Feeder with moving belt

Abstract

The invention relates to a feeder module for discharging sheets into a converter. The feeder module comprises a movable unloading conveyor comprising a plurality of belt conveyors configured to move between an unloading position (DP), in which the belt conveyors contact the lowermost sheet in the stack and unload said sheet, and a cleaning position (CP), in which the conveyor belts are located below the loading surface.

Description

Technical Field

[0001] The present invention relates to a feeder module for a converting machine, such as a rotary printing press or a converting machine configured to print and cut sheets to produce packaging elements. The invention may also relate to a digital printing press. Background Art

[0002] Converting machines are used in the production of packaging elements such as flat packs and folded boxes.

[0003] Sometimes the same converting machine is configured to print, cut, crease, and fold sheets to form packaging components.

[0004] However, it is also common to use several types of converting machines when producing packaging elements. For example, a first machine in the form of a printing press will print a sheet of material, and a second machine in the form of a die cutter will form the sheet into cut-to-shape blanks (also called flat packs). Alternatively, a folder-gluer converting machine can glue and fold the blanks to form a folding box.

[0005] A common module of most converting machines is the feeder module. The feeder module includes a loading surface on which a stack of sheets or cut-to-shape blanks can be placed. The feeder is configured to discharge the sheets or blanks one by one into the converting machine at a precise time.

[0006] Some feeder modules include a movable loading surface that moves the stack up and down so that the stack engages and disengages with a drive belt or roller in the feeder. The feeder is also equipped with a gauge that allows only one sheet to enter the converting machine at a time.

[0007] The feeder is usually equipped with a rear bar configured to support a portion of the stack. Instead of moving the loading surface linearly up and down, the pivoting motion is provided by applying a lifting force at a location at the rear of the stack. However, this solution has the effect of lifting the rear end of the sheet to a position higher than the vertical tip of the measuring instrument. This may cause the top surface of the sheet to be scratched as it passes under the tip of the measuring instrument. Summary of the invention

[0008] The object of the present invention is to alleviate the above-mentioned disadvantages of the prior art.

[0009] This object is solved by a feeder module according to claim 1 .

[0010] According to one aspect of the present invention, a feeder module for discharging sheets of material into a converting machine is provided. The feeder module includes a loading surface configured to receive a stack of sheets of material and a movable discharge conveyor including a plurality of belt conveyors.

[0011] Each belt conveyor includes an upper contact surface for contacting a sheet, and wherein the belt conveyor is configured to move between a discharge position, in which the belt conveyor contacts and discharges a lowermost sheet in the stack, and a cleaning position in which the conveyor belt is located below the loading surface.

[0012] The invention is based on the recognition that a more precise discharge of the sheet material can be provided by means of a vertical movement of the discharge conveyor.

[0013] In the context of this application, the term "converting machine" includes machines configured only for printing sheet substrates and converting machines that also include cutting and forming modules, such as rotary die cutters, slotting modules and folding modules, or flatbed die cutters.

[0014] In one embodiment, each belt conveyor is guided by a motorized drive roller and an idler roller, wherein the motorized roller is mounted on a drive shaft.

[0015] In one embodiment, the drive shaft includes a first drive shaft member and a second drive shaft member, and wherein the first set of belt conveyors is connected to the first drive shaft member and the second set of belt conveyors is connected to the second drive shaft member.

[0016] The first drive shaft member and the second drive shaft member may be connected to a common motor.The motor may be located below and in the center of the loading surface.

[0017] Preferably, the belt displacement member is arranged between the driving roller and the idler roller, and wherein the belt displacement member is configured to move the belt conveyor up and down in a vertical direction. Thus, the belt displacement member can be limited to vertical displacement. That is, without any horizontal displacement component.

[0018] In one embodiment, the displacement member is arranged within a loop formed by the belt conveyor, and wherein the displacement member is configured to contact an inner circumference of the belt conveyor.

[0019] In one embodiment, the belt displacement member includes an upper displacement surface configured to move a contact surface of the conveyor belt and a lower displacement surface configured to move a return portion of the belt conveyor belt.

[0020] In one embodiment, the upper displacement surface is provided with holes.

