Bag transfer device

Abstract

To provide a bag transfer device capable of transferring bags of various shapes, while properly supporting them.SOLUTION: A bag transfer device includes a plurality of holding parts movably provided. The plurality of holding parts includes a first holding part 41a and a second holding part 41b provided so as to be adjacent to each other in the horizontal direction. Each of the holding parts includes a left side support part 201 for supporting one side part out of a bag, and a right side support part 202 for supporting the other side part out of the bag. One out of the right side support part 202 of the first holding part 41a and the left side support part 201 of the second holding part 41b is positioned above the other.SELECTED DRAWING: Figure 11

Description

[Technical Field]

[0001] The present invention relates to a bag transfer device. [Background technology]

[0002] In a device such as a bag filling and packaging machine, a large number of bags are transported while undergoing various processes such as opening the bags, putting contents into the bags, and sealing the bag openings.

[0003] For example, in the packaging machines disclosed in Patent Documents 1 and 2, the bag is gripped at both side edges by a pair of grippers while the bag is transported along a circular path and various packaging processes are performed in sequence. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-302227 [Patent Document 2] Japanese Patent Application Laid-Open No. 2011-240962 Summary of the Invention [Problem to be solved by the invention]

[0005] In recent years, a wide variety of bags have been developed and are now in actual use. For example, bags of various sizes are used depending on the required properties of the contents. The planar shapes of bags are also becoming more diverse. Typically, bags with a symmetrical planar shape such as a rectangle are used, but recently, bags with asymmetrical planar shapes have also come into widespread use (see, for example, Figure 2(c) of Patent Document 2).

[0006] Therefore, there is a demand for a bag transfer device that can properly support and transfer bags of various shapes, as well as a demand for a smaller bag transfer device overall and for more efficient bag transfer.

[0007] The present invention has been made in view of the above circumstances, and aims to provide a technique that can properly support and transfer bags of various shapes. Another aim is to provide a technique that enables the device to be made smaller and the bags to be transferred efficiently. [Means for solving the problem]

[0008] One aspect of the present invention relates to a bag transfer device comprising a plurality of movably arranged holding sections, including a first holding section and a second holding section arranged adjacent to each other horizontally, each of the plurality of holding sections having a left support section that supports one side of a bag and a right support section that supports the other side of the bag, and one of the right support section of the first holding section and the left support section of the second holding section is positioned higher than the other.

[0009] The entirety of one of the right support portion of the first holding portion and the left support portion of the second holding portion may be positioned higher than the entirety of the other.

[0010] In each of the first holding portion and the second holding portion, one of the left support portion and the right support portion may be positioned higher than the other.

[0011] The right support portion of the first holding portion and the left support portion of the second holding portion may overlap each other in the height direction.

[0012] The left support portion may sandwich and support one side of the bag, and the right support portion may sandwich and support the other side of the bag. [Effects of the Invention]

[0013] According to the present invention, it is possible to transport bags of various shapes while properly supporting them. Furthermore, according to the present invention, it is possible to reduce the size of the device and transport bags efficiently. [Brief explanation of the drawings]

[0014] [Figure 1]FIG. 1 is a plan view (a), a cross-sectional plan view (b), and a front view (c) of a sprocket, a fixed guide member, and a linear guide member of a bag transfer device. [Figure 2] FIG. 2 is a plan view of the fixed guide member. [Figure 3] FIG. 3 is a front cross-sectional view of the fixed guide member. [Figure 4] FIG. 4 is a side cross-sectional view of the fixed guide member. [Figure 5] FIG. 5 is a plan view of the sprocket. [Figure 6] FIG. 6 is a front cross-sectional view of the sprocket and its surroundings. [Figure 7] FIG. 7 is a plan view of the endless chain. [Figure 8] FIG. 8 is a front view (partial cross section) of the endless chain. [Figure 9] FIG. 9 is a plan view (partially in cross section) of the gripper pair. [Figure 10] FIG. 10 is a side view (partial cross section) of the gripper pair. [Figure 11] FIG. 11 is a front view (partially in cross section) of the gripper pair. [Figure 12] FIG. 12 is a plan cross-sectional view of a gripper pair. [Figure 13] FIG. 13 is a plan cross-sectional view of the arm opening / closing mechanism. [Figure 14] FIG. 14 is a side cross-sectional view of an opening and closing mechanism for the gripping members of the gripper pair. [Figure 15] FIG. 15 is a side cross-sectional view of the opening and closing mechanism of the gripping members of the gripper pair in another position. [Figure 16] FIG. 16 is a plan view of the opening and closing mechanism of the gripping members of the gripper pair. [Figure 17] FIG. 17 is a plan cross-sectional view of the arm opening / closing and arm spacing adjustment mechanism of the gripper pair. [Figure 18] FIG. 18 is a side cross-sectional view of the straight portion. [Figure 19] FIG. 19 is a plan cross-sectional view of the sprocket portion. [Figure 20] FIG. 20 is a partial cross-sectional side view of the sprocket unit. [Figure 21] FIG. 21 is a plan view of another endless chain. [Figure 22] FIG. 22 is a front view (partially in cross section) of another endless chain. [Figure 23] FIG. 23 is a diagram showing a modified example of a gripper pair, in which a first gripper pair and a second gripper pair adjacent to each other are viewed in the horizontal direction (front). DETAILED DESCRIPTION OF THE INVENTION

