Title:
Wrap Removal System
Kind Code:
A1


Abstract:
A wrap removal system for removing a film wrap from a load on a conveyor, the wrap removal system including an upright support member, a beam coupled to an upper extent of the support member for movement along a height of the support member, a gripper assembly coupled to the beam and operable to engage the film wrap to create a space between the load and the film wrap, and a cutter assembly.



Inventors:
Jacobs, Jon D. (Cambria, WI, US)
Busse, Brian E. (Madison, WI, US)
Gabel Jr., Robert A. (Beaver Dam, WI, US)
Application Number:
12/441461
Publication Date:
12/10/2009
Filing Date:
10/26/2007
Primary Class:
Other Classes:
414/412
International Classes:
B65B69/00
View Patent Images:
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Primary Examiner:
TRUONG, THANH K
Attorney, Agent or Firm:
BOYLE FREDRICKSON S.C. (MILWAUKEE, WI, US)
Claims:
What is claimed is:

1. A wrap removal system for removing a film wrap from a load on a conveyor, the wrap removal system comprising: an upright support member; a beam coupled to an upper extent of the support member for movement along a height of the support member; a gripper assembly coupled to the beam and operable to engage the film wrap to create a space between the load and the film wrap; and a cutter assembly.

2. The wrap removal system of claim 1, wherein the beam is coupled to the upright support member with a plurality of rollers in a substantially cantilevered arrangement.

3. The wrap removal system of claim 1, and further comprising a sensor coupled to the beam and operable to detect a top of the load.

4. The wrap removal system of claim 1, wherein the cutter assembly includes a pair of cutting mechanisms, the pair of cutting mechanisms including a corresponding a pair of slitter blades.

5. The wrap removal system of claim 4, wherein the pair of slitter blades rotate about substantially parallel axes in opposite directions and overlap to define a cutting area.

6. The wrap removal system of claim 5, wherein a first one of the pair of slitter blades is driven through a first belt by a motor and a second one of the pair of slitter blades is driven by a second belt that is driven by the first belt.

7. The wrap removal system of claim 6, wherein the second belt is configured to frictionally engage the film wrap and pull it towards the cutting area.

8. The wrap removal system of claim 1, and further comprising a track supported by the upright support member, wherein the cutter assembly is movably coupled to the track to travel along a height of the upright support member.

9. The wrap removal system of claim 8, wherein the track is pivotably supported by the upright support member and movable between a first position remote from the load and a second position adjacent the load.

10. The wrap removal system of claim 1, and further comprising a vacuum blower, wherein the gripper assembly includes a vacuum face in fluid communication with the vacuum blower.

11. The wrap removal system of claim 10, and further comprising a valve in fluid communication between the vacuum blower and the gripper assembly, the valve being operable to change between coupling the gripper assembly to an inlet side of the vacuum blower and coupling the gripper assembly to an outlet side of the vacuum blower.

12. The wrap removal system of claim 10, wherein the vacuum face defines a substantially continuous vacuum chamber defined by a peripheral gasket of the vacuum face, and the gripper assembly further includes a plurality of spaced-apart vacuum ducts defining vacuum sub-chambers extending from the vacuum chamber.

13. The wrap removal system of claim 12, wherein the vacuum chamber is fluidly coupled to the vacuum blower through the plurality of vacuum ducts.

14. The wrap removal system of claim 13, wherein each of the plurality of vacuum ducts is substantially cone-shaped, tapering down in diameter away from the vacuum chamber.

15. The wrap removal system of claim 1, wherein the gripper assembly is pivotably coupled to the beam through a pivot arm.

16. The wrap removal system of claim 15, wherein the gripper assembly is pivotably coupled to the pivot arm.

17. The wrap removal system of claim 15, and further comprising an air jet coupled to the pivot arm and operable to direct air at a downward angle between the load and the film wrap.

18. The wrap removal system of claim 1, wherein the gripper assembly is a first gripper assembly operable to selectively engage a forward face of the load, the wrap removal system further comprising a second gripper assembly pivotably coupled to the beam and operable to selectively engage the forward face of the load.

19. The wrap removal system of claim 18, and further comprising a third gripper assembly pivotably coupled to the beam and operable to selectively engage a first lateral face of the load and a fourth gripper assembly pivotably coupled to the beam and operable to selectively engage a second lateral face of the load substantially opposite the first lateral face.

20. The wrap removal system of claim 19, wherein each of the first, second, third, and fourth gripper assemblies is coupled to a vacuum blower through a main header extending through the beam.

21. The wrap removal system of claim 1, wherein the cutter assembly includes a pair of slitter blades defining a downwardly-facing nip therebetween.

22. A method of removing a film wrap from a load on a conveyor with a wrap removal system, the method comprising: engaging the film wrap on a first vertical face of the load adjacent a top edge of the load; pulling a portion of the film wrap away from the first vertical face of the load; inserting at least a portion of a cutter assembly between the load and the portion of the film wrap that is pulled away from the first vertical face of the load; cutting the film wrap with the cutter assembly; and moving the cutter assembly vertically downward from a first position adjacent the top edge of the load to a second position adjacent a bottom edge of the load to allow separation of the film wrap from the load.

23. The method of claim 22, wherein the cutter assembly includes a first cutting mechanism having a first slitter blade, the method further comprising driving the first slitter blade of the first cutting mechanism with a first belt to rotate in a first direction.

24. The method of claim 23, wherein the cutter assembly includes a second cutting mechanism engaged with the first cutting mechanism, the method further comprising driving a second slitter blade of the second cutting mechanism to rotate in a second direction opposite the first direction.

25. The method of claim 24, wherein the second slitter blade of the second cutting mechanism is driven by a second belt, the method further comprising engaging a portion of the film wrap adjacent the cutter assembly with the second belt, and pulling the engaged portion of the film wrap towards the first and second slitter blades.

26. The method of claim 24, wherein the first belt is frictionally engaged with a second belt of the second cutting mechanism, the method further comprising driving the second belt and the second slitter blade of the second cutting mechanism with the first belt.

27. The method of claim 22, wherein engaging the film wrap on a first vertical face of the load adjacent a top edge of the load includes placing a vacuum face of a gripper assembly onto an outside surface of the film wrap thereby defining a vacuum chamber, and fluidly coupling the vacuum face with an intake side of a vacuum source.

28. The method of claim 27, wherein engaging the film wrap on a first vertical face of the load adjacent a top edge of the load includes pulling air from the vacuum chamber through a plurality of cone-shaped apertures in the vacuum face that taper down in diameter towards the vacuum source.

29. The method of claim 27, and further comprising mechanically clamping a top edge of the film wrap adjacent the top edge of the load with the gripper assembly.

30. The method of claim 27, and further comprising repositioning a valve between the vacuum source and the vacuum chamber to fluidly couple the vacuum chamber with an outlet side of the vacuum source to release the film wrap.

31. The method of claim 27, and further comprising pivoting the gripper assembly relative to the load to pull the film wrap away from the first vertical face of the load.

32. The method of claim 31, and further comprising moving the load on the conveyor during pivoting of the gripper assembly.

