Bag conveyance device and bag-making machine including bag conveyance device

Abstract

This bag conveyance device comprises a shift unit for shifting a bag laterally while conveying the bag in a conveyance direction. The shift unit comprises: a conveyance belt conveyor for conveying a bag straight in a conveyance direction while supporting the lower surface of the bag; a plurality of shifters for shifting the bag laterally when the bag is being conveyed in the conveyance direction by the conveyance belt conveyor; and a support structure for supporting each of the plurality of shifters and positioning each of the shifters above the conveyance belt conveyor. The support structure comprises a holder and a fixing tool for releasably positioning the shifters on the holder. The holder is configured such that the shifters can be positioned on the holder in a plurality of different orientations by means of the fixing tool.

Description

Bag conveying device and bag-making machine including the same

[0001] This application relates to a bag conveying device used in a bag-making machine that provides multi-column bag making, and a bag-making machine including the same.

[0002] The bag-making machine feeds at least one web in its longitudinal direction, heat-seals the web with a heater, and then cross-cuts the web in its width direction with a cross-cutting device to form bags (e.g., pouches). For example, multi-column bag making in which two or more bags are formed each time a cross-cut is made is known (e.g., Patent Document 1).

[0003] The bag-making machine includes a bag conveying device provided downstream of the cross-cutting device and configured to convey the bags obtained by the cross-cutting device. The bag conveying device includes an upper conveyor and a lower conveyor. These conveyors are each wound around a head (upstream) pulley and a tail (downstream) pulley, and include a plurality of endless and thin belts provided at intervals in the width direction of the web (the lateral direction perpendicular to the conveying direction). Grooves are formed on the outer peripheral surfaces of these pulleys at a predetermined pitch in the axial direction, and the belts engage with the grooves.

[0004] These belts are arranged with an inclination in a flaring shape such that the distance between them increases as they move in the conveying direction. A plurality of bags formed simultaneously by one cross-cut are arranged side by side in the lateral direction. These bags are discharged from the cross-cutting device, enter between the upper conveyor and the lower conveyor configured as described above, and are conveyed downstream while being sandwiched between them. Due to the fact that the upper and lower belts are arranged with an inclination in a flaring shape, as the bags are conveyed, the distance between the bags in adjacent columns gradually increases and they are separated in the lateral direction.

[0005] The bags are sorted, stacked in a fixed number for each column, and packaged. Thanks to the fact that the bags are separated for each column, the sorting operation becomes easier.

[0006] When changing the type of bag being manufactured, it may be necessary to separate the bags in one row from the bags in the adjacent row at different intervals. Also, since the bags are typically made of plastic film, they are prone to static electricity and can stick together. If the belt slope is too gentle, separating the bags may be difficult. In such cases, the operator needs to adjust the belt slope using a tool. However, this adjustment requires stopping the operation of the entire bag-making machine (production line), which is inefficient.

[0007] WO2020 / 235188

[0008] This invention provides a configuration that enables adjustment of the lateral spacing between bags without stopping the operation of a bag-making machine that provides multi-row bag production.

[0009] The present invention relates to a bag conveying device used in a bag-making machine that provides multi-row bags, for conveying a plurality of bags arranged in a lateral direction perpendicular to the bag conveying direction, wherein the bag conveying device comprises a shift unit for shifting the bags laterally while conveying them in the conveying direction, the shift unit comprising a conveying belt conveyor for conveying the bags straight in the conveying direction while supporting the lower surface of the bags, a plurality of shifters for shifting the bags laterally when the bags are being conveyed in the conveying direction by the conveying belt conveyor, and a support structure for supporting each of the plurality of shifters and positioning each of the shifters above the conveying belt conveyor, wherein the support structure comprises at least one holder, and at least one fixing device provided for each of the shifters for releasably positioning the corresponding shifter in the at least one holder, the at least one holder is configured to position each of the shifters in the at least one holder in a plurality of different orientations by the at least one fixing device.

[0010] Each of the shifters may comprise a support and a driven shift roller rotatably supported by the support and cooperating with the conveyor belt to shift the bag laterally.

[0011] Each shifter comprises a support and a shift belt conveyor supported by the support for transporting the bags diagonally with respect to the transport direction and the lateral direction, the shift belt conveyor comprising an upstream pulley, a downstream pulley, an endless shift belt wound around the upstream pulley and the downstream pulley for sandwiching the bags between the shift belt and the flat belt of the transport belt conveyor, and a motor for driving the shift belt, the shift belt may have a coefficient of friction with respect to the bags that is greater than the coefficient of friction of the flat belt with respect to the bags.

[0012] Where the shifter comprises either the shift roller or the shift belt conveyor, the at least one holder is configured to receive the support so as to be rotatable about an axis extending perpendicular to the conveying direction and the lateral direction, and the at least one fastener may be configured to releasably secure the support to the holder.

[0013] The support structure may further include a mounting beam that extends laterally across the width of the conveyor belt and to which at least one holder is attached.

[0014] The support structure may further include at least one additional fastener for removably securing the at least one holder to the mounting beam.

[0015] The at least one holder has a first mounting hole, the mounting beam has a plurality of second mounting holes spaced apart from each other in the lateral direction, and the at least one additional fastener may be a bolt inserted into the first mounting hole and the second mounting hole to fasten the at least one holder and the mounting beam.

[0016] The at least one holder has a mounting hole, the mounting beam has a laterally extending mounting slot, and the at least one additional fastener may include a bolt inserted into the mounting hole and the mounting slot to fasten the holder and the mounting beam together, and a nut fitted onto the bolt.

[0017] The at least one holder comprises a laterally extending upstream holder and a laterally extending downstream holder, and the at least one fastener may comprise an upstream fastener for releasably securing the upstream end of the support to the upstream holder and a downstream fastener for releasably securing the downstream end of the support to the downstream holder.

