Device for lifting and moving a stack of stacked flat products

Abstract

The invention relates to a device, in particular a gripping tool, preferably a robot-guided gripping tool, for lifting and moving a stack of stacked flat products, such as folded products, the device (20) comprising a horizontally movable gripper (22) for gripping below the stack (5) and a first actuator (30), the first actuator positions the gripper (22) in a first horizontal position (40) or a second horizontal position (41). The device (20) comprises a second actuator (31) which determines a horizontal additional position (42), in particular an intermediate position, for the gripper (22). The invention advantageously makes it possible to reliably grasp and handle stacks of different specifications and to prevent the grabber, in particular the grabber teeth, from colliding with the stacks, components or personnel. The invention is preferably used in the graphic industry and preferably in a folding machine or a product collector thereof, wherein a stack of stacked folded products is stacked on a tray.

Description

Technical Field

[0001] The present invention relates to a device for lifting and moving stacks of stacked flat products. Technical Field

[0003] The present invention belongs to the technical field of the graphics industry or the plate-making printing industry and, in particular, relates to the handling (e.g., gripping, holding, moving, rotating, flipping and / or setting down) of stacked, flexible, preferably printed and folded flat products (e.g., folded sheets, preferably made of paper, cardboard, paperboard, plastic or composite materials) using a manipulator, in particular an articulated-arm robot / elbow-arm robot with a mechanical arm and a gripping device. Background Art

[0004] In the field of post-press processing (post-press finishing), it has been disclosed that stacks of flat products are conveyed on a conveyor line (e.g., rollers), the stacks are grasped by a gripping device arranged on a robot arm, the stacks are lifted from the conveyor line, moved to a pallet located near the conveyor line and placed there, for example, such solutions are disclosed by DE102020103398A1 or DE202019106975U1.

[0005] FR3110152B1 discloses a conveyor line and a robot-guided gripper head. The gripper head comprises a vertically movable upper gripper element (which is implemented as a clamping element) and a horizontally movable lower gripper element (which is implemented as a pair of teeth).

[0006] DE4124077A1 discloses a device for receiving a flat flexible component. The device comprises a base device that can move on a linear axis.

[0007] DE 40 00 262 A1 discloses a gripping device with teeth which can be moved by means of a lifting rod and a pressure cylinder and can be extended into a gripping position.

[0008] A common problem encountered in practice is that sheets of different sizes (i.e. different formats) must be lifted, moved and lowered as a stack. Existing grippers can be optimized for a specific sheet format and do not work optimally for sheets of other formats. Summary of the Invention

[0009] The object of the present invention is therefore to improve the prior art and in particular to enable safe gripping and handling of stacks of different sizes and to prevent collisions of the gripper, in particular the gripper teeth, with the stack, components or persons.

[0010] According to the present invention, the above-mentioned object can be solved by the device described in the preferred technical solution of the present invention.

[0011] Advantageous and therefore preferred developments of the invention are apparent from the dependent claims, the description and the drawings.

[0012] The present invention relates to a device for lifting and moving stacks of stacked flat products, such as folded products, in particular a gripping tool, preferably a robot-guided gripping tool, wherein the device comprises a horizontally movable gripper for gripping under the stack and a first actuator, which positions the gripper in a first horizontal position or a second horizontal position, characterized in that the device comprises a second actuator, different from the first actuator, which determines a horizontal additional position, preferably an intermediate position, for the gripper.

[0013] The invention advantageously enables reliable gripping and handling of stacks of different sizes and prevents collisions between the gripper, in particular the gripper teeth, and the stack, components or persons.

[0014] The invention is preferably used in the graphic arts industry and preferably in folding machines or their product collectors, in which stacks of stacked folded products are stacked on pallets, for example.