[0015] An example of a bag transfer device 500 for a bag filling and packaging machine will be described below with reference to the drawings.

[0016] The bag transfer device 500 shown in Figure 1 comprises a sprocket 1 connected to a drive means and rotating continuously in a horizontal plane, a fixed guide member 3 arranged in the same horizontal plane and having a guide section 2 that is approximately semicircular in plan view, an endless chain (not shown) stretched between the sprocket 1 and the guide section 2, and a linear guide member 4 that guides the endless chain on a linear track between the sprocket 1 and the guide section 2.

[0017] The endless chain has multiple pairs of grippers spaced at equal intervals to grip both edges (side portions) of the bag, transporting the bag at a constant speed along the transfer trajectory t. A sub-machine base 5 is placed inside the track of the endless chain, and fixed guide members 3, linear guide members 4, and various packaging processing equipment are installed to the sides and above the sub-machine base 5.

[0018] As shown in Figures 7 and 8, the endless chain 6 is made up of multiple links 7 connected in an endless fashion via connecting shafts 9. The connecting shaft 9 is fixed to one end of one link 7 and is rotatably supported at the other end of the adjacent link 7 via bearings 10, and every link 7 is provided with a pair of grippers. An inner guide roller 11 is installed at the center of the inside of each link 7 so as to be rotatable in a vertical plane. Above and below each connecting shaft 9, an upper guide roller 12 and a lower guide roller 13 are installed so as to be rotatable in a horizontal plane.

[0019] As shown in FIGS. 2 to 4 , the fixed guide member 3 is installed on a bracket 14 at the end of the sub-machine base 5 and includes a spring support member 16 fixed to the bracket 14 via an attachment portion 15, a pair of slide rails 17 fixed to the bracket 14, a slide member 19 slidably provided on the slide rails 17, and a guide plate 20 fixed to the slide member 19. A guide portion 2 is formed on the outer periphery of the approximately semicircular side of the guide plate 20. The guide portion 2 includes a flange-shaped upper roller guide portion 21 and a flange-shaped lower roller guide portion 22 that abut against the upper guide roller 12 and the lower guide roller 13 of the endless chain 6, respectively, and a guide groove 23 located intermediate the upper roller guide portion 21 and the lower roller guide portion 22 and into which the inner guide roller 11 is fitted. A spring receiving member 24 is fixed to an inner recess of the guide plate 20, and a compression spring 25 is disposed between the spring receiving member 24 and the spring supporting member 16 to constantly urge the guide plate 20 outward. "26" is a mounting plate that mounts the guide plate 20 to the slide member 19, "27" is a mounting plate that mounts the spring receiving member 24 to the guide plate 20, and "29" is a machine base.

[0020] As shown in FIGS. 5 and 6, the sprocket 1 is fixed to the periphery of a sprocket mounting plate 28 and has equally spaced recesses 31 and 32. The sprocket 1 also has an annular support groove 33 into which the inner guide roller 11 fits. The upper guide roller 12 and the lower guide roller 13 fit into the outer peripheral surfaces of the recesses 31 and 32, respectively. The sprocket mounting plate 28 is fixed to a second hollow shaft 35 that is rotatably supported inside a stand 34 that stands on the machine base 29. A rotational drive gear 36 that connects to a drive source (not shown) is fixed to the lower end of the second hollow shaft 35. As shown in FIGS. 1 and 10, the linear guide member 4 has an inner guide rail 37, an upper guide rail 38, and a lower guide rail 39. The inner guide rail 37, the upper guide rail 38, and the lower guide rail 39 are attached to the sub-machine base 5 and each have a guide groove into which the guide rollers 11 to 13 fit.

