Stretch-hood machine with retractable counter rollers

Abstract

Various embodiments of the present disclosure provide a stretch-hood machine including a wrapping carriage supporting a reefing device. The reefing device includes a reefing finger having a film-engagement surface, a counter roller supported by the reefing finger, and a drive roller. The counter roller is movable between an extended position in which a first portion of the counter-roller is positioned forward of the film-engagement surface and a retracted position in which at least part of the first portion of the counter roller is positioned rearward of the film-engagement surface. With the counter roller in the extended position, a controller drives the drive roller to reef a segment of tubular film onto the film-engagement surface. After reefing, the controller causes the counter roller to move to the retracted position and drives the drive roller to unreef the segment of tubular film from the reefing finger while the wrapping carriage descends.

Description

STRETCH-HOOD MACHINE WITH RETRACTABLE COUNTER ROLLERSPriority

[0001] This application claims priority to and the benefit of U.S. Provisional Patent Application No. 63 / 627,941, filed February 1, 2024, the entire contents of which is incorporated herein by reference.Field

[0002] The present disclosure relates to stretch-hood machines for wrapping loads of goods with tubular stretch 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 filmopening 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 that supports a freely rotatable counter roller. The drive roller is movable toward and away from the counter roller, and a motor drives the drive roller.

[0004] To wrap a load of goods, the film-supply assembly draws the tubular film from a film roll, cuts the film to a desired length to form a segment of tubular film, and in certain instances heat seals the top of the segment of tubular film closed. The film-opening assembly opens the bottom portion of the segment of tubular film so its perimeter is substantially rectangular. The reefing devices move laterally inwardly to respective insertion positions in which they form an insertion configuration. The wrapping carriage then ascends until the reefing fingers of the reefing devices enter the open bottom portion of the segment of tubular film near its four comers. The reefing devices move laterally outwardly to respective reefing positions in which they form a reefing configuration in preparation for reefing the segment of tubular film onto the reefing fingers. The drive rollers of the reefing devices move toward their respectivecounter rollers to contact the outer surface of the segment of tubular film and force the inner surface of the segment of tubular film against the counter rollers, thereby sandwiching the film between the pairs of rollers. The motors drive their respective drive rollers in a reefing rotational direction to reef (or gather) the segment of tubular film onto curved film-engagement surfaces of the reefing fingers.

[0005] After reefing, the reefing devices move laterally outwardly to 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 segment of tubular film is sized to surround the load once the reefing devices reach the wrapping configuration. After the reefing devices reach the wrapping configuration, the wrapping carriage descends. During this descent the motors drive the drive rollers of the reefing devices in an unreefing rotational direction to unreef 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.

[0006] In certain stretch-hood machines, each counter roller is mounted to its respective reefing finger such that a portion of the counter roller is positioned forward of the film-engagement surface of the reefing finger. This positioning results in the formation of orderly folds in the film during reefing, which improves wrapping quality. A downside of this positioning of the counter rollers is that the film will stretch and thin out as it passes over the counter rollers during unreefing. This creates visible marks in the film and can result in a less stable wrapped load because the thinned portions of the film are weaker than the rest of the film.Summary

[0007] Various embodiments of the present disclosure provide a stretch-hood machine including a wrapping carriage supporting a reefing device. The reefing device includes a reefing finger having a film-engagement surface, a counter roller supported by the reefing finger, and a drive roller. The counter roller is movable between an extended position in which a first portion of the counter-roller is positioned forward of the film-engagement surface and aretracted position in which at least part of the first portion of the counter roller is positioned rearward of the film-engagement surface. With the counter roller in the extended position, a controller drives the drive roller to reef a segment of tubular film onto the film-engagement surface. After reefing, the controller causes the counter roller to move to the retracted position and drives the drive roller to unreef the segment of tubular film from the reefing finger while the wrapping carriage descends.

[0008] Various embodiments of the present disclosure provide a method of operating a stretch-hood machine including: with a counter roller supported by a reefing finger of a reefing device in an extended position in which a first portion of the counter-roller is positioned forward of a film-engagement surface of the reefing finger, reefing a segment of tubular film onto the film-engagement surface; and after the segment of tubular film has been reefed onto the filmengagement surface: moving the counter roller to a retracted position in which at least part of the first portion of the counter roller is positioned rearward of the film-engagement surface; and lowering a wrapping carriage supporting the reefing device while unreefing the segment of tubular film from the reefing finger.Brief Description of the Figures

[0009] Figure l is a perspective view of one embodiment of the stretch-hood machine of the present disclosure.

[0010] Figure 2 is a block diagram showing certain components of the stretch-hood machine of Figure 1.

[0011] Figure 3 is a side elevational view of one of the reefing devices of the stretchhood machine of Figure 1 with the reefing carriage in the home position and the counter roller in the extended position.