33. The method of claim 22, and further comprising engaging the film wrap on a second vertical face of the load and a third vertical face of the load with a pair of side gripper assemblies, both of the second and third vertical faces being adjacent to the first vertical face, the film wrap being retained by at least one of the side gripper assemblies after the film wrap is cut.

34. The method of claim 33, and further comprising feeding the film wrap from at least one of the side gripper assemblies to a disposal system.

35. The method of claim 22, and further comprising directing a flow of air between the load and the film wrap after cutting of the film wrap.

36. The method of claim 22, wherein the cutter assembly includes a first cutting mechanism and a second cutting mechanism, and the method further comprising plunging a portion of the second cutting mechanism into an exterior surface of the film wrap.

37. A wrap removal system for removing a film wrap from a load on a conveyor, the wrap removal system comprising: an upright support member; an overhead beam coupled to the support member; a first gripper assembly pivotably coupled to the overhead beam by a pivot arm and movable between a first position remote from the load and a second position adjacent the load, the first gripper assembly including a vacuum face defining a vacuum chamber in fluid communication with a vacuum source and operable to engage the film wrap and pull the film wrap away from the load; a cutter assembly movable relative to the support member and operable to cut the film wrap to allow separation of the film wrap from the load; and an air jet coupled to the pivot arm and fluidly coupled to a compressed air source, the air jet being positioned to direct air in between the load and the film wrap.

38. The wrap removal system of claim 37, and further comprising a pneumatic actuator coupled to the pivot arm and operable to move the first gripper assembly between the first position and the second position, the pneumatic actuator being fluidly coupled to the compressed air source.

39. The wrap removal system of claim 37, and further comprising a second gripper assembly pivotably coupled to the overhead beam by a second pivot arm and movable between a first position remote from the load and a second position adjacent the load, the second gripper assembly including a second vacuum face defining a second vacuum chamber in fluid communication with the vacuum source and operable to engage the film wrap and pull the film wrap away from the load, and a second air jet coupled to the second pivot arm and fluidly coupled to the air source, the second air jet being positioned to direct air in between the load and the film wrap.

40. The wrap removal system of claim 37, wherein the cutter assembly is positionable adjacent a leading face of the load between a first side face and a second side face of the load, wherein the air jet is positioned to direct air toward at least one of the first side face and the second side face to push the film wrap away from the cutter assembly.

41. The wrap removal system of claim 40, wherein the load includes a trailing face opposite the leading face, the air jet being positioned to direct air along the first and second side faces of the load towards the trailing face to inflate the wrap.

42. A method of removing a film wrap from a load on a conveyor with a wrap removal system, the method comprising: pulling a portion of the film wrap away from a first vertical face of the load; rotating a cutter member having a cutter assembly from a retracted position remote from the first vertical face of the load to an extended position adjacent the first vertical face of the load; engaging the portion of the film wrap that is pulled away from the first vertical face of the load with the cutter assembly; cutting the film wrap with the cutter assembly to allow separation of the film wrap from the load; rotating the cutter member from the extended position to the retracted position; engaging the film wrap adjacent a second vertical face of the load; and advancing the load along the conveyor away from the film wrap.

43. The method of claim 42, and further comprising moving the cutter assembly vertically downward along a track supported by the cutter member during cutting of the film wrap.

44. The method of claim 42, and further comprising rotating a first slitter blade of the cutter assembly.

45. The method of claim 44, and further comprising rotating a second slitter blade of the cutter assembly that is engaged with the first slitter blade.

46. The method of claim 45, wherein the second slitter blade is driven by a belt, and the method further comprising engaging a surface of the film wrap and pulling the film wrap towards a cutting area between the first and second slitter blades.

47. The method of claim 46, and further comprising plunging a portion of the cutter assembly into an outer surface of the film wrap prior to cutting the film wrap.

48. A cutter assembly coupled to a pivotable cutter member of a wrap removal system for removing a film wrap from a load on a conveyor, the cutter assembly comprising: a first cutting mechanism including a first slitter blade driven by a first belt; a second cutting mechanism including a second slitter blade driven by a second belt, wherein the second belt is driven by contact with the first belt; and a motor coupled to the first belt to drive the first belt.

49. The cutter assembly of claim 48, wherein the first belt is wrapped around a pair of horizontally-spaced pulleys, and the second belt is wrapped around a pair of vertically-spaced pulleys.

50. The cutter assembly of claim 49, wherein the pair of vertically-spaced pulleys includes a first pulley having a first diameter and being substantially coaxial with the second slitter blade and a second pulley having a second diameter smaller than the first diameter.

51. The cutter assembly of claim 50, wherein the second diameter is less than about 1 inch.

52. The cutter assembly of claim 50, wherein the second belt contacts the first belt adjacent the first pulley, and the second pulley extends downwardly below the first pulley to define a lowermost point of the cutter assembly.

53. The cutter assembly of claim 48, wherein the first slitter blade and the second slitter blade define a downwardly-facing nip therebetween.

54. The cutter assembly of claim 53, wherein the first and second slitter blades overlap a distance between about 0.03125 inches and about 0.0625 inches.

55. A gripper assembly coupled to an overhead beam of a wrap removal system for removing a film wrap from a load on a conveyor, the gripper assembly comprising: a body; a vacuum face coupled to the body and including a peripheral gasket capable of defining a substantially continuous vacuum chamber in fluid communication with a vacuum source when pressed against the film wrap; and a plurality of spaced-apart vacuum ducts in communication with the vacuum chamber and defining a plurality of vacuum sub-chambers.

56. The gripper assembly of claim 55, wherein the vacuum chamber is fluidly coupled to the vacuum source through the plurality of vacuum ducts.

57. The gripper assembly of claim 56, wherein each of the plurality of vacuum ducts is substantially cone-shaped, tapering down in diameter away from the vacuum chamber.

58. The gripper assembly of claim 57, wherein each of the plurality of vacuum ducts has a smallest cross-sectional area substantially equivalent to the area of a circle having a diameter of about 3/32 inches.

59. The gripper assembly of claim 56, wherein each of the plurality of vacuum ducts defines a contact area at the vacuum face that is at least 50 times as large as a smallest cross-sectional area of each of the plurality of vacuum ducts.

60. The gripper assembly of claim 56, wherein the plurality of vacuum ducts defines a sum total contact area that is between about 50 percent and about 75 percent of a total area of the vacuum face.

61. The gripper assembly of claim 56, wherein each of the plurality of vacuum ducts defines a contact area at the vacuum face that is substantially equivalent to the area of a circle having a diameter of about 11/16 inches.

62. The gripper assembly of claim 55, wherein the gripper assembly is pivotably coupled to the overhead beam through a pivot arm.

63. The gripper assembly of claim 62, wherein the gripper assembly is pivotably coupled to the pivot arm.

64. The gripper assembly of claim 63, wherein the gripper assembly is pivotably about a substantially horizontal axis relative to the pivot arm.

