Stretch-hood machine with perforator

Abstract

Various embodiments of the present disclosure provide a stretch-hood machine and method of operating a stretch-hood machine to perforate tubular film and wrap an item with the tubular film. The method includes drawing tubular film from a roll of film and perforating the tubular film after the tubular film has been drawn from the roll of film so as to form perforations arranged along a length of the tubular film. Using reefing devices, the tubular film is lowered around the item to wrap the item within an interior of the tubular film.

Description

STRETCH-HOOD MACHINE WITH PERFORATORPRIORITY

[0001] This application claims priority to and the benefit of U.S. Provisional Patent Application No. 63 / 429,128, filed November 30, 2022, the entire contents of which is incorporated by reference.FIELD

[0002] The present disclosure relates to stretch-hood machines for wrapping loads of goods with tubular stretch film, and more particularly to stretch-hood machines configured to perforate tubular film and wrap loads of goods with the tubular film.BACKGROUND

[0003] Stretch-hood machines wrap loads of goods with tubular plastic stretch film. These stretch-hood machines include a frame that supports a film-supply assembly, a film-opening assembly, and a reefmg-and-wrapping assembly. The reefing-and-wrapping assembly includes a wrapping carriage that supports four reefing devices. Each reefing device includes a support that supports a drive roller and a vertically extending reefing finger. A motor drives the drive roller, and the reefing finger supports a freely rotatable guide roller. The drive roller is movable toward and away from the guide roller.

[0004] To wrap a load of goods, the film-supply assembly draw s tubular film from a film roll, cuts the film to a desired length to form a section of tubular film, and in certain instances heat seals the top of the section of tubular film completely closed. The film-opening assembly opens the bottom portion of the section of tubular film so its perimeter is generally rectangular. Each reefing device moves laterally inwardly relative to the section of tubular film to respective insertion positions in which they form an insertion configuration. Thewrapping carriage then ascends relative to the section of tubular film until the reefing fingers of the reefing devices enter the open bottom portion of the section of tubular film near its four comers. The reefing devices then move laterally outwardly to respective reefing positions in which they form a reefing configuration in preparation for reefing the section of tubular film onto the reefing fingers. The drive rollers of the reefing devices move toward their respective guide rollers to engage the outer surface of the section of tubular film and force the inner surface of the section of tubular film against the guide rollers, thereby sandwiching the tubular film between the rollers. The motors drive their respective drive rollers in a reefing rotational direction to reef (or gather) the section of tubular film onto the reefing fingers.

[0005] After reefing, the reefing devices each move laterally outwardly into respective wrapping positions in which they form a wrapping configuration. Because the film is elastic, it stretches during this movement. The wrapping configuration is (and therefore the wrapping positions are) determined based on the size and shape of the load so the perimeter of the section of tubular film is sized to circumscribe the load once the reefing devices reach the w rapping configuration. After the reefing devices reach the w rapping configuration, the wrapping carriage descends relative to the load. During this descent the motors drive the drive rollers of the reefing devices in an unreefing rotational direction opposite the reefing rotational direction at an unreefing speed to unreef the remainder of the film from the reefing fingers. As this occurs, the film attempts to return to its unstretched size and shape and laterally retracts onto the load, which unitizes the load and / or secures the load to a pallet. This completes the wrapping process, and a conveyor conveys the load from the stretch-hood machine.

[0006] In some instances, it is desirable to provide ventilation for the load, for example to avoid moisture related problems. One possible way to provide ventilation is to use a roll of perforated film rather than standard film. This provides access betw een the interior of thetubular film and the surrounding environment, which reduces the likelihood of unw anted moisture buildup. However, switching between perforated fdm and standard film can be time consuming and expensive.SUMMARY

[0007] Various embodiments of the present disclosure provide methods and stretch-hood machines configured to perforate tubular film and wrap loads of goods with the tubular film.

[0008] In one embodiment, a method of operating a stretch-hood machine to wrap an item with tubular film comprises drawing tubular film from a roll of film. The method also includes perforating the tubular film after the tubular film has been drawn from the roll of film so as to form perforations arranged along a length of the tubular film. Further, the method includes reefing the tubular film onto reefing fingers of a plurality of reefing devices, and lowering the reefing devices around the item to wrap the item within an interior of the tubular film.

[0009] In one embodiment, a stretch-hood machine comprises a machine frame, a wrapping carriage movable relative to the machine frame between upper and lower positions, and a plurality of reefing devices supported by the wrapping carriage and configured to wrap tubular film around an item. A film-supply assembly is configured to draw tubular film from a roll of film, cut the tubular film from the roll to form a segment of tubular film, and direct the segment of tubular film to the reefing devices. The machine also includes a perforator to form perforations arranged along a length of the tubular film after the tubular film is drawn from the roll and before the reefing devices reef the segment of tubular film.BRIEF DESCRIPTION OF THE FIGURES

[0010] Figure 1 is a perspective view of one embodiment of the stretch-hood machine of the present disclosure.

[0011] Figure 2 is a block diagram showing certain components of the stretch-hood machine of Figure 1.

[0012] Figure 3 is a side elevational view of one of the reefing devices of the stretch-hood machine of Figure 1 with the reefing carriage in its home position.

[0013] Figure 4 is a perspective view of the film-opening device and the reefing devices of the stretch-hood machine of Figure 1 after the film-opening device has opened the bottom of a section of tubular film and before the reefing fingers of the reefing devices have been inserted into the bottom of the section of tubular film.

[0014] Figure 5 is a simplified top plan view that corresponds to Figure 4.

[0015] Figure 6 is a perspective view similar to Figure 4 but after the reefing fingers of the reefing devices have been inserted into the bottom of the section of tubular film and after the reefing carriages of the reefing devices have moved to their respective reefing positions.

[0016] Figure 7 is a simplified top plan view that corresponds to Figure 6.

