Bundling module for converter

Abstract

The invention relates to a strapping module (34) for applying a tape around a stack (S) of sheet elements (2 '). The strapping module includes first and second lateral guides (130a, 130b) configured to contact and guide lateral sides of the stack when the stack is introduced into the strapping module. Each guide includes a gap (G) that is aligned with the strapping area and allows the tape to pass therethrough into contact with the stack.

Description

Technical Field

[0001] This invention relates to a strapping module for a conversion machine. In particular, this invention relates to a strapping module suitable for adjusting the stacking of folding boxes and other packaged items into bundles connected by straps. Background Technology

[0002] Converter machines, such as folding glue machines, are used to produce cardboard and cardboard boxes. These machines are configured to receive cut blanks, then fold and glue them to form folding boxes or other similar packaging containers.

[0003] Folding adhesive machines typically include an adjustment section. The adjustment section is located at the exit section of the converter and is configured to arrange batches of folded boxes or packaging elements in containers (such as boxes) or to apply straps around stacks of packaging elements.

[0004] When using a strapping module, it is important that the stack of boxes to be strapped has an aligned and stable shape before the straps are applied. When stacking and strapping larger boxes (such as corrugated cardboard boxes), the boxes can be placed vertically, one on top of the other. However, for smaller boxes, such as medicine boxes, it is usually better to arrange the boxes horizontally instead. Horizontal stacking of boxes is unstable and makes it difficult to maintain a cubic shape.

[0005] An example of a strapping module is disclosed in document EP3984896. However, when a horizontal stack of folding boxes is introduced into the strapping module, it tends to open in a fan shape. Summary of the Invention

[0006] In view of the prior art, one object of the present invention is to prevent the shape of the stack of packaging elements from changing before the strap is applied around the stack S in the strapping module.

[0007] This objective is achieved by the strapping module according to claim 1 and the converter according to claim 6.

[0008] According to a first aspect of the invention, a strapping module for applying a strap around a stack of sheet elements is provided, the strapping module including a support surface and a strap guide defining a strapping area located vertically below the strap guide.

[0009] The strapping module also includes a first lateral guide and a second lateral guide configured to contact the lateral side of the stack when the stack is introduced into the strapping module, and a gap is formed in each of the first and second lateral guides.

[0010] First and second movable center guide surfaces are positioned in each corresponding gap. The center guide surfaces are movable between a closed position and an open position. In the closed position, the longitudinal extension of the center guide surface is aligned with the longitudinal extension of the first and second lateral guides, such that when the stack is transported to the strapping area, the center guide surface is configured to contact the lateral side of the stack. In the open position, the strap can move from the strap guide and contact the stack of sheet elements without contacting the first and second center guide surfaces.

[0011] The present invention is based on the understanding that discontinuous lateral guides can be provided while allowing continuous lateral guidance of the stack during the process of introducing the stack into the bundling module.

[0012] Stacking can include sheet elements, such as horizontally stacked folding boxes. The term "horizontally stacked" refers to sheet elements arranged side by side in a horizontal direction.

[0013] The longitudinal extension of the first and second lateral guides is aligned with the transport direction of the stack.

[0014] Therefore, the gap is preferably located vertically below the guide.

[0015] In one embodiment, the first and second central guide surfaces are pivotable doors.

[0016] The strapping module may also include an actuator that is connected to the pivotable door and configured to move the pivotable door between an open position and a closed position.

[0017] In one embodiment, the movable guide surface is a vertically movable surface configured to rise and fall in the vertical direction.

[0018] Preferably, at least one lateral guide in the strapping module is displaced in a lateral direction perpendicular to the transport direction of the stack through the strapping module.

[0019] According to a second aspect of the invention, a converter is provided, comprising a strapping module and a conveying module according to any one of the preceding claims, wherein the conveying module comprises a container having a stacking compartment and a first ejection mechanism having a venting member having an ejection surface configured to move between a retracted position and an extended position, and wherein the conveying module further comprises a conveying system configured to convey the container from a filling device to the strapping module.

[0020] The movable guide surface can be a pivotable door, and the pivotable door is opened under the control signal provided by the transfer module.

[0021] Control signals can be provided even when the front edge of the stack has passed through the gap.

[0022] In one implementation, a control signal is issued when the container's pop-out surface is in the extended position.