65. The gripper assembly of claim 55, wherein the gripper assembly includes at least 100 vacuum ducts.

66. The gripper assembly of claim 65, wherein the gripper assembly includes between about 400 and about 500 vacuum ducts.

Description:

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of prior filed U.S. Provisional Application No. 60/855,021, filed Oct. 27, 2006, the entire contents of which are incorporated by reference.

BACKGROUND

The present invention relates to a wrap removal system for automatically removing stretch wrap from a palletized load.

Products and article containers are typically shipped on a pallet whereby a wrap covering is wrapped around the load to secure, hold and stabilize the load. A palletized load may have multiple layers of wrap wrapped about a width of the load and extending a height of the load. Once the load reaches its destination, the wrap must be removed prior to further processing of the articles contained in the load. In some situations, the wrap is manually cut and removed from the load. Such a process is inefficient, time-consuming, and difficult, for example, because loads may reach heights of 110 inches or more. Some wrap removal machines are known for cutting and removing wrap from a load; however, such machines are not adaptable to work with loads of varying height and have poor control of the wrap after it has been removed from the load. Further, current processes for removing the wrap result in damage to the load by the wrap. The present invention relates to

SUMMARY

In one embodiment, the invention provides a wrap removal system for removing a film wrap from a load on a conveyor. The wrap removal system includes an upright support member, a beam coupled to an upper extent of the support member for movement along a height of the support member, a gripper assembly coupled to the beam and operable to engage the film wrap to create a space between the load and the film wrap, and a cutter assembly.

In another embodiment, the invention provides a method of removing a film wrap from a load on a conveyor with a wrap removal system. The film wrap is engaged on a first vertical face of the load adjacent a top edge of the load. A portion of the film wrap is pulled away from the first vertical face of the load. At least a portion of a cutter assembly is inserted between the load and the portion of the film wrap that is pulled away from the first vertical face of the load. The film wrap is cut with the cutter assembly. The cutter assembly is moved vertically downward from a first position adjacent the top edge of the load to a second position adjacent a bottom edge of the load to allow separation of the film wrap from the load.

In yet another embodiment, the invention provides a wrap removal system for removing a film wrap from a load on a conveyor. The wrap removal system includes an upright support member, an overhead beam coupled to the support member, and a first gripper assembly pivotably coupled to the overhead beam by a pivot arm and movable between a first position remote from the load and a second position adjacent the load. The first gripper assembly includes a vacuum face defining a vacuum chamber in fluid communication with a vacuum source and operable to engage the film wrap and pull the film wrap away from the load. A cutter assembly is movable relative to the support member and operable to cut the film wrap to allow separation of the film wrap from the load. An air jet is coupled to the pivot arm and fluidly coupled to a compressed air source, the air jet being positioned to direct air in between the load and the film wrap.

In yet another embodiment, the invention provides a method of removing a film wrap from a load on a conveyor with a wrap removal system. A portion of the film wrap is pulled away from a first vertical face of the load. A cutter member having a cutter assembly is rotated from a retracted position remote from the first vertical face of the load to an extended position adjacent the first vertical face of the load. The portion of the film wrap that is pulled away from the first vertical face of the load is engaged with the cutter assembly. The film wrap is cut with the cutter assembly to allow separation of the film wrap from the load. The cutter member is rotated from the extended position to the retracted position. The film wrap is engaged adjacent a second vertical face of the load, and the load is advanced along the conveyor away from the film wrap.

In yet another embodiment, the invention provides a cutter assembly coupled to a pivotable cutter member of a wrap removal system for removing a film wrap from a load on a conveyor. The cutter assembly includes a first cutting mechanism including a first slitter blade driven by a first belt. A second cutting mechanism includes a second slitter blade driven by a second belt. The second belt is driven by contact with the first belt. A motor is coupled to the first belt to drive the first belt.

In yet another embodiment, the invention provides a gripper assembly coupled to an overhead beam of a wrap removal system for removing a film wrap from a load on a conveyor. The gripper assembly includes a body, a vacuum face coupled to the body and including a peripheral gasket capable of defining a substantially continuous vacuum chamber in fluid communication with a vacuum source when pressed against the film wrap, and a plurality of spaced-apart vacuum ducts in communication with the vacuum chamber and defining a plurality of vacuum sub-chambers.

Other aspects of the invention will become apparent by consideration of the detailed description and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 and 2 are perspective views of a wrap removal system according to one embodiment of the invention, and the system in use with a palletized load supported by a conveyor system.

FIG. 3 is a front view of the wrap removal system of FIGS. 1 and 2 in use with the palletized load supported by the conveyor.

FIG. 4 is a first side view of the wrap removal system of FIGS. 1 and 2 in use with the palletized load supported by the conveyor.

FIG. 5 is an opposite side view of the wrap removal system of FIGS. 1 and 2 in use with the palletized load supported by the conveyor.

FIGS. 6-9 are perspective views of the wrap removal system of FIGS. 1 and 2.

FIG. 10 is a rear view of an overhead portion and a beam of the wrap removal system of FIGS. 1 and 2.

FIG. 11 is a perspective view of the overhead portion and the beam of FIG. 10.

FIG. 12 illustrates a gripper assembly of the wrap removal system with a clamp mechanism in an open position.

FIG. 13 illustrates the gripper assembly of the wrap removal system with the clamp mechanism in a closed position.

FIG. 14 illustrates a cutting assembly of the wrap removal system.

FIGS. 15 and 16 illustrate the cutting assembly of the wrap removal system.

FIG. 17 is a cross-sectional view of the gripper assembly taken along line 17-17 of FIG. 11.

Before any embodiments of the invention are explained in detail, it is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the following drawings. The invention is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.

DETAILED DESCRIPTION

FIGS. 1-5 illustrate a wrap removal system 10, or unwrapping apparatus, used in conjunction with a conveyor system 14 to remove film wrap such as plastic stretch wrap, from a palletized load 18. In the illustrated embodiment, the load 18 includes a plurality of articles 22 supported by a pallet 26, whereby the wrap is used to secure and stabilize the articles 22 on the pallet 26. Loads 18 enter a facility for processing, for example, at a receiving station, and advance along a conveyor 30 of the conveyor system 14 in a first direction. A belt of the conveyor 30 is removed for clarity in FIGS. 1-3. The wrap removal system 10 cuts the wrap and removes the wrap from the load 18 to a disposal system 34. FIGS. 6-9 illustrate the wrap removal system 10 in greater detail without the conveyor system 14 or the load 18.

In the illustrated embodiment, the wrap removal system 10 includes a main support member 38 positioned adjacent to the conveyor system 14, on either side of the conveyor 30. An overhead beam 42 is movably coupled to the support member 38 such that the beam 42 travels in a generally vertical direction along the support member 38. Four gripper assemblies 46 are pivotally coupled to the beam 42 and arranged to engage three sides or faces of the wrapped load 18. Two gripper assemblies 46A, 46B are configured to engage the wrap on a leading face 18A of the load 18. In the illustrated embodiment, the leading face 18A is substantially vertically oriented. Each of the remaining gripper assemblies 46C, 46D is configured to engage the wrap on one of the lateral side faces 18B of the load 18, which are also vertically oriented in the illustrated embodiment. The gripper assemblies 46A-D engage the wrap and pull the wrap away from the load 18 to facilitate cutting and removal of the wrap.