[0018] The support comprises a body that supports the shift belt conveyor, an upstream bracket provided at the upstream end of the body so as to be rotatable about an axis extending vertically of the shift belt conveyor, and a downstream bracket provided at the downstream end of the body so as to be rotatable about an axis extending vertically of the shift belt conveyor, wherein the upstream holder is configured so that the upstream bracket can be fixed at a plurality of different positions in the lateral direction on the upstream holder by the upstream fixing device, and the downstream holder may be configured so that the downstream bracket can be fixed at a plurality of different positions in the lateral direction on the downstream holder by the downstream fixing device.

[0019] The conveyor belt may include a head pulley, a tail pulley, an endless flat belt wound around the head pulley and the tail pulley, having a width that can accommodate all of the bags arranged laterally, and a motor for driving the flat belt.

[0020] The bag conveying device further comprises a stacking unit for receiving the bags from the shift unit, stacking a certain number of the bags in each row to form a bag stack, and conveying the bag stack, the stacking unit may comprise an additional conveying belt having a conveying plane at a lower position than the conveying plane of the conveying belt conveyor of the shift unit, a stopper provided for each of the rows and located above the additional conveying belt conveyor, and a first actuator for moving the stopper to a restricting position that restricts the movement of the bags in the conveying direction and a retracted position that allows the bag stack to be conveyed by the additional conveying belt conveyor.

[0021] The additional conveyor belt comprises a plurality of belts arranged with gaps between them in the lateral direction, and the stack unit may further comprise: a receiving member provided for each of the rows upstream of the stopper for receiving the bags; and a second actuator for moving the receiving member up and down within a range from a lower height where the receiving member is retracted downward from the conveying plane of the additional conveyor belt, to an upper height where the receiving member protrudes upward through the gap from the conveying plane of the additional conveyor belt, with the upper end of the receiving member lower than the conveying plane of the conveyor belt.

[0022] Furthermore, the present invention relates to a bag-making machine that provides multi-row bag production, comprising: a cross-cutting device for forming multiple bags by cross-cutting a web in the width direction of the web; and the bag conveying device arranged downstream of the cross-cutting device for conveying the multiple bags.

[0023] Figure 1A is a schematic plan view of the upstream and midstream sections of an exemplary bag-making machine, and Figure 1B is a schematic side view thereof. Figure 2A is a schematic side view showing an exemplary bag conveying device, and Figure 2B schematically shows the bag conveying device of Figure 2A in a standby state. Figure 3 is a schematic plan view of the bag conveying device of Figure 2A. Figure 4A is a plan view of an exemplary sifter, Figure 4B is a front view of Figure 4A, and Figure 4C is a side view of Figure 4B. Figures 5A and 5B show one example of a support structure, Figures 5C and 5D show another example of a support structure, and Figure 6 shows an enlarged view of area T in Figure 3. Figures 7A-7C illustrate the process of forming and conveying a bag stack. Figures 8A-8C illustrate the process of forming and conveying a bag stack. Figures 9A and 9B illustrate the process of forming and conveying a bag stack. Figures 10A and 10B are schematic diagrams illustrating related technologies. Figure 11 is a schematic side view showing another exemplary shift unit. Figure 12 is a schematic top view showing the shift unit of Figure 11. Figure 13 is a schematic side view showing yet another exemplary shift unit. Figure 14 is a schematic top view showing the shift unit of Figure 13. Figure 15 is a schematic side view showing the shifter and support structure of the shift unit of Figure 13.

[0024] Embodiments of the present application will be described below with reference to the drawings. The following are merely illustrative examples of the present application. The drawings are schematic and may not be drawn to exact size. It should also be understood that the same reference numerals are used throughout the drawings to represent identical or similar components.

[0025] As shown in Figures 1A and 1B, the bag-making machine is equipped with an accumulator 20 and a dancer mechanism 21. The raw material 1' is positioned at the uppermost part of the bag-making machine. One web 1 is taken out of the raw material 1' and continuously fed in direction X1, passing through the accumulator 20 and the dancer mechanism 21. In the process, the web 1 is slit along its longitudinal direction by a cutter (not shown) to become two body material webs 10 and 11. The webs 10 and 11 are then overlapped. The dancer mechanism 21 appropriately switches the transport of the webs 10 and 11 from continuous feeding to intermittent feeding.

[0026] The bag-making machine further includes a feeding device 25 (including a pair of drive rollers) for intermittently feeding the webs 10 and 11 in direction X1.

[0027] The bag-making machine further includes vertical heaters 22 and horizontal heaters 23 that heat-seal the webs 10 and 11 with each intermittent feed. This heat-sealing process is a three-side seal, so that the subsequently formed bag 100 is heat-sealed along three sides, with the remaining side open.

[0028] The bag-making machine further includes a plurality of slitters 24 positioned downstream of these heaters 22, 23. The slitters 24 are spaced apart in the width direction of the webs 10, 11, i.e., in the horizontal direction Y which is perpendicular to the feed direction X1. The bag-making machine of this embodiment, which provides four-row bags, includes three slitters 24. The webs 10, 11 are slit longitudinally by the slitters 24 as they are fed.

[0029] The bag-making machine further includes a cross-cutting device 26 located downstream of these components 20-25, which cross-cuts the webs 10 and 11 in the width direction. The cross-cutting device 26 includes a cross-cutter 260 that moves up and down by an actuator (not shown). Each time the intermittent feed stops, the cross-cutting device 26 cross-cuts the webs 10 and 11 in the lateral direction Y (width direction) with the cross-cutter 260. This forms the bag 100 (e.g., pouch).

[0030] This bag-making machine provides multi-row bag making, in which multiple bags (four in this embodiment) 100 are formed simultaneously with a single cross-cut. These bags 100 are arranged in the lateral direction Y (width direction of the webs 10, 11).