[0021] As the gear 36 rotates, the sprocket 1 rotates, causing the endless chain 6 to rotate accordingly. As the sprocket 1 rotates, the inner guide roller 11 fits into the support groove 33, and the upper and lower guide rollers 12 and 13 fit into the recesses 31 and 32, causing the links 7 of the endless chain 6 to rotate while positioned around the sprocket 1. After leaving the sprocket 1, the guide rollers 11-13 fit into guide rails 37-39, respectively, and travel along the straight section before entering the arc-shaped guide section 2. In the guide section 2, the inner guide roller 11 fits into the guide groove 23 and travels, while the upper and lower guide rollers 12 and 13 travel on the upper and lower roller guide sections 21 and 22. The fixed guide member 3 is biased outward by the compression spring 25, so the upper and lower guide rollers 12 and 13 are always in close contact with the roller guide sections 21 and 22. After leaving the guide section 2, the guide rollers 11 to 13 enter another straight section, and similarly fit into the guide rails 37 to 39, and travel toward the sprocket 1.

[0022] In this way, while guide rollers 11-13 are traveling, they are reliably guided by recesses 31, 32 and support grooves 33 of sprocket 1, guide section 2, and linear guide member 4, so the vertical and horizontal positions of moving link 7 are stable, and even if the weight of a filled bag or the impact during filling is transmitted to link 7 through the gripper, the link can withstand that weight and impact, allowing the gripper (and therefore the bag) to be transported accurately along transport trajectory t. Note that each link 7 has a considerable linear length, so as endless chain 6 rotates, the center-to-center distance of endless chain 6 (the distance between the center of sprocket 1 and the center of the arc of guide section 2) fluctuates while it travels one pitch (the length of link 7), but this is absorbed by compression spring 25.

[0023] Gripper pairs 41 (retaining portions) shown in FIGS. 9 to 13 are attached to the outer surface of each link 7. In FIG. 11, the area surrounded by a two-dot chain line indicated by reference numeral "41a" shows an example of the state of the gripper pair 41 (particularly the first gripper pair 41a) as viewed from the arrow "XI-A" in FIG. 9. In FIG. 11, the area surrounded by a two-dot chain line indicated by reference numeral "41b" shows an example of the state of the gripper pair 41 (particularly the second gripper pair 41b) along the cross-sectional line indicated by reference numeral "XI-B" in FIG. 9. For convenience, in FIG. 9, the reference numerals "XI-A" and "XI-B" are assigned to each gripper pair 41. In FIG. 11, the first gripper pair 41a (first retaining portion) and the second gripper pair 41b (second retaining portion), which are arranged adjacent to each other in the horizontal direction, are shown in the states corresponding to the reference numerals "XI-A" and "XI-B," respectively.

[0024] The gripper pair 41 is provided so as to be movable horizontally together with the endless chain 6, and includes a pair of arms 42, 42 that extend horizontally outward and open and close laterally at a predetermined timing. A gripping member 43, 44 that opens and closes is attached to the tip of each of the pair of arms 42, 42. Each arm 42 includes a fixed shaft 45, a sliding cylinder 46 that fits around the fixed shaft 45, a compression spring 47 that urges the sliding cylinder 46 forward (in the direction of closing the gripping members 43, 44), and a spring seat 49 fitted into the fixed shaft 45. The middle portion of the outer gripping member 43 is journaled to the tip of the fixed shaft 45 by a pin 50 so as to be horizontally rotatable. The rear end of the outer gripping member 43 is journaled to the outer tip of the sliding cylinder 46 so as to be horizontally rotatable via a connecting pin 51, a link 52, and a connecting pin 53. Therefore, when the sliding cylinder 46 moves backward against the biasing force of the compression spring 47, the gripping members 43, 44 open widely. The rear end of the fixed shaft 45 is fixed to a mounting block 54, which is fixed to the upper surface of a mounting block 56 that is fixed to the tip of a vertically extending swing fulcrum shaft 55. Therefore, when the swing fulcrum shaft 55 rotates around its axis, the pair of arms 42, 42 together with both mounting blocks 54, 56 swing left and right (open and close).

[0025] In the drawings other than Figure 11, the height direction positions of gripper pairs 41 are shown in a simplified manner, and the relative relationship between the height direction positions of left support portion 201 and right support portion 202 is not necessarily shown accurately. As will be described later, in this embodiment, one of right support portion 202 of first gripper pair 41a and left support portion 201 of second gripper pair 41b (left support portion 201 in Figure 11) is positioned higher than the other (right support portion 202 in Figure 11). The multiple gripper pairs 41 included in the illustrated bag transfer device 500 have a common configuration, and naturally, first gripper pair 41a and second gripper pair 41b shown in Figure 11 also have a common configuration.