The wrap removal system 10 also includes a cutter member 50 pivotally coupled to the main support member 38. The cutter member 50 includes a cutter assembly 54 for cutting the wrap from the load 18, whereby the cutter assembly 54 travels a height of the load 18 to cut the wrap. In the illustrated embodiment, the disposal system 34 is integrated with the wrap removal system 10 to collect the cut wrap from the load 18. In the illustrated embodiment, the disposal system 34 is positionable to the rear of the load 18 to prevent wrap from becoming entangled with the wrap removal system 10. Examples of the disposal system 34 include a spooler, a wrap bundler, or a holding container, although other known means for disposing of the wrap may be used. The spooled and/or bundled wrap is eventually taken away for recycling or disposal.

Plastic stretch wrap (not shown) is wrapped about a height of the load 18 (FIGS. 1-5). It should be readily apparent to those of skill in the art that other types of known wrap material may be used. Each load 18 includes the leading face 18A that faces forward along the conveyor path, a trailing face 18C opposite the leading face 18A, and the side faces 18B. As will be discussed in further detail below, the leading gripper assemblies 46A, 46B engage the wrap at the leading face 18A of the load 18 and are equally spaced from a centerline L of the load 18 to engage a front portion of the wrap. The side gripper assemblies 46C, 46D engage the wrap at the lateral side faces 18B proximate the trailing face 18C to support back corners of the wrap. In another embodiment, the gripper assemblies 46A-D may be positioned elsewhere on the load faces 18A-C.

FIGS. 10 and 11 illustrate the overhead beam 42 and the gripper assemblies 46 of the wrap removal system 10 according to one embodiment of the invention. The overhead beam 42 is coupled to the main support member 38, which is in turn coupled to a weighted bottom block 58 and positioned adjacent one side of the conveyor 30. In one embodiment, the bottom block 58 extends under the conveyor 30 of the conveyor system 14 and includes a weight 62 to prevent tipping of the wrap removal system 10. The support member 38 extends upwardly from the bottom block 58 and includes a track 66 upon which the beam 42 travels. The beam 42 is movably coupled to the support member 38 at the track 66. The beam 42 extends outwardly from the support member 38 such that the beam 42 is positioned above the conveyor 30, and includes rollers 70 to facilitate travel along the track 66. The beam 42 travels along a height of the support member 38 to position the gripper assemblies 46A-D proximate a top of the load 18. In the illustrated embodiment, a linear servo motor 74 causes movement of the beam 42 along the support member 38, although in further embodiments other known actuators or motors may be used to move the beam 42 relative to the main support member 38.

The beam 42 supports each of the gripper assemblies 46A-D. Each of the gripper assemblies 46A-D extends downwardly from an arm 78 pivotally coupled to the beam 42. In the illustrated embodiment, the leading gripper assemblies 46A, 46B are arranged to engage the leading face 18A of the load 18 proximate the centerline L of the load 18. The side assemblies 46C, 46D are arranged to engage the respective lateral side faces 18B of the load 18 proximate the trailing face 18C. The gripper assemblies 46A-D engage the wrap proximate a top edge of the wrap (generally at a top edge of the load 18). In the illustrated embodiment four gripper assemblies 46A-D are used, although in other constructions fewer or more gripper assemblies are included, which may be alternately positioned and/or spaced to engage the wrap at the same or different locations on the load 18. Alternately, other known gripper assemblies may be used, such as a single mechanism gripper, an array of mechanical grippers, or the like. The side gripper assemblies 46C, 46D are shortened in some constructions to a vertical length about one third of the illustrated length. The reduced length reduces the overall suction area thereby reducing the severity of any possible vacuum leakage that may occur between the gripper assemblies 46C, 46D and the wrap.

Each of the gripper assemblies 46A-D is coupled to and extends downwardly from one of the arms 78. Each arm 78 is pivotally coupled to the beam 42 at a bracket 82 that defines a pivot point. In some embodiments, the bracket 82 includes a pair of pillow block bearings. Each arm 78 includes a pneumatic actuator 86 for pivoting the arm 78, and thereby the respective gripper assembly 46A-D, about the pivot point defined by the bracket 82. In the illustrated embodiment, the pivot points defined by the brackets 82 are equally spaced about a centerline C of the conveyor 30. The arms 78 pivot between a rest position, in which the gripper assemblies 46A-D are remote from the load 18, and an engagement position, in which the gripper assemblies are positioned adjacent the load 18. In the rest position (not shown), the arms 78 are pivoted away from the load 18 and the conveyor 30 such that the load 18 may travel along the conveyor 30 without obstruction by the gripper assemblies 46A-D. In the engagement position, the arms 78 are pivoted towards the load 18 such that the gripper assemblies 46A-D face the load 18 for engagement with the wrap. In one embodiment, the arms 78 pivot between about 90 degrees and about 130 degrees between the rest position and the engagement position. In a further embodiment, other known actuators may be used to cause pivoting movement of the arms 78, such as a linear servo slide assembly, a linear actuator, a gear rack assembly, or the like.

A first end of each of the gripper assemblies 46A-D is coupled to a free end of the respective arm 78. Each of the gripper assemblies 46A-D is coupled to the respective arm 78 such that when the arm 78 is in the engagement position, a vacuum face 90 of the gripper assembly 46A-D faces the load 18. The free end of each arm 78 includes a support bracket 94 for coupling the respective gripper assembly 46A-D. The gripper assemblies 46A-D are free to rotate about a vertical axis with respect to the respective support brackets 94 and further include respective pneumatic actuators 98, or pneumatic cylinders, for pivoting the gripper assemblies 46A-D relative to the pivot arms 78. The axis of this pivot is horizontal and parallel with the respective vacuum face 90 such that the vacuum faces 90 of the gripper assemblies 46A-D do not have to be vertical. In a further embodiment, other known actuators may be used to cause pivoting movement of the gripper assemblies 46A-D, such as an electric actuator or the like. The pneumatic actuators 98 are operable to rotate the gripper assemblies 46A-D on the horizontal axis to bring a bottom end of each of the gripper assemblies 46A-D towards the load 18 such that the bottom ends of the gripper assemblies 46A-D contact the load 18 before the upper ends of the gripper assemblies 46A-D as the pivot arms 78 pivot towards the load 18. In some embodiments, the support bracket 94 includes a pair of pillow block bearings that allow the gripper assemblies to rotate on a vertical axis. Thereby, the gripper assemblies 46A-D are free to pivot to align the respective vacuum faces 90 parallel to the faces 18A, 18B of the load 18 and/or parallel to the wrap as it moves off of the load faces 18A, 18B. It should be readily apparent to those of skill in the art that in a further embodiment, one or more of the gripper assemblies 46A-D do not pivot relative to the arm 78, or about a vertical axis to position the vacuum face 90 with respect to the load 18.

