GRIPPING SYSTEM AND METHOD FOR GRIPPING A LABEL ROLL

Description

Technical field

[0001] The invention relates to a gripping system for gripping a label roll. The invention further relates to a device for handling a label roll with such a gripping system. The invention further relates to a method for operating such a gripping system or such a device. Technical background

[0002] A container handling system may include a labeling unit for labeling containers. For example, the labeling unit may label the containers with labels from a label roll (roll of label material).

[0003] Traditionally, the label rolls are manually reloaded by an operator. The user may also have to perform other tasks, such as cutting the label tape to the correct position, applying double-sided adhesive tape to the label tape, or feeding the label tape into an automatic application system.

[0004] DE 10 2021 125 133 A1 describes a mobile robot, a supply system, and a method for changing label rolls on a labeling unit for labeling containers. The mobile robot comprises a vehicle unit for moving the robot and a manipulator unit with a multi-axis manipulator and an associated end effector for manipulating label rolls. Because the end effector is designed to grip the label rolls and empty cores of label rolls in a load-bearing, circumferential manner, ergonomically problematic steps in reloading label rolls can be performed entirely by machine with high precision and in a material-friendly manner.

[0005] A disadvantage of the manipulator unit of DE 10 2021 125 133 A1 is that the clamping force is relatively low due to the small cylinders, and no real maintenance of the clamping force is demonstrated. The gripper jaws are only locked in position. Precise centering of the label roll is not possible with this manipulator unit, as, for example, the gripper jaws are not mechanically coupled. The manipulator unit is very large in diameter, larger than the diameter of the label roll itself. To transport the label roll from a pallet to a roll holder, the clamping position must be changed from an inner to an outer gripper, and the roll must be temporarily placed down, which negatively impacts cycle time and process reliability. The fact that the label roll is clamped exclusively on its outer circumference at times could damage the label tape, and the secure hold of the label roll is questionable.The manipulator unit cannot prevent the label roll from telescoping. Furthermore, partially used label rolls with loose label tape cannot be handled.

[0006] WO 2022 / 224161 A1 discloses a machine having the features of the preamble of claim 1 for checking the shape of a roll of a web-shaped product, comprising a receiving zone for at least one roll to be evaluated, a device for moving the at least one roll from the receiving zone to an unloading zone and a device for evaluating at least the outer diameter of the roll, designed to act between the receiving zone and the unloading zone.

[0007] The invention is based on the objective of creating an improved technique for handling label rolls for loading a labeling machine. Preferably, at least some of the disadvantages of the prior art described above can be overcome. Summary of the invention

[0008] The problem is solved by the features of independent claim 1. Advantageous further developments are specified in the dependent claims and the description.

[0009] One aspect of the present disclosure relates to a gripping system (e.g., pneumatic) for gripping a label roll with an annular core. The gripping system comprises an internal gripper, preferably pneumatic, preferably an internal centric gripper, which has several (e.g., three) internal clamping jaws arranged circumferentially around a central axis of the gripping system (e.g., uniformly) and which are radially movable with respect to the central axis for gripping the label roll internally on an inner circumferential surface of the annular core. The gripping system further comprises at least one distance sensor (e.g., ultrasonic sensor, reflective optical sensor, laser sensor, or capacitive sensor) arranged for detecting a distance between the gripping system and the label roll.

[0010] Advantageously, internal gripping can be the safest and most reliable method for gripping a label roll during dynamic handling operations. Clamping the gripper against the roll core prevents damage to the label roll. The measured distance(s) can be used to determine the position of the (not yet gripped) label roll relative to the gripping system. This preferably allows for fine positioning of the internal gripper relative to the label roll and / or the roll core, ensuring a particularly secure grip. Knowing the thickness (height) of the label roll to be gripped further enables the fine positioning of the internal gripper to be adjusted to a specific insertion depth into the roll core, allowing for a particularly secure internal gripping of both very narrow and very thick label rolls.

[0011] Preferably, the inner clamping jaws can be aligned parallel to the central axis.

[0012] In one embodiment, the at least one distance sensor comprises several distance sensors, which are preferably arranged circumferentially around the central axis (e.g., uniformly), preferably alternating with the several inner clamping jaws. Advantageously, the multiple distance sensors enable the relative orientation of the label roll to the gripping system to be determined. This allows the inner gripper to be moved into an optimal alignment relative to the label roll for internal gripping, namely preferably parallel to the annular roll core / coaxially inside the annular roll core.

[0013] In another embodiment, the at least one distance sensor can be aligned parallel to the central axis. Advantageously, this allows the distance parallel to the central axis to be detected.

[0014] In one embodiment, the multiple inner clamping jaws are mechanically coupled to one another for common, preferably synchronous, radial movement, preferably by means of a positively guided transmission, and particularly preferably by means of a positively guided wedge-hook transmission. Advantageously, the common, preferably synchronous, movement can enable a centric gripping of the roll core and thus of the label roll.

[0015] In a further embodiment, the multiple inner clamping jaws each have a (e.g., convex) contact surface for bearing against the inner circumferential surface of the roll core, wherein the contact surfaces are profiled, preferably ribbed or serrated. Advantageously, profiling the contact surfaces allows the inner clamping jaws to press firmly into soft cardboard roll cores and thus reliably prevent the roll core from slipping off.

[0016] In another embodiment, the multiple inner clamping jaws are each elastically pre-tensioned radially outwards with respect to the central axis (e.g., by means of a spring). Advantageously, the elastic pre-tensioning of the inner clamping jaws allows them to remain clamped outwards even when compressed air is deprived. This preferably ensures a secure hold on the label roll in the event of a malfunction, such as a compressed air failure.

[0017] In one embodiment, the inner gripper has a pressure control valve, preferably pneumatic, for adjusting the gripping force (clamping force) of the inner gripper, preferably by adjusting a counterforce or support force to the elastic preload of the multiple inner clamping jaws. Advantageously, adjusting the gripping force by means of the pressure control valve can support the use of the gripping system as a universal gripping system, since the gripping force can be adapted to label rolls of different sizes and thus weights. Particularly with narrow or partially unwound label rolls, this reduces the risk of the roll core being deformed and damaged by excessive gripping force.

