Title:
Methods and apparatus for adjustable wrapping
Kind Code:
A1


Abstract:
Methods and apparatus for wrapping products having different product profiles includes a conveyor (14, 18, 22) driven by a conveyor drive (34) transporting a product (26). A wrapping mechanism (46) includes a drive mechanism (74) moving a wrap support (86) about a wrapping mechanism axis (58) using a rotatable driver (62) and a carrier (78) extending between the driver (62) and the wrap support (86). In one preferred form, a slideable attachment between the driver (62) and the carrier (78) allows extension and retraction of the wrap support (86) according to the product profile of the product (26). In one preferred form, a guide (82) moves in an adjustable cam track (98) made up of multiple segments (102, 106) to define a path (94) of the wrap support (86). The cam track (98) corresponds to the product profile of the product (26) on the platform (30). One of the cam segments (102, 106) is separately removable to allow for adjustment of the cam track (98). The wrap support (86) engages a film (134) and wraps the film (134) around the product (26). In a preferred form, a sensor (118) detects the product (26) as it proceeds toward the conveyor (18). A tracking encoder (122) receives data from the sensor (118) and the conveyor drive (34) to track the position of the product (26). A controller (126) receives the information from the tracking encoder (122) and controls the wrapping mechanism (46) according to the wrapping profile to accommodate variable spacing of products (26). A graphical user interface (130) may be used to modify or create wrapping profiles.



Inventors:
Floding, Daniel Leonard (Alexandria, MN, US)
Pazdernik, Irvan Leo (Alexandria, MN, US)
Schoeneck, Richard Jerome (Alexandria, MN, US)
Wagner, Paul Howard (Alexandria, MN, US)
Application Number:
10/286069
Publication Date:
05/06/2004
Filing Date:
10/31/2002
Assignee:
FLODING DANIEL LEONARD
PAZDERNIK IRVAN LEO
SCHOENECK RICHARD JEROME
WAGNER PAUL HOWARD
Primary Class:
Other Classes:
53/218
International Classes:
B65B11/10; B65B21/24; B65B59/04; (IPC1-7): B65B11/02
View Patent Images:



Primary Examiner:
HARMON, CHRISTOPHER R
Attorney, Agent or Firm:
DeWitt LLP (Minneapolis, MN, US)
Claims:
1. An apparatus for wrapping a product having a product profile with a sheet of material, the apparatus comprising, in combination: a driver mounted for rotation about an axis; a wrap support for engaging and directing the sheet of material around the product; a carrier extending between the driver and the wrap support for moving the wrap support in a path around the axis; a cam track mounted relative to the axis; and a cam follower mounted relative to and moveable with the wrap support, with movement of the cam follower by rotation of the driver about the axis and relative to the cam track causing movement of the wrap support to differing radial spacings relative to the axis in the path and accommodating the product profile.

2. The apparatus of claim 1 with the cam track comprising a plurality of segments of which at least one is interchanged allowing the cam track to substantially match different product profiles.

3. The apparatus of claim 1 with the carrier comprising a linear element attached to the wrap support and radially slideable relative to the driver allowing for extension and retraction of the wrap support relative to the driver.

4. The apparatus of claim 1 further comprising, in combination: a controller computing a speed for the wrap support to fit the product profile.

5. The apparatus of claim 4 with the controller containing data for a plurality of wrapping profiles.

6. The apparatus of claim 4 further comprising, in combination: a servomotor for rotating the driver around the axis and for providing data to the controller on the position of the wrap support.

7. The apparatus of claim 6 further comprising, in combination: a sensor that detects a leading edge of the product and for providing data to the controller on the position of the product.

8. The apparatus of claim 7 further comprising, in combination: a tracking encoder that receives data from the sensor and that tracks the location of the product.

9. The apparatus of claim 4 further comprising, in combination: a sensor that detects a leading edge of the product and for providing data to the controller on the position of the product.

10. The apparatus of claim 4 with the controller computing the speed for the wrap support according to a single segment cubic spline.