In still another embodiment, the side gripper assemblies 46C, 46D are not pivotable relative to the arms 78. Rather, the gripper assemblies 46C, 46D are rotatably coupled to the free ends of the arms 78 such that the gripper assemblies 46C, 46D may rotate freely within a given range of motion about a vertical axis with respect to the arms 78.

In the illustrated embodiment, valves (not shown) operate the pneumatic cylinders 86 to pivot the arms 78 between the rest positions and the engagement positions. Each valve allows the respective cylinder 86 to have four different conditions of cylinder actuation: both ends exhausted, one end pressurized and the opposite end exhausted, the one end exhausted and the opposite end pressurized, and both ends pressurized. Further, air pressure for each end is individually adjustable. During operation, a controller controls motion of the arms 78, but also the force with which the arms 78 actuate. For example, as the leading gripper assemblies 46A, 46B pivot to their engagement positions, a large force is used, but once fully pivoted, the valve condition may change (i.e., lower the net cylinder force) such that the load 18 may be capable of moving the gripper assemblies 46A, 46B out of the fully extended engagement positions. A similar function is available for the arms 78 of the side gripper assemblies 46C, 46D.

Each of the gripper assemblies 46A-D includes a main body 102, a clamp mechanism 106, and a clamp housing 110 (FIGS. 12 and 13). The main body 102 includes the vacuum face 90, which at least partially defines a vacuum chamber when engaged with the wrap. In the illustrated embodiment, a sealing member or gasket 112 is provided at the periphery of each of the vacuum faces 90. The gaskets 112 define respective boundaries of the vacuum chambers, each of which is a substantially continuous rectangular volume in the illustrated embodiment. Each vacuum face 90 includes an array of openings 114 in its surface. A vacuum duct 118 (FIG. 17) extends through the main body 102 from each of the openings 114 to a rear face of the main body 102 opposite the vacuum face 90, whereby fluid communication is established between the vacuum chamber and a vacuum source.

During use, air is sucked from the vacuum chamber through the vacuum ducts 118 to create a suction force through the openings 114, whereby the vacuum face 90 of the respective gripper assembly 46A-D engages the wrap on the load 18. Referring to FIG. 17, the vacuum ducts 118 of each of the gripper assemblies 46A-D branch from a main air header 122 (FIGS. 10 and 11) that communicates with a vacuum source, such as a vacuum blower 126 to provide the suction force to the gripper assemblies 46A-D. In the illustrated embodiment, the main air header 122 is an internal volume defined by the beam 42, although a separate main air hose either within or outside of the beam 42 is used in other embodiments of the invention.

An example of the vacuum blower 126 used in the wrap removal system 10 is provided by Gast Manufacturing, Inc. (Benton Harbor, Mich.). In one embodiment, each of the gripper assemblies 46A-D includes a vacuum level sensor to detect how well the wrap has been engaged or if it has been engaged at all. If a number of openings 114 in the vacuum face 90 are not covered, causing the vacuum level to be below a predetermined value, the sensor will detect a lower suction force and send a signal to the controller. A 2-position vacuum control valve 210, best shown in FIGS. 6 and 7, is fluidly coupled to the vacuum blower 126 to selectively couple the main air header 122 with either an inlet/intake 126A or an outlet/exhaust 126B of the vacuum blower 126. The valve 210 allows suction to be established and stopped almost instantaneously without stopping or reversing the vacuum blower 126.

Additional vacuum cutoff valves 128 (FIGS. 1, 2, 6, 8, and 9) may be positioned between the vacuum blower 126 and each of the gripper assemblies 46A-D. The cutoff valves 128 may be selectively actuated to shut off suction to an associated one or more of the gripper assemblies 46A-D when not in use and/or when a vacuum leak is detected, whereby suction to the other gripper assemblies 46A-D is not compromised and a single vacuum blower 126 can service all of the gripper assemblies 46A-D. In some embodiments, a first vacuum cutoff valve 128 is provided between the vacuum blower 126 and the leading gripper assemblies 46A, 46B, and a second vacuum cutoff valve 128 is provided between the vacuum blower 126 and the side gripper assemblies 46C, 46D.

Returning to the structure of the gripper assemblies 46A-D, the vacuum ducts 118 are tapered down in cross-sectional area away from the respective openings 114 and away from the vacuum face 90. FIGS. 10-13 and 17 illustrate the gripper assemblies 46A-D in greater detail. Although the cross-section of FIG. 17 is taken through the side gripper assembly 46D, it illustrates features common to the gripper assemblies 46 in general. In the illustrated embodiment, each vacuum duct 118 is conical, including a large cross-sectional area at the opening 114 and a small cross-sectional area at a distance spaced from the vacuum face 90. In one embodiment, the openings 114 have a diameter of about 11/16 inches (0.6875 inches) and the smallest portion of each of the vacuum ducts 118 has a diameter of about 3/32 inches (0.09375 inches). Thus, the cross-sectional area of the vacuum duct 118 at the opening 114 is at least 50 times as large as the cross-sectional area of the vacuum duct 118 at its smallest area. The conical shape of the vacuum ducts 118 enables a relatively large surface area of wrap to be engaged while limiting the detrimental effects (by limiting the flow of air) of a vacuum leak at any of the openings 114.

In the illustrated embodiment, the gripper assemblies 46A-D include vacuum faces 90 of about 48 inches long by about 5 inches wide and are provided with 441 openings, the openings 114 being spaced ¾ inches on-center such that about 68.2 percent of the total vacuum face 90 is covered by “suction area” (i.e., the openings 114). As mentioned above, the side gripper assemblies 46C, 46D are shortened in some constructions to a vertical length about one third of the illustrated length. In such a construction, the side gripper assemblies 46C, 46D may have a vertical length of approximately 17 inches and include greater than 100 but less than 175 openings 114 and vacuum ducts 118 having a similar arrangement as described above.

Ideally, the gasket 112 of each of the gripper assemblies 46A-D creates a perfect seal on the wrap and a single, continuous vacuum chamber is formed against the wrap. However, in some embodiments (due to unevenness of the load 18 surfaces and seams/bulges in the wrap) a certain number of the openings 114 form a vacuum seal against the wrap, while others of the openings 114 do not. Thus, rather than the peripheral gasket 112 defining a single vacuum chamber, a number of the vacuum ducts 118, corresponding to the openings 114 that seal against the wrap, define a plurality of separate vacuum sub-chambers (in parallel with each other).

The clamp mechanisms 106 of the gripper assemblies 46A-D are housed in the respective clamp housings 110. Each clamp mechanism 106 pivots between an open position (FIG. 12) and a closed position (FIG. 13). Each clamp housing 110 is coupled to an upper edge of the main body 102, whereby the clamp housing 110 is pivotally coupled to the support bracket 94 of the arm 78. Each clamp mechanism 106 includes a bracket 130 pivotally coupled to the housing 110 and a plate 134 coupled to the bracket 130. In the open position, the clamp mechanism 106 is housed within the clamp housing 110 and does not interfere with positioning of the respective gripper assemblies 46A-D with the load 18. In the closed position, the plate 134 of the clamp mechanism 106 clamps down on the top edge of the wrap to secure a positive mechanical grasp. In one embodiment, the plates 134 clamp down on a top plate of the load 18 to stabilize the load 18 and prevent articles 22 from falling as pressure is released when the wrap is cut. In the illustrated embodiment, pneumatic actuators 138, or pneumatic cylinders, actuate the clamp mechanisms 106 between their open and closed positions; however, in a further embodiment, other known actuators may be used to cause pivoting movement of the clamp mechanisms 106, such as an electric actuator or the like.