[0031] The configuration from the raw material 1' to the cross-cutting device 26 is a well-known one, so a detailed explanation is omitted here. For example, instead of the web 10 and web 11 being formed from a single large web 1, web 10 may be produced from one raw material and web 11 from another. In addition, steps to form notches and corner cuts may be performed.

[0032] As shown in Figure 2A, the bag-making machine is located downstream of the cross-cutting device 26 and includes a bag conveying device 27 for conveying bags 100 arranged in the lateral direction Y. The direction of conveyance of the bags 100 by the bag conveying device 27 is indicated by X1.

[0033] The bag conveying device 27 includes a clamping unit 3, a shifting unit 4, and a stacking unit 5.

[0034] As shown in Figure 2A, the clamping unit 3 comprises an upper conveyor 30 and a lower conveyor 31. The upper conveyor 30 comprises an upper head pulley 300, an upper tail pulley 301, and a plurality of endless, thin upper belts 302 (see also Figure 3) wound around these pulleys 300 and 301 at intervals in the lateral direction Y. Similarly, the lower conveyor 31 comprises a lower head pulley 310, a lower tail pulley 311, and a plurality of endless lower belts 312 wound around these pulleys 310 and 311 at intervals in the lateral direction Y.

[0035] As shown in Figure 3, the upper belt 302 extends parallel to the conveying direction X1. The spacing between adjacent upper belts 302 is narrower than the width of the bag 100. The same applies to the lower belt 312. In this way, it is preferable that the bag 100 is held between at least two sets of belts 302 and 312. These belts 302 and 312 are narrow, flat belts with a flat outer surface.

[0036] The clamping unit 3 further includes a lifting mechanism 32 (Figure 2A) movably connected to the upper head pulley 300 in order to move the upper head pulley 300 up and down. The lifting mechanism 32 can retract the upper head pulley 300 upward by its actuator (not shown) (Figure 2B). The clamping unit 3 waits with the head pulley 300 retracted upward, waiting for the bag 100 to be introduced from the cross-cut device 26 between the two conveyors 30 and 31.

[0037] The clamping unit 3 includes at least one motor (not shown) for rotating the pulleys 300, 301, 310, and 311 around their axes, thereby driving (endlessly rotating) the belts 302 and 312. A motor for the upper conveyor 30 and a motor for the lower conveyor 31 may be provided. Alternatively, the upper belt 302 and the lower belt 312 may be driven synchronously using a single motor and a suitable transmission mechanism (including, for example, a transmission belt).

[0038] Therefore, at the moment when the bag 100 is introduced from the cross-cut device 26 between the upper conveyor 30 and the lower conveyor 31 (a timing determined based on the output of the detection sensor and the detection of signals from other devices), the clamping unit 3 lowers the upper head pulley 300 with the lifting mechanism 32, clamps the bag 100 with the belts 302 and 312, and conveys it straight in the conveying direction X1 by driving these belts 302 and 312.

[0039] The clamping unit 3 may be driven continuously by belts 302 and 312, or it may be driven only when transporting the bag 100 by timing control using sensors or the like.

[0040] The gripping unit 3 drives multiple belts 302 and 312, and there is a risk of fingers getting caught. Therefore, the gripping unit 3 is equipped with a cover 39 (Figures 2A and 2B) installed above the upper conveyor 30.

[0041] The shift unit 4 is positioned downstream of the clamping unit 3 and receives the bags 100, which are arranged in the lateral direction Y, from the clamping unit 3 and transports them in the transport direction X1. In the meantime, the shift unit 4 has the function of shifting the bags 100 in the lateral direction Y, creating a gap between each bag 100 and the bag 100 in the adjacent row, thus separating them row by row.

[0042] As shown in Figure 2A, the shift unit 4 is equipped with a conveyor belt 40 for straight conveying in the conveying direction X1 of the bag conveying device 27. The conveyor belt 40 includes a head pulley 400, a tail pulley 401, a drive pulley 402, an endless flat belt 403 wound around these pulleys 400-402, and a tension pulley 404 that engages with the flat belt 403 from the outside.

[0043] The flat belt 403 has a width larger than the widths of the webs 10 and 11 and can thus receive all of the plurality of bags 100 formed at once by cross-cutting and arranged side by side in the lateral direction Y without any of them protruding (see FIG. 3). The flat belt 403 has a flat outer surface without holes or irregularities. The flat belt 403 extends horizontally in the section from the head pulley 400 to the tail pulley 401 and defines a conveyance plane that conveys the bags 100 straight in the conveyance direction X1 while supporting their lower surfaces in this section.

[0044] The tension pulley 404 engages with the flat belt 403 from the outside to control the tension of the flat belt 403 and is biased by a biasing member (such as a spring, cylinder, etc.), not shown, toward the inside of the loop of the flat belt 403 with a predetermined force.

[0045] The motor 405 is directly or indirectly connected to the drive pulley 402, and the pulleys 400 - 402 and 404 are rotated by the motor 405, whereby the flat belt 403 is driven (runs endlessly). Other pulleys such as the pulleys 400 and 401 may function as drive pulleys when connected to the motor 405 so that the flat belt 403 is driven.

[0046] Note that the upper conveyor 30 of the sandwiching unit 3 is longer than the lower conveyor 31 and protrudes downstream, and the tail pulley 301 of the upper conveyor 30 is located directly above the head pulley 400 of the conveyor belt conveyor 40. The conveyor belt conveyor 40 receives the bags 100 from the sandwiching unit 3, places them on the flat belt 403, supports their lower surfaces, and conveys them in the conveyance direction X1.

[0047] There is a gap between the tail pulley 311 and the head pulley 400. An eliminating device (not shown) (for example, the one disclosed in JP2004 - 160780A1) may eliminate the bag 100 downward through this gap when it is determined that the bag 100 has a defect. When manufacturing small bags 100, a small-diameter roller / pulley having a rotating shaft extending in the lateral direction Y may be installed between the tail pulley 311 and the head pulley 400 to assist in delivering the small bags 100 to the conveyor belt conveyor 40.