[0023] In one implementation, when the first and second pivotable doors are opened, the straps are placed around the stack. Attached Figure Description

[0024] The invention will now be described with reference to the accompanying drawings, wherein like features are indicated by like reference numerals, and wherein: - Figure 1 This is a schematic diagram of a converter configured for a folding adhesive machine; - Figure 2a It is a schematic top view of the cut and shaped blank; - Figure 2b This is a schematic top view of the folding box; - Figure 3 This is a schematic cross-sectional view of a filling device for a folding box; - Figure 4 yes Figure 3 A schematic diagram of a loading device and a conveying system according to an embodiment of the present invention; - Figure 5a and Figure 5b This is a schematic perspective view of a strapping module with lateral guides according to an embodiment of the present invention; - Figure 6 a and Figure 6 b is a schematic diagram illustrating how to apply a strip around the stack of folded boxes; - Figure 7 This is a schematic perspective view of a container according to one embodiment of the present invention; - Figure 8a and Figure 8b It refers to the state when the pop-out surface is in the retracted position and the extended position, respectively. Figure 7 A schematic perspective view of the container; and - Figure 9 This is a schematic perspective view of a container as a stack of folded boxes is delivered to a strapping machine. Detailed Implementation

[0025] This invention can be used in converters such as folding adhesive machines and rotary die-cutting machines. For the sake of simplicity, reference is made to a folding adhesive machine.

[0026] Refer to the accompanying drawings, and especially to... Figure 1 and Figure 2aThe diagram shows a folding adhesive machine 1 and a blank 2 to be processed therein. The folding adhesive machine 1 is configured to receive the cut blank 2, then fold and glue the blank 2 to form a folding box 2' or other folded and glued packaging container. These types of packaging containers 2' are arranged in sheet form at the exit section of the folding adhesive machine 1. The blank 2 is conveyed along the transport path P through a transfer machine 1.

[0027] The folding adhesive machine 1 includes a series of workstations in the form of different modules. From the inlet to the outlet and in the transport direction T, these modules may include: a feeder module 10, an alignment module 11, a folding pre-breaking module 12, a gluing module 14, and a folding module 16. The folding adhesive machine 1 may also include a main user interface 13.

[0028] Downstream of the gluing module 14 and the folding module 16, the converter 1 may further include a transport section 20 configured to bundle or aggregate a plurality of folded boxes 2' together. The transport section 20 may include a stacking conveyor 22 and a filling device 24 configured to arrange the folded boxes 2' in a vertical stack S. The vertical stack includes a plurality of folded boxes 2' arranged side by side in a horizontal direction H.

[0029] The filling device 24 is located downstream of the stacking conveyor 22. The stacking conveyor 22 is configured to rearrange the individually spaced folded boxes 2' into a shingled flow of folded boxes 2'.

[0030] like Figure 3 As shown in the best embodiment, the stacking conveyor 22 guides the folded boxes 2' into the curved conveyor 26 in the filling device 24. The filling device 24 includes an insert 28 that can be placed in a container 40 suitable for accommodating a batch of folded boxes 2'.

[0031] Such a filling device and system are described in document EP1989115. However, the system disclosed in EP1989115 is configured to fill containers such as cardboard boxes with folding boxes 2'. However, the adjusting portion 20 according to the invention is configured to attach straps around the stack of folding boxes 2'. The filling device 24 is part of a filling system 30, which also includes a conveying module 32 configured to collect the horizontal stack S of folding boxes 2' and position the stack S in a strapping module 34.

[0032] like Figure 4 , Figure 7 and Figure 9As shown, the conveying module 32 includes at least one container 40 configured to receive a stack S of folded boxes 2' and a conveying system 38 configured to convey the container 40 between the filling device 24 and the strapping module 34. The conveying system 38 includes an introduction conveyor 39 that forms a straight introduction path to the strapping module 34.

[0033] like Figure 7 As shown, container 40 includes stacking compartments 42 and a first ejection mechanism 44. Container 40 is preferably a passive device and can be separated from any motor or drive unit fixedly connected thereto. Conveying system 38 is configured to move container 40 along a continuous transport path. Therefore, container 40 can circulate between filling device 24 and strapping module 34.

[0034] The stacking compartment 42 includes a stacking surface 43, a first lateral edge 46, and a second lateral edge 48. The lateral edges 46 and 48 are configured to maintain the stack S of horizontally stacked folding boxes 2'. The first lateral edge 46 may be fixed. Preferably, the second lateral edge 48 may be laterally displaced. In this way, the width W of the stacking compartment 42 can be varied in a lateral direction L, which is perpendicular to the transport direction T of the container. This allows for variations in the number of folding boxes 2' included in the stack S.