FIGS. 14-16 illustrate the cutter member 50 and cutter assembly 54 of the wrap removal system 10. The cutter member 54 is pivotally coupled to the main support member 38 at brackets 142, which define a pivot axis. The cutter member 50 forms a “door” having one side edge 50A coupled the main support member and an opposite, free side edge 50B. The cutter member 50 pivots about the axis of the brackets 142 between a first or retracted position (FIG. 15), in which the cutter member 50 is remote from the load 18 and clear of the conveyor 30 such that the conveyor path is free of obstruction, and a second or extended position (FIGS. 1-9 and 14), in which the cutter member 50 extends outwardly from the support member 38 above the conveyor 30 to a location adjacent the load 18. In the illustrated embodiment, the cutter member 50 is pivoted between about 90 degrees and about 110 degrees from the first position to the second position such that a face of the cutter member 50 is aligned substantially parallel to the leading face 18A of the load 18.

Referring particularly to FIGS. 14 and 15, pneumatic actuators 146, or cylinders, are coupled between support plates 150 of the main support member 38 and the cutter member 50. The pneumatic actuators 146 actuate the cutter member 50 between the first position and the second position; however, in a further embodiment, other known actuators may be used to cause pivoting movement of the cutter member 50, such as an electric actuator or the like.

The free edge 50B of the cutter member 50 supports a track 154 extending a height of the cutter member 50, and the cutter assembly 54 is movably coupled to the track 154. The cutter assembly 54 includes a guide plate 158 (FIG. 16) for guiding the cutter assembly 54 along the track 154. The cutter assembly 54 travels along the height of the track 154 between an upper extent 154A (FIG. 15) of the track 154 and a lower extent 154B (FIGS. 14 and 16) of the track 154. In the illustrated embodiment, a linear servo motor 162 (FIG. 15) causes movement of the cutter assembly 54 along the track 154, although in further embodiments other known actuators or motors may be used to move the cutter assembly 54.

Referring primarily to FIG. 16, the cutter assembly 54 includes a first cutting mechanism 166 and a second cutting mechanism 170. The first cutting mechanism 166 includes a belt 174 extending around two pulleys 178, 182 of approximately equal diameter, wherein the first pulley 178 is driven by a motor such as a gearmotor 180 and the second pulley 182 is idle. The second cutting mechanism 170 includes a belt 186 extending around two pulleys 190, 194 of differing diameters, wherein the first pulley 190 has a diameter substantially equal to the diameter of the pulleys 178, 182 of the first cutting mechanism 166. In one embodiment, the diameter of the pulleys 178, 182, 190 is about 2.3 inches, and the diameter of the second pulley 194 of the second cutting mechanism 170 is about 0.875 inches. The first pulley 190 of the second cutting mechanism 170 and the idler pulley 182 of the first cutting mechanism 166 are positioned such that the outside surfaces of the belts 174, 186 are in contact. Thereby, motion of the first belt 174 induces motion of the second belt 186 as shown by the arrows in FIG. 16. All of the pulleys 178, 182, 190, 194 rotate about parallel axes. In the illustrated embodiment, the pulleys 178, 182 of the first cutting mechanism 166 are horizontally spaced apart, and the pulleys 190, 194 of the second cutting mechanism 170 are vertically spaced apart, the second pulley 194 of the second cutting mechanism 170 defining a lowermost point of the cutter assembly 54.

In some embodiments, the first belt 174 has a double-V cross-section to accommodate the drive forces of the gearmotor 180. The second belt 186 can have a substantially flat, rectangular cross-section. In one embodiment, the second pulley 194 of the second cutting mechanism 170 consists of one or more small diameter ball bearings mounted on a fixed shaft, for example, the shaft of a bolt. In the illustrated embodiment, the second pulley 194 consists of three ball bearings having outer diameters of about 0.875 inches.

As shown in FIG. 16, a slitter blade 198 is coupled to the idler pulley 182 of the first cutting mechanism 166, and a slitter blade 202 is coupled to the first pulley 190 of the second cutting mechanism 170, whereby each blade 198, 202 rotates with the respective pulley 182, 190. In the illustrated embodiment, the blades 198, 202 have a diameter greater than the pulleys 182, 190 with the belts 174, 186 wrapped around them, for example, approximately 0.075 inches larger. During operation, the blades 198, 202 overlap and the wrap is cut by a scissors action where the blades 198, 202 make contact. In some embodiments, the blades 198, 202 overlap a distance between about 0.03125 inches and 0.0625 inches. When the cutter member 50 is in the second position, the cutter assembly 54 and particularly a cut area 206 where the cutting mechanisms 166, 170 abut, are generally centered about the centerline L of the load 18. In the illustrated embodiment, the cut area 206 defines a downwardly-facing or downwardly-opening nip into which the wrap is introduced to the slitter blades 198, 202.

In operation, the cutter assembly 54 is positioned at a top edge of the wrap such that the wrap is positioned proximate the cut area 206. As the cutter assembly 54 travels downward along the track 154, the blades 198, 202 rotate to cut the wrap. In a further embodiment, there is a gap between the cutting mechanisms 166, 170 through which the wrap passes for cutting by the blades 198, 202. It should be readily apparent to those of skill in the art that in further embodiments other known cutting means may be coupled to the cutter member 50 for similar operation.

Operation of the wrap removal system 10, including the beam 42, the gripper assemblies 46, the cutter member 50 and the cutter assembly 54, are controlled by a controller (not shown), such as a PLC. The controller controls operation of the wrap removal system 10 and the conveyor system 14 based upon a pre-set program and feedback from sensors, or in another embodiment, user commands, pre-set parameters and sensor feedback. The controller commands the wrap removal system 10 and associated components to perform a wrap removal cycle including a cutting cycle, as discussed below. In one embodiment, the wrap removal system 10 includes one or more sensors for locating a top of the load 18 and sensing when the beam 42 (e.g., a bottom surface of the beam 42 or brackets 82 of the arms 78) is properly positioned relative to the load 18. Examples of the sensors used with the wrap removal system 10 include proximity switches and photo-eyes, although other known sensors may be used such as a photocell, a sonic senor, a vision sensor, a photoelectric sensor, an encoder, or any other known position sensor.

During operation, the load 18 is transported along the conveyor 30 to the wrap removal system 10. Prior to initiation of a cutting cycle, the wrap removal system 10 is positioned in an initial position. In the initial position, the beam 42 is raised to the upper extent of the track 66, the cutter member 50 is in the first position clear of the conveyor 30, the pivot arms 78 are in the rest position such that the gripper assemblies 46A-D are in the retracted positions clear of the conveyor 30. Further, the gripper assemblies 46A-D are de-activated such that no suction force is provided thereto.