11. An apparatus for wrapping a product having a product profile with a sheet of material, the apparatus comprising, in combination: a wrap support for engaging and directing the sheet of material around the product, with the wrap support being moveable along a continuous path; a cam track; and a cam follower, with one of the cam follower and the cam track being mounted and moveable with the wrap support, with movement of the wrap support along the continuous path causing relative movement between the cam follower and the cam track to move the wrap support according to the cam track, with the cam track comprising a plurality of cam segments corresponding to a portion of the continuous path, with at least one of the plurality of cam segments being interchangeable allowing the cam track to create different shapes for the continuous path.

12. The apparatus of claim 11 with the plurality of cam segments including an upper segment and a lower segment, with the product being supported upon a platform, with the upper segment including a portion of the cam track corresponding to the path vertically above the platform and the lower segment including a portion of the cam track corresponding to the path vertically below the platform, with the at least one of the plurality of cam segments being the upper segment.

13. The apparatus of claim 12 with the upper segment and the lower segment completely defining a set route from the continuous path.

14. The apparatus of claim 11 with another cam track mounted substantially parallel to the cam track and another cam follower associated with the other cam track.

15. The apparatus of claim 11 further comprising, in combination: a controller having data corresponding to a plurality of wrapping profiles, with each wrapping profile associated with a specific product, with the data of the controller including the different shapes for the continuous path.

16. A method for wrapping a product with a sheet of material, comprising: moving a product for wrapping to a predetermined product position, with the product having a product profile; rotating a driver about an axis; engaging the sheet of material with a wrap support; extending a carrier between the driver and the wrap support for moving the wrap support in a path around the axis; moving the wrap support to differing radial spacings from the axis during rotation of the driver about the axis to direct the sheet of material around the product to accommodate the product profile of the product, with moving the wrap support comprising moving the wrap support to a desired location and recording the predetermined product position and the desired location to define a cam point; and defining a series of cam points to create a custom wrapping profile.

17. The method of claim 16 further comprising saving the custom wrapping profile for each of a plurality of products.

18. The method of claim 16 with moving the wrap support comprising: selecting a plurality of cam segments; attaching the plurality of selected cam segments to create a cam track corresponding to the product profile; and moving a cam follower relative to the cam track, with one of the cam track and the cam follower being moveable with the wrap support.

19. A method for wrapping products with a sheet of material, comprising: attaching a first plurality of interchangeable segments to form a first cam track according to a first wrapping path; transporting a first product having a first product profile for wrapping; extending and retracting a wrap support according to the first cam track to direct the sheet of material around the first product; replacing at least some of the first plurality of interchangeable segments to create a different plurality of interchangeable segments to form a second cam track according to a second wrapping path, with the second wrapping path being different from the first wrapping path; and transporting a second product having a second wrapping product for wrapping, with the second product profile being dissimilar to the first product profile.

20. An apparatus for wrapping products comprising, in combination: a conveyor system for transporting product through a wrap location for wrapping; a wrapping mechanism having at least one wrap support moving through a wrap sequence and a nonwrap sequence; with the at least one wrap support disposed to direct a sheet of material around the product at the wrap location during a wrap sequence; and a controller receiving data on the movement of the product by the conveyor system and directing movement of the at least one wrap support to begin the wrap sequence according to a wrapping profile with respect to the product.

21. The apparatus of claim 20 with the conveyor system comprising a servomotor for providing data to the controller on the movement of the product.

22. The apparatus of claim 21 with the conveyor system comprising: a first conveyor; a wrap location conveyor; and a second conveyor, the conveyor system being arranged linearly, with each conveyor having a gap with the next conveyor sufficient to allow the wrap support to pass between the conveyors, with the wrap sequence commencing as the wrap support passes the gap between the first conveyor and the wrap location conveyor and ending as the wrap support passes the gap between the wrap location conveyor and the second conveyor, with the controller positioning the wrap support during the nonwrap sequence.

23. The apparatus of claim 20 where the wrapping profile includes a location and speed for beginning the wrap sequence.

24. The apparatus of claim 23 where the controller computes the movement of the wrap support through the nonwrap sequence using a single segment cubic spline.

