EP2447197B1 - Device and method for turning stacks of sheet-shaped material - Google Patents

Description

The present invention relates to an apparatus and a method for turning stacks of sheet material according to the preamble of claims 1 and 10.

In the production of printed products for the packaging industry, such as folding cartons, sheets are first printed on a wide web in a printing press. On the sheets, several benefits of the carton to be produced are printed in each case, which are then punched out in a flatbed punch with the printed side up and stored in stacks. The punched out and stacked folding box blanks are then fed to a folding box gluing machine with the printed side down to be processed into folding boxes here.

The stacked folding box blanks must therefore be turned before processing in the folding box gluer. This is an extremely laborious step. An operator may need to turn several tons of carton a day.

From the DE 10 65 075 already a turning table for a stacking device is known. The turning table has a clamping plate and a clamping and conveying unit. About an actuator, a closing movement between the clamping plate and conveyor unit is realized for jamming an object. With a further actuator, the device is rotated in the transport direction of the object to center mounted on the turning table pivot 180 °, so that the clamped, stacked carton blanks are turned. After the turning process, these rest on the conveyor unit and are transported away from it by the turning device.

Another turning device is from the EP 1 350 748 A2 known. This turning device has a turning clamp, which is pivotable about a centrally arranged horizontal axis. The turning clamp comprises two transport elements, one of which is in the form of a series of rollers. This transport element serves to receive the stack entering the device. The second transport element is designed as a conveyor belt and serves to transport the stack after the turn by means of a pushcarriage out of the device.

Another turning device for stacks is from the US 5,743,374 known. This device has a clamp for receiving the stack. The device is laterally moved by means of a first motor for receiving and transporting the stack. By means of a second motor, the staple of the device is moved along a U-shaped path in the device via rollers on an outer side of the staple, whereby the stack is turned over and placed on an insert.

EP 0 802 137 A2 discloses a device according to the preamble of claim 1. Further, this document discloses a method for turning stacks of sheet material, comprising the following steps: feeding a stack into a pivoting fork to stack stops attached to bottom loops, the opening of the pivoting fork already as a starting position in a swivel angle is pivoted upward. Aligning the stack with the staple stops of the sub-grippers and gripping the stack. The stack is aligned by the inclination on the stack stop. Clamping the stack between lower grippers and upper grippers by height adjustment of the lower gripper. Execution of the slewing process up to the final position and retraction of the upper gripper, which previously formed the lower gripper. Discard the turned stack by singulating from below with the help of a rotary feeder, and finally turning back the pivoting fork and extending the upper gripper to the starting position.

The object of the present invention is to provide an alternative turning device which turns arcuate stacks easily, safely and reliably.

This object is achieved by the characterizing features of claim 1 and by the method steps of claim 10.

In one embodiment of the invention, the apparatus for turning stacks of sheet material comprises means for transporting the stacks into a pivoting fork of a turning station. The turning station has a pivoting fork with upper grippers, lower grippers and a stack stop. The pivot fork has on one side an opening for the import of stacks and at its other end it is pivotally mounted about a horizontal pivot axis extending transversely to the direction of entry of the stack, wherein the pivot axis is arranged eccentrically to the pivoting fork. An adaptation to different formats is achieved by the stack stop, which is advantageously carried out adjustable to the lower looper. In a further advantageous embodiment, the stack stop is executed two or more times divided. This allows for easy adaptation to and guidance of unsymmetrical blanks.

In a particularly preferred embodiment, the pivot axis in the upper region of the pivot fork is arranged eccentrically to this, so that in a simple manner and pivot angle of the pivot fork more than 180 ° can be realized. This allows the stack to be deposited even on an inclined plane. Due to the eccentric arrangement of the pivot axis in the upper region a horizontal path change and a change in height of the stack is achieved during the pivoting movement.

In a further advantageous embodiment, the lower grippers are arranged in the side parts of the device and adjustable in height relative to the upper grippers. The height adjustment takes place here advantageously by servomotors or pneumatic or hydraulic cylinders. As a result, a clamping of the stack between upper grippers and lower grippers is possible in a simple manner, so that the stack is held securely during the pivoting operation. Since the clamping can be exerted at any time during the pivoting operation, the stack can be pivoted in an advantageous manner initially unclamped, up to a pivoting angle of 70 °. As a result, the stack will align itself independently on the stack stop and the lower looper. If desired, the alignment of the stack can be further supported by additional vibrations of the pivoting fork. After alignment process, that is about from a pivoting angle of 70 ° then the clamping of the stack can be done to keep it safe during the further pivoting operation.