[0017] Figure 8 is a side elevational view of the reefing device of Figure 3 that corresponds to Figure 6.

[0018] Figure 9 is a perspective view similar to Figure 6 but after the reefing devices have reefed the section of tubular film onto their reefing fingers.

[0019] Figure 10 is a side elevational view of the reefing device of Figure 3 that corresponds to Figure 9.

[0020] Figure 11 is a perspective view of a roll of tubular film.

[0021] Figure 12A is a schematic perspective view of one example embodiment of a perforator of the present disclosure in a first position.

[0022] Figure 12B is a schematic perspective view of the perforator of Figure 12A in a second position.

[0023] Figure 13 is a schematic perspective view of another example embodiment of a perforator of the present disclosure.

[0024] Figure 14A is a schematic perspective view of another example embodiment of a perforator of the present disclosure in a first position.

[0025] Figure 14B is a schematic perspective the perforator of FIG. 14A in a second position.

[0026] Figure 15 is a schematic view of another example embodiment of a perforator of the present disclosure.

[0027] Figure 16 is a schematic front view of an example embodiment of a section of perforated tubular film.

[0028] Figure 17 is a schematic front view of another example embodiment of a section of perforated tubular film.

[0029] Figure 18 is a schematic front view of another example embodiment of a section of perforated tubular film.

[0030] Figure 19 is a schematic depiction showing a perforated stretch-hood that is wrapped around an item.DETAILED DESCRIPTION

[0031] Various embodiments of the present disclosure provide a stretch-hood machine configured to perforate tubular film and wrap loads of goods with the tubular film. Figures 1- 10, 12A, and 12B show one embodiment of the stretch-hood machine 10 of the present disclosure and the assemblies and components of the stretch-hood machine 10. The stretchhood machine 10 includes a machine frame 100, a film-supply assembly 200 supported by the machine frame 100, a film-opening assembly 300 supported by the machine frame 100, a reefmg-and-wrapping assembly 400 supported by the machine frame 100, an operator interface 500, and a controller 600. A coordinate system CS (shown in Figure 1) is used herein as a frame of reference for directional movement of various components of the stretchhood machine 10 in the X-, Y-, and Z-directions (which are perpendicular to one another in this example embodiment).

[0032] The machine frame 100 is formed from multiple tubular and / or solid members and other elements (not individually labeled) and is configured to support the other assemblies and components of the stretch-hood machine 10. The machine frame 100 defines a wrapping area within its interior and has an infeed area (not labeled) at which a palletized load (such as a load L on a pallet P) is conveyed into the wrapping area for wrapping and an outfeed area (not labeled) at which the palletized load is conveyed from the wrapping area after wrapping. The illustrated machine frame 100 is merely one example configuration, and any suitable configuration may be employed.

[0033] The film-supply assembly 200 includes suitable components configured to form a section of tubular film 40 (illustrated in Figure 11) that the stretch-hood machine 10 then uses to wrap the load L. More specifically, and as is known in the art, the film-supply assembly 200 includes components suitable to draw a length of tubular film 40 from a roll R of tubular film rotatably mounted to the machine frame 100, cut the length of tubular film 40 from the roll R to form the section of tubular film 40, and, optionally, perforate a portion of the tubularfilm 40, as described in more detail below. When drawing the tubular film 40 from the roll R, the controller 600 controls perforation of the tubular film 40. When wrapping a load L. the controller 600 determines the length of the section of tubular film 40 based (in part) on the height of the load L, as is know n in the art.

[0034] The film-opening assembly 300 includes suitable components configured to open a bottom portion of the section of tubular film 40 so it forms a generally rectangular perimeter in preparation for reefing by the reefing-and-wrapping assembly 400. More specifically, and as is known in the art, the film-opening assembly 300 includes four suction boxes and four corresponding holding devices (not labeled) that are movable laterally inward and outward in the X- and Y-directions and generally parallel to the X-Y plane relative to the section of tubular film 40. To open the bottom portion of the section of tubular film 40, the suction boxes move laterally inward in the X- and Y-directions so they are positioned adjacent the outer surface of the bottom portion of the section of tubular film 40. A vacuum is generated to draw7the bottom portion of the section of tubular film 40 onto the suction boxes, thereby partially opening the bottom portion. The holding devices then clamp the section of tubular film, and the suction boxes and holding devices move laterally outward in the X- and Y- directions and generally parallel to the X-Y plane to open the bottom portion of the section of tubular film 40 in preparation for reefing. At this point, the perimeter of the bottom portion of the section of tubular film 40 forms a generally rectangular shape in preparation for reefing. This is merely one example of the film-opening assembly 300, and other embodiments of the film-opening assembly 300 may include any other suitable components.

[0035] The reefing-and-wrapping assembly 400 includes a wrapping carriage (not shown for clarity ); a w rapping carriage actuator 410; first, second, third, and fourth reefing devices 420, 430, 440, and 450; and first and second sets of reefing-device actuators 420a and 440a.The wrapping carriage includes a suitable frame and is vertically movable relative to themachine frame 100 in the Z-direction between upper and lower positions. The wrapping carriage actuator 410, which may include any suitable actuator (such as an electric or a hydraulic motor), is operably connected to the wrapping carriage to move the wrapping carriage between its upper and lower positions.

[0036] Figures 3, 8, and 10 show the first reefing device 420, which includes a first support 421, a first reefing finger 422 extending generally vertically in the Z-direction from one end of the first support 421, a freely rotatable first guide roller 422a mounted to the first reefing finger 422, a first rail 423 supported by the first support 421, a first carriage 424 mounted to the first rail 423 and configured to move along the first rail 423 between a home position spaced-apart from the first guide roller 422a (Figure 3) and a reefing position adjacent the first guide roller 422a (Figures 8 and 10), a first drive roller 425 supported by the first carriage 424, a first roller actuator 426 supported by the first carriage 424 and operably connected to the first drive roller 425 to rotate the first drive roller 425 in opposing reefing and unreefing rotational directions, and a first camage actuator 427 operably connected to the carriage 424 to move the carnage 424 between its home and reefing positions.

