Crossbelt sortation system

• US 5,588,520 A
• Filed: 02/26/1996
• Issued: 12/31/1996
• Est. Priority Date: 09/06/1994
• Status: Expired due to Term

• Current Assignee: Dematic Corporation (KION GROUP AG)
• Original Assignee: Rapistan Demag Corporation (Siemens AG)
• Inventors: Ceglia, Teodoro, Affaticati, Artemio, Cerutti, Claudio
• Primary Examiner(s): DAYOAN, DARRELL G
• Application Number:
  US08/606,547
• Time in Patent Office: 309 Days
• Field of Search: 198/370.04, 198/370.06, 198/502.2, 198/357, 198/358, 198/349.6, 198/502.3
• US Class Current: 198/370.06
• CPC Class Codes: B61B 13/08 Sliding or levitation systems vehicles with air cushions between rails and vehicles B60V3/04
• CPC Class Codes: B61G 5/00 Couplings for special purposes not otherwise provided for
• CPC Class Codes: B65G 17/345 the surfaces being equipped with a conveyor
• CPC Class Codes: B65G 2201/02 Articles
• CPC Class Codes: B65G 2201/0288 Signatures, i.e. sections of printed magazines, papers or books
• CPC Class Codes: B65G 2203/042 Sensors
• CPC Class Codes: B65G 2203/044 Optical
• CPC Class Codes: B65G 2207/18 Crossing conveyors
• CPC Class Codes: B65G 43/08 Control devices operated by article or material being fed, conveyed or discharged and controlling the discharging devices B65G47/42
• CPC Class Codes: B65G 47/31 by varying the relative speeds of the conveyors forming the series
• CPC Class Codes: B65G 47/52 Devices for transferring articles or materials between conveyors i.e. discharging or feeding devices loading or unloading by means not incorporated in, or not operatively associated with, conveyors B65G65/00; transfer of workpieces during metal rolling B21B41/00
• CPC Class Codes: B65G 54/02 electrostatic, electric, or magnetic

Abstract

The present application discloses a method and apparatus for conveying parcels on a plurality of transport units (32) moving in a conveying path (30) between an induction station (26) and a discharge station (28). The invention provides the ability to handle parcels having a length greater than the length of a single transport unit by providing the ability to induct such parcel onto two contiguous transport units (32) and to discharge the parcel from the two contiguous transport units to a selected receiving port (46). For longer parcels, having a length greater than a given length, the parcel is inducted to two contiguous transport units by operating the induction belts and the carrier belts of the two contiguous transport units in a manner which positions the parcel on the two transport units. The carrier belts of the two transport units are operated in a manner that rotates longer parcels, having a length greater than the given length, in order to position the parcel on the two transport units. Crossbelt sortation system (25) is provided with a transport unit test station (96) that is positioned adjacent to the conveying path. The purpose of the test station is to test movement of the carrier belt associated with individual ones of the transport units passing the test station. Each of the transport units (32) includes a magnet (204a, 204b) that moves in proportion to the linear speed of the carrier belt (36) associated with that transport unit. The test station includes a sensor (200) that senses the magnet of a transport unit passing the test station. The sensor includes at least one Hall-effect cell (208a, 208b) and a magnetic antenna (210) coupled with the Hall-effect cell.

Claims

1. A method of conveying parcels on a plurality of transport units moving in a conveying path between an induction station and a discharge station, each transport unit having a driven carrier belt thereon which is moveable orthogonally to the conveying path, said induction station having at least one induction belt extending at an angle to the conveying path, said discharge station having a plurality of receiving ports positioned along said conveying path, including:

determining the length of parcels at said induction station;

for parcels having a length less than a given length operating said at least one induction belt and said carrier belt of one of said transport units to position a parcel on said one of said transport units; and

for parcels having a length greater than said given length operating said at least one induction belt and said carrier belts of at least two contiguous transport units in order to position a parcel on said at least two transport units.

2. The method of claim 1 including operating said carrier belts of said at least two transport units in a manner that rotates parcels having a length greater than said given length to position the parcel on said at least two transport units.