[0012] Figures 4A and 4B are assembled and exploded perspective views of the finger assembly of the reefing device of Figure 3.

[0013] Figures 4C and 4D are cross-sectional top plan views of the part of the finger assembly of Figures 4A and 4B taken along line 4-4 of Figure 3. The counter roller is in the extended position in Figure 4C and in the retracted position in Figure 4D.

[0014] Figure 5 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 segment of tubular film and before the reefing fingers of the reefing devices have been inserted into the bottom of the segment of tubular film.

[0015] Figure 6 is a simplified top plan view that corresponds to Figure 5.

[0016] Figure 7 is a perspective view similar to Figure 5 but after the reefing fingers of the reefing devices have been inserted into the bottom of the segment of tubular film and after the reefing carriages of the reefing devices have moved to their respective reefing positions.

[0017] Figure 8 is a simplified top plan view that corresponds to Figure 7.

[0018] Figure 9 is a side elevational view of the reefing device of Figure 3 with the reefing carriage in the reefing position and the counter roller in the extended position.

[0019] Figure 10 is a perspective view similar to Figure 5 but after the reefing devices have reefed the segment of tubular film onto their reefing fingers.

[0020] Figure 11 is a side elevational view of the reefing device of Figure 3 that corresponds to Figure 10.

[0021] Figure 12 is a side elevational view of the reefing device of Figure 3 with the reefing carriage in the unreefing position and the counter roller in the retracted position.

[0022] Figure 13 is a perspective view similar to Figure 5 but after the reefing devices have descended to just above the load in preparation for unreefing the segment of tubular film from the reefing fingers and onto the load.

[0023] Figure 14 is a flowchart of an example wrapping process of the present disclosure.

[0024] Figures 15A and 15B are assembled and exploded perspective views of another embodiment of the finger assembly of the present disclosure.

[0025] Figures 15C and 15D are cross-sectional side elevational views of the finger assembly of Figures 15A and 15B taken along line 15C-15C of Figure 15 A. The counter roller is in the retracted position in Figure 15C and the extended position in Figure 15D.Detailed Description

[0026] While the systems, devices, and methods described herein may be embodied in various forms, the drawings show and the specification describes certain exemplary and nonlimiting embodiments. Not all of the components shown in the drawings and described in the specification may be required, and certain implementations may include additional, different, or fewer components. Variations in the arrangement and type of the components; the shapes, sizes, and materials of the components; and the manners of connections of the components may be made without departing from the spirit or scope of the claims. Unless otherwise indicated, any directions referred to in the specification reflect the orientations of the components shown in the corresponding drawings and do not limit the scope of the present disclosure. Further, terms that refer to mounting methods, such as mounted, connected, etc., are not intended to be limited to direct mounting methods but should be interpreted broadly to include indirect and operably mounted, connected, and like mounting methods. This specification is intended to be taken as a whole and interpreted in accordance with the principles of the present disclosure and as understood by one of ordinary skill in the art.

[0027] Figures 1-13 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 stretch-hood 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 reefing-and-wrapping assembly 400 supported by the machine frame 100, an operator interface 900, and a controller C. A coordinate system CS, shown in Figure 1, is used herein as a frame of reference for directional movement of various components of the stretch-hood machine 10 in the X-, Y-, and Z-directions, which are perpendicular to one another in this example embodiment.

[0028] 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 afterwrapping. The illustrated machine frame 100 is merely one example configuration, and any suitable configuration may be employed.

[0029] The film-supply assembly 200 includes suitable components configured to form a segment of tubular film F that the stretch-hood machine 10 then uses to wrap the load L. More specifically, the film-supply assembly 200 includes components suitable to draw a length of tubular film from a roll R of tubular film rotatably mounted to a structure near the machine frame 100, cut the length of tubular film from the roll R to form the segment of tubular film F, and close the upper end of the segment of tubular film (such as via a heat-sealing mechanism). The controller C determines the length of the segment of tubular film F based in part on the height of the load L.

[0030] The film-opening assembly 300 includes suitable components configured to open a bottom portion of the segment of tubular film F so it forms a substantially rectangular perimeter in preparation for reefing by the reefing-and-wrapping assembly 400. More specifically, 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 substantially parallel to the X-Y plane relative to the segment of tubular film F. To open the bottom portion of the segment of tubular film F, the suction boxes move laterally inward in the X- and Y-directions so they are positioned near the outer surface of the bottom portion of the segment of tubular film F. A vacuum is generated to draw the bottom portion of the segment of tubular film F onto the suction boxes, thereby partially opening the bottom portion. The holding devices then clamp the segment of tubular film, and the suction boxes and holding devices move laterally outward in the X- and Y-directions and substantially parallel to the X-Y plane to open the bottom portion of the segment of tubular film F in preparation for reefing. At this point, the perimeter of the bottom portion of the segment of tubular film F forms a substantially rectangular shape. 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.