[0037] The second reefing device 430 is similar to the first reefing device 420 and not shown separately. The second reefing device includes a second support 431, a second reefing finger 432 extending generally vertically from one end of the second support 431, a freely rotatable second guide roller 432a mounted to the second reefing finger 432, a second rail 433 supported by the second support 431, a second carriage 434 mounted to the second rail 433 and configured to move along the second rail 433 between a home position spaced-apart from the second guide roller 432a and a reefing position adjacent the second guide roller 432a. a second drive roller 435 supported by the second carriage 434. a second roller actuator 436 supported by the second carriage 434 and operably connected to the second drive roller 435 to rotate the second drive roller 435 in opposing reefing and unreefing rotationaldirections, and a second carriage actuator 437 operably connected to the carriage 434 to move the carriage 434 between its home and reefing positions.

[0038] The third reefing device 440 is similar to the first reefing device 420 and not shown separately. The third reefing device includes a third support 441, a third reefing finger 442 extending generally vertically from one end of the third support 441, a freely rotatable third guide roller 442a mounted to the third reefing finger 442, a third rail 443 supported by the third support 441, a third carriage 444 mounted to the third rail 443 and configured to move along the third rail 443 between a home position spaced-apart from the third guide roller 442a and a reefing position adjacent the third guide roller 442a, a third drive roller 445 supported by the third carriage 444, a third roller actuator 446 supported by the third carriage 444 and operably connected to the third drive roller 445 to rotate the third drive roller 445 in opposing reefing and unreefing rotational directions, and a third carriage actuator 447 operably connected to the carriage 444 to move the carriage 444 between its home and reefing positions.

[0039] The fourth reefing device 450 is similar to the first reefing device 420 and not shown separately. The fourth reefing device includes a fourth support 451, a fourth reefing finger 452 extending generally vertically from one end of the fourth support 451. a freely rotatable fourth guide roller 452a mounted to the fourth reefing finger 452, a fourth rail 453 supported by the fourth support 451. a fourth carriage 454 mounted to the fourth rail 453 and configured to move along the fourth rail 453 between a home position spaced-apart from the fourth guide roller 452a and a reefing position adjacent the fourth guide roller 452a, a fourth drive roller 455 supported by the fourth carriage 454, a fourth roller actuator 456 supported by the fourth carriage 454 and operably connected to the fourth drive roller 455 to rotate the fourth drive roller 455 in opposing reefing and unreefing rotational directions, and a fourthcarriage actuator 457 operably connected to the carriage 454 to move the carriage 454 between its home and reefing positions.

[0040] The first, second, third, and fourth reefing devices 420, 430, 440, and 450 are mounted to the frame of the wrapping carriage in a generally rectangular arrangement. The first set of reefing-device actuators 420a is operably connected to the first and second reefing devices 420 and 430 to move the first and second reefing devices 420 and 430 laterally inwardly and outwardly in the X- and Y-directions and generally parallel to the X-Y plane relative to the wrapping carriage (and the load L and the section of tubular film 40). The second set of reefing-device actuators 440a is operably connected to the third and fourth reefing devices 440 and 450 to move the third and fourth reefing devices 440 and 450 laterally inwardly and outwardly in the X- and Y-directions and generally parallel to the X-Y plane relative to the wrapping carriage (and the load L and the section of tubular film 40).

[0041] The first set of reefing-device actuators 420a includes a first X-actuator and a first Y-actuator that are controlled independently of one another. The first X-actuator is operably connected to the first and second reefing devices 420 and 430 and configured to move the first and second reefing devices 420 and 430 relative to the wrapping carriage in the X- direction. The first Y-actuator is operably connected to the first and second reefing devices 420 and 430 and configured to move the first and second reefing devices 420 and 430 relative to the wrapping carriage in the Y-direction. In this example embodiment, the first X- and Y- actuators include electric motors controlled by separate variable-frequency drives, but the actuators may be any suitable actuators in other embodiments (such as hydraulic motors controlled by proportional solenoid valves). In this example embodiment, the first X-actuator moves the first and second reefing devices simultaneously and at the same rate towards and away from the load in the X-direction. Similarly, the first Y-actuator moves the first andsecond reefing devices simultaneously and at the same rate towards and away from the load in the Y -direction.

[0042] The second set of reefing-device actuators 440a includes a second X-actuator and a second Y-actuator that are controlled independently of one another. The second X-actuator is operably connected to the third and fourth reefing devices 440 and 450 and configured to move the third and fourth reefing devices 440 and 450 relative to the wrapping carriage in the X-direction. The second Y-actuator is operably connected to the third and fourth reefing devices 440 and 450 and configured to move the third and fourth reefing devices 440 and 450 relative to the wrapping carriage in the Y-direction. In this example embodiment, the second X- and Y-actuators include electric motors controlled by separate variable-frequency drives, but the actuators may be any suitable actuators in other embodiments (such as hydraulic motors controlled by proportional solenoid valves). In this example embodiment, the second X-actuator moves the third and fourth reefing devices simultaneously and at the same rate towards and away from the load in the X-direction. Similarly, the second Y-actuator moves the third and fourth reefing devices simultaneously and at the same rate towards and away from the load in the Y -direction.

[0043] In other embodiments, the stretch-hood machine includes a separate set of one or more reefing device actuators for each individual reefing device. In some of these embodiments, each set of reefing device actuators includes independently controlled X- and Y-actuators similar to those described above.