[0048] Further, the shift unit 4 includes a plurality of shifters 41 for shifting the bag 100 being conveyed in the conveyance direction X by the conveyance belt conveyor 40 in the lateral direction Y.

[0049] In this embodiment, each of these shifters 41 includes a support 410 and a shift roller 411 that is rotatably supported by the support 410 and cooperates with the flat belt 403 to shift the bag 100 being conveyed in the lateral direction Y, as shown in FIGS. 4A - 4C.

[0050] The support 410 includes a receiving frame 410a that surrounds the upper part of the shift roller 411 from above and rotatably receives both ends of the axis of the shift roller 411, and a cylindrical portion 410b that extends upward from the receiving frame 410a. The shift roller 411 is a driven roller with a short axis.

[0051] Further, the shift unit 4 further includes a support structure for arranging a plurality of shifters 41 side by side in the lateral direction Y and positioning each of them in various orientations. When a plurality of shifters 41 are attached to and supported by the support structure, as shown in FIG. 2A, each shifter 41 (each of its shift rollers 411) is positioned on the conveyance plane of the flat belt 403 of the conveyance belt conveyor 40, and it becomes possible to shift the bag 100 on the flat belt 403 in the lateral direction Y.

[0052] As shown in FIGS. 5A and 5B, the support structure of this embodiment includes at least one holder 42 for holding each of the shifters 41 (its support 410). The holder 42 of this embodiment is provided for each shifter 41 and is configured to rotatably receive the support 410 of the corresponding shifter 41 around an axis AX extending in the vertical direction Z (a direction perpendicular to the conveyance direction X1 and the lateral direction Y). For this purpose, the holder 42 has a holding hole 420 that penetrates in the vertical direction Z. The cylindrical portion 410b of the support 410 is rotatably received in the holding hole 420. That is, the shifter 41 is rotatable around the cylindrical portion 410b (see the arrow in FIG. 4A).

[0053] Furthermore, the support structure is provided for each shifter 41 and includes a fixing device 43 for releasably positioning the corresponding shifter 41 in the holder 42. In this embodiment, the fixing device 43 is a knob. By operating the handle portion at the base end of the fixing device 43, the operator can move its tip into and out of the holding hole 420 from the side, thereby clamping and releasing the cylindrical portion 410b between the fixing device 43 and the circumferential surface of the holding hole 420. In other words, the fixing device 43 can hold and release the support 410 in the holder 42. This allows the shifter to be releasably positioned.

[0054] When the support 410 is not fixed to the holder 42 by the fastener 43, the shifter 41 can be rotated around the axis AX (cylindrical portion 410b). That is, the shifter 41 (its shift roller 411) can be positioned at any angle of 360° around the axis of direction Z (i.e., any orientation). After adjusting the orientation, if the support 410 is fixed to the holder 42 by the fastener 43, the shifter 41 (its shift roller 411) can be positioned in the holder 42 in the adjusted orientation.

[0055] Furthermore, the support structure includes a mounting beam 44 to which the holder 42 is attached. The mounting beam 44 is attached, for example, to a frame (not shown) and extends laterally in the Y direction over the width of the flat belt 403 above the conveying plane of the conveyor belt 40 (Figure 3).

[0056] Holder 42 has a first mounting hole 421 that penetrates in the vertical direction Z. The exemplary mounting beam 44 is formed with a plurality of second mounting holes 440 that are spaced apart in the lateral direction Y and each penetrate in the vertical direction Z. Further, the support structure includes a bolt 45 (FIG. 5B) as an example of an additional fixture. The operator can align the first and second mounting holes 421, 440, and then, as shown in FIG. 5B, insert the bolt 45 into these mounting holes 421, 440, and fasten with the bolt 45 to attach and fix the holder 42 to the mounting beam 44. Thereby, the shift roller 411 can be positioned on the conveying plane of the conveyor belt conveyor 40. By selecting the second mounting hole 440, the position of the shift roller 411 can be discretely adjusted in the lateral direction Y.

[0057] In another exemplary support structure of FIGS. 5C and 5D, the mounting beam 44 has a mounting slot 441 (elongated hole) that extends in the lateral direction Y instead of the plurality of mounting holes 440. This exemplary support structure includes a nut 46 (FIG. 5D) in addition to the bolt 45 as an additional fixture. The operator can insert the bolt 45 into the mounting hole 421 and the mounting slot 441 as shown in FIG. 5D, fit the nut 46 onto the bolt 45 from the tip side, and attach and fix the holder 42 to the mounting beam 44 by fastening with the bolt 45 and the nut 46. In this example, the position of the shift roller 411 can be continuously adjusted in the lateral direction Y by the mounting slot 441.

[0058] With the above configuration, a plurality of shift rollers 411 can be arranged side by side on the conveying plane of the conveyor belt conveyor 40 at appropriate intervals in the lateral direction Y as shown in FIG. 3. And each shift roller 411 can be individually adjusted to an arbitrary orientation (angle).

[0059] Note that the mounting beam 44 may be configured to be positionally changeable in the conveying direction X1 and the opposite direction. By changing the position of the mounting beam 44, the position of the shift roller 411 can be adjusted in the conveying direction X1 and the opposite direction.

[0060] For example, at least one shift roller 411 may be assigned to one bag 100. In Figure 3, two shift rollers 411 are assigned to one bag 100.

[0061] When the bag 100 is transported by the conveyor belt 40, it passes between the flat belt 403 and the shift roller 411, sandwiched between them. The outer surface of the flat belt 403 is made of a material with a low coefficient of friction compared to the material of the bag 100. If the shift roller 411 is facing to the right with respect to the transport direction X1, the bag 100 is shifted to the right as it is transported. If the shift roller 411 is facing to the left with respect to the transport direction X1, the bag 100 is shifted to the left as it is transported. Furthermore, the larger the angle of the shift roller 411 with respect to the transport direction X1, the larger the amount of shift.

