffer assembly.

13. Apparatus according to claim 10 wherein said loading manipulator includes an extensible end effector for engaging a layer of articles on the buffer assembly and transferring the layer to a container or pallet, the end effector having upper and lower extensible sections, the upper section having a sweep gate mounted thereon, the top section being capable of extension into proximity with the transferable layer on the buffer assembly, the sweep gate being capable of sweeping the layer onto the lower section, the lower section being movable between the buffer assembly and the container or pallet to support the layer on a support surface thereof and carry the layer therebetween, the upper section also being movable between the buffer assembly and container or pallet, the sweep gate being capable of restraining the layer in the container or on the pallet when the lower section is retracted to permit the support surface of the lower section to move out from under the layer.

14. The apparatus of claim 1 wherein, the transfer means include substantially horizontal shelf assemblies including ejection conveyors for discharging the groups of articles to an associated packaging station in response to ejection control signals.

15. The apparatus of claim 1, further comprising loading manipulator means for receiving groups of articles ejected from the buffer storage assemblies and placing them on package support devices at the packaging stations.

16. Apparatus of claim 15 wherein said loading manipulator comprises a platform assembly for receiving a layer of articles stored in a buffer assembly;

means for moving the platform assembly into a packaging container in which a package will be formed to deposit the layer of articles therein; and

lift means for moving the platform assembly vertically into alignment with the layer of articles in the buffer assembly and to selected levels in the container.

17. Apparatus of claim 16 wherein the platform assembly includes telescoping sections selectively extendable toward the buffer assemblies and into the container.

18. Apparatus of claim 16 further including means for moving the loading manipulator to selected buffer assemblies and packaging containers.

19. The apparatus of claim 1, further including orientation means for selectively positioning articles on the transport conveyor upstream of the buffer assemblies along the conveyor paths so that individual articles within each group may be oriented according to said predetermined packaging criteria.

20. Apparatus of claim 19 wherein the orientation means comprises:

a gripper assembly for engaging the articles and rotating the articles to selected orientations consistent with the packaging criteria.

21. Apparatus of claim 19 wherein said orientation means includes pop-up pins which protrude above a top surface of the transport conveyor, engage selected portions of moving articles, and rotate the articles to selected orientations.

22. The apparatus of claim 1, further including coding on each of said articles for indicating the buffer storage assembly to which the article will be transferred, in an orientation pattern consistent with the packaging criteria for the group of articles in which each article will be included, and said control means includes means for reading the coding and generating the selection control signals supplied to the transfer means.

23. The apparatus of claim 22, further including reject means responsive to the reader means for ejecting, undesired articles from the transport conveyor.

24. The apparatus of claim 1, further comprising recirculation means for receiving overflow articles from the buffer storage assemblies when filled beyond capacity and returning the articles to an input end of the transport conveyor.

25. Apparatus of claim 1 wherein the groups of articles are storable in the buffer assemblies in a layer corresponding to one layer of a plurality of layers to be assembled in one of the plurality of packages, the entire layer in the buffer assemblies being transferable into the packages at one time after assembly of that layer is completed from the accumulation of individual articles, transferred from the transport conveyor.

26. Apparatus of claim 1 wherein said buffer storage assemblies are disposed laterally of the transport conveyor and the transfer means moves the articles laterally thereto.

27. Apparatus of claim 26 wherein the transport conveyor includes a plurality of spaced powered rollers and the transfer means includes conveyor belts interleaved between the rollers, means for raising the conveyor belts above the powered rollers to lift the articles therefrom, and means for rotating the belts to eject the articles into the buffer assemblies.

28. Apparatus of claim 27 wherein said buffer storage assemblies includes a buffer storage surface defined by a plurality of unpowered idler rollers on axes perpendicular to axes of the powered rollers whereby articles transferred from the transport conveyor are freely movable along the idler rollers.

29. Apparatus of claim 26 wherein the transport conveyor includes a plurality of spaced conveyor belts powered for longitudinal movement along a conveying path and the transfer means includes a plurality of powered rollers interleaved between the belts, means for raising the rollers above the belts to lift the articles thereform and means for rotating the rollers to eject the articles transversely of the belts into the buffer assemblies.

30. Apparatus of claim 29, wherein said buffer storage assemblies include a buffer storage surface defined by a plurality of unpowered idler rollers on axes parallel to axes of the powered rollers whereby articles transferred from the transport conveyor are freely movable along the idler rollers.