[0031] The reefing-and-wrapping assembly 400 includes a wrapping carriage (not shown for clarity); a wrapping-carriage actuator 410; first, second, third, and fourth reefing devices 500, 600, 700, and 800; and first and second sets of reefing-device actuators 420 and 440. 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.

[0032] Figures 3-4D, 9, 11, and 12 show the first reefing device 500, which includes a first support 505; a first rail 510 supported by the first support 505; a first carriage 515 slidably mounted to the first rail 510 and configured to move laterally (substantially parallel to the X-Y plane) along the first rail 510 among a home position (Figure 3), a reefing position (Figures 9 and 11), and an unreefing position (Figure 12); a first carriage actuator 515a operably connected to the first carriage 515 and configured to move the first carriage 515 among the home, reefing, and unreefing positions; a first drive roller 520 supported by the first carriage 515; a first driveroller actuator 520a supported by the first carriage 515 and operably connected to the first drive roller 520 and configured to rotate the first drive roller 520 in opposing reefing and unreefing rotational directions; and a first finger assembly 550 extending substantially vertically in the Z- direction from one end of the first support 505.

[0033] As best shown in Figures 4A-4D, the first finger assembly 550 includes a first base 551, a first reefing finger 552, a first counter roller 554, first bearings 556a and 556b, a first-counter-roller-mounting shaft 558, first retainers 559a and 559b, first mounting pins 560a and 560b, first counter-roller biasing elements 562a and 562b, a first retaining plate 564, and first fasteners 566. The first base 551 is connected to the first support 505, such as via suitable fasteners. The first reefing finger 552 is connected to and extends substantially vertically from the first base 551 and includes a curved first film-engagement surface 552s that faces the first carriage 515. In this example embodiment, the first base 551 and the first reefing finger 552 are integrally formed from a single piece of material, though they may be separate components connected to one another in other embodiments.

[0034] The first counter roller 554 is mounted to the first reefing finger 552 via the other components of the finger assembly 550 such that the first counter roller 554 can freely rotate and can move (and in this example embodiment, translate) between an extended position (Figures 3, 4C, 9, and 11) in which a first portion of the first counter-roller 554 is positioned forward of the film-engagement surface 552s and a retracted position (Figures 4D and 12) in which at least part of the first portion of the first counter roller 554 is positioned rearward of thefilm-engagement surface 552s. In this example embodiment, a first surface area of the first counter roller 554 is positioned forward of the film-engagement surface 552s when the first counter roller 554 is in the extended position and a second surface area of the first counter roller 554 is positioned forward of the film-engagement surface 552s when the first counter roller 554 is in the retracted position. The second surface area is less than the first surface area.

[0035] Specifically, the outer races of the first bearings 556a and 556b are press-fit into suitably sized bores defined in opposite sides of the first counter roller 554, and the first- counter-roller-mounting shaft 558 extends through bores defined by the inner races of the first bearings 556a and 556b and a bore through the center of the first counter roller 554. The first retainers 559a and 559b are installed on the ends of the counter-roller-mounting shaft 558 to retain the bearings 556a and 556b in place. The first counter roller 554 is thus rotatable about the first-counter-roller-mounting shaft 558. The first-counter-roller-mounting shaft 558 is slidably mounted at opposite ends to the first mounting pins 560a and 560b, respectively. The first counter-roller biasing elements 562a and 562b — which are compression springs in this example embodiment — circumscribe the first mounting pins 560a and 560b, respectively. The first retaining plate 564 is attached to the first reefing finger 552 via the fasteners 566 to maintain the first mounting pins 560a and 560b in a substantially horizontal orientation (substantially parallel to X-Y plane and transverse to the reefing finger 552). The counter-roller biasing elements may be any other suitable biasing elements in other embodiments, such as pneumatic or hydraulic cylinders.

[0036] The first counter roller 554 is movable — and in this example embodiment translatable substantially parallel to the X-Y plane — between an extended position shown in Figures 3, 4C, 9, and 11 and a retracted position shown in Figures 4D and 12. The first counterroller biasing elements 562a and 562b bias the first counter roller 554 to the extended position. When in the extended position, as best shown in Figure 3, a first portion of the first counter roller 554 is positioned forward of the first film-engagement surface 552s (in the direction toward the first drive roller 520). In this example embodiment, when the first counter roller 554 is in the extended position, it extends a first distance DI forward of the first film-engagement surface 552s. When in the retracted position, as best shown in Figure 12, at least part of the first portion of the first counter roller 554 is positioned rearward of the first film-engagement surface 552s (in the direction away from the first drive roller 520). In this example embodiment, when the firstcounter roller 554 is in the retracted position, it extends a second distance D2 forward of the first film-engagement surface 552s, where the second distance D2 is less than the first distance DI. In other embodiments, when the first counter roller is in the retracted position, it is retracted behind the first film-engagement surface such that no part of the first counter roller extends forward of the first film-engagement surface.