25. A method for controlling a wrap sequence and a nonwrap sequence of a wrap mechanism to allow for random spacings of products to be wrapped, comprising: receiving data on position of the product for wrapping; moving the wrap mechanism through the wrap sequence at a speed and position determined by the data of the position of the product.

26. The method of claim 25 with moving the wrap mechanism through the wrap sequence being determined by a profile of the product.

Description:

BACKGROUND

[0001] The present invention generally relates to apparatus and methods for adjustable wrapping, and particularly to methods and apparatus suitable for wrapping a wide variety of products such as cans, plastic bottles, jars, cartons, bundles, or trays and products having different profiles. In other preferred aspects, the present invention generally relates to apparatus and methods for interactive creation of wrapping profiles which could be utilized with the adjustable wrapping methods and apparatus of the present invention.

[0002] One type of conventional shrink-wrap machines employed chain drives mounted on both sides of a wrapping platform to drive a wand to wrap a product. These chain drives typically have a track which trap the chain to define a wand path or in other words the line in space created by the wand as it makes a cycle. Because the chain is trapped, adjusting or changing the wand path is difficult. This difficulty limits the size of the products that may be wrapped. This limitation is most severe in the vertical size ranges of the products these machines may wrap.

[0003] Chain drives also generally have wand paths that are substantially limited to the path of the chain drive. Furthermore, the path of the chain drive is fixed and is not adjustable to products having different product profiles. Because of, the fixed wand path, it cannot be customized to the particular product being wrapped. For example, these drives often cannot wrap products having a relatively large height. On the other hand, fixed path wrapping devices designed to wrap tall objects are subject to ballooning when wrapping lower profile products because of air trapped between the shrink-wrap and the product.

[0004] Additionally, chain drives are difficult to accelerate. Thus, chain drives are often operated at a constant speed and therefore often employ multiple wands to speed the wrapping process. This makes product spacing critical and dependent upon wand spacing. The product spacing then dictates the length of the center conveying table, which in turn can limit the vertical range of the wrapping device.

[0005] Another type of shrink-wrap machines employed a rotatable driver which rotates dual wand supports diametrically opposite to each other and slideably mounted to a cam track which moves relatives to a cam follower. The position of the cam follower can be adjusted such that the wand path is circular or is elliptical. These drives can wrap products having a relatively large height due to the elliptical wand path, but suffer from similar and other deficiencies as chain drives including but not limited to the inability to be customized from an elliptical path to the particular product being wrapped, difficulty in accelerating, multiple wands, complicated construction and the like.

[0006] Thus, there is a need for methods and apparatus for wrapping products having different profiles that do not suffer from the deficiencies of prior apparatus. In particular, there is a need for methods and apparatus that are adjustable to accommodate a large range of product profiles. Such apparatus and methods should necessitate a minimum effort or expense to accommodate the varying product profiles. There further exists a need for adjustable methods and apparatus for wrapping products that employ a single wand design and are easy to maintain. There further exists a need for methods and apparatus that can accommodate a larger size range within a smaller area and that allow for variability in product spacing. There further exists a need for methods and apparatus using a rotary wand design.

SUMMARY

[0007] The present invention solves these needs and other problems in the field of product wrapping apparatus and methods by providing, in most preferred aspects, a carrier extending between a rotatably mounted driver and a wrap support which engages and directs a sheet of material around product to be wrapped. The wrap support is moved to different radial spacings from the driver during rotation of the driver to define a path which accommodates the profile of the product to be wrapped by a cam follower mounted to the wand support and movable by rotation of the driver about the axis and by a cam track mounted relative to the axis.

[0008] In other aspects of the present invention, a cam track is formed from a plurality of cam segments which can be interchanged to define different shapes for the continuous path of a wrap support which engages and directs a sheet of material around product to be wrapped. Thus, the selection of the plurality of cam segments utilized can be based upon the profile of the product to be wrapped.

