Banding module for a converting machine

Abstract

The present invention relates to a banding module (34) for applying bands around stacks (S) of sheet elements (2'). The banding module comprises a first and a second lateral guides (130a, 130b) configured to contact and guide lateral sides of 5 the stack as it is introduced into the banding module. Each guide comprises a gap (G) which is aligned with a banding zone and allowing a band to pass through the gap and contact the stack.

Description

[0001] BANDING MODULE FOR A CONVERTING MACHINE

[0002] Field of the invention

[0003] The present invention relates to a banding module for a converting machine. In particular, it relates to a banding module suitable for conditioning stacks of folding boxes and other packaging items into bundles attached by bands.

[0004] Background

[0005] Converting machines such as folder-gluers are used in the production of paperboard and cardboard boxes. These machines are configured to receive cut- to-shaped blanks and then fold and glue them to form folding boxes or other similar packaging containers.

[0006] The folder-gluer machine often comprises a conditioning section. The conditioning section is located at an outlet portion of the converting machine and is configured to arrange batches of folding boxes or packaging elements either in receptables (such as a box) or apply bands around a stack of packaging elements.

[0007] When using a banding module, it is important that the stack of boxes to be banded together has an aligned and stable shape before the band is applied. When stacking and banding larger boxes (such as corrugated cardboard boxes), the boxes may be placed vertically above each other. However, for smaller boxes such as pharmaceutical boxes, it is common to instead arrange the boxes in a horizontal stack. A horizontal stack S of boxes is instable and is difficult to maintain in a cubical shape.

[0008] An example of a banding module is disclosed in document EP3984896. However, as the horizontal stack of folding boxes is introduced into the banding module, it has a tendency to open up in a fan-shape.

[0009] Summary

[0010] In view of the prior art, it is an object of the present invention to prevent the alteration of the shape of the stack of packaging elements before the band is applied around the stack S in the banding module. This object is solved by a banding module according to claim 1 and a converting machine according to claim 6.

[0011] According to a first aspect of the present invention, there is provided a banding module for applying bands around stacks of sheet elements, the banding module comprising a support surface, and a band guide defining a banding zone located vertically below said band guide.

[0012] The banding module further comprises a first lateral guide and a second lateral guide configured to contact lateral sides of the stack as it is introduced into the banding module, and wherein a gap is formed in each the first and second lateral guides.

[0013] A first and second movable central guide surface are positioned in each respective gap, the central guide surfaces being movable between a closed position in which a 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 the lateral sides of the stack as the stack is transported into the banding zone, and an open position in which a band can move from the belt guide and contact the stack of sheet elements without touching the first and second central guide surfaces.

[0014] The invention is based on a realization that discontinuous lateral guides can be provided, while allowing the lateral sides of the stack to be continuously guided during the introduction of the stack into the banding module.

[0015] The stack may comprise sheet elements such as horizontally stacked folding boxes. The term “horizontally stacked” means that the sheet elements are arranged side by side in the horizontal direction.

[0016] The longitudinal extension of the first and second lateral guides coincides with the direction of transportation of the stack.

[0017] The gaps are thus preferably located vertically below the band guide.

[0018] In an embodiment, the first and second central guiding surfaces are pivotable doors. The banding module may further comprise an actuator connected to the pivotable doors and configured to move the pivotable doors between the open position and the closed position.

[0019] In an embodiment, the movable guiding surfaces are vertically movable surfaces, which are configured to be raised and lowered in the vertical direction.

[0020] Preferably, at least one of the lateral guides in the banding module is displaceable in a lateral direction, which is perpendicular to a direction of transportation of the stack through the banding module.

[0021] According to a second aspect of the present invention, there is provided a converting machine comprising a banding module according to any one of the preceding claims and a transfer module, wherein the transfer module comprises a receptacle having a stacking compartment and a first ejection mechanism, the first ejection mechanism being provided with an evacuation member having an ejection surface configured to move between a retracted position and an extended position, and wherein the transfer module further comprises a conveyor system configured to transfer the receptacle from a filling device to the banding module.

[0022] The movable guiding surfaces may be pivotable doors, and wherein the pivotable doors are opened upon a control signal provided by the transfer module.

[0023] The control signal may be provided when the front edge of the stack has passed the gap.

[0024] In an embodiment, the control signal is issued when the ejection surface of the receptacle is in the extended position.