[0037] The position of the first carriage 515 controls the position of the first counter roller 554. When the first carriage 515 is in the home position shown in Figure 3, the first drive roller 520 is spaced-apart from the first counter roller 554, which the first counter-roller biasing elements 562a and 562b bias to the extended position. When the first carriage 515 is moved laterally inwardly to the reefing position shown in Figures 9 and 11, the first drive roller 520 is adjacent the first counter roller 554 so as to force the segment of tubular film F against the first counter roller 554 to facilitate reefing. When the first carriage 515 is moved further laterally inwardly to the unreefing position shown in Figure 12, the first drive roller 520 forces the first counter roller 554 to the retracted position against the biasing forces that the first counter-roller biasing elements 562a and 562b exert on the first counter roller 554.

[0038] The second reefing device 600 is similar to the first reefing device 500 and not shown separately in detail. The second reefing device 600 includes a second support 605; a second rail (not labeled) supported by the second support 605; a second carriage (not labeled) slidably mounted to the second rail and configured to move laterally (substantially parallel to the X-Y plane) along the second rail among a home position (Figure 6), a reefing position (Figure 8), and an unreefing position (not shown); a second carriage actuator 615a operably connected to the second carriage and configured to move the second carriage among the home, reefing, and unreefing positions; a second drive roller 620 supported by the second carriage; a second driveroller actuator 620a supported by the second carriage and operably connected to the second drive roller 620 and configured to rotate the second drive roller 620 in opposing reefing and unreefing rotational directions; and a second finger assembly 650 extending substantially vertically in the Z-direction from one end of the second support 605. The second finger assembly 650 is similar to the first finger assembly 550 and not shown separately in detail. The second finger assembly 650 includes a second reefing finger 652 and a second counter roller 654 mounted to the second reefing finger 652 via the other components of the finger assembly 650 such that the second counter roller 654 can freely rotate and can move (and in this example embodiment, translate)between an extended position in which a first portion of the second counter-roller 654 is positioned forward of a film-engagement surface of the second reefing finger 652 and a retracted position in which at least part of the first portion of the second counter roller 654 is positioned rearward of the film-engagement surface.

[0039] The third reefing device 700 is similar to the first reefing device 500 and not shown separately in detail. The third reefing device 700 includes a third support 705; a third rail (not labeled) supported by the third support 705; a third carriage (not labeled) slidably mounted to the third rail and configured to move laterally (substantially parallel to the X-Y plane) along the third rail among a home position (Figure 6), a reefing position (Figure 8), and an unreefing position (not shown); a third carriage actuator 715a operably connected to the third carriage and configured to move the third carriage among the home, reefing, and unreefing positions; a third drive roller 720 supported by the third carriage; a third drive-roller actuator 720a supported by the third carriage and operably connected to the third drive roller 720 and configured to rotate the third drive roller 720 in opposing reefing and unreefing rotational directions; and a third finger assembly 750 extending substantially vertically in the Z-direction from one end of the third support 705. The third finger assembly 750 is similar to the first finger assembly 550 and not shown separately in detail. The third finger assembly 750 includes a third reefing finger 752 and a third counter roller 754 mounted to the third reefing finger 752 via the other components of the finger assembly 750 such that the third counter roller 754 can freely rotate and can move (and in this example embodiment, translate) between an extended position in which a first portion of the third counter-roller 754 is positioned forward of a film-engagement surface of the third reefing finger 752 and a retracted position in which at least part of the first portion of the third counter roller 754 is positioned rearward of the film-engagement surface.

[0040] The fourth reefing device 800 is similar to the first reefing device 500 and not shown separately in detail. The fourth reefing device 800 includes a fourth support 805; a fourth rail (not labeled) supported by the fourth support 805; a fourth carriage (not labeled) slidably mounted to the fourth rail and configured to move laterally (substantially parallel to the X-Y plane) along the fourth rail among a home position (Figure 6), a reefing position (Figure 8), and an unreefing position (not shown); a fourth carriage actuator 815a operably connected to the fourth carriage and configured to move the fourth carriage among the home, reefing, and unreefing positions; a fourth drive roller 820 supported by the fourth carriage; a fourth drive-roller actuator 820a supported by the fourth carriage and operably connected to the fourth drive roller 820 and configured to rotate the fourth drive roller 820 in opposing reefing and unreefing rotational directions; and a fourth finger assembly 850 extending substantially vertically in the Z- direction from one end of the fourth support 805. The fourth finger assembly 850 is similar to the first finger assembly 550 and not shown separately in detail. The fourth finger assembly 850 includes a fourth reefing finger 852 and a fourth counter roller 854 mounted to the fourth reefing finger 852 via the other components of the finger assembly 850 such that the fourth counter roller 854 can freely rotate and can move (and in this example embodiment, translate) between an extended position in which a first portion of the fourth counter-roller 854 is positioned forward of a film-engagement surface of the fourth reefing finger 852 and a retracted position in which at least part of the first portion of the fourth counter roller 854 is positioned rearward of the film-engagement surface.