[0044] The operator interface 500 is configured to receive inputs from an operator and, in certain embodiments, to output information to the operator. The operator interface includes one or more input devices configured to receive inputs from the operator. In various embodiments, the one or more input devices include one or more buttons (such as hard or softkeys), one or more switches, and / or a touch panel. In various embodiments, the operator interface 500 includes a display device configured to display information to the operator, such as information about the palletized load, the status of the wrapping operation, or the settings of the stretch-hood machine 10. The operator interface may include other output devices instead of or in addition to the display device, such as one or more speakers and / or one or more lights. In certain embodiments, the operator interface 500 is formed as part of the stretch-hood machine 10 and is, for instance, mounted to the machine frame 100. In other embodiments, the operator interface is remote from the stretch-hood machine 10.

[0045] The controller 600 includes a processing device communicatively connected to a memory device. The processing device may include any suitable processing device such as, but not limited to, a general-purpose processor, a special-purpose processor, a digital-signal processor, one or more microprocessors, one or more microprocessors in association with a digital-signal processor core, one or more application-specific integrated circuits, one or more field-programmable gate array circuits, one or more integrated circuits, and / or a state machine. The memory device may include any suitable memory device such as, but not limited to, read-only memory, random-access memory, one or more digital registers, cache memory, one or more semiconductor memory devices, magnetic media such as integrated hard disks and / or removable memory, magneto-optical media, and / or optical media. The memory device stores instructions executable by the processing device to control operation of the stretch-hood machine 10.

[0046] The controller 600 is communicatively and operably connected to the film-supply assembly 200 and any perforator included therein (e.g., perforator 220, as described further below); the film-opening assembly 300; the wrapping carriage actuator 410; the first and second sets of reefing-device actuators 420a and 440a; and the first, second, third, and fourth sets of roller actuators 426, 436, 446, and 456; the first, second, third, and fourth carriageactuators 427, 437, 447, and 457. The controller 600 is communicatively connected to the operator interface 500 to: (1) receive signals from the operator interface 500 that represent inputs received by the operator interface 500; and (2) send signals to the operator interface 500 to cause the operator interface 500 to output (such as to display) information.

[0047] Upon initiation of a wrapping process, a section of tubular fdm is created. In this example embodiment, the controller 600 controls the film-supply assembly 200 to draw tubular film 40 from the film roll R, optionally perforating the tubular film 40, and cut the film to a desired length (which depends on the height of the load) to form the section of tubular film 40. The bottom portion of the section of tubular film is then opened. In this example embodiment, the controller 600 controls the film-opening assembly 300 (and more particularly, the suction boxes and holding devices) to open the bottom portion of the section of tubular film 40 so the shape of its perimeter is generally rectangular, as explained above.

[0048] The reefing devices are then moved to their insertion positions. In this example embodiment, the controller 600 controls the first and second sets of reefing-device actuators 420a and 440a to move the respective reefing devices 420, 430. 440, and 450 laterally inwardly relative to the section of tubular film 40 (in the X- and Y- directions and generally parallel to the X-Y plane) to their respective insertion positions in which they form an insertion configuration. Figures 4 and 5 show the reefing devices 420, 430. 440, and 450 at their insertion positions. The insertion positions are preset (such as by the operator) based on several factors, including the size of the film (e.g., its unstretched perimeter). At this point, and as shown in Figure 3 for the reefing device 420, the first, second, third, and fourth carriages 424, 434. 444, and 454 of the first, second, third, and fourth reefing devices 420, 430, 440. and 450 are in their respective home positions. The wrapping carriage is then raised so the reefing fingers of the reefing devices are received in the open bottom portion of the section of tubular film. In this example embodiment, the controller 600 controls the wrappingcarriage actuator 410 to raise the wrapping carriage so the reefing fingers 422, 432, 442, and452 of the respective reefing devices 420, 430, 440, and 450 are received in the open bottom portion of the section of tubular film 40.

[0049] The reefing devices are then moved to their reefing positions, and the reefing devices reef the section of tubular film onto the reefing fingers. In this example embodiment, the controller 600 controls the first and second sets of reefing-device actuators 420a and 440a to move the respective reefing devices 420, 430, 440, and 450 laterally outwardly relative to the section of tubular film 40 (in the X- and Y- directions and generally parallel to the X-Y plane) to their respective reefing positions in which they form a reefing configuration in preparation for reefing the section of tubular film 40. The controller 600 then controls the first, second, third, and fourth carriage actuators 427, 437, 447, and 457 to move the respective carriages 424, 434, 444, and 454 from their respective home positions to their respective reefing positions, which causes the drive wheels 425, 435, 445, and 455 of the reefing devices 420, 430, 440, and 450 to contact the inner surface Fis of the section of tubular film 40 and force the outer surface Fos of the section of tubular film 40 against the respective guide wheels 422a, 432a, 442a, and 452a. Figures 6-8 show the reefing devices 420, 430. 440, and 450 in their reefing positions after their carriages have moved to their respective reefing positions. In certain embodiments, the carriages move to their reefing positions as the reefing devices move to their reefing positions. The controller 600 then controls the first, second, third, and fourth roller actuators 426, 436, 446, and 456 to drive the first, second, third, and fourth drive rollers 425, 435, 445. and 455 in a reefing rotational direction to reef the section of tubular film 40 onto the reefing fingers 422, 432, 442. and 452. Figures 9 and 10 show the reefing devices 420, 430, 440, and 450 after reefing.

[0050] The reefing devices then begin moving toward respective wrapping positions so as to form a wrapping configuration. In this example embodiment, the controller 600 controlsthe first and second sets of reefing-device actuators 420a and 440a to begin moving the respective reefing devices 420, 430, 440, and 450 from their respective reefing positions to their respective wrapping positions, causing the section of tubular film to stretch. Here, the wrapping positions of the respective reefing devices are located laterally outward (in the X- and Y- directions and generally parallel to the X-Y plane) relative to the reefing positions. Additionally, the reefing devices each follow a 45-degree path within the X-Y plane as they move from their respective reefing positions to their respective wrapping positions (though the movement path and resulting angle may differ in other embodiments).

