Feeder module for conversion machine

Abstract

The invention relates to a feeder module (12) for a conversion machine (1), the feeder module being configured to allow only sheets at the lowest position in a stack to be conveyed under a front stop at a time. The feeder module comprises a suction rod (28) configured to apply suction to an underside of the sheet and guide the sheet under the front stop, and wherein the suction rod comprises a first set of air ports (36) configured to apply suction to the sheet and a second set of air ports (40) configured to blow the sheet.

Description

TECHNICAL FIELD

[0001] The present invention relates to a feeder module for a converting machine. In particular, the present invention relates to a feeder module suitable for feeding sheets one by one into a converting machine. BACKGROUND

[0002] Converting machines, such as folder gluers and rotary die cutters, are used in the production of paperboard and carton boxes. These machines are configured to produce sheets into packaging elements, such as flat carton and folding boxes.

[0003] These converting machines comprise a plurality of different working modules, which can print, cut and score, and sometimes glue and fold, the sheets, thereby producing boxes or packaging elements.

[0004] These converting machines typically comprise a feeder module, which is designed to receive a stack of sheets on a loading surface and to feed the sheets one by one into the converting machine.

[0005] Sometimes, pre-printed sheets are placed in the feeder and further processed in the converting machine by cutting, scoring and sometimes by gluing and folding. The pre-printed sheets are often conveyed with the printed side facing down.

[0006] The feeder module is provided with a counter and a small gap to allow only one sheet to be discharged at a time. In addition, the feeder module comprises a drive belt or drum, which is configured to push the sheets forward by friction. The restriction at the counter and the drive drum often causes the underside of the sheets in contact with the drive belt or drum to be rubbed and damaged. In particular, if the underside of the sheets is pre-printed when placed in the feeder module, the printed pattern on the sheets can be damaged. SUMMARY

[0007] In view of the prior art, it is an object of the present invention to provide an improved feeder module, in which deformation marks are prevented.

[0008] This object is solved by a feeder module according to claim 1.

[0009] According to a first aspect of the present invention, there is provided a feeder module for a converting machine, the feeder module comprising: a loading surface configured to receive a stack of sheets, a front stop configured to abut against a front edge of the stack and to allow only the lowest positioned sheet in the stack to be conveyed under the front stop at a time, a drive element configured to move the lowest positioned sheet in the stack under the front stop and forward in a transport direction, Furthermore, the feeder module includes a suction rod configured to apply suction to the underside of the lowest-positioned sheet and guide the lowest-positioned sheet under a front stop. The suction rod includes a first set of air ports and a second set of air ports. The first set of air ports is configured to apply suction to the lowest-positioned sheet, and the second set of air ports is configured to blow air onto the lowest-positioned sheet. The first set of air ports includes a plurality of suction ports, and the second set of air ports includes a plurality of blowing ports.

[0010] This is based on the understanding that air cushions and suction can be generated simultaneously. The interaction between the suction and the air cushion positions the sheet at a certain distance from the suction rod, or at least reduces the friction between the sheet and the suction rod.

[0011] In this embodiment, the first set of air inlets and the second set of air inlets are arranged in a transverse direction perpendicular to the transport direction.

[0012] Preferably, the first group of air ports and the second group of air ports are arranged on the same line and alternately, such that the suction port from the first group of air ports is located between the two blowing ports from the second group of air ports.

[0013] In this embodiment, the airflow rate through the suction port is greater than the airflow rate through the blowing port.

[0014] The first set of air inlets may be equipped with a funnel-shaped inlet.

[0015] In this embodiment, the second set of air inlets has elliptical holes.

[0016] In one embodiment, the absolute value of the low air pressure at the suction port orifice is lower than the absolute value of the positive pressure at the blowing port orifice.

[0017] In an embodiment, the low air pressure in the air duct connected to the suction port is between 3000 Pa and 5000 Pa, preferably about 4000 Pa, and a positive pressure exists in the air supply duct connected to the blowing port between 200,000 Pa and 500,000 Pa, preferably about 400,000 Pa. This allows for the formation of an air cushion with a maximum height lower than the gap between the front stop and the suction rod.