[0025] In an embodiment, the band is placed around the stack when the first and second pivotable doors are open.

[0026] Brief description of the drawings

[0027] The invention will now be described with reference to the appended drawings, in which like features are denoted with the same reference numbers and in which:

[0028] Fig. 1 is a schematic view of a converting machine in the configuration of a folder gluer; Fig. 2a is schematic top view of a cut-to shaped blank;

[0029] Fig 2b is schematic top view of a folding box;

[0030] Fig. 3 is a schematic cross-sectional view of a filling device for folding boxes;

[0031] Fig. 4 is a schematic diagram of the filling device of figure 3 and together with a conveying system according to an embodiment of the present invention;

[0032] Figs. 5a and 5b are schematic perspective views of a banding module provided with lateral guides according to an embodiment of the present invention;

[0033] Figs. 6a and 6b are schematic diagrams showing how a band can be applied around a stack of folding boxes,

[0034] Fig. 7 is a schematic perspective view of a receptacle according to an embodiment of the present invention;

[0035] Figs. 8a and 8b are schematic perspective views of the receptacle of figure 7 with an ejection surface in a retracted and extended position, respectively; and

[0036] Fig. 9 is a schematic perspective view of the receptacle when delivering a stack of folding boxes to a banding machine.

[0037] Detailed description

[0038] The present invention can be used in converting machines like for instance folder- gluers and rotary die-cutter machines. In order to simplify the present description, reference is made to a folder-gluer machine.

[0039] Referring to the figures and in particular to figures 1 and 2a, which illustrate a folder-gluer machine 1 and a blank 2 to be processed therein. The folder-gluer machine 1 is configured to receive the cut- to-shaped blank 2, and then fold and glue the blank 2 to form a folding box 2’ or other folded and glued packaging containers. These types of packaging containers 2’ are provided in a sheet form at the outlet portion of the folder-gluer machine 1 . The blanks 2 are conveyed along a transportation path P through the converting machine 1.

[0040] The folder-gluer machine 1 comprises a series of different workstations in the form of modules. The modules may include, from an inlet to an outlet and in a direction of transportation T: a feeder module 10, an alignment module 11 , a fold prebreaking module 12, a gluing module 14 and a folding module 16. The folder-gluer machine 1 may further comprise a main user interface 13.

[0041] Downstream of the gluing and folding modules 14, 16, the converting machine 1 may further comprise a delivery section 20 configured to bundle or group a plurality of folding boxes 2’ together. The delivery section 20 may comprise an accumulation conveyor 22 and a filling device 24 configured to arrange the folding boxes 2’ in vertical stacks S. The vertical stack comprises a plurality of folding boxes 2’ arranged side by side in the horizontal direction H.

[0042] The filling device 24 is located downstream of the accumulation conveyor 22. The accumulation conveyor 22 is configured to rearrange individual and spaced apart folding boxes 2’ into a shingled stream of folding boxes 2’.

[0043] As best seen in figure 3, the accumulation conveyor 22 directs the folding boxes 2’ into a curvilinear conveyor 26 in the filling device 24. The filling device 24 comprises an insertion head 28 which can be positioned inside a receptacle 40 suitable for containing a batch of folding boxes 2’.

[0044] Such a filling device and system are described in document EP1989115. However, the system disclosed in EP1989115 is configured to fill receptacles such as cardboard boxes with folding boxes 2’. However, the conditioning section 20 according to the present disclosure is configured to attach bands around stacks of folding boxes 2’. The filling device 24 is part of a filling system 30 which further includes a transfer module 32 configured to collect a horizontal stack S of folding boxes 2’ and position the stack S in a banding module 34.

[0045] As best seen in figures 4, 7 and 9, the transfer module 32 comprises at least one receptacle 40 configured to receive a stack S of folding boxes 2’ and a conveyor system 38 configured to transfer the receptacle 40 between the filling device 24 and the banding module 34. The conveyor system 38 comprises an introduction conveyor 39 which forms a straight introduction path to the banding module 34. As best seen in figure 7, the receptacle 40 comprises a stacking compartment 42 and a first ejection mechanism 44. The receptable 40 is preferably a passive device and can be deprived from any motor or drive device fixedly connected to it. The conveyor system 38 is configured to move the receptacle 40 along a continuous transportation path. Hence, the receptacle 40 may be circulated between the filling device 24 and the banding module 34.