[0015] The present invention offers the advantage that the gripper and its (protruding teeth) can be moved from its largely retracted position in the housing or rest position or inoperative position not only into a single (gripping or operating) position and positioned there, but also into at least two mutually different (gripping or operating) positions, one of which is referred to as an additional position and, in particular, an intermediate position. The intermediate position, such as the semi-extended position, can be used in particular to grip and hold small formats, while the fully extended position can preferably handle large formats. This has the advantage that, with small formats, no teeth protrude (excessively) beyond the gripped stack and, when lowering it, collide with a stack already placed on the pallet and displace or knock it over; this also avoids the risk of injury to the operator due to protruding teeth.

[0016] The robotic arm for guiding the gripping tool is preferably part of a robotic system, which generally also includes a robot base and can be designed as a conventional industrial robot, including a fence for operator protection, in particular an articulated arm robot with three to seven axes of rotation, or as a so-called collaborative robotic system, in particular a so-called cobot. The latter does not require a fence, as the system has its own sensor system and uses this to detect contact with the operator and prevent possible injuries, such as injuries caused by the automatic stopping of the robotic arm's movement. As an alternative to a cobot, a collaborative robotic system can also be implemented as an industrial robot with an additional area scanner (to detect operators in the danger zone) and an automatic stopping device.

[0017] Expansion scheme of the present invention

[0018] The following will describe preferred developments of the present invention (in short: developments). These developments can also be combined with one another if this is not technically impossible.

[0019] One development is characterized in that the second actuator can determine the additional position by carrying out an adjustment motion of the gripper.

[0020] One development is characterized in that the second actuator can adjust a movable stop for the gripper, or that the adjustment movement can move the stop. One development is characterized in that the stop is rotatably mounted. One development is characterized in that the second actuator can position the stop in a passive position or in at least one active position. In the active position, the stop can serve as a stop for the gripper and thereby position the movable stop during its movement, in particular stop it in an additional position. One development is characterized in that the stop is coupled to the second actuator via a connecting rod.

[0021] One embodiment is characterized in that the first actuator and / or the gripper can be stopped in its active position at the stop when retracting. One embodiment is characterized in that the first actuator and / or the gripper can move the stop out of its active position when extending, for example taking it with it.

[0022] One development is characterized in that the second actuator can preferably be a pneumatic cylinder, a hydraulic cylinder or an electric cylinder.

[0023] One development is characterized in that the device can include at least one further actuator which determines a respective further horizontal additional position for the gripper.

[0024] One development is characterized in that the gripper is arranged on the device so as to be movable relative to the frame and / or housing of the device, in particular so as to be retractable and extendable.

[0025] The features and feature combinations disclosed in the above technical fields, the summary of the invention and the development solutions section as well as the following example section represent further advantageous development solutions of the invention in any combination.

[0026] Alternatives

[0027] Alternatively to the above invention, the object can be achieved in that the second actuator adjusts the gripper (in at least two positions; relative to the first actuator) or the first actuator (in at least two positions; together with the gripper) so as to determine a horizontal additional position of the gripper.

[0028] As a further alternative to the above-described invention, the object can be achieved by having a first actuator determine an additional horizontal position for the gripper, for example by moving the gripper into the additional position. In this case, the second actuator can be omitted. In this case, the first actuator can be designed as a (preferably pneumatic) multi-position cylinder.

[0029] As a further alternative to the above invention, the object can be achieved in that the gripper comprises a movable element, for example a tooth, which can be moved into an additional position by an actuator. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figures 1 to 4 1 and 2 show preferred embodiments and extensions of the present invention. Corresponding features in the figures are denoted by the same reference symbols. For clarity, repeated reference symbols in the figures are omitted.

[0031] Figure 1 A schematic diagram of a conveyor section of a machine is shown with a preferred embodiment of the device according to the invention.

[0032] Figure 2 A sectional view of a preferred embodiment of the device according to the invention is shown, with the stop in the passive position.

[0033] Figure 3 The same preferred embodiment of the device according to the invention is shown in section, with the stop in the active position.