[0026] The swing fulcrum shaft 55 is rotatably supported within a cylindrical portion 59 of a holder 57, and the holder 57 is fixed to the outer surface of the link 7 at a mounting portion 60. A cylindrical member 64 with three levers 61-63 attached is fixed to the lower end of one of the swing fulcrum shafts 55, and a cylindrical member 67 with two levers 65-66 attached is fixed to the lower end of the other swing fulcrum shaft 55. Two cam rollers 69, one above the other, are rotatably supported at the tip of the lever 61. These cam rollers run along a distance adjustment cam (described later) to rotate one of the swing fulcrum shafts 55. A bushing 71 is rotatably attached to the tip of the lever 62 via a support pin 70. The bushing 71 fits into a groove-shaped notch in the lever 65, thereby simultaneously rotating the other swing fulcrum shaft 55 in the opposite direction. A connecting shaft 73 is horizontally rotatably attached to a support pin 72 at the tip of the lever 66. A bushing 75 is fixed horizontally to a holder pin 74 rotatably attached to the tip of the lever 63. A connecting shaft 73 is slidably fitted into the bushing 75, and a compression spring 76 is installed around the connecting shaft 73. The compression spring 76 presses the cam roller 69 against the gap adjustment cam. Reference numeral "73a" denotes a stopper.

[0027] A fulcrum shaft 77 is rotatably supported at the outermost portion of the holder 57, and the lower end of an opening / closing lever 79 is fixed to this fulcrum shaft 77. An opening / closing roller 80 is rotatably mounted at the upper end of the opening / closing lever 79 and is pressed inward at a predetermined timing by a pressing portion of an opening / closing member (described later). A support shaft 81 is fixed horizontally slightly below the opening / closing roller 80, and pressure rollers 82 are rotatably mounted on both ends of the support shaft 81. Each pressure roller 82 abuts against an operating member 83 on the outer periphery of the sliding tube 46. When the opening / closing roller 80 is pressed inward, the pressure roller 82 pushes the operating member 83 inward, opening the gripping members 43 and 44 against the biasing force of the compression spring 47. The opening / closing lever 79 is biased outward by the compression spring 47, but an abutment portion 84 at the lower end of the opening / closing lever 79 abuts against a stopper pin 85 mounted downward on the holder mounting portion 60, preventing it from further tilting.

[0028] Next, the opening and closing operation of the gripping members 43, 44 will be described. As shown in FIGS. 14 to 16, an opening and closing member 86 that operates the opening and closing roller 80 is installed on the sub-machine base 5 in the bag feeding process section of this bag filling packaging machine. The opening and closing member 86 includes a pressing portion 87 that presses the opening and closing roller 80 and an opening and closing plate 89 to which the pressing portion 87 is attached. A slide member 90 is fixed to the underside of the opening and closing plate 89. The slide member 90 is slidably mounted along a slide rail 92 fixed to a mounting plate 91 provided on the upper surface of the sub-machine base 5. A cam drive shaft 94 is installed upright on the machine base 29, a cam 93 is attached to the cam drive shaft 94, and a cam roller 96 at the tip of a lever 95 is fitted into a cam groove of the cam 93. The lever 95 is fixed near the lower end of a fulcrum shaft 97 that is rotatably installed upright on the machine base 29. A lever 99 is fixed to the upper end of the lever 95 protruding above the sub-machine base 5. The lever 99 is connected to the opening / closing plate 89 via a connecting rod 100.

[0029] The cam drive shaft 94 rotates, causing the opening / closing plate 89 to reciprocate at a predetermined timing. As the multiple (four in this case) bag feeding and transferring devices 500101 grip the upper edge of the bag W and approach the gripper pair 41, the pressing portion 87 moves inward to press the opening / closing roller 80, and the gripping members 43, 44 of the multiple (four in this case) gripper pairs 41 open simultaneously. Then, while the bag feeding and transferring device 500101 moves in synchronization with the transfer of the gripper pair 41, the pressing portion 87 moves outward, the gripping members 43, 44 close to grip the bag W, and the grippers of the bag feeding and transferring device 500101 release the bag W and move away from the vicinity of the gripper pair 41. This allows the bag to be fed. In the discharge process section of this bag filling packaging machine, an opening / closing member 86 and a device similar to the drive mechanism for the opening / closing member 86 are installed, and the gripping members 43, 44 of the gripper pair 41 are opened, causing the filled bag to drop and be discharged.

[0030] Next, the opening and closing operation of the arms 42 will be described. As shown in Figures 17 and 18, four spacing adjustment cams 102-105 are arranged along a linear path and contact the cam roller 69 to adjust (open and close) the spacing between the arms 42, 42 in accordance with each packaging process. A spacing adjustment cam 106 that rotates together with the sprocket 1 is arranged where the sprocket 1 is provided. The spacing adjustment cam 102 is located in the bag feeding process section. The spacing adjustment cam 103 is located in the bag mouth opening and solid material introduction process section, where the spacing between the arms 42, 42 narrows. The location of the spacing adjustment cam 106 is the liquid filling process section, and the spacing adjustment cam 104 is located in the steam injection process section. The subsequent spacing adjustment cam 105 is located in the sealing and discharge process section, where the spacing between the arms 42, 42 widens again. The distance adjusting cams 102 to 106 are set to their respective heights so that the distance adjusting cams 102, 106, and 105 come into contact with the upper roller 69a of the cam roller 69, and the distance adjusting cams 103 and 104 come into contact with the lower roller 69b.