[0041] The first, second, third, and fourth reefing devices 500, 600, 700, and 800 are mounted to the frame of the wrapping carriage in a substantially rectangular arrangement. The first set of reefing-device actuators 420 is operably connected to the first and second reefing devices 500 and 600 and configured to move the first and second reefing devices 500 and 600 laterally inwardly and outwardly in the X- and Y-directions and substantially parallel to the X-Y plane relative to the wrapping carriage (and the load L and the segment of tubular film F). The second set of reefing-device actuators 440 is operably connected to the third and fourth reefing devices 700 and 800 and configured to move the third and fourth reefing devices 800 and 800 laterally inwardly and outwardly in the X- and Y-directions and substantially parallel to the X-Y plane relative to the wrapping carriage (and the load L and the segment of tubular film F).

[0042] The first set of reefing-device actuators 420 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 500 and 600 and configured to move the first and second reefing devices 500 and 600 relative to the wrapping carriage in the X-direction. The first Y-actuator is operably connected to the first and second reefing devices 500 and 600 and configured to move the first and second reefing devices 500 and 600 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 proportionalsolenoid 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 and second reefing devices simultaneously and at the same rate towards and away from the load in the Y-direction.

[0043] The second set of reefmg-device actuators 440 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 700 and 800 and configured to move the third and fourth reefing devices 700 and 800 relative to the wrapping carriage in the X- direction. The second Y-actuator is operably connected to the third and fourth reefing devices 700 and 800 and configured to move the third and fourth reefing devices 700 and 800 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.

[0044] 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.

[0045] The operator interface 900 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 soft keys), one or more switches, and / or a touch panel. In various embodiments, the operator interface 900 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 parameters 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. Incertain embodiments, the operator interface 900 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.

[0046] The controller C 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, readonly 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 (such as to carry out the wrapping process described below).

[0047] The controller C is communicatively and operably connected to the filmsupply assembly 200; the film-opening assembly 300; the wrapping-carriage actuator 410; the first and second sets of reefing-device actuators 420 and 440; the first, second, third, and fourth carriage actuators 515a, 615a, 715a, and 815a; and the first, second, third, and fourth sets of drive-roller actuators 520a, 620a, 720a, and 820a to control operation of these components to carry out a wrapping process 1000, as described below. The controller C is communicatively connected to the operator interface 900 to: (1) receive signals from the operator interface 900 that represent inputs received by the operator interface 900; and (2) send signals to the operator interface 900 to cause the operator interface 900 to output (such as to display) information.

[0048] Figure 14 is a flowchart of an example wrapping process 1000 of the present disclosure. An example of each step of the wrapping process 1000 is provided for the stretchhood machine 10 described above and shown in the Figures.

[0049] Upon initiation of the wrapping process 1000, a load is moved into a wrapping area of the stretch-hood machine, as block 1002 indicates. In this example embodiment, a conveyor moves the load L into the wrapping area of the machine frame 100 of the stretch-hood machine 10. A segment of tubular film is then created, as block 1004 indicates.In this example embodiment, the controller C controls the film-supply assembly 200 to draw tubular film from the film roll R, cut the film to a desired length to form the segment of tubular film F, and heat seal the top of the segment of tubular film F closed. The bottom portion of the segment of tubular film is then opened, as block 1006 indicates. In this example embodiment, the controller C controls the film-opening assembly 300 (and more particularly, the suction boxes and holding devices) to open the bottom portion of the segment of tubular film F so its perimeter is substantially rectangular, as explained above.

[0050] The wrapping carriage is then raised so at least part of the reefing fingers of the reefing devices are received in the open bottom portion of the segment of tubular film, as block 1008 indicates. In this example embodiment, the controller C controls the wrappingcarriage actuator 410 to raise the wrapping carriage so the reefing fingers 552, 652, 752, and 852 of the respective reefing devices 500, 600, 700, and 800 are received in the open bottom portion of the segment of tubular film F, as shown in Figures 5 and 6. The reefing devices are then moved laterally outwardly to respective reefing positions, as block 1010 indicates. In this example embodiment, the controller C controls the first and second sets of reefing-device actuators 420 and 440 to move the respective reefing devices 500, 600, 700, and 800 laterally outwardly relative to the segment of tubular film F (in the X- and Y- directions and substantially parallel to the X-Y plane) to their respective reefing positions in which they form a reefing configuration in preparation for reefing the segment of tubular film F.