[0034] Figure 4 A further preferred embodiment of the device according to the invention is shown in section, wherein there are two stops. DETAILED DESCRIPTION

[0035] Figure 1 A partial view shows a machine 1 in the graphics industry, preferably a post-processing machine 1, in particular a folding machine 1, and a preferably linear conveyor section 2 arranged downstream of the machine 1. The conveyor section is, for example, a roller table 2 with conveyor rollers having a conveying direction 3 and at least one motor 4 for preferably horizontally conveying a continuous stack 5 of stacked products, for example printed and folded paper sheets. The machine 1 and the conveyor section 2 are arranged on the floor 80 of a production facility, for example a printing plant, and are accessible to an operator 81.

[0036] also, Figure 1A device for transferring stacks 5, in particular for placing stacks 5 on a pallet 8, is shown. The device comprises a robot 10 with a movable robotic arm 11 (e.g. an articulated arm with a plurality of joints 12), on which a gripping tool 20 for gripping individual stacks 5 is arranged. A danger zone 13 is defined by the maximum movement of the robotic arm 11. The gripping tool 20 respectively grips one stack 5, lifts it from the conveyor section 2 and holds the stack 5 to the pallet 8 during the robot movement 14. In this way, the stacks 5 transported away from the machine 1 are placed one after another on the pallet 8 and form a pallet stack there (adjacent to each other and stacked on top of each other according to a predetermined placement pattern). In Figure 1 In the example, two pallets 8 are placed on the longitudinal side of the conveyor section. For example, the robot 10 is also placed on the longitudinal side of the conveyor section; alternatively, it can also be arranged at the end of the conveyor section 2. There is a control device 15, which controls the movement 14 of the robot arm 11 and the movement of the gripper 1 of the gripping tool 20 when transferring the stack 5. The operator 81 can remove the stack 5 at the end of the conveyor section 2 for inspection. The details of the gripping tool 20 are shown below. Figures 2 to 4 .

[0037] Figure 2 and Figure 3 A device 20, in particular a robot-guided gripper, is shown, comprising a housing 21, a gripper 22 that is movable horizontally (see direction 90), and a gripper 23 (with an actuator) that is movable vertically (see direction 91). A first actuator 30 is provided for horizontally displacing the gripper 22 (relative to the housing 21) and is connected to the gripper 22. The first actuator 30 can move the gripper 22 back and forth from a first position 40 to a second position 41, or can position the gripper 22 between these two positions 40 and 41. The first position 40 is preferably a position in which the gripper 22 grasps and handles a large stack 5a (with the first actuator 30 retracted), while the second position 41 is a position in which the gripper 22 is completely or almost completely retracted into the housing 21 (with the first actuator 30 fully extended).

[0038] According to the invention, the device 20 comprises a second actuator 31, preferably a pneumatic cylinder, which determines or defines an additional position 42, in particular an intermediate position 42. In the additional position 42, small stacks 5b can be gripped and processed (the terms "large" and "small" are to be understood in conjunction with each other). For this purpose, the stop 33, which is connected to the second actuator 31 via a connecting rod 35, is in its passive position 45 (see Figure 2 ) and active position 46 (see Figure 3) (see adjustment movement 44 of second actuator 31) or positioned in one of two positions 45 or 46. The connecting rod 35 can then be mounted rotatably about the rotation point 37. If the stop 33 is in the passive position 45, the gripper 22 can be moved forward and backward as described above. If, on the other hand, the stop is in the active position 46, it forms a stop for the gripper 22 in the intermediate position 42, i.e., the gripper 22 moved by the first actuator 30 can only be moved back and forth between the second position 41 and the additional position 42. If the stop 33 is moved or positioned back into the passive position again, the gripper 22 can again be moved back and forth between the first position 40 and the second position 41.