[0031] Each of the gap adjustment cams 102-105 opens and closes the arms 42, 42, and at the same time adjusts the gap between the arms 42, 42 according to the bag size. The adjustment mechanism for the gap adjustment cams 102, 105 includes an adjustment drive shaft 107 journaled on the side of the sub-machine base 5, and adjustment shafts 108-110 journaled on the side of the sub-machine base 5 and connected to the adjustment drive shaft 107 by a sprocket 114 and a chain 115. Similarly, the adjustment mechanism for the gap adjustment cams 103, 104 includes an adjustment drive shaft 111, and adjustment shafts 112, 113 connected to the adjustment drive shaft 111 by a sprocket 114 and a chain 115. Male threads are formed on the tip of each adjustment drive shaft and adjustment shaft 107-113, and nut members 116 are threadedly engaged with these male threads. Distance adjustment cams 102-105 are attached to nut members 116 via brackets 117 (see FIG. 18). Therefore, when gears 119, 120 are driven by a servo motor or the like (not shown) to rotate, each adjustment drive shaft and adjustment shaft 107-113 rotates, and each distance adjustment cam 102-105 moves in parallel. This adjusts the distance between arms 42, 42 to a position corresponding to the bag size.

[0032] The gap adjusting cam 106 is also designed to adjust the gap between the arms 42, 42 in accordance with the bag size. That is, as shown in Figure 19, the gap adjusting cam 106 has inclined cam contact surfaces 121 formed on its outer periphery that correspond to each cam roller 69 (69a), and is designed to rotate relative to the sprocket mounting plate 28 (i.e., relative to the sprocket 1). Therefore, by rotating the gap adjusting cam 106 relative to the sprocket 1, the position (distance from the center of rotation of the sprocket 1) of the cam roller 69 (69a) that contacts the cam contact surface 121 changes, adjusting the gap between the arms 42, 42.

[0033] 6 and 20, the adjustment mechanism for the gap adjustment cam 106 will be described in detail. The gap adjustment cam 106 is an annular member. The inner periphery of the gap adjustment cam 106 engages with the outer periphery groove of a holder 123, allowing it to rotate relatively to the sprocket mounting plate 28. The holders 123 are attached to the lower ends of support stands 122, which are installed at equal intervals below the sprocket mounting plate 28. An adjustment shaft 124 is rotatably supported below the sprocket mounting plate 28. A cam roller 126 is attached to the inner end of the adjustment shaft 124 via a lever 125, and a roller 129 is attached to the outer end of the adjustment shaft 124 via a lever 127. The lever 127 passes through a hole 130 formed in the gap adjustment cam 106, and the roller 129 fits into an elongated hole 132 in an abutment member 131 attached to the underside of the gap adjustment cam 106. Furthermore, a tension spring 133 is installed via a spring hook between the sprocket mounting plate 28 and the spacing adjustment cam 106. The tension spring 133 applies a rotational force to the spacing adjustment cam 106, causing the cam roller 126 to always abut against the upper surface of the cylindrical cam 134.

[0034] The cylindrical cams 134 are fixed to a suitable number of support members 135 (three in this example) arranged around the stand 34. Each of the support members 135 is fixed to a nut member 136. Rotating shafts 137, the same number as the support members 135 (i.e., the same number as the nut members 136), are rotatably supported on the machine base 29 around the stand 34, and male threads formed at the ends of the rotating shafts 137 are threadedly engaged with the nut members 136. A small-diameter gear 139 is fixed to the lower end of each rotating shaft 137. These small-diameter gears 139 mesh with a common large-diameter gear 140 rotatably held around the stand 34. Furthermore, a pulley 141 is fixed below the small-diameter gear 139 on one rotating shaft 137. Therefore, when the pulley 141 is rotated by a servo motor or the like (not shown), all of the rotating shafts 137 rotate simultaneously, and the cylindrical cams 134 change height while maintaining horizontality. As a result, the height of cam roller 126 changes, adjustment shaft 124 rotates, roller 129 swings, and gap adjustment cam 106 rotates, changing its position relative to sprocket 1. This changes the position of cam roller 69 (69a) (the distance from the center of rotation of sprocket 1), adjusting the gap between arms 42, 42.