[0051] The drive rollers of the reefing devices are moved into contact with the outer surface of the segment of tubular film to force the inner surface of the segment of tubular film against counter rollers on the reefing fingers, as block 1012 indicates. The counter rollers are in respective extended positions in which first portions of the counter rollers are positioned forward of film-engagement surfaces of the respective reefing fingers, as block 1012 also indicates. In this example embodiment, the controller C controls the first, second, third, and fourth carriage actuators 515a, 615a, 715a, and 815a to move the carriages of the respective reefing devices 500, 600, 700, and 800 from their respective home positions to their respective reefing positions. This causes the drive rollers 520, 620, 720, and 820 of the reefing devices 500, 600, 700, and 800 to contact the inner surface FIN of the segment of tubular film F and force the outer surface Four of the segment of tubular film F against the respective counter rollers 554, 654, 754, and 854. Figures 7-9 show the reefing devices 500, 600, 700, and 800 in their reefing positions after theircarriages 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.

[0052] The drive rollers are driven to reef the segment of tubular film onto the filmengagement surfaces of the reefing fingers, as block 1014 indicates. In this example embodiment, the controller C then controls the first, second, third, and fourth drive-roller actuators 520a, 620a, 720a, and 820a to drive the first, second, third, and fourth drive rollers 520, 620, 720, and 820 in a reefing rotational direction to reef the segment of tubular film F onto the reefing fingers 552, 652, 752, and 852. Figures 10 and 11 show the reefing devices 500, 600, 700, and 800 after reefing. The reefing devices are moved laterally outwardly to respective wrapping positions, as block 1016 indicates. The segment of tubular film stretches during this movement. In this example embodiment, the controller C controls the first and second sets of reefing-device actuators 420 and 440 to move the reefing devices 500, 600, 700, and 800 from their respective reefing positions to their respective wrapping positions. In certain embodiments, the drive rollers are driven to unreef part of the segment of tubular film as the reefing devices move from their reefing positions to their wrapping positions.

[0053] The counter rollers on the reefing fingers are moved to respective retracted positions in which at least part of the first portions of the counter rollers are positioned rearward of the film-engagement surfaces of the respective reefing fingers, as block 1018 indicates. In this example embodiment, the controller C controls the first, second, third, and fourth carriage actuators 515a, 615a, 715a, and 815a to move the carriages of the respective reefing devices 500, 600, 700, and 800 from their respective reefing positions to their respective unreefing positions, as shown in Figure 12. This causes the drive rollers 520, 620, 720, and 820 of the reefing devices 500, 600, 700, and 800 to force their respective counter rollers 554, 654, 754, and 854 to move to their retracted positions, as shown in Figure 12. In other embodiments, the counter rollers on the reefing fingers are moved to their respective retracted positions before the reefing devices move from their respective reefing positions to their respective wrapping positions. In further embodiments, the counter rollers on the reefing fingers are moved to their respective retracted positions while the reefing devices are moving from their respective reefing positions to their respective wrapping positions.

[0054] The wrapping carriage is lowered while the segment of tubular film is unreefed from the reefing fingers, as block 1020 indicates, which enables the segment of tubularfilm to contract onto the load. In this example embodiment, the controller C controls the wrapping-carriage actuator 410 to lower the wrapping carriage while controlling the first, second, third, and fourth drive-roller actuators 520a, 620a, 720a, and 820a to drive the first, second, third, and fourth drive rollers 520, 620, 720, and 820 in an unreefing rotational direction opposite the reefing rotational direction to unreef the remainder of the segment of tubular film F from the reefing fingers 552, 652, 752, and 852. Figure 13 shows the reefing devices 500, 600, 700, and 800 just before unreefing the segment of tubular film F onto the load. As the segment of tubular film F is unreefed, it attempts to return to its unstretched size and shape and laterally contracts onto the load L, which unitizes the load and / or secures the load to a pallet. The wrapped load is then moved out of the wrapping area of the stretch-hood machine, as block 1022 indicates, thereby ending the wrapping process 1000. In this example embodiment, a conveyor moves the load L out of the wrapping area of the machine frame 100 of the stretch-hood machine 10.

[0055] The ability of the counter rollers to move between extended and retracted positions improves upon known stretch hood machines. This enables the stretch-hood machine to form of orderly folds in the film during reefing when the counter rollers are in their extended positions — which improves wrapping quality — before retracting the counter rollers so they do not mark, thin, or weaken the film during unreefing.