[0018] In one embodiment, the internal gripper has a check valve, preferably pneumatic, to maintain a gripping force (clamping force) of the internal gripper. Advantageously, in the event of a fault, the gripping force can be maintained by means of the check valve until the robot comes to a standstill. Optionally, the secure clamping of the label roll can then be further ensured by the elastic pretension, even if a gradual pressure loss were to occur through the check valve.

[0019] According to the invention, the gripping system further comprises an external gripper, preferably pneumatic, with several (e.g., four or six) external clamping jaws, which are arranged externally around the central axis (e.g., evenly spaced) and are radially movable with respect to the central axis to secure the label roll to an outer circumferential surface of the label roll. Advantageously, the external gripper enables additional external clamping of the label rolls. Narrow label rolls, in particular, can tend to telescoping, for example, if they are only clamped at the core and are subjected to dynamic forces during rapid robot movements. To increase process reliability and reduce the cycle time for roll changes, the gripping system can therefore be equipped with the external gripper, which can particularly improve the handling of narrow label rolls.Since the label roll is still held in place by the inner gripper over the core, and the outer gripper applies only a comparatively small force to the label roll, the risk of damage can be minimized. The outer gripper also advantageously allows for the handling of partially used label rolls where the end is no longer secured (e.g., with tape) but is loose. This also creates a possibility for automated product changeovers, as the gripping system can secure partially used label rolls, remove them from the reels, and transport them, for example, to a processing station.

[0020] In one embodiment, the multiple outer clamping jaws are rounded and / or made of an elastically compressible material and / or of a softer material than the inner clamping jaws. Advantageously, a rounded shape of the clamping jaws or a soft and / or elastic material for the outer clamping jaws can help to minimize damage to the label roll.

[0021] In another embodiment, the maximum gripping force (clamping force) achievable by the outer gripper is smaller than the maximum gripping force (clamping force) achievable by the inner gripper. Advantageously, this allows the label roll to be secured only on the outside, while the actual gripping is performed by the inner gripper.

[0022] In one embodiment, the multiple outer clamping jaws are mechanically coupled to the multiple inner clamping jaws for radial movement with respect to the central axis. Additionally, the outer clamping jaws are radially movable with respect to the central axis independently of the multiple inner clamping jaws. Alternatively or additionally, the outer gripper is attached externally to the multiple inner clamping jaws. Alternatively or additionally, the multiple outer clamping jaws are movable parallel to the central axis, preferably extending and retracting. Advantageously, the mechanical coupling, and particularly preferably the direct attachment of the outer gripper to the inner clamping jaws, ensures a direct force transmission during clamping. The outer gripper can thus be advantageously designed to be particularly rigid and lightweight.

[0023] According to the invention, the multiple outer clamping jaws comprise several (e.g., two or three) first outer clamping jaws and several (e.g., two or three) second outer clamping jaws. The multiple first outer clamping jaws are arranged circumferentially around the central axis (e.g., evenly spaced) to the outside of the multiple inner clamping jaws. The multiple second outer clamping jaws are also arranged circumferentially around the central axis (e.g., evenly spaced) to the outside of the multiple first outer clamping jaws. Advantageously, a configuration with first (inner) outer clamping jaws and second (outer) outer clamping jaws can provide a very large clamping range for clamping label rolls of varying diameters while maintaining a compact and simple design. Preferably, the outer gripper can thus secure all common label roll diameters up to 600 mm externally.

[0024] In one embodiment, the outer gripper has several radial lifting cylinders connected to the outer clamping jaws for radial movement of these jaws about the central axis. Preferably, each of the radial lifting cylinders can be attached externally to each of the internal clamping jaws. Advantageously, the connection, preferably the direct attachment, of the radial lifting cylinders to the inner clamping jaws ensures a direct force transmission during clamping. As already mentioned, this allows the outer gripper to be advantageously designed to be particularly rigid and lightweight.

[0025] In another embodiment, each of the multiple radial lifting cylinders has a displacement sensor. Advantageously, the displacement sensors can be used to check the outer diameter of the label roll when clamping it externally. It is also possible to verify the correct positioning of the external clamping jaws if the outer diameter of the label roll is known. Furthermore, telescoping of poorly wound label rolls can be advantageously detected if the outer diameter of the roll changes downwards due to the label tape slipping or unwinding. In such cases, a warning can be issued, and operator intervention can be initiated.

[0026] In one embodiment, each of the multiple radial lifting cylinders is connected to two of the outer clamping jaws for radial movement of these two outer clamping jaws (e.g., one of the first outer clamping jaws and one of the second outer clamping jaws). Advantageously, this simplifies the design of the outer gripper and allows for a more compact construction.

[0027] In a further embodiment, the outer gripper has several axial lifting cylinders which are connected to the outer clamping jaws parallel to the central axis for axial movement of the multiple outer clamping jaws, wherein preferably each of the several axial lifting cylinders is connected to each of the outer clamping jaws for axial movement of that specific outer clamping jaw. Advantageously, the axial extension and retraction allows the outer clamping jaws to be retracted when they are not needed, for example, if they would interfere with internal gripping or if they would interfere with positioning the gripping system. Advantageously, the axial extension and retraction also allows, for example, only certain outer clamping jaws, e.g., only the first or only the second outer clamping jaws, to engage with an outer circumferential surface of the label roll.

[0028] In one embodiment, the multiple radial lifting cylinders for radially moving the multiple axial lifting cylinders are connected to the multiple axial lifting cylinders along with the outer clamping jaws with respect to the central axis. Preferably, each of the multiple radial lifting cylinders can be connected to each of the multiple axial lifting cylinders for radially moving these two axial lifting cylinders. Alternatively or additionally, the multiple axial lifting cylinders are connected between the multiple radial lifting cylinders on the one hand and the outer clamping jaws on the other.

[0029] Another aspect of the present disclosure relates to a device for handling a label roll with an annular core. The device comprises a gripping system as disclosed herein. The device further comprises a robot, preferably stationary, preferably a multi-axis robot, particularly preferably an articulated robot, wherein the robot carries the gripping system as an end effector. The device further comprises a processing unit configured to operate the robot for (e.g., fine-)positioning the gripping system for gripping the label roll by means of the inner gripper, depending on a distance between the label roll and the gripping system detected by the at least one distance sensor. Optionally, the processing unit can also be configured to operate the robot for (e.g.,The device can be used to finely position the gripping system for gripping the label roll using the inner gripper, furthermore depending on a detected or predetermined thickness of the label roll, preferably to adjust the immersion depth of the inner gripper into the roll core depending on the thickness. Advantageously, the device can achieve the same advantages that have already been explained with reference to the gripping system.