The wrap removal system 10 receives a signal from a receiving conveyor system (not shown) or the conveyor system 14 that the load 18 is present in the system 14 and ready for processing. The conveyor 30 advances the load 18 to the wrap removal system 10 and a first photo-eye sensor (not shown) mounted to the conveyor system 14. Once the load 18 reaches the first sensor, advancement of the load 18 along the conveyor 30 ceases. The load 18 stops with the leading face 18A positioned rearward of the main support member 38, although in a farther embodiment the leading face 18A may be aligned with the support member 38. The wrap removal system 10 seeks and locates a top of the load 18, for example with a photo sensor, and lowers the beam 42 along the track 66 until the beam 42 is positioned just above the top of the load 18 and/or the brackets 82 of the arms 78 are positioned about the centerline L of the load 18. In one embodiment, a photo-eye sensor detects a top of the load 18 and signals a timer delay to stop lowering the beam 42 before the beam 42 contacts the load 18. In the illustrated embodiment, the beam 42 is lowered until the upper edges of the gripper assemblies 46A-D are substantially aligned with the top of the load 18. Movement of the beam 42 relative to the conveyor 30 allows for use of the wrap removal system 10 with loads 18 of varying height. In some embodiments, the beam 42 may travel about 50 inches between a maximum height and a minimum height, although other ranges are optional.

Next, the arms 78 of the leading gripper assemblies 46A, 46B are pivoted to the engagement position such that the openings 114 face the leading face 18A of the load 18. The cutter member 50 pivots to the second position such that the cutter assembly 54 faces the load 18. The conveyor 30 advances the load 18 forward until the leading face 18A contacts the vacuum faces 90 of the leading gripper assemblies 46A, 46B. In one embodiment, a second photo-eye sensor mounted to the conveyor system 14 or the main support member 38 detects when a leading edge 18A of the load 18 is properly positioned relative to the main support member 38. In another embodiment of the invention, advancement of the load 18 ceases when the load 18 pushes against the leading gripper assemblies 46A, 46B. In such embodiments, sensors (e.g., contact or pressure sensors) are provided to detect when the conveyor 30 has advanced the load 18 forward into contact with the leading gripper assemblies 46A, 46B.

Once the leading gripper assemblies 46A, 46B contact the load 18, the vacuum blower 126 is actuated to provide a suction force to the leading gripper assemblies 46A, 46B such that the vacuum faces 90 engage the wrap. A vacuum level sensor (not shown) associated with the gripper assemblies 46A-D detects the vacuum level, indicative of whether the wrap is held by the vacuum faces 90. The conveyor 30 reverses a set distance, e.g., approximately one to two inches, to move the load 18 away from the gripper assemblies 46A, 46B such that the gripper assemblies 46A, 46B pull the wrap away from the leading face 18A of the load 18, creating a gap therebetween. The gap provides space for the clamp mechanisms 106 and for the cutting mechanisms 166, 170 to engage the top edge of the wrap, although in some embodiments the gripper assemblies 46A, 46B may rotate away from the load 18 to increase the gap prior to cutting. In one embodiment, the suction force from the vacuum blower 126 pulls the wrap away from the load 18 a set distance. After the gripper assemblies 46A, 46B engage the wrap, the clamp mechanisms 106 are actuated to the closed position (FIG. 13). The plates 134 of the clamp mechanisms 106 clamp down on the top edge of the wrap to secure a positive mechanical grasp on the wrap.

The cutter member 50 can be rotated to the engagement position immediately after the leading gripper assemblies 46A, 46B are rotated to the engagement positions or after the gap is created between the wrap and the leading face 18A of the load 18. The cutter assembly 54, which is positioned at the upper extent 154A of the track 154 and substantially aligned with a centerline L of the load 18, is lowered towards the top edge of the wrap. As the cutter assembly 54 lowers, the second pulley 194 (i.e., smaller pulley) of the second cutting mechanism 170 contacts the top edge of the wrap. The belt 186 of the second cutting mechanism 170 is positioned inside the wrap and faces an interior surface of the wrap. The movement of the belt 174 pulls the wrap outwardly and upwardly away from the load 18. The cutting mechanisms 166, 170 pull the wrap between the two belts 174, 186 and through the cut area 206 to cut the wrap. In the illustrated embodiment, the cutter assembly 54 pauses after initial contact with the wrap to pull the top edge of the wrap onto the rotating surface of the first belt 174. The cutter assembly 54 is lowered along the track 154 from the top edge of the wrap through the bottom edge of the wrap (e.g., the lower extent 154B of the track 154) to cut the wrap along a length.

In one embodiment, the second cutting mechanism 170 does not contact the load 18, but is not positioned too far from the load 18 such that the wrap tears or the second cutting mechanism 170 pops out of the wrap. In one embodiment, the wrap removal system 10 includes sensors to ensure that the cutting mechanisms 166, 170 do not contact the load 18 or are too far from the load 18. To correct a position of the cutter assembly 54 with respect to the load 18, the conveyor 30 advances or reverses to move the load 18 an appropriate distance.

In some embodiments, and in some cutting sequences, the second cutting mechanism 170 can be plunged directly into the wrap. Under some circumstances, it may not be possible to pull the top edge of the wrap fully away from the load 18, whereby a gap can be created to insert at least a portion of the second cutting mechanism 170. In such circumstances, the small pulley 194 is pushed down into contact with an exterior surface of a portion of the wrap that is pulled away from the load 18 (although a portion of the wrap may still extend over the top edge of the load 18). The cutter assembly 54 can be lowered to press the pulley 194 into the wrap, locally deforming the wrap around the portion of the belt 186 that is wrapped around the pulley 194. The belt 186 frictionally engages the wrap and rotates to pull the top edge of the wrap off the load 18 and toward the cut area 206 for cutting. Similarly, the belt 186 is operable to pull the lower edge of the wrap off of the load 18 and towards the cut area 206. Thus, a load 18 having a “full wrap”, in which the wrap extends over the top edge and under a bottom edge of the load 18 or the pallet 26, can be unwrapped with the wrap removal system 10.

Once the cutter assembly 54 finishes the cut, the cutter member 50 opens, or pivots, back to the first position. As the cutter member 50 swings back to the first position, the cutter assembly 54 travels back up the track 154 to the upper extent 154A in preparation for another cutting cycle.