[0051] After the reefing devices reach the wrapping configuration, the wrapping carriage descends relative to the load (in the Z-direction indicated in Figure 1). During this descent the motors drive the drive rollers of the reefing devices in the unreefing rotational direction at an unreefing speed to unreef the remainder of the film from the reefing fingers. As this occurs, the film attempts to return to its unstretched size and shape and laterally contracts onto the load, which unitizes the load and / or secures the load to a pallet. This completes the wrapping process, and a conveyor conveys the load from the stretch-hood machine.

[0052] Figures 12A and 12B illustrate one example embodiment of the use of a perforator 220 for forming perforations in the central portion of a segment of tubular film 40 for wrapping an item that includes the pallet P and the load L. The roll of tubular film R used in this example embodiment is shown in Figure 11. As shown, the tubular film 40 provided on the roll R has a tubular form with an opening 41 at the loose end of the tubular film 40 that provides access to the interior of the tubular film 40. The tubular film 40 comes off the roll as a flat sheet having a width that extends from an edge that runs along a first side 42 of the sheet to an edge that runs along the second side 45 of the sheet. Along each side of the sheet of tubular film 40, part of the film is folded to form a gusset. For example, as shown in Figure 11, a first gusset 43 is formed along the first side 42 and extends inward toward the center ofthe sheet of tubular film to a folded edge 44. Similarly, a second gusset 46 is formed along the second side 45 and extends inward toward the center of the sheet to a folded edge 47. When the tubular film 40 is opened to provide an interior space for a load, the folded edges 44, 47 of the gussets 43, 46 move away from one another so that the interior of the tubular film 40 may expand.

[0053] When the tubular film 40 lies flat, such as when it is removed from the roll of film R and before it is opened, the area of the sheet between the first side 42 of the sheet and the folded edge 44 of the first gusset 43 is stacked in four layers. Similarly, the area of the sheet between the second side 45 and the folded edge 47 of the second gusset 46 is also stacked in four layers. On the other hand, each of the first and second gussets 43, 46 have a width that is less than half the width of the roll of film R, such that a gap exists between the folded edge 44 of the first gusset 43 and the folded edge 47 of the second gusset 46. Within the area of the gap between the folded edge 44 of the first gusset 43 and the folded edge 47 of the second gusset 46, the flat tubular film 40 has two layers.

[0054] Figures 12A and 12B illustrate a perforator 220 associated with the film-supply assembly 200 of the stretch-hood machine 10. as described in detail above. A roller 210 that is part of the film-supply assembly 200 directs the tubular film 40 to the perforator 220 where the tubular film 40 is perforated to form holes through the layers of the tubular film. The stretch-hood machine may also include additional rollers to direct the tubular film 40 to other parts of the machine, such as the film-opening assembly. The perforator 220 shown in Figures 12A and 12B includes a perforating roller 230 and a receiving roller 240 that are configured to receive the tubular film in a flat configuration and form holes through a portion of the tubular film.

[0055] The perforating roller 230 extends from the first side 42 of the tubular film to the second side 45 of the tubular film. The receiving roller 240 similarly extends from the first side 42 of the tubular film to the second side 45 of the tubular film. The perforating roller 230 includes perforating pins 232 that are positioned in a row along the circumference of the perforating roller 230. In the illustrated embodiment, there are two rows of perforating pins 232, the perforating pins are evenly spaced along the rows, and the two rows are equally spaced around the circumference of the perforating roller 230. In other embodiments, there may be more than two rows of perforating pins. Further, in some embodiments, the rows of perforating pins may be unevenly spaced around the circumference of the perforating roller. Moreover, the spacing of the perforating pins along the rows may be uneven. For example, in some embodiments, a gap in the perforating pins may be provided along the row, for instance to avoid the folded edge of a gusset, or to avoid a comer of the expanded tubular film.

[0056] Figure 12A shows the perforator 220 in a disengaged state such that the tubular film 40 can be moved through the perforator 220 when a new segment of tubular film is draw n from the roll of tubular film. Similarly, if the controller of the stretch-hood machine does not activate the perforator 220, the tubular film 40 can be moved through the perforator without being perforated. Figure 12B shows the perforator 220 in an engaged state for forming perforations in the tubular film 40. In the illustrated embodiment, the perforating roller 230 may be moved laterally to decrease the distance between the perforating roller 230 and the receiving roller 240. When the perforating roller 230 is in the engaged position, the perforating pins 232 are configured to press through the layers of the tubular film 40 and into the surface of the receiving roller 240. The perforating pins 232 press through the layers of the tubular film 40 as the perforating roller 230 rotates about an axis and the holes are formed as the perforating pins 232 press into the surface of the receiving roller 240.

[0057] As described above, the area of the sheet of the tubular film 40 between the first side 42 of the sheet and the folded edge 44 of the first gusset 43 is stacked in four layers and the area of the sheet between the second side 45 and the folded edge 47 of the second gusset 46 is also stacked in four layers. In these areas, the perforations will be formed through all four layers. In the two-layer central section of the tubular film, the perforations will be formed through those two layers.

[0058] In the illustrated embodiment, the tubular film 40 is passed through the perforator 220 as the perforating roller 230 and the receiving roller 240 rotate such that perforations are formed each time the perforating pins 232 engage with the receiving roller 240. More particularly, perforations are formed every time the perforating roller 230 completes a half rotation while the perforator 220 is in an engaged state. In other embodiments where the perforating roller has more than two rows of perforating pins, perforations may be formed incrementally based on the number of rows of perforating pins.

[0059] Figure 13 illustrates an embodiment of a perforator of a stretch-hood machine that provides a plurality of perforating rollers for forming various configurations of perforations. In the illustrated embodiment, the perforator 1220 includes a first perforating roller 1230, a second perforating roller 1240, and a third perforating roller 1250. Similar to the perforating roller 230 illustrated in Figure 13, each of the perforating rollers 1230, 1240, and 1250 extend from the first side 42 of the tubular film 40 to the second side 45 of the tubular film 40.