[0030] In one embodiment, the at least one distance sensor comprises multiple distance sensors. The processing unit is further configured to to determine the orientation of the label roll relative to the gripping system depending on the distances detected by the multiple distance sensors, and to operate the robot to align the gripping system for gripping the label roll using the internal gripper, furthermore depending on the determined orientation, preferably to align the multiple internal clamping jaws parallel to the roll core for gripping the label roll.

[0031] As already explained, this allows for a particularly gentle and secure gripping of the label roll, thus enabling great dynamics in the handling of the gripped label roll, even with a very narrow label roll.

[0032] In another embodiment, the gripping system or robot has a camera, preferably a 2D or 3D camera, for picking up the label roll, and the processing device is further configured to: to determine the position of a label roll based on a camera image and to operate the robot to (e.g., pre-)position the gripping system for gripping the label roll using the inner gripper, depending on the determined position; and / or to determine the positions of several label rolls within a roll stack based on a camera image and to operate the robot to (e.g., pre-)position the gripping system for gripping the topmost label roll of the roll stack using the inner gripper, depending on the determined positions.

[0033] The camera can advantageously enable pre-positioning of the gripping system, allowing for subsequent fine-tuning using at least one distance sensor. The camera can also be used to rotate the gripping system around its central axis so that the external clamping jaws are positioned to engage the gaps between the label rolls of one or more roll stacks. This allows for external clamping to occur at the earliest possible stage.

[0034] In one embodiment, the gripping system further comprises an outer gripper, preferably pneumatic, with several outer clamping jaws. These jaws are preferably arranged outside the outer surface of the inner clamping jaws in a circumferential direction around the central axis (e.g., evenly spaced) and are radially movable with respect to the central axis to secure the label roll to an outer circumferential surface of the label roll. The outer gripper can have several radial lifting cylinders connected to the outer clamping jaws for radial movement of the multiple outer clamping jaws with respect to the central axis. Each of the multiple radial lifting cylinders has a displacement measuring sensor. The processing device is further configured as follows: to determine the diameter of a label roll secured externally by means of the external clamping jaws, depending on a signal output from the displacement sensors; and optionally to compare the determined diameter with a target diameter of the label roll to detect correct positioning of the multiple external clamping jaws; and / or to determine the diameter several times in succession for the same label roll to detect telescoping of the label roll when the diameter decreases.

[0035] Another aspect of the present disclosure relates to a device for labeling containers. The device comprises a (e.g., rotary) labeling unit with a labeling unit for labeling the containers. The device further comprises a device for handling a label roll as disclosed herein. The robot is configured to automatically load a roll holder connected to the labeling unit with a label roll using the gripping system, to unwind the respective label roll onto a labeling belt for feeding to the at least one labeling unit for labeling the containers. Preferably, a clamping shaft of the roll holder and the multiple inner clamping jaws can be shaped and / or arranged complementarily to one another, preferably to allow the multiple inner clamping jaws to be inserted into spaces between clamping elements of the clamping shaft during a label roll transfer.

[0036] Another aspect of the present disclosure relates to a container handling system (e.g., for tempering, manufacturing, cleaning, coating, testing, filling, closing, pasteurizing, labeling, printing, marking, laser marking, and / or packaging containers for liquid or pasty media, preferably beverages, liquid food products, or products from the pharmaceutical or healthcare industries). The container handling system may include the gripping system or the device as disclosed herein.

[0037] For example, the containers can be designed as bottles, cans, canisters, cartons, vials, tubes, etc.

[0038] Preferably, the term "processing device" can refer to electronics (e.g., implemented as a driver circuit or with microprocessor(s) and data storage) and / or mechanical, pneumatic, and / or hydraulic control systems, which, depending on their design, can perform control tasks, regulation tasks, and / or processing tasks. Although the term "control" is used here, it can also appropriately encompass or refer to "regulation" or "control with feedback" and / or "processing."

[0039] Another aspect of the present invention relates to a method for operating a gripping system according to claim 1 or a device according to claim 10, wherein the method comprises: Detecting at least one distance between the gripping system and a label roll using at least one distance sensor; (e.g., fine-)positioning and / or aligning the inner gripper to an annular core of the label roll depending on the at least one detected distance, preferably by means of a robot; gripping the label roll internally at an inner circumferential surface of the core by means of the multiple inner clamping jaws of the inner gripper after positioning and / or alignment, preferably effected by an elastic preload of the multiple inner clamping jaws; and optionally: securing the internally gripped label roll to an outer circumferential surface of the label roll by means of multiple outer clamping jaws of an outer gripper of the gripping system; and / or adjusting a gripping force (clamping force) of the inner gripper by means of a pressure regulating valve, preferably pneumatic; and / or aligning the inner gripper to a clamping shaft of a roll holder (e.g.,(connected to a labeling unit) during a label roll transfer between the inner gripper and the clamping shaft, preferably such that the multiple inner clamping jaws can plunge into spaces between clamping elements of the clamping shaft.

[0040] The process allows for the achievement of the same advantages that have already been explained with reference to the gripping system.

[0041] The previously described preferred embodiments and features of the invention can be combined with one another as desired, as long as the scope of the independent claims is not exceeded. Brief description of the characters

[0042] Further details and advantages of the invention are described below with reference to the accompanying drawings. These show: Figure 1 is a perspective view of a device according to an embodiment of the present disclosure; Figure 2 is a perspective view of a gripping system according to an embodiment of the present disclosure; and Figure 3 is a side view of the exemplary gripping system.

[0043] The embodiments shown in the figures are at least partially identical, so that similar or identical parts are provided with the same reference numerals and, to avoid repetition, reference is also made to the description of the other embodiments or figures for their explanation. Detailed description of exemplary embodiments

[0044] The Figure 1 shows a device 10 with a robot 20, a processing unit 22 (only schematically shown in Figure 1 (shown) and a gripping system 24. The Figures 2 and 3The gripping system 24 is shown in greater detail. The device 10 can preferably be included in a container treatment plant.

[0045] The device 10 is designed for handling a label roll 12. The device 10 can pick up the label roll 12 from a roll holder 14, move it to a roll receptacle 16, and place it onto the roll receptacle 16. The device 10 can also pick up a label roll 12 from the roll receptacle 16, move it to the roll holder 14, and place it on the roll holder 14.