In a particularly preferred embodiment, the upper gripper are designed as roller rails. This embodiment has several advantages. On the one hand, after the turning process, the roller rails can be moved out from under the stack without causing any sanding marks on the blanks, since the belts unroll directly under the pile. At the same time it is possible when using multiple rails, even stacks of unbalanced blanks to give the maximum support, since the rails can be retracted differently far relative to the stack and can also be moved individually when pulling out.

According to the invention, the lower looper and / or upper looper are arranged freely positionable transversely to the inlet direction of the stack. This is a simple adaptation to different Blank formats possible. When using more than two sub-grippers and / or upper grippers, a further adaptation to asymmetrical blanks is additionally possible in a simple manner.

In a further preferred embodiment, the pivoting fork is adjustable via a height adjustment device. The height adjustment device is in this case attached to the side parts of the device and the pivot axis is mounted in guides in the side parts of the device. As a result, a simple height adjustment of the turned stack is possible relative to the remaining stack in the insert. Likewise, during the withdrawal of the roller rails, the pivoting fork can be further adapted to the degrading residual stack in the inserter. As a result, the distance between the upper edge of the rest of the stack and lower edge of the turned stack remains almost constant, which has a positive effect on the falling behavior of the turned stack. Advantageously, the height adjustment device is mounted obliquely in the side parts of the device and the pivot axis is mounted in inclined guides in the side parts of the device. In a preferred embodiment, the height adjustment, for example, consist of a rack and a driven gear. However, any other motorized, pneumatic or hydraulic height adjustment is possible.

In a particularly preferred embodiment, the transport device for the transport of the stack in the pivoting fork is designed in two parts. The first part of the transport device is located in the Stapelzuführvorrichtung and goes until just before the start of the pivoting fork. The second part of the transport device extends over the depth of the pivoting fork. Advantageously, both transport devices have independent individual drives. As a result, they can be operated separately via sensors and controllers. Also different speeds are possible. As a result, gaps of different sizes between the individual stacks can be compensated for and it can always be ensured that a new stack is in the waiting position while the pivoting fork turns a stack.

1. a) Zuführen eines Stapels in die Schwenkgabel bis an einen Stapelanschlag
2. b) Anheben des Stapels mittels höhenverstellbarer Untergreifer oder durch Drehen der Schwenkgabel
3. c) Schwenken der Schwenkgabel bis zu einem Schwenkwinkel von etwa 70°
4. d) Ausrichten des Stapels am Stapelanschlag und Untergreifern
5. e) Klemmen des Stapels zwischen Untergreifern und Obergreifern durch weitere Höhenverstellung der Untergreifer
6. f) Weiterführung des Schwenkvorgangs bis in die Endposition
7. g) Zurückfahren der Obergreifer
8. h) Ablegen des gewendeten Stapels
9. i) Zurückdrehen der Schwenkgabel und Ausfahren der Obergreifer in die Ausgangsposition
10. j) Wiederholung der Schritte a) bis i), bis alle Stapel abgearbeitet sind.

In a method according to the invention, the stacks are turned in the following method steps:

1. a) feeding a stack in the pivoting fork to a stack stop
2. b) lifting the stack by means of height-adjustable lower gripper or by turning the pivoting fork
3. c) pivoting the pivoting fork up to a pivoting angle of about 70 °
4. d) Aligning the stack with the stack stop and sub-grippers
5. e) Clamping the stack between sub-grippers and upper grippers by further height adjustment of the lower gripper
6. f) Continuation of the pivoting process up to the end position
7. g) Retracting the upper gripper
8. h) depositing the turned stack
9. i) Turning back the pivoting fork and extending the upper gripper to the starting position
10. j) Repeat steps a) to i) until all stacks have been processed.

The stacks are aligned up to a pivot angle of about 70 °. Because the pivoting angle can also be greater than 180 °, the stacks can also be deposited on an inclined plane.