[0060] Each of the perforating rollers 1230, 1240, and 1250 include various perforating pins of different configurations and shapes. The first perforating roller 1230 includes square perforating pins 1234 that have a rectangular prism shape and are configured to form square apertures in the tubular film. The second perforating roller 1240 includes small perforating pins 1244 that have a small cylindrical shape and are configured to form small circular holesin the tubular film. The third perforating roller 1250 includes large perforating pins 1254 which also have a cylindrical shape and are configured to form larger circular holes in the tubular film. The larger perforating pins 1254 of the third perforating roller 1250 have a larger diameter than the small perforating pins 1244 of second perforating roller 1240. In the illustrated embodiment, each of the perforating rollers 1230, 1240, 1250 include two rows of perforating pins that are equally spaced around the circumference of the perforating rollers such that perforations are formed every half rotation when the roller is engaged.

[0061] Because there are various perforating rollers 1230, 1240, and 1250 in the perforator 1220, the controller of the stretch-hood machine can selectively activate the first perforating roller 1230, second perforating roller 1240, or the third perforating roller 1250 to form the perforations. When a particular perforating roller is activated, that perforating roller can form perforations in the tubular film of the corresponding shape while the other perforating rollers remain inactive. The other two perforating rollers will remain in a disengaged state. In the illustrated configuration, perforating roller 1240 is engaged while perforating rollers 1230, 1250 are disengaged.

[0062] It should be understood that the illustrated embodiment of Figure 13 is just one potential embodiment of a perforator with selectable perforating rollers. In other embodiments, the perforating rollers could have several other shapes of perforating pins. Additionally, the perforator could have any number of perforating rollers, each with different configurations of perforating pin shapes, sizes, and quantities. For example, in some embodiments, there may be a plurality of perforating rollers and the perforating rollers may have perforating pins that are the same shapes and sizes, but each perforating roller may have a different number of perforating pins. In that example, the user would be able to control how many perforations will be made by the perforator by controlling which perforating roller engages and which perforating rollers are disengaged.

[0063] Figures 14A and 14B illustrate another embodiment of a perforator of a stretchhood machine that allows for forming perforations in a tubular fdm. Figure 14A shows an embodiment of a perforator 2220 that is similar to that shown in Figures 12A and 12, except the perforator 2220 includes a perforating rail 2230 and a receiving rail 2240 instead of perforating and receiving rollers. Figure 14A shows the perforator 2220 in a disengaged state, while Figure 14B shows the perforator 2220 in an engaged state.

[0064] In the disengaged state, the tubular film 40 can be moved through the perforator 2220 when a new segment of tubular film is drawn from the roll of tubular film. Similarly, if the perforator 2220 is not activated to engage, the tubular film 40 can be moved through the perforator without being perforated. Figure 14B show s the perforator 2220 in an engaged state for forming perforations in the tubular film 40. In the illustrated embodiment, the perforating rail 2230 may be moved laterally to decrease the distance between the perforating rail 2230 and the receiving rail 2240. When the perforating rail 2230 is in the engaged position, perforating pins 2232 are configured to press through the layers of the tubular film 40 and into the surface of the receiving rail 2240. To form another set of perforations within the same segment of tubular film, the perforating rail 2230 may engage and disengage several times as the segment of tubular film is drawn through the perforator 2220.

[0065] In other embodiments, the perforator may include more than one perforating rail and one receiving rail, similar to the perforator shown in Figure 13. Further, in some embodiments, several perforating rails may be configured to perforate simultaneously so as to form several rows of perforations at one time. Moreover, in some embodiments, the perforating rails may include different quantities, shapes, and sizes of perforating pins.

[0066] Figure 15 illustrates another embodiment of a perforator 3220 of a stretch-hood machine that allows for forming perforations through the tubular film. Perforator 3220includes a first rail 3230 and a receiving rail 3240. The first rail 3230 includes a perforating assembly 3234 that laterally traverses the length of the first rail 3230 based on where the perforations are to be formed. The perforating assembly 3234 includes a perforating pin that can extend to press through the tubular film 40 to press into the receiving rail 3240 to form a perforation. To form multiple perforations, the perforating assembly 3234 can traverse the first rail 3230 to several points along the same axis, forming perforations at each point. The controller of the stretch-hood machine can operate the perforating assembly 3234 to perforate the tubular film at uniform distances between points or unequal distances between points. Further, the controller can operate the perforating assembly to select a particular quantity of perforations to form. As with the embodiments described above, the perforator 3220 may remain disengaged such that the tubular film 40 can pass through the perforator 3220 without perforations being formed. In other embodiments, the perforator may have several perforating assemblies. Additionally, the perforator may include more than one rail, where each of the rails may include at least one perforating assembly.

[0067] Figures 16 to 18 illustrate example embodiments of perforated tubular film for use in a stretch-hood machine. Figure 16 shows an embodiment of perforated tubular film 1640 that includes rows of perforations 1652 that span from a first side 1642 to a second side 1645 of the tubular film 1640. Similar to the tubular film 40, an area of the sheet between the first side 1642 of the sheet and a folded edge 1644 of a first gusset 1643 is stacked in four layers and the area of the sheet between the second side 1645 and a folded edge 1647 of a second gusset 1646 is also stacked in four layers. In these areas, the perforations 1652 are formed through all four layers. In the two-layer central section of the tubular film, the perforations 1652 are formed only through two layers. In this embodiment, the perforations 1652 are configured such that when the perforated tubular film 1640 is wrapped around a load on a pallet, as shown in Figure 19, the tubular film will be perforated on all four sides of the load.In other embodiments, the perforations may be spaced unevenly in both the vertical and horizontal directions. Additionally, the perforations may be other shapes or sizes. Further, other embodiments may include more or fewer rows of perforations.