[0046] The roller tray 14 can be a pallet, as in the Figure 1 as shown. Alternatively, the roll tray 14 can be, for example, a work table on which label rolls 12 can be placed.

[0047] The roll holder 14 can be manually refilled with label rolls 12 by a user, for example using a pallet jack or forklift. Alternatively or additionally, refilling the label rolls at the roll holder 14 can be automated, for example using an automated guided vehicle (AGV).

[0048] The roll holder 16 can, for example, be a roll plate for picking up and unwinding the label roll 12. The roll holder 16 can be horizontally oriented, as shown in Figure 1 as shown. Alternatively, the roller holder 16 can be, for example, vertically oriented.

[0049] Preferably, the roll holder 16 can have a clamping shaft 18. A label roll 12 can be clamped to the roll holder 16 by means of the clamping shaft 18.

[0050] The clamping shaft 18 preferably has several clamping elements for securing a label roll 12. The clamping elements can, for example, be radially movable with respect to a central longitudinal axis of the clamping shaft 18, e.g., extendable and retractable. Preferably, the clamping elements are arranged (e.g., evenly) distributed around the circumference of the clamping shaft 18. The clamping elements can be spaced apart from one another. Preferably, the clamping elements are arranged equidistant from each other and / or from the central longitudinal axis of the clamping shaft 18. The clamping elements can, for example, be designed as clamping jaws or clamping strips.

[0051] The roller holder 16 can be connected to a labeling unit of a labeling device for supplying the labeling unit with a label strip unwound from a label roll (not shown in the figures). The labeling unit can be designed for applying labels from the label strip onto containers. The labeling unit can, for example, be interchangeably attached to and detached from a periphery of the labeling device, e.g., via a quick-coupling mechanism, preferably without tools. The labeling device can be rotatable by means of a drive. Preferably, the labeling device can be designed as a rotary labeling device with a carousel rotatable by means of the drive. Containers can be held at intervals from one another on a circumference of the carousel in processing stations and labeled by means of the labeling unit. Alternatively, the labeling device can, for example, be...It may be designed as a linear labeling device, e.g. with only one treatment station or with several treatment stations arranged in a row next to and / or behind each other.

[0052] However, it is also possible that the roller receptacle 16 is, for example, simply a pallet, a worktable, or a conveyor.

[0053] The robot 20 can carry the gripping system 24 as an end effector. The robot 52 can use the gripping system 24 to automatically load the roll holder 16 with a label roll 12 from the roll storage 14.

[0054] Preferably, robot 20 is a multi-axis robot, particularly preferably an articulated robot. The articulated robot can be, for example, a 5-axis, 6-axis, or 7-axis articulated robot. Other robot types are also conceivable. Preferably, robot 20 is a stationary robot. However, it is also possible for robot 20 to be a mobile robot. Robot 20 can be an industrial robot with or without collaborative functionality.

[0055] The processing unit 22 can be configured to operate the robot 20 and / or the gripping system 24. For example, the processing unit 22 can operate the robot 20 to move, position, and / or align the gripping system 24. For example, the processing unit 22 can operate the gripping system 24 to grip (e.g., internal and / or external gripping) a label roll 12 and to release a gripped label roll 12.

[0056] The gripping system 24 is preferably a pneumatic gripping system. The gripping system 24 is designed to grip a label roll 12 with an annular core. The gripping system 24 has a central axis M.

[0057] Preferably, the gripping system 24 is dimensioned and designed so that it can grip label rolls 12 with a diameter in a range between approximately 160 mm and 600 mm.

[0058] The gripping system 24 comprises an inner gripper 26, preferably pneumatic, and several distance sensors 34. The gripping system 24 also comprises an outer gripper 38, preferably pneumatic.

[0059] Preferably, the internal gripper 26 can be an internal centric gripper. The internal centric gripper can be self-centering. The internal centric gripper can close centrally and grip the annular core of the label roll 12 centrally from the inside.

[0060] Preferably, the internal gripper 26 can grip a label roll 12 by clamping / clamping the label roll 12 from the inside at the roll core.

[0061] The internal gripper 26 has several internal clamping jaws 28. Preferably, exactly two or three internal clamping jaws 28 are included.

[0062] The inner clamping jaws 28 can, for example, be cylindrical segment-shaped. The inner clamping jaws 28 can, for example, extend elongatedly, preferably parallel to the central axis M.

[0063] The inner clamping jaws 28 are arranged circumferentially around the central axis M. The inner clamping jaws 28 can be spaced apart from each other. Preferably, the inner clamping jaws 28 are arranged equidistant from each other and / or from the central axis M. For example, the inner clamping jaws 28 can be arranged at angles of 360° / number of inner clamping jaws to each other with respect to the central axis M.

[0064] Preferably, an arrangement of the inner clamping jaws 28 can be substantially complementary to an arrangement of the clamping elements of the clamping shaft 18 (see Figure 1 ). During the transfer of a label roll 12 to or from the clamping shaft 18, the inner clamping jaws 28 can preferably be aligned such that they each dip into a gap between two clamping elements of the clamping shaft 18.

[0065] The inner clamping jaws 28 can each have a contact surface for bearing against the inner circumferential surface of the core of the label roll 12. The contact surfaces can be directed radially outwards with respect to the central axis M. The contact surfaces can preferably be convex. Preferably, the contact surfaces are profiled, e.g., grooved or serrated.

[0066] The inner clamping jaws 28 can be, for example, metallic milled parts or metallic forged parts.

[0067] The inner clamping jaws 28 are radially movable with respect to the central axis M for gripping the label roll 12 on an inner circumferential surface of the annular roll core. Radial movement can preferably be effected by means of elastic preload and / or pneumatic pressure on the inner gripper 26.

[0068] For example, the internal gripper 26 can have a pneumatic cylinder-piston unit that is mechanically coupled to the internal clamping jaws 28 via a gearbox. Preferably, an elastic element can be arranged in the cylinder for pre-tensioning the piston against the cylinder.

[0069] Alternatively, any other suitable drive can be used to drive the radial movement of the inner clamping jaws 28.

[0070] Preferably, the inner clamping jaws 28 can be mechanically coupled to one another. For example, the inner clamping jaws 28 can move together, preferably synchronously, radially with respect to the central axis M by means of the mechanical coupling. The mechanical coupling can, for example, be designed as a positively guided transmission, preferably as a positively guided wedge-hook transmission.