Fig. 1

zeigt eine erfindungsgemäße Vorrichtung mit Stapelzuführvorrichtung, Wendestation und Einleger

Fig. 2

zeigt die Vorrichtung von Fig. 1 nach Abschluss des Wendevorganges

Fig. 3

zeigt die wesentlichen Teile der erfindungsgemäßen Wendestation in einer perspektivischen Seitenansicht

Fig. 4

zeigt die wesentlichen Teile der erfindungsgemäßen Wendestation in einer weiteren perspektivischen Seitenansicht

Fig. 5

zeigt einen Schnitt durch einen Obergreifer

Fig. 6a-6h

zeigen den Bewegungsablauf des Schwenkvorganges in schematischen Darstellungen

Fig. 7a-7d

zeigen alternative Teilbewegungsabläufe beim Schwenkvorgang in schematischen Darstellungen

The invention will be explained below with reference to various embodiments.

Fig. 1

shows an inventive device with Stapelzuführvorrichtung, turning station and depositor

Fig. 2

shows the device of Fig. 1 after completion of the turning process

Fig. 3

shows the essential parts of the turning station according to the invention in a perspective side view

Fig. 4

shows the essential parts of the turning station according to the invention in a further perspective side view

Fig. 5

shows a section through a top gripper

Fig. 6a-6h

show the sequence of movements of the pivoting process in schematic representations

Fig. 7a-7d

show alternative partial movements during the pivoting process in schematic representations

FIG. 1 shows the inventive device 1 for turning of stacks 5. The stack 5 are fed via a Stapelzuführvorrichtung 2 of the pivoting fork 12 of a turning station 3. The feed of the stack 5 via roller cheeks 6, wherein the stack 5 are aligned laterally on a Stapelausrichteblech 7. The Stapelausrichteblech 7 may advantageously have height marks 37. This helps the operator to place the allowable stack weights in each case to stay within the allowable tolerances. The stacks 5 are transported up to a stack stop 11 of the pivoting fork 12 by the roller cheeks 6. Alternatively, the transport can also be done by a split roller cheek system 6, 6 ', as later Figure 7a is explained in more detail. Below the roller cheeks 6 lower looper 10 of the pivoting fork 12 are arranged. These are height-adjustable and lift the introduced into the pivoting fork 12 stack 5 at. The stack is alternatively raised by pivoting the pivoting fork. The upper fork 9 further comprises upper grippers 9, which are arranged via drive heads 24 and the lower grippers 10 via a cross-beam 26 and side parts 25 pivotably about a pivot axis 8 at this. During the pivoting process, the stack 5 aligns with the lower gripper 10 and the stack stop 11 and is clamped by further height adjustment of the lower looper 10 relative to the upper grippers 9 between them. At the end of the pivotal movement, the upper gripper 9 are moved back and the stack 5 falls through a four-sided closed shaft, formed from positioning tabs 14, side stack guides 13 and the stack stop 11 in the depositor 4.

In FIG. 2 the state is shown at the end of the pivoting movement. The stack 5 is turned, clamped between upper looper 9 and lower looper 10th

In FIG. 3 and 4 the essential parts of the turning station 3 according to the invention are shown within the device 1. The turning station 3 has a pivoting fork 12, the upper gripper 9 and lower gripper 10 and a stack stop 11 has. The stack stop 11 is mounted adjustably on the lower looper 10. As a result, the pivot fork 12 can be easily adjusted to different, even asymmetric stack formats. For small blank widths, the stack can be turned with only one lower looper 10. In order to prevent tilting of the stack, a slip-on shoe 35 can advantageously be attached to the lower looper 10. This increases the contact surface for the stack, which facilitates alignment of the lower looper to the center of gravity of the stack. Advantageously, the slip-on shoe is narrower than two lower loops next to each other. The upper grippers 9 are designed as rollers 22, which are driven by belts 21, which are driven by a motor 17, a toothed belt pulley 20, a toothed belt 23 and a square shaft 16 (see below) FIG. 5 detailed). When turning the stack or in the case of the emergency stop function, the roller rails 22, depending on the position of the pivoting fork 22 (for example in a vertical position), could slowly slide downwards. This is advantageously prevented by the torque of the short-circuited motor 17 and by a spring-applied brake 36.

The upper grippers 9 are mounted in so-called drive heads 24. The drive heads 24 are mounted on the pivot axis 8, around which the complete pivot fork 12 can be pivoted. The lower looper 10 are attached to a crossbeam 26, which are mounted in guides 18 in the side parts 25 of the pivot fork 12 and can be adjusted by a linear drive 15 relative to the upper grippers 9 in height. The linear drive may be a servomotor, pneumatic cylinder or hydraulic cylinder.