[0021] Preferably, the upper displacement surface and the lower displacement surface are provided with a sliding surface configured to contact an inner circumference of the belt conveyor.

[0022] In one embodiment, the belt shifting member is connected to a second drive mechanism, and wherein the second drive mechanism comprises a second motor and a timed mechanism.The timed mechanism may comprise an eccentric drive shaft.

[0023] In one embodiment, a feeder module according to the preceding claim, wherein the feeder module comprises a suction box provided with a plurality of suction compartments, and wherein the first and second drive shaft members are located in the suction box, and wherein the suction compartments are arranged symmetrically with respect to a central axis of the loading surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The present invention will now be described with reference to the accompanying drawings, in which like features are indicated by like reference numerals, and in which:

[0025] - Figure 1 is a schematic perspective view of a converter in a flexographic printing press configuration;

[0026] - Figure 2a is a schematic cross-sectional view of a feeder module according to an embodiment of the present invention;

[0027] - Figure 2b is a detailed view of a stack of sheets on a loading surface of a feeder module;

[0028] - Figure 3a is a schematic cross-sectional view of a loading surface of the feeder module of FIG. 2 ;

[0029] - Figure 3b is a schematic cross-sectional view of another embodiment of a loading surface of the feeder module of FIG. 2 ;

[0030] - Figure 4a and Figure 4b are side views of the discharge mechanism in a first position and a second position, respectively; and

[0031] - Figure 5 is a partially cutaway top view of a loading surface and a discharge mechanism according to an embodiment of the present invention;

[0032] - Figure 6 Figure 4 and Figure 5 a cross-sectional view of the discharge mechanism; and

[0033] - Figure 7 is a schematic perspective view of a belt assembly and drive mechanism according to an embodiment of the present invention. DETAILED DESCRIPTION

[0034] General description of Masterflex, DRO and FFG machines

[0035] With reference to the accompanying drawings, in particular Figure 1, which shows a conversion machine 1 in the form of a printing press. Even though not shown, the invention can also be used in other conversion machines, such as flatbed die cutters, rotary die cutters or flexographic folder-gluers, which also include a conversion unit including a slotter assembly or a rotary die cutter assembly. These machines can be equipped with the same feeder module, which will be described below.

[0036] like Figure 1 As shown, the conversion machine may include, in sequence in the transport direction T: a loader 10 for automatically loading a stack of sheets 2, a feeder 12, a printing module 14 including a plurality of printing units 15, and a conveying module 16 including a stacking device 17. Optionally, the conversion machine 1 may also include a digital printing module (not shown).

[0037] A main operator interface 18 may also be provided near the conversion machine.The conversion machine 1 may also include strapping and palletizing modules.

[0038] like Figure 2a and Figure 2b As shown, the feeder module includes an upper feeder assembly 20 and a lower feeder assembly 22. The upper feeder assembly 20 and the lower feeder assembly 22 are mounted to a common module frame.

[0039] The lower feeder assembly 22 includes a loading surface 24 configured to receive a stack S of sheets 2 and a sheet discharge mechanism 26 configured to discharge the sheets 2 sequentially into the converting machine 1 in a transport direction T. The sheet discharge mechanism 26 includes a plurality of belt conveyors 30 arranged side by side.

[0040] The upper feeder assembly 20 includes a measuring instrument 32. The measuring instrument 32 has a distal vertical end 32' disposed at a distance d1 from the loading surface 24. The distance d1 between the distal vertical end 32' and the loading surface 24 defines a gap through which the lowermost sheet 2 in the stack S can pass.

[0041] The feeder module 12 further includes a feeder roller assembly 34. The feeder roller assembly 34 is located on the downstream side of the measuring instrument 32 and is configured to grab each sheet 2 to pull the sheet 2 from the loading surface 24. The feeder roller assembly 34 includes an upper feeder roller 35a and a lower feeder roller 35b.