[0035] like Figure 7 , Figure 8a and Figure 8b As shown, the first ejection mechanism 44 includes an emptying member 50 and a return mechanism 52. The emptying member 50 includes an ejection surface 54 that is movable between a retracted position and an extended position. When the ejection surface 54 is in the retracted position, the stacking compartment 42 is configured to receive and hold the stack S of the folded boxes 2'. When the ejection surface 54 is in the extended position, the stack S is ejected from the stacking compartment 42.

[0036] The evacuation member 50 includes a slider 56 connected to a mating rail 58 on a first lateral edge 46 of the stacking compartment 42. The slider 56 also includes an engagement portion 60 configured to releasably and momentarily engage with a connecting member 62 of the second ejection mechanism 64.

[0037] Therefore, the first ejection mechanism 44 is configured to be activated by the second ejection mechanism 64 upstream of the strapping module 34.

[0038] like Figure 8a and Figure 8b As best shown, the second ejection mechanism 64 includes a connecting mechanism 66 and a linear displacement device 68. The second ejection mechanism 64 is preferably positioned laterally to the inlet conveyor 39 of the conveying system 38, and thus upstream of the strapping module 34.

[0039] The connecting mechanism 66 includes a connecting actuator 70, which is in the form of a cylinder with a piston rod 71. A connector 62 is disposed on the free end of the piston rod 71. The connector 62 has a shape that mates with the engagement portion 60 in the slider 56. The connecting actuator 70 may be, for example, a pneumatic actuator. The piston rod 71 can be extended such that the connector 62 is received in the engagement portion 60 of the slider 56 and mechanically connected to the slider 56. When the venting member 50 reaches its extended position, the piston rod 71 can be retracted.

[0040] The engaging portion 60 in the slider 56 can be a cavity. The cavity 60 can be provided with an inclined engaging surface. This inclined engaging surface allows the connector 62 to be released from the slider 56 when the venting member 50 reaches the extended position.

[0041] A connecting mechanism 66 is attached to a linear shifting device 68, which is configured to move the connector 62 along the transport direction T. As the connector 62 shifts, the slider 56 also shifts in the same movement. Figure 8b As best shown, the linear displacement mechanism 68 may include a linear drive member 74 in the form of a drive piston 74. The first cylinder rod 76 and the second cylinder rod 78 are guide rods configured to ensure stable linear displacement of the connecting mechanism 66.

[0042] When container 40 is in the discharge position relative to strapping module 34, the second discharge mechanism 64 is connected to the first discharge mechanism 44. The discharge position can be defined as the location that contacts or is very close to the stacking surface 43 and the support surface 80 of strapping module 34. Therefore, the term "very close" can correspond to the distance at which the stack of folding box 2' can be transferred to the support surface 80 in strapping module 34.

[0043] The conveying module 32 also includes a sensing element 65 configured to detect the passage of the container 40. The sensing element 65 may be in the form of a switch 65. The sensing element 65 may be attached to the frame member 37 introduced into the conveyor 39 and may be displaced in the transport direction T. In this way, the activation position of the connecting member 62 can be calibrated.

[0044] The container 40 preferably includes a protrusion 67 that engages with a switch 65, whereby the switch senses the passage of the protrusion 67.

[0045] The return mechanism 52 of the first ejection mechanism 44 allows the ejection surface 54 to return to its retracted position (see...). Figure 8a This forms a stacked compartment 42. The retracted position is the rest position of the return mechanism 52.

[0046] The return mechanism 52 includes a connecting member 90 with a variable length and an elastic member 92. The connecting member 90 includes a first distal end connected to a base 95 of the container 40 and a second distal end connected to a slider 56. The connecting member 90 extends when the slider 56 is in the extended position and retracts when the slider 56 is in the retracted position.

[0047] In an advantageous embodiment, the connecting member 90 has an accordion structure. The accordion structure includes a plurality of interconnected linear members 91. The linear members are attached to each other in a first outer pivot joint 93a, a second outer pivot joint 93b, and a central pivot joint 93c.

[0048] The elastic member 92 is preferably a compression spring, which is pre-tensioned such that the folding structure retracts when the elastic member 92 is in its rest position. The elastic member 92 may be a gas spring. The elastic member 92 is connected to a first outer pivot joint 93a and a second outer pivot joint 93b. Alternatively, the elastic element may include a first gas spring and a second gas spring, which are connected to a pair of parallel, different outer pivot joints 93a, 93b.

[0049] The connecting member 90 allows for a longer travel distance between the retracted and extended positions, while the change in the length of the compression spring is relatively short.

[0050] Return to reference Figure 4 The conveying system 38 is configured to transport containers 40 from the loading area LA of the filling device 24 to the strapping module 34. The conveying system 38 can simultaneously convey multiple containers 40 along a rotating path. Therefore, the containers 40 circulate from the filling device 24 to the strapping module 34. The conveying system 38 includes multiple conveyors, which can be arranged to form a square or rectangular path.