[0009] In further aspects of the present invention, custom wrapping profiles are created by controlling the position of the wrap support based upon the product location and movement data and to accommodate the product profile. In a preferred form, data is contained in a controller for multiple product profiles, and a graphical user interface may be used to create additional wrapping profiles or modify an existing wrapping profile to accommodate product profiles.

[0010] It is thus an object of the invention to provide novel apparatus and methods for wrapping products.

[0011] It is yet another object of the present invention to provide such novel product wrapping apparatus and methods that have different product profiles.

[0012] It is yet another object of the present invention to provide such novel product wrapping apparatus and methods that are easily adjustable.

[0013] It is yet another object of the present invention to provide such novel product wrapping apparatus and methods that can accommodate a larger vertical size range than a standard fixed circular path.

[0014] It is yet another object of the present invention to provide such novel product wrapping apparatus and methods that may accommodate products entering at random intervals.

[0015] It is further an object of the present invention to provide such novel product wrapping apparatus and methods that are adjustable to different wrapping speeds.

[0016] It is further an object of the present invention to provide such novel product wrapping apparatus and methods that employ a wand support moved at differing radial spacings from the axis by a rotating driver and a cam track fixed relative to the axis.

[0017] It is further an object of the present invention to provide such novel product wrapping apparatus and methods that use a cam track that is smaller than the wand path.

[0018] It is further an object of the present invention to provide such novel product wrapping apparatus and methods that do not trap the cam track.

[0019] It is further an object of the present invention to provide such novel product wrapping apparatus and methods that can accommodate varying wrapping paths such as circular, elliptical, or trapezoidal.

[0020] It is further an object of the present invention to provide such novel product wrapping apparatus and methods that employ a single wand.

[0021] These and further objects and advantages of the present invention will become clearer in light of the following detailed description of an illustrative embodiment of this invention described in connection with the drawings.

DESCRIPTION OF THE DRAWINGS

[0022] The illustrative embodiment may best be described by reference to the accompanying drawings where:

[0023] FIG. 1 shows a partial perspective view of a wrapping apparatus utilizing preferred methods according to the preferred teachings of the present invention, with portions of the apparatus removed to show details of the construction of one preferred embodiment of the invention.

[0024] FIG. 2 shows a flow chart of a process that may be employed to create a wrapping profile using the wrapping apparatus of FIG. 1.

[0025] All figures are drawn for ease of explanation of the basic teachings of the present invention only; the extensions of the figures with respect to number, position, relationship, and dimensions of the parts to form the preferred embodiment will be explained or will be within the skill of the art after the following description has been read and understood. Further, the exact dimensions and dimensional proportions to conform to specific force, weight, strength, and similar requirements will likewise be within the skill of the art after the following description has been read and understood.

[0026] Where used in the various figures of the drawings, the same numerals designate the same or similar parts. Furthermore, when the terms “side,” “end,” “bottom,” “first,” “second,” “laterally,” “longitudinally,” “row,” “column,” and similar terms are used herein, it should be understood that these terms have reference only to the structure shown in the drawings as it would appear to a person viewing the drawings and are utilized only to facilitate describing the illustrative embodiment.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] An apparatus for adjustable wrapping of products utilizing methods according to the preferred teachings of the present invention is shown in the drawings and is generally designated 10. A conveyor system provides for transport of products through the wrapping apparatus 10. In one preferred form, the conveyor system includes a first conveyor 14, a platform conveyor 18 and a second conveyor 22. In a preferred form, the conveyor system is arranged to transport the product 26 in a generally linear fashion over the first conveyor 14, the platform conveyor 18 and the second conveyor 22. Each conveyor is separated by a narrow gap from an adjacent conveyor. In one preferred embodiment, the conveyors may each comprise an endless belt. During operation of the adjustable wrapping apparatus 10, the first conveyor 14 transports the products 26 for deposit onto a platform 30 defined by and including the platform conveyor 18. The platform conveyor 18 transports the products 26 across the platform 30 of the adjustable wrapping apparatus 10 for wrapping, with the products 26 being transported having an outline when viewed from the side or in a vertical plane perpendicular to the platform conveyor 18 and parallel to the transport direction of the platform conveyor 18 or in other words a product profile. The platform conveyor 18 then deposits the products 26 onto the second conveyor 22. The second conveyor 22 transports the products 26 for further processing. For example, the second conveyor 22 may move the product 26 to a heat tunnel to complete shrink-wrapping.