[0071] Preferably, the inner clamping jaws 28 are each elastically pre-tensioned radially outwards with respect to the central axis M. For example, the inner gripper 26 can have an elastic element. The elastic element can pre-tension the inner clamping jaws 28 radially outwards with respect to the central axis M, preferably by elastically pre-tensioning a piston against a cylinder of the inner gripper 26. For example, the elastic element can be arranged in a cylinder of the inner gripper 26. The elastic element can be, for example, a spring, preferably a helical spring. The helical spring is preferably arranged coaxially with the central axis M. Preferably, the inner clamping jaws 28 can be pre-tensioned radially outwards in the unpressurized state (without compressed air pressurizing the cylinder of the inner gripper).

[0072] It is also possible that the inner gripper 26 has a, preferably pneumatic, check valve 30 to maintain a gripping force of the inner gripper 26 (see Figure 2 ).

[0073] Preferably, the internal gripper 26 has a function for adjusting the gripping force or clamping force. For example, the internal gripper 26 can have a pressure regulating valve 32. The pressure regulating valve 32 can be a pneumatic pressure regulating valve (see Figure 2 ).

[0074] The pressure regulating valve 32 can adjust the gripping force preferably by adjusting a counterforce to the elastic preload of the inner clamping jaws 28 caused by the elastic element. For example, the clamping force can thus be reduced for narrow label rolls 12. The elastic element for preloading the inner clamping jaws 28 can be adapted accordingly to the heaviest possible label roll 12.

[0075] Alternatively, the pressure control valve 32 can adjust the gripping force, for example, by adjusting a support force to match the elastic preload of the inner clamping jaws 28 caused by the elastic element. In this case, the elastic element for preloading the inner clamping jaws 28 can be designed to be weaker than in the previous case. The heaviest possible label roll 12 can then, for example, only be held under low dynamic forces or when stationary. During production, the gripping force can then be increased accordingly by supplying compressed air to the cylinder of the inner gripper 26. This compressed air supply can optionally be adjusted to the corresponding label roll type by means of the pressure control valve 32.

[0076] Preferably, the gripping force / clamping force of the internal gripper 26 can be adjusted to the material of the core of the label roll 12 by means of the pressure control valve 32. For example, the processing device 22 can adjust the operation (position) of the pressure control valve 32 depending on a given core material. Thus, for example, a plastic core may require a greater gripping force than a cardboard core.

[0077] The pressure control valve 32 can be manually or automatically adjustable. For example, the processing unit 22 can be configured to adjust the pressure control valve 32 depending on a desired gripping force of the internal gripper 26 and / or depending on a predetermined weight of the label roll 12 and / or depending on the material of the core of the label roll 12.

[0078] The at least one distance sensor 34 is arranged to detect a distance between the gripping system 24 and the label roll 12. Preferably, the at least one distance sensor 34 can be aligned parallel to the central axis M.

[0079] In detail, each distance sensor 34 can preferably detect a distance between a side (top) of the label roll 12 facing the gripping system 24 and the respective distance sensor 34.

[0080] Preferably, the at least one distance sensor 34 can detect both the distance to the wound label tape of the label roll 12 and the distance to the core of the label roll 12. Since the label tape can extend beyond the core, damage to the label tape can be prevented by taking the different detected distances into account when positioning the gripping system 24 using the processing device 22. If, on the other hand, only the distance to the core were detected and taken into account, there would be a risk that the inner clamping jaws would be inserted too far into the label roll 12.

[0081] The at least one distance sensor 34 can be designed, for example, as an ultrasonic sensor, a reflective light sensor, a laser sensor or a capacitive sensor or similar.

[0082] Preferably, several distance sensors 34 are included, e.g., exactly two or three distance sensors 34. The distance sensors 34 can preferably be arranged distributed circumferentially around the central axis M. Preferably, the distance sensors 34 and the inner clamping jaws 28 can alternate circumferentially around the central axis M.

[0083] For example, the distance sensors 34 can be arranged equidistant from the central axis M and / or from each other. For example, distance sensors 34 can be arranged at angles of 360° / number of distance sensors to each other with respect to the central axis M.

[0084] Preferably, the processing device 22 can operate the robot 20 to position the gripping system 24 for gripping the label roll 12 by means of the internal gripper 26, depending on the detected distance or distances. Preferably, the internal gripper 26 can thus be positioned at a relatively precise distance to the label roll 12.

[0085] Optionally, the positioning of the gripping system 24 can also depend on the thickness (height) of the label roll 12. Preferably, the immersion depth of the inner gripper 26 into the roll core can be adjusted depending on the thickness of the label roll 12. The thickness can be specified, for example, via a known, detected, or predetermined grade parameter of the label roll 12. Alternatively, the thickness can be detected, for example, by means of a camera 36 (see Figure 3 ).

[0086] Preferably, by taking the thickness into account, the clamping length along the central axis M can be optimized or maximized without the risk of the inner clamping jaws 28 protruding beyond the roll core. For example, this allows even a very narrow label roll 12 to be picked up from a stack without damaging or displacing the label roll 12 below it. With a wide or thick, and therefore heavy, label roll 12, the inner clamping jaws 28 can be inserted further into the roll core, thus ensuring secure clamping of the label roll 12.

[0087] Preferably, the gripping system 24 can also have an alignment function. For example, the processing device 22 can further be configured to determine the orientation of the label roll 12 relative to the gripping system 24 based on the distances detected by the multiple distance sensors 34. The robot 20 can then be operated to align the gripping system 24 for gripping the label roll 12 using the inner gripper 26, further depending on the determined orientation. Preferably, the inner clamping jaws 28 can thus be aligned parallel to the core of the label roll 12, so that the label roll 12 can be gripped particularly securely and centrally.

[0088] For example, the distance between the gripping system 24 and the label roll 12 can be measured at several points, e.g., three. This measurement can preferably be carried out by several, e.g., three, distance sensors 34 evenly spaced around the circumference. Alternatively, the measurement can be carried out by only one distance sensor 34, which can be moved by the robot 20 to several, e.g., three, different measuring positions.

[0089] The processing unit 22 can be configured to calculate the inclination of the gripping system 24 relative to the label roll 12 from the distance measured at several points. The processing unit 22 can be configured to compensate for (level) this inclination by the robot 20 by adjusting the pose of the gripping system 24.