[0018] In one embodiment, the suction rod includes an air conduit and a plurality of inclined channels extending therefrom, wherein the inclined channels have an outlet formed by an opening in the air inlet.

[0019] The first set of air ports can be connected to the suction box, which is also in fluid communication with air ports around the drive element on the loading surface. Attached Figure Description

[0020] The invention will now be described with reference to the accompanying drawings, wherein similar features are indicated by the same reference numerals, and wherein: -Figure 1 This is a schematic diagram of a converter configured with a flexible folding and gluing machine; - Figure 2a It is a schematic top view of the printed sheet; - Figure 2b It is a schematic top view of the cut and shaped blank; - Figure 2c It is a schematic 3D diagram of a folding box; - Figure 2d It is by Figure 2c A schematic 3D diagram of a box assembled from folding boxes; - Figure 3 This is a partial schematic perspective view of a feeder module according to an embodiment of the present invention; - Figure 4a This is a detailed perspective view of the suction rod according to an embodiment of the present invention; and - Figure 4b and 4c This is a schematic cross-sectional view showing the outline of the suction rod according to an embodiment of the present invention in the corresponding first section AA and second section BB. Detailed Implementation

[0021] This invention can be used as a converter for, for example, printing presses, rotary die-cutting machines, and folding and gluing machines (such as flexographic folding and gluing machines). For the sake of simplicity, reference is made to flexographic folding and gluing machines.

[0022] Refer to the attached drawings, especially Figure 2a and 2b It shows an example of sheet 2 and blank 2' made of cardboard, and the blank 2' is used to manufacture such as Figure 2c The folding box 2'' is shown. The folding box 2'' can then be assembled as shown. Figure 2d The three-dimensional box 2''' is shown. Sheet 2 is placed into the converter ( Figure 1 The feeder module 12 may already have pattern 5 provided. Alternatively, the sheet 2 can be printed in the converter 1.

[0023] In manufacturing folding boxes 2'' or flat packaging boxes, sheets 2 made of paper, cardboard, plastic, etc., are loaded into a conversion machine 1. The sheets 2 are transformed into blanks 2' by processing them in multiple workstations. These workstations convert the sheets 2 through printing, creasing, and cutting. Some types of conversion machines 1 (such as folding and gluing machines 1) also include gluing and folding modules to produce folding boxes and other similar packaging containers.

[0024] Figure 1The diagram schematically illustrates a converter 1 in the form of a flexographic folding and gluing machine 1. The converter 1 may sequentially include, in the transport direction T: a loader 10 for automatically loading multiple sheets, a feeder 12, a printing module including multiple flexographic printing units 14, a converter module 16 including a slotting unit and at least one cutting unit 18, and a folding and gluing module 20. The converter 1 may further include optional modules such as a counting ejection module, a strapping machine, and a palletizer (not shown).

[0025] The converter 1 includes a conveying system C configured to transport the sheet 2 along the transport direction T. The conveying system C may include a drive roller and a conveyor belt (not shown). Vacuum transfer is typically used in and between different work modules, in which the sheet 2 is transported on its upper surface. If there are different printing units configured to print on the top and bottom sides of the sheet 2 respectively, the transport side in the printing unit may be changed.

[0026] like Figure 3 As shown, the feeder module 12 includes a loading surface 24, a front stop 26, and an elongated suction rod 28. The feeder module 12 is configured to receive a stack of sheets 2 on the loading surface 24 and unload the sheets 2 one by one into the conveying system C of the converter 1.

[0027] The feeder module 12 includes multiple drive elements 30 and a movable support surface 32. The drive elements 30 may be drive rollers or belts. The stack of sheets 2 is moved vertically up and down via the movable support surface 32. The movable support surface 32 includes multiple rods 33. The rods 33 are arranged between the drive elements 30. Therefore, the support surface 32 is configured to move between a contact position and a gap position. In the gap position, the lowest sheet 2 is in contact with the support surface 32 and is vertically positioned above the drive element 30. In this position, the lowest sheet 2 is not in contact with the drive element 30.

[0028] At the contact position, the support surface 32 is vertically positioned below the drive element 30, thereby causing the lowest sheet 2 to contact the drive element 30 and be driven forward along the transport direction T. This up-and-down movement of the movable support surface 32 ensures that only one sheet 2 is gripped and transported at a time.