[0062] As shown in Figure 3, the operator positions the shift roller 411 assigned to the bag 100 on the right side of the conveying direction X1 relative to the center line C of the simultaneously formed bag 100 group so that it faces to the right when viewed from the conveying direction X1, and positions the shift roller 411 assigned to the bag 100 on the left side of the conveying direction X1 relative to the center line C so that it faces to the left when viewed from the conveying direction X1.

[0063] Furthermore, at this time, the operator makes the angle of the shift roller 411 assigned to the bags 100 proximal to the center line C relatively small, and the angle of the shift roller 411 assigned to the bags 100 distal to the center line C relatively large. With such adjustments, the bags 100 can be separated laterally in the Y direction at equal intervals in each row by passing them over these shift rollers 411. Therefore, the shift unit 4 can transport the bags 100 downstream with equal intervals in each row.

[0064] Such adjustments are merely examples. Parameters related to the adjustment of the number, orientation (angle), and position of the shift rollers 411 may be determined according to the number of rows, the material and size of the bags, etc.

[0065] With the configuration described above, the shift unit 4 can freely adjust the spacing between the rows, enabling separation at equal intervals as described above.

[0066] As shown in Figure 2A, the stack unit 5 is located downstream of the shift unit 4. It receives the bags 100, which are separated by row, from the shift unit 4, stacks a certain number of bags in each row to form a bag stack ST (Figure 8B, etc.), and then sends the bag stack ST further in the transport direction X1.

[0067] The stack unit 5 includes an (additional) conveyor belt 50, a stopper 51, a first actuator 52 (Figures 2A and 2B only), a partition plate 53 (Figure 3), a receiving member 54 (Figures 2A and 2B), and a second actuator 55 (Figures 2A and 2B only). The conveyor belt 50 has a conveying width that is even greater than the conveying width of the conveyor belt 40 (width of the flat belt 403) (see Figure 3). The conveyor belt 50 has a conveying plane at a lower position than the conveying plane of the conveyor belt 40.

[0068] The partitioning plates 53 are arranged on the conveyor belt 50 with a gap in the lateral direction Y, and when each row of bags 100 is discharged from the shift unit 4, it enters the area between the two partitioning plates 53. In this way, the bags 100 are clearly separated by row.

[0069] At least one stopper 51 (two in the embodiment shown in Figure 3) is provided for each row. The stoppers 51 are positioned above the conveying plane of the conveyor belt 50. In this embodiment, the stoppers 51 are pole-shaped, but they may also be plate-shaped.

[0070] The first actuator 52 moves the stopper 51 up and down between a restricting position (Figure 7A) and a retracted position (Figure 8B).

[0071] Figure 6 shows an enlarged view of region T in Figure 3. The conveyor belt 50 may include, for example, a plurality of endless, thin flat belts 500 that are spaced apart (gap) from each other in the lateral direction Y and extend straight in the conveying direction X1, as shown in Figure 6. The conveyor belt 50 conveys the bag stack ST in the conveying direction X1 by endlessly rotating these flat belts 500 while supporting its lower surface. The conveyor belt 50 is supported by a support frame (not shown) and is housed inside the support frame, with space secured below it for arranging a receiving member 54 and a second actuator 55.

[0072] The receiving members 54 are located upstream of the stopper 51 and are provided in multiples (two in this embodiment) for each row, and are used to receive the bags 100 from the conveyor belt 40. The receiving members 54 may have, for example, a plate shape.

[0073] The second actuator 55 moves the receiving member 54 up and down within a range from a lower height (Figure 8A) where the receiving member 54 is retracted downward from the conveying plane of the conveying belt 50, to an upper height (Figure 7A) where the receiving member 54 protrudes upward from the conveying plane of the conveying belt 50 through the gap between the two belts 500, and its upper end is slightly lower than the conveying plane of the conveying belt 40.

[0074] As shown in Figure 7A, with the stopper 51 in the restricting position and the receiving member 54 at the upper height, when a bag 100 is discharged from the conveyor belt 40, it is received by the receiving member 54 and placed on top of it. Even if the bag 100 is launched forcefully from the conveyor belt 40, it will hit the stopper 51 and fall onto the receiving member 54. This process is repeated, and the bags 100 are stacked one after another. During this process, the stacking unit 5 uses the second actuator 55 to lower the receiving member 54 as the bags 100 are stacked (Figures 7A-7C).

[0075] When a certain number of bags 100 are stacked to form a bag stack ST, the receiving member 54 descends below the conveying plane of the conveying belt conveyor 50 (Figure 8A).

[0076] When the stack unit 5 determines that a bag stack ST has been formed based on signals from sensors such as those that detect the passage of the bags 100, it responds by moving the stopper 51 upward from the restricting position to the retracted position using the first actuator 52 (Figure 8B). When the stopper 51 is in the retracted position, there is no stopper 51 in front of the bag stack ST, so the bag stack ST can be transported in the transport direction X1 by the transport belt conveyor 50.

[0077] The stack unit 5 may determine that a bag stack ST has been formed by detecting the thickness of the stacked bag stack ST with a sensor, or by counting the number of bags 100 discharged from the conveyor belt 40 onto the receiving member 54 with a sensor.

[0078] The stacking unit 5 guides the bag stack ST through the conveyor belt 50, passing below the stopper 51 (Figure 8C). Next, the stacking unit 5 uses the first actuator 52 to lower the stopper 51 to the regulating position, and the second actuator 55 to raise the receiving member 54 to the upper height (Figure 9A). Then, the stacking unit 5 waits for the next bag 100 to be discharged from the conveyor 40 (Figure 9B).

[0079] The above steps are repeated, and each time a bag stack ST is formed, it is transported downstream. This separates the bags 100, and therefore the bag stack ST, into rows. An operator or robot then packages the bag stack ST by attaching a band to it.