[0090] The optical camera 36 can be part of the gripping system 24, as exemplified in Figure 3is shown. Alternatively, camera 36 can, for example, be carried directly by robot 20. Camera 36 can, for example, be a 2D or 3D camera.

[0091] The camera 36 is designed to capture the label roll 12. Depending on a picture taken by the camera 36, ​​the processing unit 22 can, for example, determine the position of the label roll 12 on the roll tray 14 and operate the robot to position the gripping system 24 to grasp the label roll 12. It is also possible for the positions of several label rolls 12 within a roll stack to be determined from a single picture taken by the camera 36, ​​and for these positions to be used to position the gripping system 24.

[0092] For example, depending on the image captured by camera 36, ​​the gripping system 24 can be pre-positioned relative to the label roll 12. For fine positioning, the distances detected by the distance sensors 34 can then be taken into account.

[0093] It is also possible to determine a distance and / or orientation between the gripping system 24 and the label roll 12 from a (e.g. 3D) recording of the camera 36.

[0094] It is also possible that the device 10 can automatically align itself with respect to the roller mount 16 and / or the tension shaft 18 by means of the distance sensors 34 and / or the camera 36.

[0095] The outer gripper 38 can secure the already internally gripped label roll 12 at an outer circumferential surface of the label roll 12. Preferably, the maximum gripping force achievable by the outer gripper 38 can be less than the maximum gripping force achievable by the inner gripper 26.

[0096] The external gripper 38 has several external clamping jaws 40, 42, and can have several radial lifting cylinders 44 and / or several axial lifting cylinders 46, 48.

[0097] The outer clamping jaws 40, 42 serve to secure the label roll externally. The outer clamping jaws 40, 42 are radially movable with respect to the central axis M to secure the label roll 12 on an outer circumferential surface of the label roll 12.

[0098] The outer clamping jaws 40, 42 can preferably be designed for gentle external clamping of the label roll 12. For example, the outer clamping jaws 40, 42 can be rounded. The outer clamping jaws 40, 42 can be made of an elastically compressible material. The outer clamping jaws 40, 42 can be made of a softer material than the inner clamping jaws 28.

[0099] The outer clamping jaws 40, 42 can, for example, be T-shaped or rod-shaped. Preferably, the outer clamping jaws 40, 42 can be oriented radially towards the central axis M.

[0100] The outer clamping jaws 40, 42 are arranged circumferentially around the central axis M, outside the inner clamping jaws 28. Several first (inner) outer clamping jaws 40 and several second (outer) outer clamping jaws 42 are included.

[0101] The first outer clamping jaws 40 are arranged outside the inner clamping jaws 28 in a circumferential direction around the central axis M, preferably equidistant from each other and / or from the central axis M. For example, the first outer clamping jaws 40 can be arranged at angles of 360° / number of first outer clamping jaws to each other with respect to the central axis M.

[0102] The second outer clamping jaws 42 are arranged outside the first outer clamping jaws 40 in a circumferential direction around the central axis M, preferably equidistant from each other and / or from the central axis M. For example, the second outer clamping jaws 42 can be arranged at angles of 360° / number of second outer clamping jaws to each other with respect to the central axis M.

[0103] The first and second outer clamping jaws 40, 42, together with their lifting cylinders 44 and, if applicable, 46, 48, can enable a very large clamping range. The first outer clamping jaws 40 can secure label rolls 12 with a smaller diameter on the outside than the label rolls 12 that the second outer clamping jaws 42 can secure on the outside.

[0104] For example, the first set of outer clamping jaws can secure 40 label rolls (12 mm diameter) with an outer diameter between approximately 160 mm and 380 mm. The second set of outer clamping jaws (42 mm diameter) can, for example, secure label rolls (12 mm diameter) with an outer diameter between approximately 380 mm and 600 mm.

[0105] The radial lifting cylinders 44 serve to apply the clamping force to the outer circumferential surface of the label roll 12 via the outer clamping jaws 40, 42.

[0106] Specifically, the radial lifting cylinders 44 can be connected to the outer clamping jaws 40, 42 and move them radially with respect to the central axis M. Preferably, each of the radial lifting cylinders 44 can be connected to one of the first outer clamping jaws 40 and one of the second outer clamping jaws 42 for the radial movement of these two outer clamping jaws 40, 42.

[0107] The outer gripper 38 can be attached externally to the multiple inner clamping jaws 28, preferably by screws. For example, each of the radial lifting cylinders 44 can be attached externally to each of the inner clamping jaws 28, preferably by screws, e.g., on the end face. This allows the outer clamping jaws 40, 42 to be mechanically coupled to the inner clamping jaws 28 for radial movement with respect to the central axis M. By extending and retracting the radial lifting cylinders 44, the outer clamping jaws 40, 42 can then also be moved radially with respect to the central axis M independently of the multiple inner clamping jaws 28.

[0108] Preferably, the outer clamping jaws 40, 42 can also be movable parallel to the central axis M, preferably extendable and retractable. Specifically, the axial lifting cylinders 46, 48 can be connected to the outer clamping jaws 40, 42 and move the outer clamping jaws 40, 42 parallel to the central axis M. Preferably, each of the axial lifting cylinders 46, 48 is connected to each of the outer clamping jaws 40, 42 for moving these outer clamping jaws 40, 42 parallel to the central axis M.

[0109] Preferably comprising several first (inner) axial lifting cylinders 46 and several second (outer) axial lifting cylinders 48.

[0110] The first axial lifting cylinders 46 can be arranged radially inside the second axial lifting cylinders 48 with respect to the central axis M. The first axial lifting cylinders 46 can be arranged circumferentially around the central axis M, preferably equidistant from each other and / or from the central axis M. The second axial lifting cylinders 28 can be arranged circumferentially around the central axis M, preferably equidistant from each other and / or from the central axis M.

[0111] The first axial lifting cylinders 46 can be connected to the first outer clamping jaws 40 for axial movement of the first outer clamping jaws 40 parallel to the central axis M. The second axial lifting cylinders 48 can be connected to the second outer clamping jaws 42 for axial movement of the second outer clamping jaws 42 parallel to the central axis M.

[0112] When extending and retracting the axial lifting cylinders 46, 48, the outer clamping jaws 40, 42 can preferably be guided on at least one guide column each.