[0056] Figures 15A-15D show an alternative finger assembly 1550 that includes a counter-roller actuator operably connected to the counter roller and configured to move the counter roller. The finger assembly 1550 includes a base 1551 and a reefing finger 1552 connected to and extending substantially vertically from the base 1551 and including a curved film-engagement surface 1552s. The finger assembly 1550 includes a counter roller 1554 movably mounted to the reefing finger 1552 such that the counter roller 1554 can freely rotate and can move (and in this example embodiment, pivot) between an extended position (Figure 15D) in which a first portion of the counter-roller 1554 is positioned forward of the filmengagement surface 1552s and a retracted position (Figure 15C) in which at least part of the first portion of the counter roller 1554 is positioned rearward of the film-engagement surface 1552s.

[0057] Specifically, the outer races of bearings 1556a and 1556b are press-fit into suitably sized bores defined in opposite sides of the counter roller 1554, and a counter-roller- mounting shaft 1558 extends through bores defined by the inner races of the bearings 1556a and1556b and a bore through the center of the counter roller 1554. The counter roller 1554 is thus rotatable about the counter-roller-mounting shaft 1558. Retainers 1559a and 1559b are installed on the ends of the counter-roller-mounting shaft 1558 to retain the bearings 1556a and 1556b in place.

[0058] The counter-roller-mounting shaft 1558 is fixedly mounted (such as via suitable fasteners) to two spaced-apart substantially parallel arms 1574 and 1576 of a counterroller mount 1570. A body 1572 of the counter-roller mount 1570 is pivotably connected to the reefing finger 1552 by a pivot shaft 1580. The pivot shaft 1580 extends through two collars 1581 and 1583 press-fit into bores through the respective arms 1574 and 1576 and through a spacer 1585 positioned between the arms 1576 and 1576. Once mounted, the counter-roller mount 1570 is pivotable about the pivot shaft to move the counter roller 1554 between an extended position, shown in Figure 15D, and a retracted position, shown in Figure 15C. When in the extended position, a first portion of the counter roller 1554 is positioned forward of the first filmengagement surface 1552s. When in the retracted position, at least part of the first portion of the counter roller 1554 is positioned rearward of the first film-engagement surface 1552s.

[0059] In this example embodiment, a biasing element (not shown) biases the counter roller 1554 to the retracted position, and a counter-roller actuator 1590 is operably connected to the counter-roller mount 1570 and configured to pivot the counter-roller mount to move the counter roller 1554 from the retracted position to the extended position. In this example embodiment, the counter-roller actuator 1590 includes a solenoid actuator, though any suitable actuator may be employed. In other embodiments, the biasing element biases the counter roller to the extended position, and the counter-roller actuator is operably connected to the counter-roller mount and configured to pivot the counter-roller mount to move the counter roller from the extended position to the retracted position. In still other embodiments, the counter-roller actuator is operably connected to the counter-roller mount and configured to pivot the counter-roller mount to move the counter roller from the retracted position to the extended position and from the extended position to the retracted position. In various embodiments , the counter-roller actuator is operably connected to the counter-roller and configured to translate the counter roller.

Claims

Claims1. A stretch-hood machine comprising: a wrapping carriage; a wrapping-carriage actuator operably connected to the wrapping carriage and configured to move the wrapping carriage between an upper position and a lower position; a reefing device supported by the wrapping carriage and comprising: a reefing finger comprising a film-engagement surface; a counter roller supported by the reefing finger and movable between an extended position in which a first portion of the counter-roller is positioned forward of the filmengagement surface and a retracted position in which at least part of the first portion of the counter roller is positioned rearward of the film-engagement surface; a drive roller; and a drive-roller actuator operably connected to the drive roller and configured to drive the drive roller; and a controller configured to: with the counter roller in the extended position, control the drive-roller actuator to drive the drive roller to reef a segment of tubular film onto the film-engagement surface; and after the segment of tubular film has been reefed onto the film-engagement surface: cause the counter roller to move to the retracted position; and control the wrapping-carriage actuator to move the wrapping carriage toward the lower position while controlling the drive-roller actuator to drive the drive roller to unreef the segment of tubular film from the reefing finger.

2. The stretch-hood machine of claim 1, wherein the reefing device further comprises a counter-roller biasing element biasing the counter roller to the extended position.

3. The stretch-hood machine of claim 2, further comprising: a carriage supporting the drive roller; anda carriage actuator operably connected to the carriage and configured to move the carriage, wherein the controller is configured to control the carriage actuator to move the drive roller to cause the counter roller to move to the retracted position.

4. The stretch-hood machine of claim 3, wherein the controller is configured to control the carriage actuator to move the drive roller laterally inwardly to cause the counter roller to move to the retracted position.