[0028] A single conveyor drive 34 may provide motive force for the platform conveyor 18, first conveyor 14 and second conveyor 22. Alternatively, each conveyor 14, 18, and 22 may be separately driven. In one preferred embodiment, the conveyor drive 34 may comprise a servomotor. In an alternative embodiment, the conveyor drive 34 may comprise a stepping motor. In one preferred form, the conveyor system employs a single conveyor drive 34 and may be mounted along the second conveyor 22. The conveyor drive 34 can engage a series of cogs 38 and a timing belt 42 to drive the conveyor system. As will be recognized by those skilled in the art, alternate methods of driving the conveyors 14, 18 and 22 may be used without departing from the scope of the present invention.

[0029] The adjustable wrapping apparatus 10 according to the preferred teachings of the present invention includes a wrapping mechanism 46. A beam 50 traverses the platform 30 laterally across the conveying direction of the platform conveyor 18. First and second cylindrical collars 54 are mounted to the beam 50 on opposite sides of the platform conveyor 18 and define a wrapping mechanism axis 58 also extending laterally across the conveying direction of the platform conveyor 18.

[0030] A driver 62 is rotatably mounted on each of the cylindrical collars 54 for rotation about the wrapping mechanism axis 58. Suitable provisions rotate the drivers 62 on the cylindrical collars 54. In the most preferred form, a shaft 66 is rotatably mounted to the beam 50 generally parallel to and spaced from the wrapping mechanism axis 58. The drivers 62 are in a rotatable relationship to the shaft 66, such as may be done by timing belts 70 extending around pulleys on the drivers 62 and the shaft 66. The shaft 66 is itself in a rotatable relationship to a drive mechanism 74. The drive mechanism 74 is mounted to the beam 50 generally parallel to and spaced from the shaft 66. The drive mechanism 74 rotates the shaft 66, as may be done by a timing belt 72 extending around pulleys on shaft 66 and drive mechanism 74. In the preferred embodiment, the rotational movement is transferred from the drive mechanism 74 to the shaft 66 through timing belt 72, and from the shaft 66 to the drivers 62 through timing belts 70. Movement of the drive mechanism 74 thus causes rotation of the drivers 62 around each respective cylindrical collar 54.

[0031] A carrier 78 is mounted to each of the drivers 62. The carriers 78 are disposed generally perpendicularly to the wrapping mechanism axis 58, though the carriers 78 may be offset from an intersecting perpendicular relationship to the wrapping mechanism axis 58 to accommodate the width of the cylindrical collars 54. In the preferred form, carriers 78 are linear elements and are formed by first and second shafts slideably received in driver 62 parallel to one another on opposite sides of the wrapping mechanism axis 58 and by a crossbar 90 joining the first and second shafts. The carriers 78 may have a slideable attachment to the drivers 62, allowing the carriers 78 to generally move in a radial direction relative to the wrapping mechanism axis 58.

[0032] The carriers 78 have attached at one end a cam follower or guide 82 and a wrap support 86. In one preferred form, the crossbar 90 mounts the guide 82 relative to and moveable with the wrap support 86. In the preferred form, wrap support 86 is in the form of a single wand that extends between crossbars 90 on opposite sides of the apparatus 10. The wrap support 86 may be offset in a radial direction from the guide 82 relative to the wrapping mechanism axis 58. This allows the wrap support 86 to have a greater radial spacing from the wrapping mechanism axis 58 than the guide 82. Rotation of the drivers 62 thus causes movement of the carriers 78, guides 82, and the wrap support 86 about the wrapping mechanism axis 58.