3. The method of claim 2 wherein said manner that rotates parcels includes operating said carrier belts of said at least two transport units until a parcel is positioned over the leading one of said at least two transport units and stopping said carrier belt of said leading one of said at least two transport units while operating said carrier belts of at least one following one of said at least two transport units until the parcel is positioned on said at least two transport units.

4. The method of claim 1 wherein operating said at least one induction belt includes determining the availability of at least one carrier unit and accelerating a parcel on said at least one induction belt to a loading speed according to a fixed velocity profile upon the availability of at least one carrier unit.

5. The method of claim 4 wherein said accelerating is initiated as a function of at least the length and width of said parcel.

6. The method of claim 1 wherein said determining includes measuring the length of parcels on said induction belts.

7. The method of claim 1 including discharging said parcels to selected ones of said ports.

8. The method of claim 7 wherein said discharging includes rotating parcels that are positioned on at least two of said transport units while discharging said parcels that are positioned on at least two of said transport units.

9. The method of claim 8 wherein said rotating includes operating the carrier belt of a forward one of said at least two transport units while not operating the carrier belt of at least one trailing one of said at least two transport units.

10. The method of claim 9 including operating said carrier belt of said at least one trailing one of said transport units after a time delay.

11. The method of claim 10 wherein said operating of said carrier belts of both said forward one and said at least one trailing one of said at least two transport units is initiated at the same fixed location with respect to the selected one of said ports.

12. The method of claim 9 wherein said operating said carrier belt of said forward one of said at least two transport units is initiated as a function of the distance of the leading edge of the parcel on said carrier belt of said forward one of said at least two transport units frown the selected one of said ports.

13. The method of claim 12 wherein said operating said carrier belt of said forward one of said at least two transport units is initiated as a function of the distance of said forward one of said at least two transport units from the selected one of said ports and the distance of said leading edge of the parcel from a leading edge of said forward one of said at least two transport units.

14. The method of claim 7 wherein said discharging includes operating the carrier belt of the at least one of said transport units conveying a parcel as a function of the distance of the leading edge of the parcel on said carrier belt of said at least one of said transport units from the selected one of said ports.

15. The method of claim 14 wherein said discharging includes operating the carrier belt of the at least one of said transport units conveying a parcel as a function of the distance of said at least one of said transport units from the selected one of said ports and the distance of said leading edge of the parcel from a leading edge of said at least one of said transport units.

16. The method of claim 7 wherein at least certain ones of said ports are chutes combined in vertical pairs including a flap for directing parcels to one of a pair of chutes and wherein said discharging includes setting the position of said flap.

17. The method of claim 16 including initiating said setting as a function of the distance of the leading edge of the parcel on said carrier belt of said at least one of said transport units from the selected one of said ports.

18. The method of claim 17 including initiating said setting as a function of the distance of said at least one of said transport units from the selected one of said ports and the distance of said leading edge of the parcel from a leading edge of said at least one of said transport units.

19. A crossbelt sortation system comprising:

a plurality of transport units moving in a conveying path between an induction station and a discharge station, each transport unit having a driven carrier belt thereon which is moveable orthogonally to the conveying path;

said discharge station having a plurality of receiving ports positioned along said conveying path; and

said induction station having at least one induction belt extending at an angle to the conveying path, a parcel length input device for inputting data indicative of the length of parcels and an induction control that is responsive to said length input device for operating said at least one induction belt and said carrier belts of particular ones of said transport units in a manner that positions a parcel having a length less than a given length on one of said transport units and a parcel having a length greater than said given length on at least two contiguous transport units.

20. The system in claim 19 wherein said induction control operates said carrier belts of said at least two transport units in a manner that rotates parcels having a length greater than said given length to position the parcel on said at least two transport units.

21. The system in claim 20 wherein said induction control rotates parcels by operating said carrier belts of said at least two transport units until a parcel is positioned over the leading one of said at least two transport units and stopping said carrier belt of said leading one of said at least two transport units while operating said carrier belt of at least one following one of said at least two transport units until the parcel is positioned on said at least two transport units.