31. Apparatus of claim 30, wherein said powered rollers are selectively rotatable in opposite directions to thereby laterally transfer the articles to the right or left of the transport conveyor.

32. Apparatus of claim 30, further including shaft encoder mechanisms coupled to drive shafts associated with the belts for determining the positions of the belts of the conveyors and thus articles thereon, and sending associated position signals to said control means.

33. Apparatus of claim 32, further including sensor means at an entrance to the transport conveyor for sensing entry of articles thereto and generating enable signals to the shaft encoder mechanisms to initiate transmission of the position signals to the control means.

34. Apparatus of claim 29, wherein said powered rollers are selectively rotatable in opposite directions to thereby laterally transfer the articles to the right or left of the transport conveyor.

35. Apparatus of claim 29, wherein the buffer storage assemblies are disposed on both left and right sides of the transport conveyor and there is further provided a loading manipulator disposed below the transport conveyor for selective alignment with a chosen buffer assembly on the right or left sides when the control means signals that a transferable layer of articles in that buffer assembly is ready for transfer, and, buffer elevator mechanisms for each buffer storage assembly for lowering that buffer assembly into lateral alignment with the loading manipulator and returning the buffer assembly to a plane of the conveying path of the transport conveyor once the layer of articles is transferred from the buffer assembly to the loading manipulator.

36. Apparatus of claim 35, further including a stop plate on one edge of each buffer assembly having a linear surface orthogonal to the longitudinal axis of the transport conveyor, a movable compression plate disposed on an opposite edge of the buffer assembly, said movable compression plate having a linear compression surface parallel to the linear surface of the stop plate, and a compression actuator for moving said compression plate toward said stop plate to edge justify the layer of articles in the buffer assembly against the stop plate prior to transfer of the layer to the loading manipulator.

37. Apparatus of claim 36 wherein the elevator mechanism comprises a scissors support device and a hydraulic actuator for moving the scissors to lower or raise the buffer assemblies.

38. Apparatus according to claim 35, wherein said loading manipulator includes an extensible end effector for engaging a layer of articles on the buffer assembly and transferring the layer to a container or pallet, the end effector having upper and lower extensible sections, the upper section having a sweep gate mounted thereon, the top section being capable of extension into proximity with the transferable layer on the buffer assembly, the sweep gate being capable of sweeping the layer onto the lower section, the lower section being movable between the buffer assembly and the container or pallet to support the layer on a support surface thereof and carry the layer therebetween, the upper section also being movable between the buffer assembly and container or pallet, the sweep gate being capable of restraining the layer in the container or on the pallet when the lower section is retracted to permit the support surface of the lower section to move out from under the layer.

39. Apparatus of claim 38 wherein each extensible section includes at least two telescoping parts.

40. Apparatus according to claim 29 further including a safety assembly associated with each of a plurality of containers or pallets to be loaded with the layers of articles, said safety assembly comprising:

a frame surrounding the container or pallet; and

a curtain mounted on said frame, said curtain being selectively movable over a discharge opening defined in a rear side of the frame, or an input opening in the front side of the frame facing the buffer assemblies, to open one of those openings while choosing the other, to thereby shield a worker unloading the container or pallet from the loading manipulator.

41. Apparatus according to claim 26, further including a safety assembly associated with each of a plurality of containers or pallets to be loaded with the layers or articles, said safety assembly comprising:

a frame surrounding the container or pallet; and

a curtain mounted on said frame, said curtain being selectively movable over a discharge opening defined in a rear side of the frame, or an input opening in the front side of the frame facing the buffer assemblies, to open one of those openings while closing the other, to thereby shield a worker unloading the container or pallet from the loading manipulator.

42. Apparatus of claim 41 further including a track extending around said frame, and means for movably supporting the curtain in said track.

43. Apparatus of claim 42 wherein said curtain includes a plurality of vertical slats, hinged together on vertical edges thereof.

44. Apparatus according to claim 26 comprising first a second transport conveyors for selectively receiving articles moving along the conveying path, the longitudinal axis of the transport conveyors being parallel, a plurality of buffer assemblies being provided along each transport conveyor on a side thereof facing the other transporter conveyor, and a loading manipulator disposed between the respective groups of buffer assemblies of the first and second transport conveyors, said loading manipulator being movable longitudinally of the conveyors into selective lateral alignment with chosen ones of the buffer assemblies as instructed by the control means.