[0080] Figures 10A and 10B show a shift unit 9 related to the technology that can shift the bag 100 in the lateral direction Y. The shift unit 9 comprises a plurality of endless upper belts 92 (four in Figure 10A for simplification, but more in reality) wound around an upper head pulley 90 and an upper tail pulley 91, and a plurality of endless lower belts 95 wound around a lower head pulley 93 and a lower tail pulley 94. The upper belts 92 engage with the grooves of the pulleys 90 and 91 in a flared shape that increases in distance from each other in the conveying direction X1. The lower belts 95 are similar. With this configuration, the shift unit 9 conveys the bag 100 in the conveying direction X1 while also moving it in the lateral direction Y, thereby increasing the distance between the bags 100. The belts 92 and 95 are round belts with a circular cross-section.

[0081] The related technology requires adjusting the inclination of belts 92 and 95 using a tool to change the lateral Y-spacing between bags 100. However, this requires stopping the bag-making machine.

[0082] When industrial equipment includes driven components within reach of the operator, it is common practice to cover such components with a cover while the equipment is in operation to prevent the operator from touching them while they are moving. In particular, countries and regions with a high level of safety awareness, such as developed countries, tend to legally require such safety measures. In the related technologies shown in Figures 10A and 10B, a large cover 99 that completely encloses the components is usually installed above them as a safety measure to prevent fingers from getting caught in the driving belts 92 and 95.

[0083] Therefore, the operator must stop the bag-making machine and open the cover 99 before they can begin adjusting the inclination of the belts 92 and 95. Furthermore, the adjustments required after restarting the machine to enable sorting take time. When switching specifications to manufacture bags of different sizes, extensive adjustments must be redone. Thus, the related technology is cumbersome and inefficient.

[0084] The related technology discharges the bags 100 forcefully from the belts 92 and 95, which may cause the bags 100 to scatter downstream. This may necessitate extra rework during sorting. For example, if the related technology is adopted, the bags 100 may hit the stopper 51 (Figure 2A, etc.) forcefully, bounce back upstream, and bend and stack up as they fall.

[0085] Therefore, the shift unit 9 of the related technology may be further equipped with a pair of conveying rollers for reduction (Figure 10B) downstream to suppress the discharge speed. The conveying speed of the conveying roller pair 96 is slower than the conveying speed of the belts 92 and 95.

[0086] On the other hand, in this embodiment, the operator can access the fixing device 43 and the shift roller 411 from above the shift unit 4 to adjust the spacing between the bags 100 and adjust the angle of the shift roller 411, which can be done without stopping the operation of the bag-making machine. Therefore, the embodiment of the present invention has the advantage that the spacing between the bags 100 can be adjusted even while the bag-making machine is running (production line is in operation). This leads to improved efficiency.

[0087] Furthermore, in this embodiment, since driven shift rollers 411 are used instead of multiple driven belts, the safety cover 99 above is unnecessary. In other words, this embodiment of the present invention also improves accessibility for adjusting the spacing of the bags 100, making the adjustment work easier.

[0088] In this embodiment, the shift roller 411 is a driven roller, and the lateral shift of the bag 100 in the Y direction causes deceleration of the bag 100. This reduces the forceful impact with the stopper 51, thus eliminating the need for the deceleration conveyor roller pair 96 of related technologies. Furthermore, from an SDG perspective, bags made of monomaterials are attracting attention, but such bags lack rigidity. The deceleration configuration of this embodiment suppresses the bending of the bag, making it very suitable for multi-row bag manufacturing of monomaterials.

[0089] As described above, the bag conveying device 27 of the embodiment, by having a shift unit 4, provides easy and efficient separation and partitioning of bags in the lateral direction Y for each row in multi-row bag making.

[0090] The following describes another embodiment of the shift unit 4. Components identical or similar to those in the previous embodiment are denoted by the same reference numerals, and their descriptions are omitted.

[0091] Figures 11 and 12 show another embodiment of the shift unit 4. Note that the specific configuration of the bag conveying device 27 located upstream and downstream of the shift unit 4 is the same as in the previous embodiment, and therefore is not shown here.

[0092] As shown in Figure 11, each shifter 41 in this embodiment is equipped with a shift belt conveyor 412 instead of a shift roller 411. Each shift belt conveyor 412 includes an upstream pulley 412a, a downstream pulley 412b, and an endless shift belt 412c wound around these pulleys 412a and 412b.

[0093] The shift belt 412c is supported by a support structure such that its lower linear extension faces the upper linear extension of the flat belt 403 of the conveyor belt 40. As a result, when the bag 100 is conveyed from upstream, it is sandwiched between both belts 412c and 403. The shift belt 412c may be a flat belt or a round belt. The width of the shift belt 412c is basically smaller than the width of one bag 100 that is manufactured. The materials of both belts 412c and 403 are selected considering the material of the bag 100 so that the coefficient of friction of the shift belt 412c against the bag 100 is greater than the coefficient of friction of the flat belt 301 against the bag 100.

[0094] Furthermore, the shift belt conveyor 412 is equipped with a motor 412d that is directly or indirectly connected to the upstream pulley 412a, with the upstream pulley 412a acting as the drive pulley and the downstream pulley 412b acting as the driven pulley. The motor 412d rotates the pulleys 412a and 412b, thereby driving the shift belt 412c clockwise (endless rotation) in Figure 11.

[0095] The shifter 41 of this embodiment also includes a support 410, and the shift belt conveyor 412 is mounted and supported on the support 410 so that the shift belt 412c can be driven. The support structure of this embodiment, although not specifically illustrated here, has the same configuration as in the previous embodiment, so that the support 410 (and therefore the shift belt conveyor 412) can rotate around the axis in the Z direction, thereby allowing the operator to change the orientation of each shifter 41 (and its shift belt conveyor 412), and in addition, to change its lateral Y position.