[0113] The axial lifting cylinders 46, 48 can be connected between the multiple radial lifting cylinders 44 and the outer clamping jaws 40, 42. Preferably, the multiple radial lifting cylinders 44, for radial movement of the axial lifting cylinders 46, 48, together with the outer clamping jaws 40, 42, can be connected to the axial lifting cylinders 46, 48 with respect to the central axis M.

[0114] For example, each of the radial lifting cylinders 44 can be connected to two of the axial lifting cylinders 46, 48 (e.g., one of the first axial lifting cylinders 46 and one of the second axial lifting cylinders 48) for radial movement of these two axial lifting cylinders 46, 48. Preferably, two axial lifting cylinders 46, 48 can be mounted on each radial lifting cylinder 44.

[0115] A procedure for handling the label roll 12 may, for example, include the following steps.

[0116] To pick up a label roll 12, the label roll 12 can first be gripped at an inner circumferential surface of the roll core by means of the inner clamping jaws 28 of the inner gripper 26. The internally gripped label roll 12 can then be secured at an outer circumferential surface of the label roll 12 by means of the multiple outer clamping jaws 40 or 42. For external securing, the outer clamping jaws 40 or 42 can first be extended by means of the axial lifting cylinders 46 or 48. Then, the outer clamping jaws 40 or 42 can be moved radially inwards towards the central axis M by means of the radial lifting cylinders 44 until the desired external clamping is achieved on the outer circumferential surface of the label roll 12.

[0117] Preferably, the external gripper 38 can be designed such that, in the retracted state of the axial lifting cylinders 46, 48, a disturbance contour caused by the external clamping jaws 40, 42 is smaller than an outer diameter of a label roll of 550 - 600 mm.

[0118] Preferably, the radial lifting cylinders 44 can each have a displacement measuring sensor, preferably an analog one. Depending on a signal output from the displacement measuring sensors, the processing device 22 can, for example, determine the diameter of a label roll 12 secured externally by means of the external clamping jaws 40 or 42.

[0119] Preferably, the determined diameter can be compared with a target diameter of the label roll 12 to detect correct positioning of the multiple outer clamping jaws 40, 42.

[0120] It is also possible to determine the diameter several times in succession on the same label roll 12, in order to detect (undesired) telescoping of the label roll 12 when the diameter decreases.

[0121] The invention is not limited to the preferred embodiments described above. Rather, a multitude of variants and modifications are possible without departing from the scope of protection of the claims.

[0122] All range specifications herein are to be understood as disclosed in such a way as to disclose all values ​​falling within the respective range individually, e.g. also as preferred narrower outer limits of the respective range. Reference symbol list

[0123] 10 Device for handling label rolls 12 Label roll 14 Roll tray 16 Roll holder 18 Tensioning shaft 20 Robot 22 Processing unit 24 Gripping system 26 Internal gripper 28 Internal clamping jaw 30 Check valve 32 Pressure regulating valve 34 Distance sensor 36 Camera 38 External gripper 40 External clamping jaw 42 External clamping jaw 44 Radial lifting cylinder 46 Axial lifting cylinder 48 Axial lifting cylinder MCenter axis

Claims

1. A gripping system (24) for gripping a label roll (12) having an annular roll core, wherein the gripping system (24) has: a, preferably pneumatic, inner gripper (26), preferably an inner centric gripper, wherein the inner gripper (26) has a plurality of inner clamping jaws (28) which are arranged distributed in a circumferential direction around a central axis (M) of the gripping system (24) and are movable radially with respect to the central axis (M) for gripping the label roll (12) on an inner circumferential face of the annular roll core; and at least one distance sensor (34), which is arranged for detecting a distance between the gripping system (24) and the label roll (12), wherein: the gripping system (24) further has a, preferably pneumatic, outer gripper (38) with a plurality of outer clamping jaws (40, 42), which are arranged on the outside of the plurality of inner clamping jaws (28) in a circumferential direction around the central axis (M) and are movable radially with respect to the central axis (M) for securing the label roll (12) on an outer circumferential face of the label roll (12), characterized in that: the plurality of outer clamping jaws (40, 42) have a plurality of first outer clamping jaws (40) and a plurality of second outer clamping jaws (42), the plurality of first outer clamping jaws (40) are arranged externally of the plurality of inner clamping jaws (28) in a circumferential direction around the central axis (M), and the plurality of second outer clamping jaws (42) are arranged on the outside of the plurality of first outer clamping jaws (40) in a circumferential direction around the central axis (M).

2. The gripping system (24) according to claim 1, wherein: the at least one distance sensor (34) has a plurality of distance sensors (34) which are arranged distributed in a circumferential direction around the central axis (M), preferably alternately with the plurality of inner clamping jaws (28); and / or the at least one distance sensor (34) is aligned parallel to the central axis (M).

3. The gripping system (24) according to claim 1 or claim 2, wherein: the plurality of inner clamping jaws (28) are mechanically coupled to one another for joint, preferably synchronous, radial movement, preferably by means of a positively driven transmission, particularly preferably by means of a positively driven wedge-hook transmission; and / or the plurality of inner clamping jaws (28) each have a contact face for contacting the inner circumferential face of the roller core, wherein the contact faces are profiled, preferably corrugated or serrated.

4. The gripping system (24) according to any of the preceding claims, wherein: the plurality of inner clamping jaws (28) are each elastically biased radially outwards with respect to the central axis (M); and / or the inner gripper (26) has a, preferably pneumatic, pressure control valve (32) for adjusting a gripping force of the inner gripper (26), preferably by adjusting a counterforce or supporting force to an elastic bias of the plurality of inner clamping jaws (28); and / or the inner gripper (26) has a, preferably pneumatic, non-return valve (30) for holding a gripping force of the inner gripper (26).

5. The gripping system (24) according to any of the preceding claims, wherein: - the plurality of outer clamping jaws (40, 42) are rounded and / or are made of an elastically compressible material and / or are made of a softer material than the inner clamping jaws (28); and / or - the maximum gripping force that can be exerted by the outer gripper (38) is less than the maximum gripping force that can be exerted by the inner gripper (26).

6. The gripping system (24) according to any of the preceding claims, wherein: the plurality of outer clamping jaws (40, 42) are mechanically coupled to the plurality of inner clamping jaws (28) for radial movement with respect to the central axis (M) with the plurality of inner clamping jaws (28) and the outer clamping jaws (40, 42) are additionally movable radially with respect to the central axis (M) independently of the plurality of inner clamping jaws (28); and / or the outer gripper (38) is mounted externally on the plurality of inner clamping jaws (28); and / or the plurality of outer clamping jaws (40, 42) are movable parallel to the central axis (M), preferably retractable and extendable.