[0033] Suitable provisions are provided according to the preferred teachings of the present invention to provide for radial movement of the wrap support 86 toward and away from the wrapping mechanism axis 58. This allows the wrap support 86 to have different radial spacings from the wrapping mechanism axis 58 during movement in a continuous path 94 about the wrapping mechanism axis 58. The different radial spacings of the wrap support 86 during movement about the wrapping mechanism axis 58 allows the wrap support 86 to follow the path 94 corresponding to the wrap path for the product 26. Various methods can be employed to provide for the different radial spacings of the wrap support 86 during rotation about wrapping mechanism axis 58. In one preferred embodiment, the slideable attachment of the carriers 78 to the drivers 62 allows movement of the carriers 78 in a radial direction relative to the wrapping mechanism axis 58 and the drivers 62. In an alternate embodiment, extension of the wrap support 86 is accomplished through a slideable attachment of the carrier 78 to the wrap support 86. Other ways of allowing extension and retraction of the wrap support 86 may also be employed without departing from the scope of the invention, such as a telescoping shaft, a rack and pinion drive, a motor driven system or robotic arms with two pivoting movements.

[0034] In one preferred embodiment, first and second cam tracks 98 guide the movement of the wrap support 86 along the path 94. The first cam track 98 is mounted relative to the wrapping mechanism axis 58 by securement on the first cylindrical collar 54 in the preferred form shown. In the preferred form, a second cam track 98 is mounted parallel to the first cam track 98 on the second cylindrical collar 54. Each cam track 98 shown in the preferred form are adjustable and are formed from two or more segments and in the preferred form includes an upper segment 102 interchangeable with a lower segment 106. The upper segment 102 of cam track 98 corresponds to the path 94 vertically above the platform 30 while the lower segment 106 of cam track 98 corresponds to the path 94 vertically below the platform 30, with the interchangeable upper segment 102 being formed as a single component in the form shown. Cam hold-downs 108 removably secure the upper segment 102 with the lower segment 106 in the form shown. In the most preferred form, the lower segments 106 are attached to a frame 110, with the cylindrical collars 54 being supported by the frame 110 which then supports the beam 50 and the platform conveyor 18. Conveyors 14 and 22 may be supported by the frame 110.

[0035] The guides 82 engage the cam tracks 98. As the drivers 62 rotate moving the carriers 78 around the wrapping mechanism axis 58, the guides 82 move relative to and follow the cam tracks 98. As the guides 82 travel in the cam tracks 98, the radial spacing of the guides 82 from the wrapping mechanism axis 58 follows the radial spacing of that portion of the cam tracks 98 from the wrapping mechanism axis 58 to accommodate the profile of the product 26. The engagement of the guides 82 with the cam tracks 98 thus causes the wrap support 86 to follow the path 94 of a shape corresponding to the cam tracks 98. The cam tracks 98 may be advantageously designed to compel movement of the wrap support 86 around the wrapping mechanism axis 58 along the path 94 corresponding to the profile of the product 26. In one preferred embodiment, the upper segment 102 may be easily exchanged with alternative upper segments 102. Each upper segment 102 may correspond to and substantially match a preselected product profile. In this preferred embodiment, accommodation to products 26 having widely varying profiles may thus be easily accomplished by exchanging cam segments 102. Those skilled in the art will recognize that other arrangements of the adjustable cam track 98 are possible, such as three or more cam segments, or the use of a lower segment 106 which does not define a set route in the continuous path 94 without departing from the scope of the present invention.

[0036] In a most preferred form, location of the products relative to the wrapping mechanism 46 is determined. In one embodiment, a sensor 118 detects the leading edge of a product 26 as it moves toward the platform 30 and may comprise a photo eye. In an alternate embodiment, the sensor 118 may comprise a mechanical trigger. In a preferred form, the sensor 118 is disposed to detect products 26 prior to transfer to the platform conveyor 18. The sensor 118 is mounted along one side of the first conveyor 14 and directs a beam of light to the opposite side of the first conveyor 14 across the conveying direction of the first conveyor 14. The sensor 118 detects the leading edge of the product 26 when the product 26 breaks the beam. However, it can be appreciated that the product location can be detected in other manners such as when the apparatus 10 of the present invention is integrated into with other packaging equipment which can provide product location and movement data for use by apparatus 10.