[0096] When the shift belt conveyor 412 is oriented diagonally with respect to the transport belt conveyor 40 (i.e., the transport direction X), the bag 100 is held between the belts 403 and 412c of these transporters 40 and 412 while they are in motion. Due to the relatively high coefficient of friction of the shift belt 412c, the bag 100 is transported diagonally along the shift belt 412c. In other words, the bag 100 moves not only in the transport direction X by the shift belt conveyor 412 but also in the lateral direction Y (shift).

[0097] Therefore, by appropriately setting the orientation of each shifter 41 (shift belt conveyor 412) as shown in Figure 12, it is possible to appropriately space the rows of bags 100 and transport them downstream in that state, similar to the previous embodiment. Furthermore, with the same support structure as the previous embodiment, the spacing between the rows can be easily adjusted without preparing separate tools as in related technologies and without stopping the bag-making machine.

[0098] In the embodiment using the shift roller 411, the lateral Y-shift of the bag 100 occurs only at the contact point between the roller 411 and the bag 100, resulting in an unstable trajectory for the bag 100. On the other hand, in this embodiment using the shift belt conveyor 412, the lateral Y-shift occurs while the bag 100 is in contact with the longitudinally oriented shift belt 412c, that is, over the entire length of the shift belt 412c. Therefore, the trajectory of the bag 100 is more stable than in the previous embodiment, and the bags 100 can be spaced apart reliably and accurately.

[0099] In this embodiment, multiple belts 412c driven by a motor 412d (drive source) are used. However, the support 410 covers the shift belt conveyor 41 (and its shift belts 412c) almost entirely from above, functioning as a cover. From a safety standpoint, a small cover that only covers the upstream pulley 412a, which is the drive pulley, is sufficient, and a large cover 99 like those in related technologies is unnecessary. Furthermore, even if such a small cover is provided, the orientation of the shifter 41 can be adjusted by accessing the fixing device 43 (omitted in this embodiment) without removing it. In other words, although this embodiment has driven components, it ensures safety without a large cover 99 that covers the entire shift unit 4, and the orientation of the shifter 41 can be adjusted while the bag-making machine is running, thereby eliminating the aforementioned inconveniences of related technologies.

[0100] Figures 13, 14, and 15 illustrate a shift unit 4 according to yet another embodiment. The shifter 41 in this embodiment is of the type that includes a support 410 and a shift belt conveyor 412. This embodiment differs from the previous two embodiments in its support structure, as described below.

[0101] As shown in Figure 14, the holder 42 in this embodiment consists of a rail-shaped upstream holder 42A that extends laterally in the Y direction across the width of the conveyor belt 40, and a rail-shaped downstream holder 42B that is positioned downstream of the upstream holder 42A at a distance and extends laterally in the Y direction across the width of the conveyor belt 40, and is shared by all shifters 41.

[0102] As shown in Figures 13 and 15, the fixing device 43 of this embodiment consists of an upstream fixing device 43A for releasably fixing the upstream end of the support 410 to the upstream holder 42A, and a downstream fixing device 43B for releasably fixing the downstream end of the support 410 to the downstream holder 42B.

[0103] In this embodiment, the support 410 comprises a body 410c for supporting the shift belt conveyor 412, an upstream bracket 410dA attached to the upstream end of the body 410c so as to be rotatable around an axis extending vertically of the shift belt conveyor 412 by pins or the like, and a downstream bracket 410dB attached to the downstream end of the body 410c so as to be rotatable around an axis extending vertically of the shift belt conveyor 412 by pins or the like.

[0104] As shown in Figure 15, the upstream and downstream brackets 410dA and 410dB each have a roughly C-shaped cross-section. The upstream bracket 410dA is externally fitted onto the upstream holder 42A so as to be slidable on the rail-shaped upstream holder 42A, and the downstream bracket 410dB is externally fitted onto the downstream holder 42B so as to be slidable on the rail-shaped downstream holder 42B. The upstream / downstream fixing devices 43A / 43B are knobs that are attached to the upstream / downstream brackets 410dA / 410dB and are configured to press and fix the upstream / downstream brackets 410dA / 410dB to the upstream / downstream holders 42A / 42B when operated.

[0105] The operator can releasably fix the upstream / downstream brackets 410dA / 410dB at any position in the lateral direction Y on the rail-shaped upstream / downstream holders 42A / 42B by operating the upstream / downstream fixing devices 43A / 43B.

[0106] This allows both the orientation and the position in the lateral direction Y of the shifter 41 (body 410c, shift belt conveyor 412) to be adjusted by changing the position of the upper and lower ends of each shifter 41 in the lateral direction Y (see Figure 14). In this embodiment as well, the orientation of the shifter 41 can be easily adjusted by accessing the fixing devices 43A / 43B without stopping the operation of the bag-making machine.

[0107] In this embodiment as well, even if a small cover is provided to cover only the upstream roller 412a for safety reasons, the upstream fixing device 43A is located outside the small cover, and the upstream fixing device 43A can be accessed without removing the cover. Thus, in this embodiment as well, safety can be ensured, and the fixing devices 43A and 43B can be operated (i.e., the orientation of the shifter 41 can be adjusted) while the bag-making machine is in operation.