When the cutter member 50 clears the leading gripper assemblies 46A, 46B, while maintaining engagement with the wrap, the arms 78 of the leading gripper assemblies 46A, 46B are pivoted away from the load 18 to the rest position. Cut ends of the wrap open away from the load 18 as the leading gripper assemblies 46A, 46B pivot to the retracted positions clear of the conveyor 30. In one embodiment, the conveyor 30 advances the load 18, for example approximately 4-6 inches, to prevent the wrap from stretching as the arms 78 pivot about the axis of the brackets 82. Next, the arms 78 of the side gripper assemblies 46C, 46D move towards the load 18 to the engagement position such that the vacuum face 90 faces the respective side face 18B of the load 18. In one embodiment, once the arms 78 move to the engagement position, the side gripper assemblies 46C, 46D pivot to the engagement position such that the vacuum faces 90 contact the wrap. In still another embodiment, the side gripper assemblies 46C, 46D freely rotate relative to the free ends of the arms 78. In a further embodiment, the side gripper arms 78 may move simultaneously with or immediately after the arms 78 of the leading gripper assemblies 46A, 46B move to the engagement position. In one embodiment, a sensor mounted to the conveyor system 14 or the main support member 38 detects when the side gripper assemblies 46C, 46D are properly positioned with respect to the load 18.

Once the side gripper assemblies 46C, 46D contact the load 18, the vacuum blower 126 provides a suction force to the side gripper assemblies 46C, 46D as well such that the vacuum faces 90 engage the wrap and pull the wrap away from the load 18. This operation can be performed by opening one or more of the vacuum cutoff valves 128 between the side gripper assemblies 46C, 46D and the vacuum blower 126.

The vacuum level sensor in the gripper assemblies 46 detects whether the wrap is held by the vacuum faces 90. After the side gripper assemblies 46C, 46D engage the wrap, the respective clamp mechanisms 106 are actuated to the closed position. The plates 134 of the clamp mechanisms 106 clamp down on the top edge of the wrap to secure a positive grip on the wrap. In one embodiment, the arms 78 of the side gripper assemblies 46C, 46D retract slightly from the load 18 to allow the clamp mechanisms 106 to clamp the wrap. When the wrap is engaged by the side gripper assemblies 46C, 46D, the leading gripper assemblies 46A, 46B may release the wrap (after pulling the cut wrap away from the leading face 118A of the load 18).

In some embodiments, air jets 214A, 214B blow air into a space between the wrap and the load 18 to assist in separating the wrap from the load 18. The airjets 214A, 214B are coupled to the arms 78 of the leading gripper assemblies 46A, 46B and the side gripper assemblies 46C, 46D, respectively. The air jets 214A, 214B can be directed towards the gaps between the wrap and the load 18 to blow the wrap away from the load 18 after the wrap is fully cut. In some embodiments, the air jets 214A on the arms 78 of the leading gripper assemblies 46A, 46B may be active during cutting and directed to blow the cut edges of the wrap away from the cutter assembly 54. The air jets 214A, 214B are positioned to direct air along the lateral side faces 18B and towards the trailing face 18C of the load 18 to inflate the wrap and/or create separation between the load 18 and the wrap. In some embodiments, arms 78 of the side gripper assemblies 46C, 46D may pivot out of the engagement position to pull the wrap away from the load 18. In one embodiment, the side gripper assemblies 46C, 46D maintain a pulling force to the wrap under tension, whether or not actual movement of the gripper assemblies 46C, 46D occurs.

Furthermore, the wrap removal system 10 may include air jets (not shown) on the conveyor 30 positioned to blow air into a space between the wrap and the load 18 to assist in separating the wrap from the load 18. For example, each one of a first pair of air jets may be provided forward (downstream along the conveyor 30) of the beam 42 and positioned to blow air in a direction having upward, rearward (upstream along the conveyor 30), and laterally outward components. Each of the first pair of air jets may be positioned adjacent a bottom edge of the respective side faces 18B of the load 18. A second pair of air jets on the conveyor 30 may be provided rearward of the first pair of air jets and positioned to blow air in a direction having upward and rearward components. The air jets 214A, 214B positioned on the arms 78 along with the air jets provided on the conveyor 30 can be particularly useful in overcoming a static electrical attraction between the wrap and the load 18, for example between a plastic wrap and a load 18 containing plastic items. In some embodiments, a compressed air source is fluidly coupled to the air jets 214A, 214B and any additional air jets to provide a supply of air, although compressed gases other than air are optional. The compressed air source can also supply the pneumatic actuators of the wrap removal system 10.

To remove the wrap from the load 18, the conveyor 30 moves the load 18 forward. Simultaneously, the beam 42 raises along the track 66 of the main support member 38. Coordinated movement between the conveyor 30 and the beam 42 of the wrap removal system 10 pulls the wrap away from the load 18 as the load 18 continues to travel along the conveyor 30. Once the load 18 is clear of the wrap and the wrap removal system 10, up to three of the gripper assemblies 46A-D are de-activated to release the wrap. In the illustrated embodiment, the side gripper assembly 46D closest to the disposal system 34 remains activated to engage the wrap and feed, or engage, the wrap to the disposal system 34. Once the disposal system 34 receives the wrap, the remaining gripper assembly 46D is de-activated to release the wrap. The wrap removal system 10, and associated components, return to the initial position in preparation for the next load 18 and to begin another wrap removal cycle.

The stretch wrap removal system 10 is adjustable and adaptable to work with loads 18 of varying heights. The gripper assemblies 46 are arranged to engage wrap proximate a top of the load 18. Further, the gripper assemblies 46 are coupled to a beam 42 that travels in a vertical direction to locate the top of the load 18. Sensors and a controller determine when the beam 42 is properly positioned relative to the top of the load 18. Thereby, loads of varying heights may be used by the wrap removal system 10. The side arms 78 and gripper assemblies 46C, 46D provide better control as the wrap is removed from the load 18. Further, the wrap may be pulled up by raising the beam 42, which also improves the system's ability to remove wrap from the load 18 in a controlled fashion. In addition, the larger sized and number of holes 114 on the vacuum faces 90 of the gripper assemblies 46 ensures that a secure hold on the wrap is achieved.

The wrap removal system automatically removes stretch wrap from a palletized load and transfers the removed wrap to a disposal system, such as a spooler or wrap bundler. In one embodiment, the wrap removal system includes an overhead beam that seeks a top of the load. Vacuum grippers are mounted to the beam and arranged to engage sides of a wrapped load that is advancing along a conveyor system. The grippers are positioned proximate the load and engage the wrap. Leading grippers pivot away from the load to pull the wrap away from the surface of the load. A cutter assembly engages a top edge of the wrap and cuts the wrap between the top edge and a bottom edge. Once the cut has been made, side grippers engage the wrap and pull the wrap away from the load, and the load moves forward along the conveyor system to further pull the wrap away from the load. When the wrap is fully removed from the load, the wrap is engaged by the disposal system.

Although particular embodiments of the present invention have been shown and described, other alternative embodiments will be apparent to those skilled in the art and are within the intended scope of the present invention. The foregoing description of the present invention has been presented for purposes of illustration and description. Furthermore, the description is not intended to limit the invention to the form disclosed herein. Consequently, variations and modifications commensurate with the above teachings, and the skill or knowledge of the relevant art, are within the scope of the present invention. The embodiments described herein are further intended to explain best modes known for practicing the invention and to enable others skilled in the art to utilize the invention in such, or other, embodiments and with various modifications required by the particular applications or uses of the present invention.