[0029] The front stop 26 may be in the form of a stop plate and is arranged downstream of the drive element 30 along the transport direction T. The front stop has a distal end 29, which is arranged such that a gap C1 is formed between the suction rod 28 and the front stop 26. The gap C1 is selected to correspond to the thickness of one sheet substrate 2, or at least less than the combined thickness of two sheet substrates 2. The front stop 26 ensures that only one sheet 2 is conveyed through the gap C1 and into the converter 1 at a time.

[0030] The front stop 26 may include a first stop plate 27a and a second stop plate 27b, which are arranged side by side in a transverse direction L perpendicular to the transport direction T.

[0031] A slender suction rod 28 is positioned vertically below the front stop 26 to ensure that the sheet 2 is guided below the front stop 26. The suction rod 28 includes a first set of air ports 36 configured as a plurality of suction ports 36'. The first set of air ports 36 is configured to apply suction to the underside of the sheet 2, thereby guiding the sheet 2 below the front stop 26. The suction ports 36' are arranged on a line extending in a transverse direction L perpendicular to the transport direction T.

[0032] like Figure 4a and 4b As shown, the suction port 36' may be provided with a funnel-shaped inlet. The funnel shape is designed to apply suction force over a larger area of ​​the sheet (compared to if the suction port 36' were straight).

[0033] The suction rod 28 further includes a second set of air ports 40, which includes a plurality of air outlets 40'. The air outlets 40' (also referred to as air blowing ports) are configured to blow air onto the underside of the sheet 2.

[0034] The second set of air inlets 40 may have elliptical orifices. The orifices may be positioned such that their extension in the transport direction T is longer than in the lateral direction L. The elliptical shape allows the inclined air passage 41 to have a circular cross-section along a direction perpendicular to the longitudinal extension of the air passage 41.

[0035] Preferably, the suction port 36' and the air outlet 40' are arranged on the same line. This line is arranged vertically below the front stop 26, at an upstream distance of 5 to 15 mm, preferably about 10 mm. This distance is chosen so that the leading edge 3 of the sheet 2 is gripped before it passes under the front stop 26.

[0036] The suction airflow through each suction port 36' can be between 30 and 47 liters per minute, preferably about 40 liters per minute. In the air duct 51 connected to the group of suction ports 36, there is a low pressure P1 between 3000 Pa and 5000 Pa, preferably about 4000 Pa.

[0037] The airflow Q2 through each air outlet 40' is preferably between 24 and 32 liters per minute, preferably about 25 liters per minute. A positive pressure P2 exists in the air supply duct 50 connected to the group of air outlets 40 and is between 200,000 Pa and 500,000 Pa, preferably about 400,000 Pa.

[0038] There may be a total of approximately 64 suction ports (36') and approximately 63 air ports (40').

[0039] Therefore, the low airflow rate Q2 through the outlet 40' is less than the airflow rate Q1 through the suction port 36.

[0040] However, the absolute value of the pressure P2 in the air supply duct 50 connected to the orifice of the outlet 40' is equal to or higher than the absolute value of the pressure P1 at the orifice of the suction port 36'. This allows the formation of an air cushion with a limited distance of 1 or 2 mm from the suction rod 28.

[0041] The diameter of the suction port 36' can be approximately 6 mm and the diameter of the second air port 40' can be approximately 1.5 mm.

[0042] Therefore, the air inlet 40' is configured to apply a strong blowing force only very close to the suction rod 28. This results in the air pad existing only near the suction rod 28, such as within a distance limit of approximately 1 mm from the air inlet 40'. This prevents the sheet 2 from touching the front stop 26.

[0043] The distance between the suction port 36' and the adjacent blowing port 40' is chosen such that different areas are formed in the transverse direction L, where the sheet 2 is alternately suctioned and blown away by the suction rod 28. The distance between the suction ports 36' can be between 20 mm and 40 mm, preferably about 30 mm. This distance also provides sufficient suction force distribution for the small-sized sheet 2. The blowing port 40' is positioned between the two suction ports 36'. Thus, the first and second air ports 36', 40' are arranged in an alternating sequence such that one out of every two air ports is a blowing port 40'. The suction rod 28 can be made of metal. For example, the suction rod 28 can be manufactured in an additive manufacturing process.