[0046] The stacking compartment 42 comprises a stacking surface 43, a first lateral edge 46 and a second lateral edge 48. The lateral edges 46, 48 are configured to retain the stack S of horizontally stacked folding boxes 2’. The first lateral edge 46 may be fixed. Preferably, the second lateral edge 48 is laterally displaceable. In such a way, the width W of the stacking compartment 42 can be changed in a lateral direction L, which is perpendicular to the direction of transportation T of the receptacle. This allows a variation of the number of folding boxes 2’ to be included in the stack S.

[0047] As best seen in figures 7, 8a and 8b, the first ejection mechanism 44 comprises an evacuation member 50 and a return mechanism 52. The evacuation member 50 comprises an ejection surface 54 which 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 a stack S of folding boxes 2’. When the ejection surface 54 is in the extended position, the stack S is pushed out from the stacking compartment 42.

[0048] The evacuation member 50 comprises a slider 56 connected to a cooperating slide rail 58 on the first lateral edge 46 of the stacking compartment 42. The slider 56 further comprises an engagement portion 60 configured to releasably and momentarily engage with a connection member 62 of a second ejection mechanism 64.

[0049] The first ejection mechanism 44 is thus configured to be activated by the second ejection mechanism 64 upstream of the banding module 34.

[0050] As best seen in figures 8a and 8b, the second ejection mechanism 64 comprises a connection mechanism 66 and a linear displacement device 68. The second ejection mechanism 64 is preferably positioned laterally of the introduction conveyor 39 of the conveyor system 38 and thus upstream of the banding module 34.

[0051] The connection mechanism 66 comprises a connection actuator 70 in the form of a cylinder provided with a piston rod 71. A connection head 62 is provided on a free end of the piston rod 71 . The connection head 62 has a cooperating shape to the engagement portion 60 in the slider 56. The connection actuator 70 may for instance be a pneumatic actuator. The piston rod 71 can be extended such that the connection head 62 is received in the engagement portion 60 of the slider 56 and become mechanically connected to the slider 56. The piston rod 71 can be retracted when the evacuation member 50 has reached its extended position.

[0052] The engagement portion 60 in the slider 56 may be a cavity. The cavity 60 may be provided with a sloping engagement surface. The sloping engagement surface S allows the connection head 62 to release from the slider 56 when the evacuation member 50 reaches the extended position.

[0053] The connection mechanism 66 is attached to the linear displacement device 68, which is configured to move the connection head 62 in the direction of transportation T. As the connection head 62 is displaced, the slider 56 is also displaced with it in the same movement. As best seen in figure 8b, the linear displacement mechanism 68 may comprise a linear drive member 74 in the form of a drive piston 74. A first cylinder rod 76 and a second cylinder rod 78 are guiding rods configured to ensure a stable linear displacement of the connection mechanism 66.

[0054] The second ejection mechanism 64 connects to the first ejection mechanism 44 when the receptacle 40 is in a discharge position in relation to the banding module 34. The discharge position can be defined as a position in which the stacking surface 43 is in contact with or in close proximity with a support surface 80 of the banding module 34. The term “close proximity” may thus correspond to a distance where the stack of folding boxes 2’ can be transferred to the support surface 80 in the banding module 34.

[0055] The transfer module 32 further comprises a sensing element 65 which is configured to detect the passage of the receptacle 40. The sensing element 65 can be in the form of a switch 65. The sensing element 65 may be attached to a frame member 37 of the introduction conveyor 39 and may be displaced in the direction of transportation T. In such a way, the activation position of the connection member 62 can be calibrated.

[0056] The receptacle 40 preferably comprises a protrusion 67 which engages with the switch 65 whereby the switch senses the passage of the protrusion 67.

[0057] The return mechanism 52 of the first ejection mechanism 44 allows the ejection surface 54 to return to its retracted position (see figure 8a) and to form the stacking compartment 42. The retracted position is the resting position of the return mechanism 52.

[0058] The return mechanism 52 comprises a connection member 90 provided with a variable length, and a resilient member 92. The connection member 90 comprises a first distal end connected to a base 95 of the receptacle 40 and a second distal end connected to the slider 56. The connection member 90 is extended when the slider 56 is in the extended position and is retracted when the slider 56 is in the retracted position.

[0059] In an advantageous embodiment, the connection member 90 has an accordion structure. The accordion structure comprises a plurality of interconnected linear members 91 . The linear elements are attached to each other in a first external pivot joint 93a, a second external pivot joint 93b and a central pivot joint 93c.