The functioning of the upper gripper 9 is off FIG. 5 to recognize. Within the roller rail 22, a belt 21 which is guided over various rollers 34 and a drive shaft 16 extends. By means of a clamping element 27, the belt tension is adjustable. By the drive of the belt 21 via the drive shaft 16, the roller rail is displaced relative to the drive head 24 in the arrow direction.

In the Figures 6a - 6h is now shown in schematic representations of the movement of the turning device according to the invention.

In FIG. 6a It is shown how the stack 5 is retracted into the pivoting fork 12 to the stack stop 11 of the Stapelzuführeinrichtung 2. After that ( FIG. 6b ) begins the pivoting fork 12 with its pivoting movement about the pivot axis 8 and raises the stack 5 at. During this movement, the stack 5 aligns with the lower looper 10 and the stack stop 11. This alignment process is completed at about 70 ° of the pivoting movement and the lower looper 10 move in the direction of upper gripper 9 (FIG. FIG. 6c ) and clamp the stack 5 between upper gripper 9 and lower gripper 10 a. The stack 5 is further pivoted to its end position, which is in the present representation at about 195 ° pivot angle ( FIG. 6d ).

FIG. 6d also shows two sensors 29, 30. The sensor 29 is manually adjustable in height by the operator and provides signals to the pivot fork 12 when the stack 4 still in the stacker is processed to a desired height, so that a new stack 5 turned and should be launched. The lower sensor 30 is also adjustable in height and provides a signal when the stack still in the stacker 4 has been reduced to a critical minimum height without a new reversed stack has been placed. As a result of this signal, a subsequent machine can be turned off. After the completed turning process is now, as in FIG. 6e illustrated, the pivoting fork 12 based on the height adjustment device 31 (FIGS. FIG. 1 ) lowered in height almost to the top of the rest of the pile. Now, the upper gripper 9, which, as already described, are designed as roller rails 22, pulled out. When pulling out the movable roller rails 22, the stack 5 between upper gripper 9 and lower gripper 10 remains clamped. By clamping too early slipping out of the pivot fork 12 is avoided. After the roller rails 22 have been pulled out completely under the stack 5, the turned stack 5 falls ( FIG. 6f ) now almost as a block through a four-sided closed shaft, formed from positioning tabs 14, lateral stack guides 13 and stack stop 11 guided in the insert. To assist in addition, the pivoting fork 12 can be lowered by means of the height adjustment device 31 in the arrow direction. The control for the height adjustment device 31 takes place here via sensors 29 and a control unit, not shown. Thereafter, the pivoting fork 12 rotates back to about 15 ° before its vertical position. At the same time the pivot fork 12 moves in the direction of arrow by means of the height adjustment device 31 in its uppermost position. Thereafter extend the extendable rails 22 in the starting position and the pivoting fork rotates completely back to the starting position ( FIG. 6h ).

In Figure 7a an alternative partial movement sequence in the supply of the stack 5 is shown in the pivoting fork 12. Unlike the batch feeder according to FIG. 6a are in Figure 7a the roller cheeks 6 and 6 'in two parts. The roller cheeks 6 transport the stack in the Stapelzuführvorrichtung 2 and have their own, not shown drive. The transport of the stack 5 in the pivoting fork 12 is taken over by roller cheeks 6 ', which are driven by a separate drive, not shown. The roller cheeks 6, 6 'are controlled by sensors, which are not shown in greater detail, and a controller. The stacks 5 are transported in the Stapelzuführvorrichtung to a parking position at the end of the roller cheeks 6. If the pivot fork 12 is in the receiving position, the two roller cheeks 6, 6 'receive the signal for transporting the next stack 5 into the swivel fork 12. Because of the independent drives, different gaps in the stack feeder 2 are compensated.