5. The stretch-hood machine of claim 4, wherein the controller is further configured to, after the segment of tubular film has been unreefed from the reefing finger, control the carriage actuator to move the drive roller laterally outwardly to enable the counter-roller biasing element to force the counter roller to move back to the extended position.

6. The stretch-hood machine of claim 1, wherein a second portion of the counter roller is positioned forward of the film-engagement surface of the reefing finger when the counter roller is in the retracted position, wherein the second portion is smaller than the first portion.

7. The stretch-hood machine of claim 1, wherein none of the counter roller is positioned forward of the film-engagement surface of the reefing finger when the counter roller is in the retracted position.

8. The stretch-hood machine of claim 1, further comprising one or more reefing- device actuators operably connected to the reefing device and configured to move the reefing device between a reefing position and a wrapping position, wherein the controller is further configured to: control the drive-roller actuator to drive the drive roller to reef the segment of tubular film onto the film-engagement surface while the reefing device in the reefing position; and after the segment of tubular film has been reefed onto the film-engagement surface of the reefing finger:control the one or more reefing-device actuators to move the reefing device from the reefing position to the wrapping position such that the segment of tubular film is stretched; and cause the counter roller to move to the retracted position after the reefing device has reached the wrapping position.

9. The stretch-hood machine of claim 1, further comprising one or more reefing- device actuators operably connected to the reefing device and configured to move the reefing device between a reefing position and a wrapping position, wherein the controller is further configured to: control the drive-roller actuator to drive the drive roller to reef the segment of tubular film onto the film-engagement surface while the reefing device in the reefing position; and after the segment of tubular film has been reefed onto the film-engagement surface of the reefing finger and after the counter roller has reached the retracted position, control the one or more reefing-device actuators to move the reefing device from the reefing position to the wrapping position such that the segment of tubular film is stretched.

10. The stretch-hood machine of claim 1, wherein the reefing device further comprises a counter-roller actuator operably connected to the counter roller and configured to move the counter roller, wherein the controller is configured to control the counter-roller actuator to cause the counter roller to move to the retracted position.

11. The stretch-hood machine of claim 10, wherein the counter-roller actuator is configured to move the counter roller from the extended position to the retracted position, wherein the reefing device further comprises a counter-roller biasing element biasing the counter roller to the extended position.

12. The stretch-hood machine of claim 10, wherein the counter-roller actuator is configured to move the counter roller from the retracted position to the extended position, wherein the reefing device further comprises a counter-roller biasing element biasing the counter roller to the retracted position.

13. The stretch-hood machine of claim 10, wherein the counter-roller actuator is configured to move the counter roller from the extended position to the retracted position and from the retracted position to the extended position.

14. A method of operating a stretch-hood machine, the method comprising: with a counter roller supported by a reefing finger of a reefing device in an extended position in which a first portion of the counter-roller is positioned forward of a film-engagement surface of the reefing finger, reefing a segment of tubular film onto the film-engagement surface; and after the segment of tubular film has been reefed onto the film-engagement surface: moving the counter roller to a retracted position in which at least part of the first portion of the counter roller is positioned rearward of the film-engagement surface; and lowering a wrapping carriage supporting the reefing device while unreefing the segment of tubular film from the reefing finger.

15. The method of claim 14, wherein reefing the segment of tubular film onto the film-engagement surface comprises driving a drive roller to reef the segment of tubular film onto the film-engagement surface, wherein moving the counter roller to the retracted position comprises moving the drive roller against a biasing force exerted on the counter roller by a counter-roller biasing element that biases the counter roller to the extended position.

16. The method of claim 15, wherein moving the counter roller to the retracted position comprises moving the counter roller laterally inwardly.

17. The method of claim 16, further comprising, after the segment of tubular film has been unreefed from the reefing finger, moving the drive roller laterally outwardly to enable the counter-roller biasing element to force the counter roller to move back to the extended position.

18. The method of claim 14, further comprising: reefing the segment of tubular film onto the film-engagement surface while the reefing device is in a reefing position; andafter the segment of tubular film has been reefed onto the film-engagement surface of the reefing finger: moving the reefing device from the reefing position to a wrapping position such that the segment of tubular film is stretched; and moving the counter roller to the retracted position after the reefing device has reached the wrapping position.

19. The method of claim 14, further comprising: reefing the segment of tubular film onto the film-engagement surface while the reefing device is in a reefing position; and after the segment of tubular film has been reefed onto the film-engagement surface of the reefing finger and after the counter roller has reached the retracted position, moving the reefing device from the reefing position to a wrapping position such that the segment of tubular film is stretched.

20. The method of claim 14, wherein moving the counter roller to the retracted position comprises controlling a counter-roller actuator to move the counter roller to the retracted position.

Images