[0060] The resilient member 92 is preferably a compression spring which is pre-tensioned such that the accordion structure is retracted when the resilient member 92 is in its resting position. The resilient member 92 may be a gas spring. The resilient member 92 is connected to a first and a second external pivot joints 93a, 93b. Alternatively, the resilient element may comprise a first and a second gas springs connected to pairs of different external pivot joints 93a, 93b in parallel.

[0061] The connection member 90 allows a long travel distance between the retracted position and the extended position in combination with a relatively short modification in length of the compression spring.

[0062] Referring back to figure 4, the conveyor system 38 is configured to transport the receptacle 40 from a loading area LA of the filling device 24 to the banding module 34. The conveyor system 38 may simultaneously convey a plurality of receptacles 40 along a rotational path. Hence, the receptacles 40 are circulated around from the filling device 24 to the banding module 34. The conveyor system 38 comprises a plurality of conveyors which may be arranged to form a square or rectangular path.

[0063] The conveyor system 38 may comprise a combination of roller conveyors and belt conveyors. The rollers conveyors are preferably provided with a low friction coefficient. In such a way, the rollers can convey the receptacle 40 in the direction of transportation T, while allowing a sliding lateral positioning of the receptacle 40.

[0064] A lateral alignment guide 100 may be positioned along an introduction path to the banding module 34. The introduction path may correspond to a straight introduction conveyor 39 located immediately upstream of the banding module 34. The alignment guide 100 preferably comprises an obliquely arranged portion and may further comprise a straight portion. The alignment guide 100 directs the receptacle 40 against a side edge of the introduction conveyor 39. The receptacle 40 is thus guided along a predefined path in-between the lateral alignment guide 100 and an opposite lateral edge 41 of the introduction conveyor 39.

[0065] The loading area LA may comprise superposed conveyors, where the superposed conveyors are configured to transport the receptacle 40 in perpendicular directions in relation to each other. A first conveyor may comprise a plurality of elongated rollers, and a second conveyor located vertically above the first conveyor may comprise a plurality of linear bars configured to grasp and move the receptacle 40 in the lateral direction L to position the receptacle 40 in the introduction path to the banding module 34.

[0066] As illustrated in figures 5a, 5b, 6a and 6b, the banding module 34 is configured to apply a circular band 120 around the stack S of folding boxes 2’.

[0067] The banding module 34 comprises a support surface 80 configured to receive the stack S of folding boxes 2’ from the transfer module 32. The support surface 80 can be a low-friction support surface, such as a metallic surface. To this effect, the stack S of folding boxes 2’ can be conveyed into the banding module 34 when the ejection surface 54 is in its extended position, as the stack S can slide on the support surface 80. Alternatively, in a non-illustrated embodiment, the support surface 80 can be formed by a conveyor, such as a belt conveyor. The banding module 34 may comprise a roll 124 with a strip-like material such as a band 120. The banding module 34 further comprises a band guide 126 configured to direct the band 120 around the stack S of folding boxes 2’. The band guide 126 enables the band 120 to form a loop around the stack S. The band guide 126 comprises a band channel with an inlet opening and an outlet opening. The band guide 126 holds the loop into shape but enables the band 120 to move vertically out from the band guide 126 when the band 120 is tensioned. A banding zone Z is located in a central portion of the support surface 80, and in particular vertically below the band guide 126.

[0068] The band 120 is unwound from the roll 124 by a conveying mechanism which may comprise a belt drive roller and a counter roller (not illustrated). The band 120 is pinched in-between the drive roller and the counter roller such that traction from the drive roller is conveyed to the band. The conveying mechanism preferably comprises a plurality of diverting rollers configured to guide the conveying path of the band 120.

[0069] Before the formation of a loop, the beginning of the band 120 is fixedly held with a clamping mechanism. The loop is initially corresponding to the size of the band guide 126 and is therefore larger than the circumference of the stack S. The conveying mechanism first forms the loop and then reduces the size of the loop by pulling back the band 120. The belt drive roller may thus be rotated in a first direction to form the loop and then rotated in a second direction (opposite from the first direction) to pull back the band 120 such that the loop reduces in size and encircles the stack S in a snug manner.