[0035] As shown in Figure 6, a plurality of filling nozzles 142 for the liquid material are arranged above the sprocket 1 along the transfer trajectory t of the bags W. These filling nozzles 142 are attached to a lifting member 143. The lifting member 143 rotates a predetermined angle in the same direction as the sprocket 1, following the sprocket 1, descending and ascending during the rotation process, and then returning to its original position, thereby performing a reciprocating rotation. When the lifting member 143 descends, the filling nozzle 142 is inserted into the open bag mouth of the bag W, and the bag W is filled with the liquid material. The lifting and rotating mechanism for the lifting member 143 includes a support member 144 that supports the lifting member 143 so that it can be raised and lowered freely, a first hollow shaft 145 that rotates back and forth through a predetermined angle at a predetermined timing, a cylindrical cam 146 fixed on the sprocket mounting plate 28, an arc-shaped cam 147 fixed to the first hollow shaft 145, a cam roller 149 that runs along these cams, a lever 150 that rotates the support member 144 back and forth, and a rotating cylinder 151 that supports the lever 150 so that it can be rotated freely around the first hollow shaft 145, but detailed explanations of these components will be omitted.

[0036] 21 and 22 show another endless chain 156. This endless chain 156 differs from the endless chain 6 described above in that each link 157 has integrally formed extensions 157a, 157b that are arc-shaped in plan view and cover the connecting portions on the left and right side surfaces of its outer periphery. One extension 157a has a smaller diameter than the other extension 157b, and fits inside extension 157b in a nested manner. This prevents the outer surfaces of the connecting portions from being exposed, even when the endless chain 156 is bent in an arc shape at the sprocket 1 or guide unit 2, preventing dust and other foreign matter from entering the connecting portions from the outside.

[0037] [Gripper vs.] As described above, the bag transfer device 500 of this embodiment includes a plurality of gripper pairs 41 (including the above-mentioned first gripper pair 41a and arm 42b (see FIG. 11)) arranged adjacent to each other in the horizontal direction. These gripper pairs 41 are moved along an endless track extending in the horizontal direction by power transmitted via a drive source (not shown) acting as a drive device, gear 36, sprocket 1, and endless chain 6. Each gripper pair 41 includes a left support portion 201 that supports one side portion (left side portion) of the bag W, and a right support portion 202 that supports the other side portion (right side portion) of the bag W. As shown in Figure 11, of the gripper pairs 41 arranged adjacent to each other, the right support portion 202 of one gripper pair 41 (first gripper pair 41a) located relatively to the left and the left support portion 201 of the other gripper pair 41 (second gripper pair 41b) located relatively to the right are positioned such that the entirety of one is higher than the entirety of the other.

[0038] In the illustrated example, in each of all gripper pairs 41 including first gripper pair 41a and second gripper pair 41b, the entirety of one (left support portion 201) of left support portion 201 and right support portion 202 is positioned higher than the entirety of the other (right support portion 202). Note that the height position of each gripper pair 41 can be based on, for example, a horizontally movable portion included in each gripper pair 41, and in the illustrated example, can be based on gripping member 43, gripping member 44, and arm 42.

[0039] The bag transfer device 500 having the above-described configuration can transfer bags W of various shapes while properly supporting them, and can even transfer bags W with asymmetrical planar shapes while properly supporting them.

[0040] Generally, processing of each bag W (e.g., opening processing, filling processing, bag mouth sealing processing, etc.) often requires deformation of a portion of the bag W near the bag mouth (usually a portion near the upper edge of the bag W). Therefore, from the perspective of transporting the bag W while appropriately supporting the bag W so that the bag mouth can be opened and closed stably, it is preferable to support a portion of the bag W near the bag mouth (e.g., a portion near the bag mouth that does not include the area to be sealed) that does not interfere with each processing step with the gripper pair 41. However, when one of the side portions of the bag W (particularly the portion near the bag mouth) has a special shape, as in the bag shown in Figure 2(c) of Patent Document 2, it is difficult with conventional bag transport devices to support both side portions of the bag W (particularly the portion near the bag mouth) in the same way at the same height.

[0041] On the other hand, as in the bag transfer device 500 of this embodiment, by varying the height positions of the left support portion 201 and the right support portion 202 of each gripper pair 41, it is possible to flexibly accommodate various shapes of both side portions of a bag W. For example, even when transferring a bag W in which the left side portion has a side edge that extends linearly in the height direction but the side edge of the right side portion (particularly the portion near the bag opening at the upper edge of the bag W) has a complex shape, the bag transfer device 500 of this embodiment can support the left side portion of the bag W (particularly the portion near the bag opening) with the left support portion 201 of each gripper pair 41, while supporting the right side portion of the bag W (for example, a portion with a simple shape away from the bag opening (for example, a portion with an edge that extends linearly in the height direction)) with the right support portion 202.