[0068] Figure 17 illustrates an example embodiment of perforated tubular film for use in a stretch-hood machine. Figure 17 shows a perforated tubular film 1740 that includes rows of perforations 1752. Similar to the tubular film 40, an area of the sheet between a first side 1742 of the sheet and a folded edge 1744 of a first gusset 1743 is stacked in four layers and the area of the sheet between a second side 1745 and a folded edge 1747 of a second gusset1746 is also stacked in four layers. The perforations 1752 are vertically spaced in the section of tubular film between the folded edge 1744 of the first gusset 1743 and the folded edge1747 of the second gusset 1746. Because the perforations 1752 are only formed between the folded edges 1744, 1747 of the gussets 1743, 1746, the perforations 1752 only go through two layers of film. Therefore, in this embodiment, when the perforated tubular film 1740 is wrapped around a load on a pallet, the perforations 1752 will be on two sides of the load. In other embodiments, the perforations may be spaced unevenly in both the vertical and horizontal directions. Additionally, the perforations may be other shapes or sizes. Further, other embodiments may include more or fewer rows of perforations. Figure 18 illustrates another example embodiment of perforated tubular film which includes perforations 1852 with larger diameters than the perforations 1752 of the embodiment shown in Figure 17.

[0069] Figure 19 shows a segment of perforated tubular film 1940 that has been wrapped around a load L on a pallet P by a stretch-hood system. For clarity, the stretch-hood machine is not shown in Figure 19. The tubular film 1940 includes perforations 1952 which may help control moisture or other environmental conditions inside the tubular film.

[0070] Further, in some embodiments, a perforator includes other cutting devices, including a laser cutter or a waterjet.

[0071] While the above embodiments are described in the context of tubular film from a single roll of film, in some embodiments, the stretch-hood machine may include several rolls of film. For example, the stretch-hood machine may hold rolls of film of different width, strength or other characteristics. In some embodiments including multiple rolls of film, the stretch-hood machine may be configured to direct film from each roll of film to the same perforator or perforators. In other embodiments, the stretch-hood machine may include separate perforators associated with each of the rolls of film. For example, a first perforator may be configured to perforate film from a first roll and a second perforator may be configured to perforate film from a second roll.

[0072] The disclosure also provides a method of performing a series of wrapping operations for wrapping items with and without forming perforations in the tubular film. For example, in a series of wrapping operations a first wrapping operation includes: receiving a first item in a stretch-hood machine; drawing tubular film from a roll of film; perforating the tubular film after the tubular film has been drawn from the roll of film so as to form perforations arranged along a length of the tubular film; reefing the tubular film onto reefing fingers of a plurality of reefing devices; lowering the reefing devices around the item to wrap the item within an interior of the tubular film; and removing the wrapped first item from the stretch-hood machine.

[0073] A second wrapping operation in the series of wrapping operations includes: receiving a second item in the stretch-hood machine; drawing additional tubular film from the roll of film; positioning the additional tubular film on the reefing devices without perforating the additional tubular film; reefing the additional tubular film onto reefing fingers of thereefing devices; lowering the reefing devices around the item to wrap the second item within an interior of the additional tubular film; and removing the wrapped second item from the stretch-hood machine.

[0074] The forming of the perforations in the first wrapping operation may be carried out according to any of the above-described methods using any of the described perforators.

[0075] Thus, in various embodiments, the present disclosure provides a method of operating a stretch-hood machine to wrap an item with tubular film. The method includes drawing a section of tubular film from a roll of film and perforating the tubular film after the tubular film has been draw n from the roll of film so as to form perforations arranged along a length of the tubular film. The method also includes reefing the tubular film onto reefing fingers of a plurality of reefing devices lowering the reefing devices around the item to wrap the item within an interior of the tubular film.

[0076] In various such embodiments of this method, the tubular film is perforated while traveling from the roll of film to the reefing fingers.

[0077] In various such embodiments of this method, the perforations are arranged to allow airflow through the film.

[0078] In various such embodiments of this method, the perforations are arranged in columns that extend along the length of the tubular film.

[0079] In various such embodiments of this method, the perforations of the tubular film are arranged to be spaced from comers of the item when the item is wrapped within the interior of the tubular film.

[0080] In various such embodiments of this method, the method further comprises selecting, using a controller of the stretch-hood machine, a quantity of the perforations formed along the length of tubular film.

[0081] In various such embodiments of this method, the method further comprises selecting, using a controller of the stretch-hood machine, a first set of perforating pins for perforating the tubular film.

[0082] In various such embodiments of this method, the stretch-hood machine includes a second set of perforating pins.

[0083] In various such embodiments of this method, the perforating pins of the first set have a different size than the perforating pins of the second set.

[0084] In various such embodiments of this method, the perforating pins of the first set have a different shape than the perforating pins of the second set.

[0085] In various such embodiments of this method, the method further comprises removing the first item from the stretch-hood machine, receiving a second item in the stretchhood machine, drawing additional tubular film from the roll of film, and positioning the additional tubular film on the reefing devices without perforating the additional tubular film. This method further includes reefing the additional tubular film onto reefing fingers of the reefing devices; and lowering the reefing devices around the item to wrap the second item within an interior of the additional tubular film.

[0086] In various such embodiments of this method, the tubular film that is draw n from the roll is unperforated film.

[0087] In various such embodiments of this method, the method further comprises removing the first item from the stretch-hood machine, placing a second item in the stretch-hood machine, drawing additional unperforated tubular film 40 from the roll of film, positioning the additional unperforated tubular film on the reefing devices, reefing the additional unperforated tubular film onto reefing fingers of the reefing devices, and lowering the reefing devices around the item to wrap the second item within an interior of the additional unperforated tubular film.