22. The system in claim 19 wherein said induction control determines the availability of at least one carrier unit and accelerates a parcel on said at least one induction belt to a loading speed according to a fixed velocity profile upon the availability of at least one carrier unit.

23. The system in claim 22 wherein said induction control initiates the acceleration as a function of at least the length and width of said parcel.

24. The system in claim 19 wherein said length input device includes a measuring station that measures the length of parcels on said induction belts.

25. The system in claim 19 wherein said discharge station includes a sortation control that operates said carrier belts in a manner that discharges parcels carded by said transport units to selected ports.

26. The system in claim 25 wherein said sortation control operates said carrier belts of said at least two transport units carrying a parcel in a manner that rotates the parcel carried by said at least two transport units while discharging that parcel.

27. The system in claim 26 wherein said sortation control rotates a parcel carried by said at least two transport units by operating the carrier belt of a forward one of said at least two transport units while not operating the carrier belt of at least one following one of said at least two transport units.

28. The system in claim 27 wherein said sortation control rotates a parcel carried by said at least two transport units by operating the carrier belt of said at least one following one of said transport units after a time delay.

29. The system in claim 28 wherein said sortation control initiates said operating of said carrier belts of both said forward one and said at least one following one of said at least two transport units at a same fixed location with respect to the selected one of said ports.

30. The system in claim 26 wherein said sortation control initiates operating of the carrier belt of said forward one of said at least two transport units as a function of the distance of the leading edge of the parcel on that transport unit from the selected one of said ports.

31. The system in claim 30 wherein said sortation control initiates operating of the carrier belt of said forward one of said at least two transport units as a function of the distance of said forward one of said at least two transport units from the selected one of said ports and the distance of said leading edge of the parcel from a leading edge of said forward one of said at least two transport units.

32. The system in claim 25 wherein said sortation control initiates operating of the carrier belt of the at least one of said transport units conveying a parcel as a function of the distance of the leading edge of the parcel on that carrier belt from the selected one of said ports.

33. The system in claim 32 wherein said sortation control initiates operating of the carrier belt of the at least one of said transport units conveying a parcel as a function of the distance of said at least one of said transport units from the selected one of said ports and the distance of said leading edge of the parcel from a leading edge of said at least one of said transport units.

34. The system in claim 25 wherein at least certain ones of said ports each include at least two vertically related chutes and a flap for directing parcels to one of said at least two chutes and wherein said sortation control sets the position of said flap.

35. The system in claim 34 wherein said sortation control initiates setting the position of said flap as a function of the distance of the leading edge of the parcel on said carrier belt of said at least one of said transport units from the one of said ports associated with that flap.

36. The system in claim 35 wherein said sortation control initiates said setting as a function of the distance of said at least one of said transport units from the one of said ports associated with that flap and the distance of said leading edge of the parcel from a leading edge of said at least one of said transport units.

37. A crossbelt sortation system comprising:

a plurality of transport units moving in a conveying path between an induction station and a discharge station, each transport unit having a driven carrier belt thereon which is moveable orthogonally to the conveying path;

said discharge station having a plurality of receiving ports positioned along said conveying path;

said induction station having at least one induction belt extending at an angle to the conveying path; and

a transport unit test station positioned adjacent said conveying path for testing movement of the carrier belt associated with individual ones of said transport units passing the test station, each of said transport units including a magnet that moves in proportion to the linear speed of the carrier belt associated with that transport unit and said test station includes a sensor that senses the magnet of a transport unit passing the test station, said sensor including at least one magnetic-field sensitive device and a magnetic antenna coupled with said at least one magnetic-field sensitive device.

38. The system in claim 37 wherein each of said transport units further includes a rotatable pulley that rotates with linear movement of the carrier belt associated with that transport unit, wherein said magnet is positioned on said pulley for rotating with said pulley at a rotational speed that is a function of the linear speed of the associated carrier belt.

39. The system in claim 37 wherein said magnetic antenna is elongated in the direction of movement of said transport units along said conveying path.