[0037] In the preferred form shown, the sensor 118, the conveyor drive 34 and the drive mechanism 74 are connected to separate tracking encoders 122 to provide location and movement data. The tracking encoders 122 use the location and movement data to track the position of the product 26 and the position of the wrapping mechanism 46. The tracking encoders 122 then pass data representing the location and speed of the product 26 to a controller 126 for coordinating the wrapping motion. By way of example and not limitation, the controller 126 can coordinate the motion of the wrapping mechanism 46 with the motion of the product 26 to create a wrapping profile by adjusting the speed of various components of the wrapping apparatus 46. In one preferred embodiment, the controller 126 initiates the wrapping process by receiving location information from the tracking encoders 122 and activates the wrapping mechanism 46 according to a stored wrapping profile. The controller 126 can further be connected to a graphical user interface 130. The graphical user interface 130 may, in one preferred form, edit and display a wrapping profile. By way of example and not limitation, an Allen Bradley Control Logix PLC may serve as the controller 126.

[0038] In the preferred embodiment, detection of a product 26 to be wrapped triggers activation of the drive mechanism 74 and the wrapping mechanism 46. In this embodiment, the drive mechanism 74 provides for movement of a wand system, comprising the drivers 62, the carriers 78, the guides 82, the wrap support 86 and the crossbar 90, around the wrapping mechanism axis 58. As the wand system moves around the wrapping mechanism axis 58, engagement of the guides 82 with the cam tracks 98 causes extension of the wrap support 86 so as to follow the path 94 of a shape corresponding to the cam tracks 98. The extension and retraction of the wrap support 86 provides for movement of the wrap support 86 along the path 94 while being driven by the driver 62 about the wrapping mechanism axis 58. The path 94 corresponds to the shape of the cam tracks 98 that are advantageously chosen according to the profile of the product 26. Different paths 94 may be selected by employment of different upper segments 102 corresponding to the profiles of different products 26. By way of example and not limitation, the wrapping path 94 can either be circular, elliptical, or trapezoidal, depending on product and size range. The type of the product 26 may vary in size and shape, requiring different wrapping profiles. The wrapping profile generally describes a motion that accomplishes the wrapping of the product 26 or in other words the coordination of wand position versus product position for the product 26 being wrapped and having a product profile.

[0039] In an exemplary wrapping procedure, the sensor 118 detects the approach of a product 26. The controller 126 computes a desired wand system speed to position the wrap support 86 at a preselected location and speed relative to the platform 30 to begin wrapping. As the product 26 enters the platform 30, the wrap support 86 engages a film 134. The engagement of the wrap support 86 with the film 134 at the gap between the first conveyor 14 and the platform conveyor 18 begins the wrapping profile. In one preferred form, a film drive may feed the film 134 onto platform conveyor 18 from below the conveyor 14. The controller 126 may advantageously drive the wand system so that the wrap support 86 impacts the film 134 at a desired speed, and specifically slow enough when engaging the film 134 to prevent pulling the film 134 from under the product 26.

[0040] The wrap profile of the wrapping mechanism 46 continues by the movement of the wrap support 86 through the wrapping profile of the product 26. The movement of the wrap support 86 pulls the film 134 over the product 26 at a desired height and speed. In this regard, the wrapping motion can be profiled to control the tail of film 134 better. The wrap profile of the wrapping mechanism 46 completes as the wrap support 86 proceeds through the gap between the platform conveyor 18 and the second conveyor 22. The controller 126 then computes a desired speed for the wand system through the nonwrap sequence using the position of the next product 26 to be wrapped. For example, if the products 26 are closely spaced, the travel of the wand system below the platform 30 must be extremely fast. In one preferred embodiment, the controller 126 employs a single segment cubic spline to compute the desired wand system motion using the position of the platform conveyor 18 as an input and the position of the wrap support 86 as the output.