[0044] like Figure 4b and 4c As best viewed, the upper surface of the suction rod 28 may have an upstream portion 46 and a downstream portion 48. The downstream portion 48 is positioned lower than the upstream portion 46 in the vertical direction. The suction rod 28 is mounted in the feeder module 12 such that the transition point 47 between the upstream portion 46 and the downstream portion 48 is vertically located below the front stop 26. This recessed downstream portion 48 prevents the leading edge of the sheet 2 from touching the suction rod 28 after passing the lines of the air ports 36', 40'.

[0045] A vacuum pump can be connected to the first set of air ports 36. The first set of suction ports 36 can be connected to the vacuum pump via a common air duct 50. Figure 4cAs shown, the air inlet 40' is connected to a common air supply duct 50. The longitudinal extension of the air supply duct 50 coincides with the longitudinal extension of the suction rod 28. The air supply duct 50 is laterally positioned along the transport direction T and located downstream of the suction compartment. Each air inlet 40' can be connected to a separate and angled suction channel 41.

[0046] In an advantageous embodiment, the loading surface 24 includes air vents 52 located around the drive element 30. A suction box may be positioned vertically below the air vents 52. The suction box may be further fluidly connected via an air conduit 51 to a first set of suction ports 36 in the suction rod 28. A suction device (such as a vacuum generator) may be connected to the suction box.

Claims

1. An infeed module (12) for a converting machine (1), the infeed module comprising: a loading surface (24) configured to receive a stack of sheets (2), a front stop (26) configured to abut against a front edge of the stack and to allow only the lowest in position sheet in the stack to be conveyed under the front stop at a time, a drive element (30) configured to move the lowest in position sheet in the stack under the front stop and forward in a transport direction (T), and wherein the infeed module comprises a suction bar (28) configured to exert suction on an underside of the lowest in position sheet and to guide the lowest sheet under the front stop, and wherein the suction bar comprises a first set of air ports (36) configured to exert suction on the lowest sheet and a second set of air ports (40) configured to blow air on the lowest sheet, and wherein the first set of air ports comprises a plurality of suction ports (36') and the second set of air ports comprises a plurality of blow ports (40').

2. The feeder module of claim 1, wherein, The first set of air ports (36) and the second set of air ports (40) are arranged along a lateral direction (L) perpendicular to the transport direction (T).

3. The feeder module of claim 2, wherein, The first set of air ports (36) and the second set of air ports (40) are arranged on the same line and in an alternating manner, such that a suction port (36') from the first set of air ports (36) is located between two blow ports (40') from the second set of air ports (40).

4. The feeder module of any of the preceding claims, wherein, An air flow rate through a suction port (36') is greater than an air flow rate through a blow port (40').

5. The feeder module of any of the preceding claims, wherein, The first set of air ports (36) is provided with a funnel-shaped inlet.

6. The feeder module of any of the preceding claims, wherein, The second set of air ports (40) has an oval-shaped aperture.

7. The feeder module of any of the preceding claims, wherein, An absolute value of an air low pressure (PI) at the aperture of a suction port (36') is lower than an absolute value of a positive pressure (P2) at the aperture of a blow port (40').

8. The feeder module of any of the preceding claims, wherein, An air low pressure (PI) in an air duct (51) connected to the aperture of a suction port (36') is between 3000 Pa and 5000 Pa, preferably about 4000 Pa, and wherein a positive pressure (P2) is present in an air supply duct (50) connected to a blow port (40') and is between 200000 and 500000 Pa, preferably about 400000 Pa.

9. The feeder module of any of the preceding claims, wherein, The suction bar comprises an air guide and a plurality of inclined channels (41) extending therefrom, and wherein the inclined channels have outlets formed by the apertures of the blow ports (40).

10. Feeder module according to the preceding claim, wherein, The first set of air ports (36) is connected to a suction box which is also in fluid communication with air ports (52) around the drive element (30) on the loading surface (24).

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