[0070] Thereafter, the band 120 is adhesively bonded or welded to form a closed ring. A cutting device cuts the final loop off from the remaining band 120 connected to the roll 124. This type of band mechanism is commonly known in the prior art and is further described in the document EP3984896.

[0071] As the stack S is ejected from the stacking compartment 42, it tends to open up and fall apart if the lateral sides of the stack S are no longer supported.

[0072] As illustrated in figures 5a and 5b, the banding module 34 therefore comprises a first lateral guide 130a and a second guide 130b. The lateral guides 130a, 130b each comprise an inlet guide surface 135 and an outlet guide surface 136. The guide surfaces 135, 136 retain the lateral edges of the stack S as the stack S is transferred into the banding zone Z.

[0073] A gap G is located between the inlet guide surface 135 and the outlet guide surface 136. The gap G is located in the banding zone Z and allows the band 120 to move in a vertical direction V towards the stack and contact the stack S without interfering with the first and second lateral guides 130a, 130b. The inlet guide surface 135 and outlet guide surface 135 of the banding module 34 also hold the stack S in shape while the band 120 is applied around the stack.

[0074] The inlet and outlet guide surfaces 135, 136 are preferably aligned with the first and second lateral guides 46, 48 of the stacking compartment 42. Preferably, at least one of the first and second lateral guides 130a, 130b is laterally movable such that it can be aligned with the movable lateral guide 48 of the stacking compartment 42.

[0075] In such a way, the first and second lateral guides 46, 48 of the stacking compartment 42 and the first and second lateral guides 130a, 130b of the banding module 34 cooperate to create continuous lateral guides for the stack S in the direction of transportation T.

[0076] The first and second lateral guides 130a, 130b in the banding module each further comprises a movable central guide surface 137 arranged between the inlet guide surface 135 and the outlet guide surface 136. The central guide surfaces 137 are movable between a first position where the central guide surfaces 137 are aligned with the respective inlet guide surface 135 and the outlet guide surface 136, and a second position in which the central guide surfaces 137 are not are aligned with the respective inlet guide surface 135 and the outlet guide surface 136.

[0077] Hence in the first position, the central guide surfaces 137 are in contact with the lateral sides of the stack S. In the second position, the central guide surfaces 137 are not in contact with the stack, and a gap G is provided such that the band 120 can be looped and tensioned around the stack S.

[0078] The inlet guide surfaces 135 and the outlet guide surfaces 136 may be stationary, while the central guide surfaces 137 are movable. The movable central guide surface 137 may be configured as a pivotable door 137. The door 137 is opened when the stack S is stationary positioned in the banding module 34. Alternatively, the door 137 can be opened when the stack is contacted by the outlet guide surface 135. The door 137 can be opened and closed with an actuator, such as a pneumatic actuator.

[0079] The door 137 is opened upon the reception of a control signal. The control signal is issued when the presence of the stack is detected in the banding zone Z. The detection can be effectuated by an optical sensor, a contactless proximity sensor or a mechanical switch. In an embodiment, the control signal can be issued when a predetermined stroke length of the second ejection mechanism 64 is reached. The control signal may thus be issued from a signal provided by a mechanical switch.

[0080] The banding module further comprises a control circuitry 110 comprising a memory 112 and a control unit 114. The control unit is configured to activate the actuator to move open the first and second central guiding surfaces upon reception of the detection signal.

Claims

CLAIMS1. A banding module (34) for applying bands around stacks (S) of sheet elements (2’), the banding module comprising a support surface (80), and a band guide (126) defining a banding zone (Z) located vertically below said band guide, wherein the banding module further comprises a first lateral guide (130a) and a second lateral guide (130b) configured to contact lateral sides of the stack as it is introduced into the banding module, and wherein a gap (G) is formed in each the first and second lateral guides (130a, 130b), and wherein a first and second movable central guide surface (137) are positioned in each respective gap, the central guide surfaces being movable between a closed position in which a 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 the lateral sides of the stack as the stack is transported into the banding zone, and an open position in which a band (120) can move from the belt guide and contact the stack of sheet elements (2’) without touching the first and second central guide surfaces.

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

3. The banding 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 banding module according to claim 1 , wherein the movable guiding surfaces are vertically movable surfaces, which are configured to be raised and lowered in the vertical direction.

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

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

7. The converting machine according to the preceding claim, wherein the movable guiding surfaces are pivotable doors, and wherein the pivotable doors are opened upon 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 receptacle (40) is in the 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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