[0042] Furthermore, of the gripper pairs 41 provided adjacent to each other, the right support portion 202 of one gripper pair 41 (first gripper pair 41a) and the left support portion 201 of the other gripper pair 41 (second gripper pair 41b) may be provided to partially overlap each other in the height direction. In other words, by providing the left support portion 201 and the right support portion 202 so that the projection in the height direction of the right support portion 202 of one gripper pair 41 (first gripper pair 41a) and the projection in the height direction of the left support portion 201 of the other gripper pair 41 (second gripper pair 41b) partially overlap each other, it is possible to effectively utilize horizontal space.

[0043] In one modified example of the gripper pairs (i.e., the first gripper pair 41a and the second gripper pair 41b) shown in FIG. 23, the entire left support portion 201 that grips the left side portion Wl of each bag W is positioned higher than the entire right support portion 202 that grips the right side portion Wr. In the example shown in FIG. 23, the left support portions 201 between the gripper pairs are positioned at the same height, and the right support portions 202 are also positioned at the same height. The bag W illustrated in FIG. 23 has an openable / closable bag opening formed at the top Wt and a foldable portion formed at the bottom Wb. By unfolding the foldable portion of the bottom Wb, the volume of the bag W can be increased and the bag W can be placed in a self-standing state.

[0044] For example, if the height positions of the left support portion 201 and the right support portion 202 between adjacent gripper pairs 41 are the same, these gripper pairs 41 must be installed horizontally apart from each other, which makes it impossible to effectively utilize the horizontal space. This can lead to an increase in the horizontal size of the bag transfer device 500. Furthermore, in order to reduce the horizontal size of such a bag transfer device 500, it is necessary to reduce the number of gripper pairs 41.

[0045] On the other hand, when the right support portion 202 (first gripper pair 41a) and the left support portion 201 (second gripper pair 41b) of adjacent gripper pairs 41 partially overlap each other in the height direction, the size of the horizontal space required to install the gripper pairs 41 does not necessarily depend on the size of the horizontal space required for the support portions 201, 202, and the horizontal space can be used effectively (see FIG. 23). This makes it possible, for example, to reduce the horizontal size of the bag transfer device 500 or increase the number of gripper pairs 41. In addition, by adjusting the spacing between the support portions 201, 202 of each gripper pair 41, bags W of various widths can be held and transferred without changing the overall size of the bag transfer device 500, and it is also possible to increase the maximum width of bags W that can be handled compared to conventional methods.

[0046] The amount of misalignment in the height direction between the left support portion 201 and the right support portion 202 is not particularly limited. From the viewpoint of avoiding unintended collisions between the left support portion 201 and the right support portion 202, it is preferable to provide a sufficient amount of space in the height direction between the left support portion 201 and the right support portion 202. On the other hand, from the viewpoint of achieving good symmetry in the behavior of the bag W when each gripper pair 41 opens and closes the bag W, it is preferable that the height positions of the left support portion 201 and the right support portion 202 are as close as possible. Typically, a misalignment in the height direction between the left support portion 201 and the right support portion 202 of about 0.3 cm to 5 cm can effectively avoid unintended collisions between the left support portion 201 and the right support portion 202 and often achieve good symmetry in the behavior of the bag W when each gripper pair 41 opens and closes.

[0047] The above-described advantages are particularly effective when the bag W is supported by "clamping the bag W" in the bag transfer device 500. In other words, when the left support portion 201 of each gripper pair 41 supports one side of the bag W by clamping it, and the right support portion 202 supports the other side of the bag W by clamping it, it is possible to effectively enjoy the advantages obtained by "one of the right support portion 202 of the first gripper pair 41a and the left support portion 201 of the second gripper pair 41b being positioned higher than the other."

[0048] For example, when holding a bag W by vacuum-suctioning the side of the bag W, the installation position of the vacuum suction device (holding unit) has a relatively large degree of freedom, and it is possible to hold the bag W by the vacuum suction device without the vacuum suction device protruding horizontally from the side edge of the bag W or with the vacuum suction device protruding only slightly. In such cases, even if adjacent holding units are installed at the same height, it may be possible to position the holding units sufficiently close to each other horizontally. On the other hand, when holding a bag W by clamping its side, the horizontally extending clamping body (gripper (e.g., arm 42, gripping member 43, and gripping member 44)) often protrudes horizontally a considerable amount from the side edge of the bag W. In such cases, by using the bag transfer device 500 of the present embodiment described above, it is possible to effectively and appropriately support bags W having various side shapes and reduce the impact of the horizontal size of the clamping body on the horizontal space of the entire device.