[0041] The features of the adjustable wrapping methods and apparatus of the invention overcome obstacles to efficient wrapping. For example, the single wand system of the most preferred form of the present invention allows for variable spacing of products 26 with dynamic adjustment of the wrapping procedures, whereas double wand systems often require a controlled spacing, as one wrap begins as the preceding wrap ends. However, utilizing the preferred methods of the present invention, multiple wand systems could be employed in random spacings between product situations where only one wand is in its wrap profile at a time while the others are in its nonwrap profile such as by lowering the axis 58 below the platform conveyor 18. Furthermore, wrapping may be customized to each product 26 to minimize the height of the wrapping path to decrease the amount of air forced under the film 134 as it encloses the product 26. This adjustment reduces the amount of ballooning during wrapping, allowing for faster and more efficient wrapping with fewer stoppages. On the other hand, the variable radial movement of the wrap support 86 allows for wrapping of products 26 through a large vertical size range. Also, the dynamic computation of the wand system speed allows for adaptation of wand system speed to the film drive speed. This provides for feeding the film 134 as the wrapping mechanism 46 pulls the film 134, allowing for a film drive without storage or a buffer zone. Also, wand overload and associated reset parts required on conventional wrapping machines can be eliminated.

[0042] The present invention further includes a process to create a wrapping profile which can be utilized in the apparatus 10 of the present invention. The process begins in step 200 by moving the product 26 to a predetermined position. Using a preferred embodiment of the apparatus of the invention described herein, the sensor 118 can be used to detect the product 26 upon loading onto the platform 30. Using data from the sensor 118 and the conveyor drive 34, the location of the product 26 can be accurately tracked by its respective tracking encoder 122 and the controller 126. The product 26 is jogged to a desired location and the wand system is moved to a desired position, with these positions being recorded such as 1 by pressing a “teach” button to define a cam point in a second step 210. In one preferred embodiment, the controller 126 stores the cam point, which includes the position of the product 26 and of the wrap support 86. This is repeated as long as more cam points are desired in a third step 220. This creates a series of cam points. The series of cam points are used to create a custom wrapping profile in a fourth step 230. The custom wrapping profile may also include a desired wrapping speed for the wand system. The custom wrapping profile may then be stored in the memory of the controller 126 in a fifth step 240. The controller 126 also provides for storage of wrapping profiles of multiple products. A graphical user interface 130 may be used to display and edit the custom wrapping profiles in a sixth step 250.

[0043] In one aspect of the present invention, movement of the wrap support 86 occurs as the result of rotation of driver 62 about the axis 58. It should be appreciated that such an arrangement creates a clean appearance, has considerably fewer components, is lighter, is not as subject to wear, and is easier to accelerate with less force than prior chain drives of prior wrapping machines. Further, cam track 98 of the most preferred form may be smaller than the path 94 of the wrap support 86 as compared to a chain drive which requires the chain carrying the wands to be larger than the path of the wands. Additionally, it is believed that such rotational drive of the wrapping mechanism 46 is believed to have synergistic results with the adjustable cam track 98 of the most preferred form as it is not necessary to utilize change parts or to disassemble driver 62, carrier 78, or wrap support 86 when changing to different wrap paths.

[0044] Now that the basic teachings of the present invention have been explained, many extensions and variations will be obvious to one having ordinary skill in the art. For example, although apparatus 10 of the most preferred form includes the combination of several, unique features believed to obtain synergistic results, wrapping apparatus could be constructed according to the teachings of the present invention including such features singly or in other combinations. Particularly, the rotational drive for wrap support 86 could be utilized with a nonvariable wrap profile or with other manners of extending and retracting the wrap support 86 according to the teachings of the present invention. Similarly, the adjustable cam track 98 could be utilized according to the teachings of the present invention with other driving manners including chain drives. Likewise, the methods for controlling the wrap operation could be utilized to eliminate random timing infeed systems according to the preferred teachings of the present invention with other types of wrap support drives and/or other manners of allowing adjustment of the wand path.

[0045] Thus since the invention disclosed herein may be embodied in other specific forms without departing from the spirit or general characteristics thereof, some of which forms have been indicated, the embodiments described herein are to be considered in all respects illustrative and not restrictive. The scope of the invention is to be indicated by the appended claims, rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are intended to be embraced therein.