[0042] like Figure 3a and Figure 3bAs best shown, the belt conveyor 30 can be arranged in a suction box 36. The suction box 36 may include a plurality of compartments 38. The compartments 38 may be separated from each other by partition walls 40. Preferably, the partition walls 40 are arranged so that the suction compartments 38 are symmetrical with respect to the central axis A of the loading surface 24. In one embodiment, there may be two suction compartments 38, 38, which are located on both sides of the central axis A. Each suction compartment 38, 38 may be connected to a separate vacuum pump (not shown). In another embodiment, there may be three suction compartments in the form of a central suction compartment 38, a first suction compartment 38, and a second suction compartment 38. The central suction compartment 38 may be connected to a first suction pump, and both the first and second lateral suction compartments may be connected to a second suction pump.

[0043] The loading surface 24 is a flat surface configured to receive a stack S of sheets 2. The loading surface 24 is attached to the chassis of the feeder module. The loader module 10 can place a stack S of sheets on the loading surface 24 as described in document EP2408698B1.

[0044] like Figure 5 As best shown, the loading surface 24 includes a plurality of elongated surfaces 42. The elongated surfaces 42 are spaced apart from one another in the lateral direction L such that a slot 44 is formed between each of the elongated surfaces 42. The belt conveyor 30 is located in the slot 44.

[0045] like Figure 4a and Figure 4b , Figure 5 and Figure 7 As shown, the sheet unloading mechanism 26 includes a plurality of belt conveyors 30 , a belt guiding mechanism 48 , and a belt shifting mechanism 50 .

[0046] Each belt conveyor 30 is provided with an upper contact surface 52 in contact with the bottom surface of the sheet 2 and a return portion 54 located vertically below the contact surface 52. Therefore, the upper contact portion 52 of the belt conveyor 30 is exposed on the sheet 2 in the elongated groove 44.

[0047] The belt conveyor 30 is movable in unison between a discharge position DP, where the contact surface 52 of the belt conveyor 30 is located vertically above the loading surface 24, and a cleaning position CP, where the contact surface 52 of the belt conveyor 30 is located vertically below the loading surface 24. At the discharge position DP, the lowermost sheet 2 in the stack S contacts the belt conveyor 30, which drives the sheet 2 forward in the transport direction T.

[0048] Each belt is mounted on a belt guide mechanism 48. The belt guide mechanism 48 includes a drive roller 56 and an idler roller 58 around which the belt is mounted. The drive roller 56 and the idler roller 58 are rotatably attached to the chassis of the feeder module 12 in a first bracket 60a and a second bracket 60b.

[0049] The drive rollers 56 may be connected to a drive shaft 62 that extends through the center of all the drive rollers 56. In this way, all of the belt conveyors 30 are driven in unison. Figure 7 As best shown, the discharge conveyor 25 includes a first set 25a of belt conveyors 30 connected to a first drive shaft member 33a and a second set 25b of belt conveyors 30 connected to a second drive shaft member 33b. The first drive shaft member 33a and the second drive shaft member 33b may be connected to a common motor 39. Drive pulleys 37a, 37b may be arranged to interconnect each drive shaft member 33a, 33b to the common motor 39.

[0050] The common motor may be located centrally below the loading surface 24. In another variation (not shown), the motors may be located on opposite outer lateral sides of the loading surface 24.

[0051] Therefore, the drive connection from the motor 39 to each corresponding drive shaft 33a, 33b can be located at the center of the loading surface. Alternatively, in an embodiment not shown, two motors 39 can be provided, and the drive connection between each motor 39 and each drive shaft 33a, 33b can be located at the outer part of the loading surface 24.

[0052] Preferably, the drive roller 56 and the idler roller 58 have the same diameter. In this way, the track of the belt conveyor is symmetrical. The drive roller 56 and the idler roller 58 can be toothed and configured to engage with the inner concave surface of the belt conveyor 30.

[0053] like Figure 4a , Figure 4b and Figure 6 As best shown, the belt shifting mechanism 50 includes a shifting member 64 located within the inner periphery of each belt conveyor 30. The shifting member 64 includes an upper shifting surface 65a and a lower shifting surface 65b. The upper shifting surface 65a is configured to move the upper contact surface 52 of the belt conveyor 30 upward. The lower shifting surface 65b of the shifting member 64 is configured to move the return portion 54 of the belt conveyor 30 vertically downward.