[0088] In various embodiments, the present disclosure provides a stretch-hood machine. The stretch-hood machine includes a machine frame, a wrapping carriage, a plurality of reefing devices supported by the wrapping carriage, a film-supply assembly, and a perforator. The wrapping carriage is movable relative to the machine frame between upper and lower positions. The reefing devices are configured to reef a segment of tubular film, stretch the segment of tubular film and unreef the segment of tubular film. The film-supply assembly is configured to draw tubular film from a roll of film, cut the tubular film from the roll to form the segment of tubular film, and direct the segment of tubular film to the reefing devices. The perforator is configured to form perforations arranged along a length of the tubular film after the tubular film is drawn from the roll and before the reefing devices reef the segment of tubular film.

[0089] In various such embodiments of this stretch-hood machine, the stretch-hood machine further comprises a controller configured to selectively activate the perforator.

[0090] In various such embodiments of this stretch-hood machine, the perforator includes a first set of perforating pins and a second set of perforating pins.

[0091] In various such embodiments of this stretch-hood machine, the stretch-hood machine further comprises a controller configured to selectively activate the first set of perforating pins or the second set of perforating pins.

[0092] In various such embodiments of this stretch-hood machine, the first set of perforating pins have a different size than the second set of perforating pins.

[0093] In various such embodiments of this stretch-hood machine, the first set of perforating pins have a different shape than the second set of perforating pins.

[0094] In various such embodiments of this stretch-hood machine, the stretch-hood machine further comprises a controller configured to determine the number of perforations formed in the tubular film.

[0095] Various changes and modifications to the above-described embodiments described herein will be apparent to those skilled in the art. These changes and modifications can be made without departing from the spirit and scope of this present subject matter and without diminishing its intended advantages. Not all of the depicted components described in this disclosure may be required, and some implementations may include additional, different, or fewer components from those expressly described in this disclosure. Variations in the arrangement and type of the components; the shapes, sizes, and materials of the components; and the manners of attachment and connections of the components may be made without departing from the spirit or scope of the claims as set forth herein. Also, unless otherwise indicated, any directions referred to herein reflect the orientations of the components shown in the corresponding drawings and do not limit the scope of the present disclosure. This specification is intended to be taken as a whole and interpreted in accordance with the principles of the invention as taught herein and understood by one of ordinary skill in the art.

Claims

CLAIMS1. A method of operating a stretch-hood machine to wrap an item with tubular film, the method comprising: drawing tubular film from a roll of film; perforating the tubular film after the tubular film has been drawn from the roll of film so as to form perforations arranged along a length of the tubular film; reefing the tubular film onto reefing fingers of a plurality of reefing devices; and lowering the reefing devices around the item to wrap the item within an interior of the tubular film.

2. The method of claim 1 , wherein the tubular film is perforated while traveling from the roll of film to the reefing fingers.

3. The method of claim 1, wherein the perforations are arranged to allow airflow through the film.

4. The method of claim 1. wherein the perforations are arranged in columns that extend along the length of the tubular film.

5. The method of claim 1. wherein the perforations of the tubular film are arranged to be spaced from comers of the item when the item is wrapped within the interior of the tubular film.

6. The method of claim 1, further comprising selecting, using a controller of the stretch-hood machine, a quantity of the perforations formed along the length of tubular film.

7. The method of claim 1, further comprising selecting, using a controller of the stretch-hood machine, a first set of perforating pins for perforating the tubular film.

8. The method of claim 7, wherein the stretch-hood machine includes a second set of perforating pins.

9. The method of claim 8. wherein the perforating pins of the first set have a different size than the perforating pins of the second set.

10. The method of claim 8, wherein the perforating pins of the first set have a different shape than the perforating pins of the second set.

11. The method of claim 1 , further comprising: removing the first item from the stretch-hood machine; receiving a second item in the stretch-hood machine; drawing additional tubular film from the roll of film; positioning the additional tubular film on the reefing devices without perforating the additional tubular film; reefing the additional tubular film onto reefing fingers of the reefing devices; and lowering the reefing devices around the item to wrap the second item within an interior of the additional tubular film.

12. The method of claim 1, wherein the tubular film that is drawn from the roll is unperforated film.

13. The method of claim 12, further comprising: removing the first item from the stretch-hood machine; placing a second item in the stretch-hood machine; drawing additional unperforated tubular film from the roll of film; positioning the additional unperforated tubular film on the reefing devices;reefing the additional unperforated tubular film onto reefing fingers of the reefing devices; and lowering the reefing devices around the item to wrap the second item within an interior of the additional unperforated tubular film.

14. A stretch-hood machine comprising: a machine frame; a wrapping carriage movable relative to the machine frame between upper and lower positions; a plurality' of reefing devices supported by the wrapping carriage and configured to reef a segment of tubular film, stretch the segment of tubular film, and unreef the segment of tubular film; a film-supply assembly configured to draw tubular film from a roll of film, cut the tubular film 40 from the roll to form the segment of tubular film, and direct the segment of tubular film to the reefing devices; and a perforator configured to form perforations arranged along a length of the tubular film after the tubular film is draw n from the roll and before the reefing devices reef the segment of tubular film.

15. The stretch-hood machine of claim 14, further comprising a controller configured to selectively activate the perforator.

16. The stretch-hood machine of claim 14. wherein the perforator includes a first set of perforating pins and a second set of perforating pins.

17. The stretch-hood machine of claim 16, further comprising a controller configured to selectively activate the first set of perforating pins or the second set of perforating pins.

18. The stretch-hood machine of claim 17, wherein the first set of perforating pins have a different size than the second set of perforating pins.

19. The stretch-hood machine of claim 17. wherein the first set of perforating pins have a different shape than the second set of perforating pins.

20. The stretch-hood machine of claim 14, further comprising a controller configured to determine the number of perforations formed in the tubular film.

Images