[0108] 1, 10, 11 Web 100 Bags 26 Cross-cutting device 27 Bag conveying device 3 Clamping unit 4 Shift unit 40 Belt conveyor 400 Head pulley 401 Tail pulley 403 Flat belt 405 Motor 41 Shifter (e.g., shift belt conveyor) 410 Support 410c Body 410dA Upstream bracket 410dB Downstream bracket 411 Shift roller 412 Shift belt conveyor 42 Holder 42A Upstream holder 42B Downstream holder 421 Mounting hole 43 Fixing device (e.g., knob) 43A Upstream fixing device 43B Downstream fixing device 44 Mounting beam 440 Mounting hole 441 Mounting slot 45 Bolt (as additional fixing device) 46 Nut (as additional fixing device) 5 Stack unit 50 (Additional) conveyor belt 51 Stopper 52 First actuator 54 Receiving member 55 Second actuator AX Axis C Center line ST Bag stack X1 Conveying direction Y Lateral direction Z Vertical direction

Claims

1. A bag conveying device used in a bag-making machine that provides multi-row bags, for conveying a plurality of the bags arranged laterally perpendicular to the bag conveying direction, wherein the bag conveying device comprises a shift unit for shifting the bags laterally while conveying them in the conveying direction, the shift unit comprising a conveying belt conveyor for conveying the bags straight in the conveying direction while supporting the lower surface of the bags, a plurality of shifters for shifting the bags laterally when the bags are being conveyed in the conveying direction by the conveying belt conveyor, and a support structure for supporting each of the plurality of shifters and positioning each of the shifters above the conveying belt conveyor, wherein the support structure comprises at least one holder, and at least one fixing device provided for each of the shifters for releasably positioning the corresponding shifter in the at least one holder, the at least one holder is configured to position each of the shifters in the at least one holder in a plurality of different orientations by the at least one fixing device.

2. The bag conveying device according to claim 1, wherein each shifter comprises a support and a driven shift roller rotatably supported by the support and cooperating with the conveyor belt to shift the bag laterally.

3. The bag conveying device according to claim 1, wherein each shifter comprises a support and a shift belt conveyor supported by the support for conveying the bags diagonally with respect to the conveying direction and the lateral direction, the shift belt conveyor comprising an upstream pulley, a downstream pulley, an endless shift belt wound around the upstream pulley and the downstream pulley for sandwiching the bags between the shift belt and the flat belt of the conveying belt conveyor, and a motor for driving the shift belt, the shift belt having a coefficient of friction with respect to the bags greater than the coefficient of friction of the flat belt with respect to the bags.

4. The bag conveying device according to claim 2, wherein the at least one holder is configured to rotatably receive the support about an axis extending perpendicular to the conveying direction and the lateral direction, and the at least one fastener is configured to releasably secure the support to the holder.

5. The bag conveying device according to claim 3, wherein the at least one holder is configured to rotatably receive the support about an axis extending perpendicular to the conveying direction and the lateral direction, and the at least one fastener is configured to releasably secure the support to the holder.

6. The bag conveying device according to claim 1, wherein the support structure further comprises a mounting beam that extends laterally across the width of the conveying belt and to which the at least one holder is attached.

7. The bag conveying device according to claim 6, wherein the support structure further comprises at least one additional fastener for removably securing the at least one holder to the mounting beam.

8. The bag conveying device according to claim 7, wherein the at least one holder has a first mounting hole, the mounting beam has a plurality of second mounting holes spaced apart from each other in the lateral direction, and the at least one additional fastener is a bolt inserted into the first mounting hole and the second mounting hole to fasten the at least one holder and the mounting beam.

9. The bag conveying device according to claim 7, wherein the at least one holder has a mounting hole, the mounting beam has a laterally extending mounting slot, and the at least one additional fastener includes a bolt inserted into the mounting hole and the mounting slot for fastening the holder and the mounting beam, and a nut fitted onto the bolt.

10. The bag conveying device according to claim 3, wherein the at least one holder comprises a laterally extending upstream holder and a laterally extending downstream holder, and the at least one fastener comprises an upstream fastener for releasably securing the upstream end of the support to the upstream holder and a downstream fastener for releasably securing the downstream end of the support to the downstream holder.

11. The bag conveying device according to claim 10, wherein the support comprises a body that supports the shift belt conveyor, an upstream bracket provided at the upstream end of the body so as to be rotatable about an axis extending vertically of the shift belt conveyor, and a downstream bracket provided at the downstream end of the body so as to be rotatable about an axis extending vertically of the shift belt conveyor, wherein the upstream holder is configured so that the upstream bracket can be fixed at a plurality of different positions in the lateral direction on the upstream holder by the upstream fixing device, and the downstream holder is configured so that the downstream bracket can be fixed at a plurality of different positions in the lateral direction on the downstream holder by the downstream fixing device.

12. The bag conveying device according to claim 1, wherein the conveying belt conveyor comprises a head pulley, a tail pulley, an endless flat belt wound around the head pulley and the tail pulley, having a width that can accommodate all of the plurality of bags arranged laterally, and a motor for driving the flat belt.

13. The bag conveying device according to claim 12, further comprising: a stacking unit for receiving the bags from the shift unit, stacking a certain number of the bags in each row to form a bag stack, and conveying the bag stack, wherein the stacking unit comprises: an additional conveying belt having a conveying plane at a lower position than the conveying plane of the conveying belt conveyor of the shift unit; a stopper provided for each of the rows and located above the additional conveying belt conveyor; and a first actuator for moving the stopper to a restricting position that restricts the movement of the bags in the conveying direction and a retracted position that allows the bag stack to be conveyed by the additional conveying belt conveyor.

14. The bag conveying device according to claim 13, wherein the additional conveying belt comprises a plurality of belts arranged with gaps between them in the lateral direction, and the stacking unit further comprises: a receiving member provided for each of the rows upstream of the stopper for receiving the bags; and a second actuator for moving the receiving member up and down within a range from a lower height where the receiving member is retracted downward from the conveying plane of the additional conveying belt, to an upper height where the receiving member protrudes upward through the gap from the conveying plane of the additional conveying belt, and the upper end of the receiving member is lower than the conveying plane of the conveying belt.

15. A bag-making machine that provides multi-row bag production, comprising: a cross-cutting device for forming multiple bags by cross-cutting a web in the width direction of the web; and a bag conveying device according to claim 1, which is arranged downstream of the cross-cutting device and for conveying the multiple bags.

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