[0051] The conveying system 38 may include a combination of roller conveyors and belt conveyors. The roller conveyor preferably has a low coefficient of friction. In this way, the rollers can transport the container 40 in the transport direction T while allowing for lateral positioning of the container 40 in a sliding manner.

[0052] The lateral alignment guide 100 can be positioned along an introduction path to the strapping module 34. This introduction path can correspond to a straight introduction conveyor 39 located immediately upstream of the strapping module 34. The alignment guide 100 preferably includes an inclined portion and may also include a straight portion. The alignment guide 100 abuts against the side edge of the introduction conveyor 39 to guide the container 40. Therefore, the container 40 is guided along a predetermined path between the lateral alignment guide 100 and the opposite lateral edges 41 of the introduction conveyor 39.

[0053] The loading area LA may include stacked conveyors configured to transport container 40 in a direction perpendicular to each other. A first conveyor may include a plurality of elongated rollers, and a second conveyor located vertically above the first conveyor may include a plurality of linear rods configured to grip and move container 40 in a lateral direction L to position container 40 in an introduction path to strapping module 34.

[0054] like Figure 5a , Figure 5b , Figure 6 a and Figure 6 As shown in b, the strapping module 34 is configured to apply a circular strap 120 around the stack S of the folded box 2'.

[0055] The strapping module 34 includes a support surface 80 configured to receive a stack S of folded boxes 2' from the conveying module 32. The support surface 80 may be a low-friction support surface, such as a metallic surface. Therefore, when the pop-out surface 54 is in its extended position, the stack S of folded boxes 2' can be conveyed into the strapping module 34 because the stack S can slide on the support surface 80. Alternatively, in embodiments not shown, the support surface 80 may be formed by a conveyor (e.g., a belt conveyor).

[0056] The strapping module 34 may include a roller 124 with a strip material (e.g., strap 120). The strapping module 34 also includes a strap guide 126 configured to guide the strap 120 around the stack S of the folded box 2'. The strap guide 126 enables the strap 120 to form a loop around the stack S. The strap guide 126 includes a strap channel having an inlet opening and an outlet opening. The strap guide 126 holds the loop in shape but allows the strap 120 to be vertically removed from the strap guide 126 when tensioned. The strapping area Z is located at the center of the support surface 80, specifically vertically below the strap guide 126.

[0057] The belt 120 is unwound from the drum 124 via a conveying mechanism, which may include a drive roller and an opposing roller (not shown). The belt 120 is clamped between the drive roller and the opposing roller, such that the traction force from the drive roller is transmitted to the belt. The conveying mechanism preferably includes a plurality of guide rollers configured to guide the conveying path of the belt 120.

[0058] Before the loop is formed, the initial portion of the tape 120 is held securely by a clamping mechanism. This loop initially corresponds to the dimensions of the tape guide 126 and is therefore larger than the circumference of the stack S. The conveying mechanism first forms the loop and then reduces its size by pulling the tape 120 back. Thus, the tape drive roller can rotate in a first direction to form the loop and then rotate in a second direction (opposite to the first direction) to pull the tape 120 back, causing the loop to shrink and snug around the stack S.

[0059] Subsequently, the strap 120 is glued or welded to form a closed loop. A cutting device cuts the final loop from the remaining strap 120 attached to the roller 124. This type of strapping mechanism is known in the prior art and is further described in document EP3984896.

[0060] When stack S is ejected from stack compartment 42, stack S tends to open and disintegrate if the lateral side of stack S is no longer supported.

[0061] like Figure 5a and Figure 5b As shown, the strapping module 34 therefore includes a first lateral guide 130a and a second guide 130b. Both lateral guides 130a and 130b include an inlet guide surface 135 and an outlet guide surface 136. When the stack S is transferred into the strapping area Z, the guide surfaces 135 and 136 hold the lateral edges of the stack S.

[0062] The gap G is located between the inlet guide surface 135 and the outlet guide surface 136. The gap G is located within the strapping area Z and allows the strap 120 to move vertically V toward the stack and contact the stack S without interfering with the first lateral guide 130a and the second lateral guide 130b. When the strap 120 is applied around the stack, the inlet guide surface 135 and the outlet guide surface 135 of the strapping module 34 also maintain the shape of the stack S.

[0063] The inlet guide surface 135 and the outlet guide surface 136 are preferably aligned with the first lateral guide 46 and the second lateral guide 48 of the stacking compartment 42. Preferably, at least one of the first lateral guide 130a and the second lateral guide 130b is laterally movable such that it can be aligned with the movable lateral guide 48 of the stacking compartment 42.