[0054] The upper displacement surface 65a and the lower displacement surface 65b are parallel to each other. The upper displacement surface 65a and the lower displacement surface 65b can be horizontal. The upper displacement surface 65a and the lower displacement surface 65b are preferably connected to each other via at least one vertical member 66a, 66b. Preferably, a first vertical member 66a and a second vertical member 66b are provided. The at least one vertical member 66a, 66b can extend across the loading surface 24 so as to interconnect all the upper displacement surfaces 65a and the lower displacement surfaces 65b of all belt conveyors 30.

[0055] like Figure 5 As shown, at least the upper displacement surface 65a can be provided with holes 68. In this way, the airflow from the suction box can flow through the displacement member 64. The upper displacement surface 65a and the lower displacement surface 65b can also be provided with sliding surfaces configured to contact the belt conveyor 30. The sliding surface is a low friction surface, such as a smooth metal surface. In addition, the belt conveyor 30 can be provided with holes 45.

[0056] The shifting mechanism 50 is moved in the vertical direction by the motor 75, the toothed drive roller 74, the pulley 71 and the timing mechanism 76. The timing mechanism may include an eccentric shaft 76. The first bracket 78 and the second bracket 80 connect the eccentric shaft 76 to the shifting member 64. As the eccentric shaft 76 rotates, the shifting member 64 moves up and down in the vertical direction V. Therefore, the belt shifting member 64 is connected to the second motor 75 separated from the motor 39.

[0057] The upper displacement surface 65a and the lower displacement surface 65b are symmetrically positioned relative to the drive roller 56 and the idler roller 58. Therefore, the displacement member 64 symmetrically supports the upper contact portion 52 and the return portion 54 of the belt conveyor 30. The up and down movement of the displacement member 64 is preferably the same distance. This allows the length of the belt conveyor on both sides of the displacement member to have the same change, thereby limiting the change in belt tension.

Claims

1. A feeder module (12) for discharging sheets (2) into a conversion machine (1), the feeder module comprising a loading surface (24) configured to support a stack (S) of sheets (2), a movable discharge conveyor (25) comprising a plurality of belt conveyors (30), wherein each belt conveyor comprises an upper contact surface (52) configured to contact the sheets (2), and wherein the belt conveyors are configured to move between a discharge position (DP) and a cleaning position (CP), wherein in the discharge position (DP) the belt conveyors contact the lowest sheet in the stack and discharge the sheet, and in the cleaning position (CP) the belt conveyors are located below the loading surface.

2. The feeder module of claim 1, wherein each of the belt conveyors is guided by a motorized drive roller and an idler roller, wherein the motorized roller is mounted on a drive shaft.

3. The feeder module according to claim 2, wherein the drive shaft comprises a first drive shaft member and a second drive shaft member, and wherein a first set of belt conveyors (25a) is connected to the first drive shaft member and a second set of belt conveyors (25b) is connected to the second drive shaft member.

4. The feeder module according to claim 2 or 3, wherein a belt shifting member (64) is arranged between the drive roller and the idler roller, and wherein the belt shifting member is configured to move the belt conveyor up and down in a vertical direction.

5. Feeder module according to the preceding claim, wherein the displacement member is arranged within a loop formed by the belt conveyor, and wherein the displacement member is configured to contact an inner periphery of the belt conveyor.

6. A feeder module according to the preceding claim, wherein the belt displacement member comprises an upper displacement surface configured to move the contact surface of the conveyor belt upwards and a lower displacement surface configured to move the return portion of the belt conveyor belt downwards.

7. Feeder module according to the preceding claim, wherein the upper displacement surface is provided with holes.

8. Feeder module according to the preceding claim, wherein the upper displacement surface and the lower displacement surface are provided with sliding surfaces configured to contact the inner periphery of the belt conveyor.

9. Feeder module according to the preceding claim, wherein the belt displacement member is connected to a second drive mechanism (73), and wherein the second drive mechanism comprises a second electric motor (75) and a timing mechanism (76).

10. A feeder module according to the preceding claim, wherein the timing mechanism is an eccentric drive shaft.

11. A feeder module according to the preceding claim, wherein the feeder module comprises a suction box provided with a plurality of suction compartments, and wherein the first drive shaft member and the second drive shaft member are located in the suction box, and wherein the suction compartments are arranged symmetrically relative to the central axis (A) of the loading surface.

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