[0039] Figure 4 As shown, in addition to the second actuator 31, at least one further actuator 32 may be provided. The further actuator 32 can be moved or positioned back and forth between its passive position and its active position. The further stop 34 can be connected to the further actuator 32 via a further connecting rod 35 and, for example, can be mounted so as to be rotatable about the same center of rotation 37. In this way, two different additional positions 42, such as two different intermediate positions, can be determined or defined by the stop 33 and the further stop 34. This, in turn, means that the gripper 22 can be moved back and forth between the second position 41 and one of the two additional positions 42. Although the active positions of the two stops 33 and 34 are different, the passive positions can be the same. In this case, the two active positions differ at least in the horizontal direction 90.

[0040] Reference Signs List

[0041] 1. Machines, especially folding machines

[0042] 2 conveying section, especially roller table

[0043] 3 conveying direction

[0044] 4 motors

[0045] 5Pile of flat products

[0046] 5a large stack (large size)

[0047] 5b small stack (small size)

[0048] 6 Receiving position, in the conveying section

[0049] 7 Placement location, on the tray

[0050] 8 one / multiple pallets

[0051] 9-pallet stacking

[0052] 10Robots / Robot Systems

[0053] 11Robotic Arm

[0054] 12 joints

[0055] 13 Danger Zone

[0056] 14 (Placement) Movement

[0057] 15 control device

[0058] 20 devices, especially gripping tools

[0059] 21 frame or housing

[0060] 22 grabbers (horizontally movable)

[0061] 23 Gripper with actuator (can move vertically)

[0062] 30 First Actuator

[0063] 31 Second actuator

[0064] 32 Additional actuators

[0065] 33 Stop

[0066] 34 Additional stops

[0067] 35 connecting rod

[0068] 36 Additional connecting rod

[0069] 37 Rotation Point

[0070] 40 First position (grasping position for large stacks)

[0071] 41 Second position (grasping device fully retracted)

[0072] 42 additional positions, especially the middle position (gripping position for small stacks)

[0073] 43 additional positions, especially the middle position (grasping position for medium-sized stacks)

[0074] 44 Adjustment movement of the actuator

[0075] 45 Passive position of the stop

[0076] 46 Active position of the stop

[0077] 47 Adjustment movement of the gripper

[0078] 80 Floor space of production facilities

[0079] 81 Operator

[0080] 90 levels

[0081] 91 vertical.

Claims

1. A device for lifting and moving a stack of stacked flat products, wherein the device (20) comprises a gripper (22) capable of horizontal movement for gripping under the stack (5) and a first actuator (30) for positioning the gripper (22) in a first horizontal position (40) or a second horizontal position (41), characterized in that The device (20) comprises a second actuator (31) which determines a horizontal additional position (42) for the gripper (22).

2. The device according to claim 1, characterized in that The second actuator (31) determines an additional position (42) by performing an adjusting movement (44).

3. The device according to claim 1, wherein The second actuator (31) adjusts a movable stop (33) for the gripper (22).

4. The device according to claim 1, wherein The stop (33) is rotatably mounted.

5. The device according to one of the preceding claims, characterized in that The second actuator (31) positions the stop (33) in a passive position (45) or in at least one active position (46).

6. The device according to one of the preceding claims, characterized in that The stopper (33) is coupled to the second actuator (31) via a connecting rod (35).

7. The device according to one of the preceding claims, characterized in that The first actuator (30) stops in its active position (46) at the stop (33) when retracted.

8. The device according to claim 7, characterized in that The first actuator (30) moves the stop (33) out of its active position (46) when extended.

9. The device according to one of the preceding claims, characterized in that The second actuator (31) is a pneumatic cylinder, a hydraulic cylinder or an electric cylinder.

10. The device according to one of the preceding claims, characterized in that The device (20) comprises at least one further actuator (32) which determines a respective further horizontal additional position (43) for the gripper (22).

11. The device according to one of the preceding claims, characterized in that The gripper (22) can be arranged on the device (20) so as to be movable relative to the frame (21) and / or the housing (21) of the device (20).

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