[0049] The present invention is not limited to the above-described embodiments and modifications. For example, various modifications may be made to the elements of the above-described embodiments and modifications. Furthermore, the configurations of the above-described embodiments and modifications may be combined in whole or in part. [Explanation of symbols]

[0050] 1 sprocket, 2 guide portion, 3 fixed guide member, 4 linear guide member, 5 sub-machine base, 6 endless chain, 7 link, 9 connecting shaft, 10 bearing, 11 inner guide roller, 12 upper guide roller, 13 lower guide roller, 14 bracket, 15 mounting portion, 16 support member, 17 slide rail, 19 slide member, 20 guide plate, 21 upper roller guide portion, 22 lower roller guide portion, 23 guide groove, 24 spring receiving member, 28 sprocket mounting plate, 29 machine base, 31 recess, 32 recess, 33 support groove, 34 stand, 35 second hollow shaft, 36 gear, 37 inner guide rail, 38 upper guide rail, 39 lower guide rail, 41 gripper pair, 41a first gripper pair, 41b second gripper pair, 42 arm, 43 Grip member, 44 Grip member, 45 Fixed shaft, 46 Sliding cylinder, 49 Spring seat, 50 Pin, 51 Connecting pin, 52 Link, 53 Connecting pin, 54 Mounting block, 55 Swing fulcrum shaft, 56 Mounting block, 57 Holder, 59 Cylindrical portion, 60 Mounting portion, 61 Lever, 62 Lever, 63 Lever, 64 Cylindrical member, 65 Lever, 66 Lever, 67 Cylindrical member, 69 Cam roller, 69a Upper roller, 69b Lower roller, 70 Support pin, 71 Bush, 72 Support pin, 73 Connecting shaft, 74 Holder pin, 75 Bush, 77 Fulcrum shaft, 79 Opening / closing lever, 80 Opening / closing roller, 81 Support shaft, 82 Pressing roller, 83 Operating member, 84 Contact portion, 85 Stopper pin, 86 Opening and closing member, 87 pressing portion, 89 opening and closing plate, 90 sliding member, 91 mounting plate, 92 slide rail, 93 cam, 94 cam drive shaft, 95 lever, 96 cam roller, 97 fulcrum shaft, 99 lever, 100 connecting rod, 101 bag feeding and transferring device, 102 spacing adjustment cam, 103 spacing adjustment cam, 104 spacing adjustment cam, 105 spacing adjustment cam, 106 spacing adjustment cam, 107 adjusting drive shaft, 107 adjusting shaft, 108 adjusting shaft, 109 adjusting shaft, 110 adjusting shaft, 111 adjusting drive shaft, 112 adjusting shaft, 113 adjusting shaft, 114 sprocket, 115 chain, 116 nut member, 117 bracket, 119 gear, 120 gear, 121 cam abutment surface, 122 supporting stand, 123 Holder, 124 Adjustment shaft, 125Lever, 126 cam roller, 127 lever, 129 roller, 130 hole, 131 abutment member, 132 elongated hole, 134 cylindrical cam, 135 support member, 136 nut member, 137 rotating shaft, 139 small diameter gear, 140 large diameter gear, 141 pulley, 142 filling nozzle, 143 lifting member, 144 support member, 145 first hollow shaft, 146 cylindrical cam, 147 arc-shaped cam, 149 cam roller, 150 lever, 151 rotating cylinder, 156 endless chain, 157 link, 157a extension portion, 157b extension portion, 201 left support portion, 202 right support portion, 500 bag transfer device, t transfer trajectory, W bag, Wt top portion, Wb bottom portion, Wl Left lateral part, Wr right lateral part

Claims

1. a plurality of holding sections including a first holding section and a second holding section arranged adjacent to each other in a horizontal direction, the plurality of holding sections being movably arranged; each of the plurality of holding portions includes a left support portion that supports one side portion of the bag and a right support portion that supports the other side portion of the bag; one of the right support portion of the first holding portion and the left support portion of the second holding portion is positioned higher than the other, A bag transfer device in which, in each of the first holding portion and the second holding portion, one of the left support portion and the right support portion is positioned higher than the other within a range of 0.3 cm to 5 cm.

2. 2. The bag transfer device according to claim 1, wherein the entirety of one of the right support portion of the first holding portion and the left support portion of the second holding portion is positioned higher than the entirety of the other.

3. 3. The bag transfer device according to claim 1, wherein the right support portion of the first holding portion and the left support portion of the second holding portion overlap each other in the height direction.

4. A bag transfer device as described in any one of claims 1 to 3, wherein the left support portion supports one of the side portions of the bag by clamping it, and the right support portion supports the other side portion of the bag by clamping it.

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