45. Apparatus according to claim 1 further including a safety assembly associated with each of a plurality of containers or pallets to be loaded with the layers of articles, said safety assembly comprising:

a frame surrounding the container or pallet; and

a curtain mounted on said frame, said curtain being selectively movable over a discharge opening defined in a rear side of the frame, or an input opening in the front side of the frame facing the buffer assemblies, to open one of those openings while choosing the other, to thereby shield a worker unloading the container or pallet from the loading manipulator.

46. Apparatus of claim 45 further including a track extending around said frame, means for movably supporting the curtain in said track.

47. Apparatus of claim 46 wherein said curtain includes a plurality of vertical slats, hinged together on vertical edges thereof.

48. The apparatus of claim 1, wherein the articles comprise mail trays.

49. A method for automatically forming a plurality of packages of groups of articles comprising the steps of:

moving a plurality of the articles along a conveying path in a substantially continuous motion;

selectively moving selected articles from the conveying path to selected buffer storage assemblies in response to selection control signals;

generating the selection control signals according to predetermined packaging criteria for each package of the plurality of groups of articles to be formed at each of the respective buffer storage assemblies;

storing groups of articles in the buffer assemblies in a layer corresponding to one layer of a plurality of layers to be assembled in one of the plurality of packages; and

transferring the entire layer in the buffer assemblies into the packages at one time after assembly of that layer is completed from the accumulation of individual articles, transferred from the conveying path.

50. The method of claim 49, further including the step of selectively orienting articles in the conveying path upstream of the buffer assemblies so that individual articles within each group may be oriented according to said predetermined packaging criteria.

51. The method of claim 50 wherein the articles are substantially rectangular first size trays having longitudinal axes, and the axes of the trays in the respective layers are relatively oriented to form selected patterns.

52. The method of claim 51 wherein the pattern includes at least three trays with the respective axes parallel.

53. The method of claim 52 including the further steps of:

determining the height of the first size trays;

monitoring the buffer locations of second size trays determined to be than the first size trays taller in a given buffer layer; and

directing other said second size trays to the next layer buffered to positions such that the two successive layers are stackable in a package in a substantially level arrangement.

54. The method of claim 51 wherein the axes of at least two trays are parallel and one or more trays have axes orthogonal to the axes of the at least two trays thereby forming a brick-laid pattern.

55. The method of claim 54 including the further step of determining the length of the first size trays,

separating and storing second size trays which are half the length of the first size trays, grouping the second size trays into pairs, and

inserting the pairs into a layer being formed in a buffer assembly to approximate a standard tray.

56. The method of claim 54 including the further steps of:

determining the height of the first size trays;

monitoring the buffer locations of second size trays determined to be taller than the first size trays in a given buffer layer; and

directing other said second size trays to the next layer buffered to positions such that the two successive layers are stackable in a package in a substantially level arrangement.

57. The method of claim 51 including the further step of determining the length of the first size trays,

separating and storing second size trays which are half the length of the first size trays, grouping the second size trays into pairs, and

inserting the pairs of second size trays into a layer being formed in a buffer assembly to approximate a first size tray.

58. The method of claim 49 wherein the articles are substantially rectangular first size mail trays having longitudinal axes, and the axes of the trays in the respective layers are relatively oriented to form selected patterns.

59. The method of claim 58 including the further steps of:

determining the height of the first size mail trays;

monitoring the buffer locations of second size mail trays determined to be taller than the first size mail trays in a given buffer layer; and

directing other said second size mail trays to the next layer buffered to positions such that the two successive layers are stackable in a package in a substantially level arrangement.

60. The method of claim 49, wherein the articles comprise mail trays.

61. Apparatus for transferring a plurality of articles to be stacked in layers in a container or on a pallet between a buffer storage assembly which accumulates the articles, one of said layers at a time, and the container or pallet comprising:

an extensible end effector for engaging the layer of articles on the buffer assembly and transferring the layer to the container or pallet, the end effector having upper and lower extensible sections, the upper section having a sweep gate mounted thereon, the top section being capable of extension into proximity with the transferable layer on the buffer assembly, the sweep gate being capable of sweeping the layer into the lower section, the lower section being movable between the buffer assembly and the container or pallet to support the layer on a support surface thereof and carry the layer therebetween, the upper section also being movable between the buffer assembly and container or pallet, the sweep gate being capable of restraining the layer in the container or on the pallet when the lower section is retracted to permit the lower support surface of the section to move out from under the layer.

62. Apparatus of claim 61 wherein each extensible section includes at least two telescoping parts.