[0064] In this way, the first lateral guide 46 and the second lateral guide 48 of the stacking compartment 42 and the first lateral guide 130a and the second lateral guide 130b of the strapping module 34 cooperate to create continuous lateral guidance for the stack S in the transport direction T.

[0065] Each of the first lateral guide 130a and the second lateral guide 130b in the strapping module further includes a movable central guide surface 137 disposed between the inlet guide surface 135 and the outlet guide surface 136. The central guide surface 137 is movable between a first position, in which the central guide surface 137 is aligned with the corresponding inlet guide surface 135 and the outlet guide surface 136, and in a second position, in which the central guide surface 137 is not aligned with the corresponding inlet guide surface 135 and the outlet guide surface 136.

[0066] Therefore, in the first position, the central guide surface 137 contacts the lateral side of the stack S. In the second position, the central guide surface 137 does not contact the stack, and a gap G is provided so that the tape 120 can loop around the stack S and be tensioned.

[0067] The inlet guide surface 135 and the outlet guide surface 136 can be stationary, while the center guide surface 137 is movable.

[0068] The movable center guide surface 137 can be configured as a pivotable door 137. The door 137 is open when the stack S is stationary in the strapping module 34. Alternatively, the door 137 can be opened when the stack contacts the outlet guide surface 135. The door 137 can be opened and closed using an actuator (e.g., a pneumatic actuator).

[0069] Door 137 opens upon receiving a control signal. A control signal is issued when the presence of a stack is detected in the bundling area Z. Detection can be achieved using an optical sensor, a non-contact proximity sensor, or a mechanical switch.

[0070] In one embodiment, a control signal can be issued when the predetermined stroke length of the second ejection mechanism 64 is reached. Therefore, the control signal can be issued based on the signal provided by the mechanical switch.

[0071] The strapping module also includes a control circuit 110, which includes a memory 112 and a control unit 114. The control unit is configured to activate an actuator upon receiving a detection signal to move and open the first and second center guide surfaces.

Claims

1. A strapping module (34) for applying a strap around a stack (S) of sheet elements (2'), the strapping module comprising a support surface (80) and a strap guide (126) defining a strapping zone (Z) vertically below the strap guide, wherein the strapping module further comprises a first lateral guide (130a) and a second lateral guide (130b) configured to contact lateral sides of the stack as the stack is introduced into the strapping module, and wherein a gap (G) is formed in each of the first and second lateral guides (130a, 130b), and wherein a first and a second movable central guide surface (137) is positioned in each respective gap, the central guide surfaces being movable between a closed position in which the longitudinal extension of the central guide surfaces is aligned with the longitudinal extension of the first and second lateral guides and such that the central guide surfaces are configured to contact lateral sides of the stack as the stack is transported into the strapping zone, and an open position in which a strap (120) can be moved from the strap guide and contact the stack of sheet elements (2') without contacting the first and second central guide surfaces.

2. The strapping module according to claim 1, wherein the first and second central guide surfaces (137) are pivotable doors.

3. The strapping module according to claim 2, further comprising an actuator (82) connected to the pivotable doors and configured to move the pivotable doors between the open position and the closed position.

4. The strapping module according to claim 1, wherein the movable guide surfaces are vertically movable surfaces configured to be raised and lowered in a vertical direction.

5. The strapping module according to any one of the preceding claims, wherein at least one of the lateral guides (130a, 130b) in the strapping module is displaceable in a lateral direction (L) perpendicular to the direction of transport (T) of the stack through the strapping module.

6. A converting machine (1) comprising a strapping module (34) according to any one of the preceding claims and a transfer module (32), wherein the transfer module (32) comprises a container (40) having a stack compartment (42) and a first ejection mechanism (44) provided with an evacuation member (50) having an ejection surface (54) configured to be moved between a retracted position and an extended position, and wherein the transfer module further comprises a transfer system (38) configured to transfer the container from a filling device (24) to the strapping module (34).

7. The converting machine according to the preceding claim, wherein the movable guide surfaces are pivotable doors, and wherein the pivotable doors are opened under a control signal provided by the transfer module.

8. The converting machine according to the preceding claim, wherein the control signal is provided when the front edge of the stack has passed the gap (G).

9. The converting machine according to any one of claims 6 to 8, wherein the control signal is issued when the ejection surface (54) of the container (40) is in an extended position.

10. The converting machine according to any one of claims 6 to 9, wherein the band is placed around the stack (S) when the first and second pivotable doors (137) are open.

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