In the FIGS. 7b to 7d is another alternative partial movement sequence in the filing of the inverted stack 5 in the insert 4 shown. The insert 4 may optionally include a height and retractable stackable leading edge support 28 that is now extended to receive the stack leading edge of the pivoted stack 5. The pivoted stack 5 rests on the upper grippers 9 and on the stack front edge support 28. As in the FIGS. 7c and 7d shown, the upper gripper 9, which are as already described as rolling rails, are now pulled out. At the same time, the stack leading edge support 28 is pulled out. The turned stack 5 falls now ( FIG. 7d ), as already described above, by a four-sided closed shaft, formed from adjusting tabs 14, side stack guides 13 and the stack stop 11 guided in the insert. 4

LIST OF REFERENCE NUMBERS

1

Apparatus for turning stacks

2

Stapelzuführvorrichtung

3

turning station

4

depositors

5

stack

6, 6 '

role cheeks

7

Stack alignment sheet

8th

swivel axis

9

upper looper

10

lower looper

11

stack stop

12

pivoting fork

13

lateral stacking guides in the insert

14

Deputy tongues

15

linear actuator

16

drive shaft

17

engine

18

guide

19

guide element

20

Timing pulley

21

belt

22

roll bar

23

toothed belt

24

powerhead

25

Side part of the swivel fork

26

crossbeam

27

clamping element

28

Stack front edge support

29

sensor

30

sensor

31

height adjustment

32

Side part of the device

33

inclined guides

34

guide rollers

35

Aufsteckschuh

36

Spring-loaded brake

37

height marker

Claims (15)

1. A device for turning stacks (5) of sheet-shaped material comprising a device for transporting (2) the stacks (5) into a pivot fork (12), a turning unit (3), said pivot fork (12) having at least one upper gripper (9), at least one lower gripper (10) and at least one stack stop (11), said pivot fork (12) having one end with an opening for introducing the stacks (5) and being pivotably supported at the other end around a horizontal pivot shaft (8) extending transverse to said introduction direction of the stacks (5), and said pivot shaft (8) being disposed off-center relative to said pivot fork (12),
   characterized in that
   the lower grippers (10) and/or the upper grippers (9) are disposed to be freely positionable in a direction traverse to the direction of the introduction direction of the stacks (5).
2. The device according to claim 1,
   characterized in that
   said pivot shaft (8) is disposed at an upper region of said pivot fork (12).
3. The device according to any one of the preceding claims,
   characterized in that
   the pivot angle of said pivot fork (12) is can be larger than 180°.
4. The device according to any one of the preceding claims,
   characterized in that
   said lower grippers (10) are disposed in guides in the lateral parts (25) of said pivot fork (12) and relative to said upper grippers (9) for height adjustment.
5. The device according to claim 4,
   characterized in that
   it comprises servomotors or pneumatic cylinders or hydraulic cylinders implementing said height adjustment of said lower grippers (10).
6. The device according to any one of the preceding claims,
   characterized in that
   said upper grippers (9) are embodied as rolling tracks (22).
7. The device according to any one of the preceding claims,
   characterized in that
   said upper grippers (9) are freely adjustable in length in a direction perpendicular to said pivot shaft (8).
8. The device according to any one of the preceding claims,
   characterized in that
   the pivot fork (12) includes more than two of said lower grippers (10) and/or or more than two of said upper grippers (9).
9. The device according to any one of the preceding claims,
   characterized in that
   the pivot fork (12) comprises a height adjustment device (31) for adjusting a height of said pivot fork (12).
10. The device according to claim 9,
    characterized in that
    said height adjustment device (31) is disposed on the lateral parts (32) of the device (1) and said pivot shaft (8) is supported in guides (33) in the lateral parts (32) of said device (1).
11. The device according to claim 9 or 10,
    characterized in that
    height adjustment device (31) is controlled by sensors (29).
12. The device according to claim 9,
    characterized in that
    the guides (33) extend obliquely in said lateral parts (32) of said device (1).
13. The device according to any one of the preceding claims,
    characterized in that
    the transporting device for transporting the stacks (5) into said pivot fork (12) has a two-piece construction, wherein the transport devices (6) and (6') each have respective independent drives.
14. A method for turning stacks of sheet-shaped material, characterized in that the method comprises the following steps:

    a) feeding a stack to a stack stop in the pivot fork;

    b) lifting the stack with height-adjustable lower grippers or by rotating the pivot fork (12);

    c) pivoting the pivot fork to a pivot angle of approximately 70°;

    d) aligning the stack against the stack stop and the lower grippers;

    e) clamping the stack between the lower grippers and upper grippers by adjusting a height of the lower grippers;

    f) continuing pivoting until reaching a final position;

    g) withdrawing the upper grippers;

    h) depositing the turned stack;

    i) rotating the pivot fork back and extending the upper grippers into the initial position; and

    j) repeating steps a) to i) until all stacks have been processed.
15. The method according to claim 14, which comprises the additional step of adjusting the height of the pivot fork to adapt to the position of the residual stack.

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