40. The system in claim 39 wherein said magnetic antenna is made from a ferromagnetic material.

41. The system in claim 37 wherein said magnetic antenna is made from a ferromagnetic material.

42. The system in claim 37 wherein said antenna includes a pair of pole shoes that are galvanically isolated by said magnetic-field sensitive device.

43. The system in claim 42 wherein said pole shoes are elongated in the direction of movement of said transport units along said conveying path.

44. The system in claim 43 including a pair of magnetic-field sensitive devices galvanically isolating said pole shoes.

45. The system in claim 44 wherein said pair of magnetic-field sensitive devices are offset from each other in the path of movement of said magnet in response to linear movement of the carrier belt associated with that transport unit.

46. The system in claim 44 including a circuit coupled to said magnetic-field sensitive devices for producing an indication of the speed and direction of movement of the carrier belt associated with a transport unit passing said test station.

47. The system in claim 46 wherein said indication includes at least one digital word.

48. The system in claim 38 including a pair of said magnets radially positioned on opposite sides of said pulley.

49. The system in claim 37 wherein said magnetic-field sensitive device is a Hall-effect cell.

50. The system in claim 37 wherein said magnetic-field sensitive device is an inductive pick-up coil.

51. A method of conveying parcels on a plurality of transport units moving in a conveying path between an induction station and a discharge station, each transport unit having a driven carrier belt thereon which is moveable orthogonally to the conveying path, said induction station having at least one induction belt extending at an angle to the conveying path, said discharge station having a plurality of receiving ports positioned along said conveying path, including:

operating said at least one induction belt and said carrier belts of at least two contiguous transport units in order to position at least particular ones of said parcels on said at least two transport units by rotating each such parcel to position the parcel on said at least two transport units.

52. The method of claim 51 wherein said rotating includes operating said carrier belts of said at least two transport units until a parcel is positioned over the leading one of said at least two transport units and stopping said carrier belt of said leading one of said at least two transport units while operating said carrier belts of at least one following one of said at least two transport units until the parcel is positioned on said at least two transport units.

53. The method of claim 51 wherein operating said at least one induction belt includes determining the availability of at least one carrier unit and accelerating a parcel on said at least one induction belt to a loading speed according to a fixed velocity profile upon the availability of at least one carrier unit.

54. The method of claim 53 wherein said accelerating is initiated as a function of at least the length and width of said parcel.

55. The method of claim 51 including discharging said parcels to selected ones of said ports.

56. The method of claim 55 wherein said discharging includes rotating parcels that are positioned on at least two of said transport units while discharging said parcels that are positioned on at least two of said transport units.

57. The method of claim 56 wherein said discharging includes operating the carrier belt of a forward one of said at least two transport units while not operating the carrier belt of at least one trailing one of said at least two transport units.

58. The method of claim 57 wherein said discharging includes operating said carrier belt of said at least one trailing one of said transport units after a time delay.

59. The method of claim 58 wherein said operating of said carrier belts of both said forward one and said at least one trailing one of said at least two transport units is initiated at the same fixed location with respect to the selected one of said ports.

60. The method of claim 57 wherein said operating said carrier belt of said forward one of said at least two transport units is initiated as a function of the distance of the leading edge of the parcel on said carrier belt of said forward one of said at least two transport units from the selected one of said ports.

61. The method of claim 60 wherein said operating said carrier belt of said forward one of said at least two transport units is initiated as a function of the distance of said forward one of said at least two transport units from the selected one of said ports and the distance of said leading edge of the parcel from a leading edge of said forward one of said at least two transport units.

62. The method of claim 55 wherein said discharging includes operating the carrier belt of the at least one of said transport units conveying a parcel as a function of the distance of the leading edge of the parcel on said carrier belt of said at least one of said transport units from the selected one of said ports.

63. The method of claim 62 wherein said discharging includes operating the carrier belt of the at least one of said transport units conveying a parcel as a function of the distance of said at least one of said transport units from the selected one of said ports and the distance of said leading edge of the parcel from a leading edge of said at least one of said transport units.