7. The gripping system (24) according to any of the preceding claims, wherein: the outer gripper (38) has a plurality of radial lift cylinders (44) which are connected to the outer clamping jaws (40, 42) for radially moving the plurality of outer clamping jaws (40, 42) with respect to the central axis (M), wherein preferably: - one each of the plurality of radial lift cylinders (44) is mounted externally on each of the plurality of internal clamping jaws (28); and / or - the plurality of radial lift cylinders (44) each have a displacement sensor; and / or - one each of the plurality of radial lift cylinders (44) is connected to two each of the outer clamping jaws (40, 42) for the radial movement of these two outer clamping jaws (40, 42).

8. The gripping system (24) according to any of the preceding claims, wherein: the outer gripper (38) has a plurality of axial lift cylinders (46, 48) which are connected to the outer clamping jaws (40, 42) for axially moving the plurality of outer clamping jaws (40, 42) parallel to the central axis (M), wherein preferably one each of the plurality of axial lift cylinders (46, 48) is connected to each of the outer clamping jaws (40, 42) for axially moving this one outer clamping jaw (40, 42).

9. The gripping system (24) according to claim 7 and claim 8, wherein: the plurality of radial lift cylinders (44) are connected to the plurality of axial lift cylinders (46, 48) for radially moving the plurality of axial lift cylinders (46, 48) together with the outer clamping jaws (40, 42) with respect to the central axis (M), wherein preferably: - one each of the plurality of radial lift cylinders (44) is connected to two each of the plurality of axial lift cylinders (46, 48) for radially moving these two axial lift cylinders (46, 48); and / or - the multiple axial lift cylinders (46, 48) are connected between the plurality of radial lift cylinders (44) and the outer clamping jaws (40, 42).

10. An apparatus (10) for handling a label roll (12) having an annular roll core, wherein the apparatus (10) has: a gripping system (24) according to any of the preceding claims; a, preferably stationary, robot (20), preferably multi-axis robot, particularly preferably articulated arm robot, wherein the robot (20) carries the gripping system (24) as an end effector; and a processing device (22) configured to operate the robot (20) for positioning the gripping system (24) for gripping the label roll (12) by means of the inner gripper (26) depending on a distance between the label roll (12) and the gripping system (24) detected by the at least one distance sensor (34); and optionally the processing device (22) is further configured to operate the robot (20) for positioning the gripping system (24) for gripping the label roll (12) by means of the inner gripper (26) further in dependence on a detected or predetermined thickness of the label roll (12), preferably for adapting an immersion depth of the inner gripper (26) into the roll core depending on the thickness.

11. The apparatus (10) according to claim 10, wherein: the at least one distance sensor (34) has a plurality of distance sensors (34); and the processing device (22) is further configured to - determine an orientation of the label roll (12) relative to the gripping system (24) depending on the distances detected by the plurality of distance sensors (34), and - operate the robot (20) for aligning the gripping system (24) for gripping the label roll (12) by means of the inner gripper (26) furthermore in dependence on the determined alignment, preferably for aligning the plurality of inner clamping jaws (28) parallel to the roll core for gripping the label roll (12).

12. The apparatus (10) according to claim 10 or claim 11, wherein: the gripping system (24) or the robot (20) has a camera (36), preferably a 2D or 3D camera, for recording the label roll (12), and the processing device (22) is further configured to: - determine a position of the label roll (12) depending on a recording of the camera (36) and to operate the robot (20) for positioning the gripping system (24) for gripping the label roll (12) by means of the inner gripper (26) depending on the determined position; and / or - determine positions of a plurality of label rolls (12) within a roll stack depending on a recording of the camera (36) and to operate the robot (20) for positioning the gripper system (24) for gripping a respective uppermost label roll (12) of the roll stack by means of the inner gripper (26) depending on the determined positions.

13. The apparatus (10) according to any of claims 10 to 12, wherein: the gripping system (24) further has a, preferably pneumatic, outer gripper (38) with a plurality of outer clamping jaws (40, 42), which are arranged on the outside of the plurality of inner clamping jaws (28) in a circumferential direction around the central axis (M) and are movable radially with respect to the central axis (M) for securing the label roll (12) on an outer circumferential face of the label roll (12), the outer gripper (38) has a plurality of radial lift cylinders (44) which are connected to the outer clamping jaws (40, 42) for radially moving the plurality of outer clamping jaws (40, 42) with respect to the central axis (M), the plurality of radial lift cylinders (44) each have a displacement sensor, and the processing device (22) is further configured to: - determine a diameter of a label roll (12) secured on the outside by means of the outer clamping jaws (40, 42) depending on a signal output of the displacement measuring sensors; and optionally - compare the determined diameter with a nominal diameter of the label roll (12) to detect correct positioning of the multiple outer clamping jaws (40, 42); and / or - determine the diameter several times in succession for the same label roll (12) to detect telescoping of the label roll (12) when the diameter is reduced.

14. A method of operating a gripping system (24) according to any of claims 1 to 9 or an apparatus (10) according to any of claims 10 to 13, wherein the method has: detecting at least one distance between the gripping system (24) and a label roll (12) by means of the at least one distance sensor (34); positioning and / or aligning the inner gripper (26) to an annular roll core of the label roll (12) as a function of the at least one detected distance, preferably by means of a robot (20); innerly gripping the label roll (12) on an inner circumferential face of the roll core by means of the plurality of inner clamping jaws (28) of the inner gripper (26) after positioning and / or aligning, preferably effected by an elastic pretension of the plurality of inner clamping jaws (28); and optionally: securing the internally gripped label roll (12) to an outer circumferential face of the label roll (12) by means of the plurality of outer clamping jaws (40, 42) of the outer gripper (38) of the gripping system (24); and / or adjusting a gripping force of the inner gripper (26) by means of a, preferably pneumatic, pressure control valve (32); and / or aligning the inner gripper (26) with a clamping shaft (18) of a roll receptacle (16) during a label roll transfer between the inner gripper (26) and the clamping shaft (18), preferably in such a way that the plurality of inner clamping jaws (28) can penetrate into spaces between clamping elements of the clamping shaft (18).