Vacuum cylinder unit for label transfer

Abstract

A vacuum cylinder unit for transferring a label to a container under vacuum support and a labeling device equipped therewith are described. The vacuum cylinder unit includes a stationary lower portion, a drive shaft surrounded by the stationary lower portion, and a vacuum cylinder coupled to the drive shaft in a centered linkage by a zero point clamping system. The zero-point clamping system comprises a clamping pin integrated in the vacuum cylinder and a clamping tank rigidly connected to the drive shaft, the clamping tank having a closing mechanism to be pneumatically opened for clamping the clamping pin, and sealing rings are arranged in the lower part, which sealing rings can be inflated, so that the clamping pin can be clamped in the clamping tank. The sealing rings are arranged between the drive shaft and the lower part so as to seal an annular gap between the drive shaft and the lower part so as to form an annular channel between the sealing rings for supplying compressed air to the closing mechanism, so that the vacuum cylinder can be manually lifted from the drive shaft at any rotation position with a small vertical lift. Most of the weight of the clamping system is transferred to the region of the drive shaft.

Description

Technical Field

[0001] The invention relates to a vacuum cylinder unit according to the preamble of claim 1 , and to a labeling device for labeling containers equipped therewith. Background Art

[0002] As is known, vacuum cylinder units are components of labeling devices for applying labels provided on a roll to containers, such as bottles, by means of hot glue. In this case, the vacuum cylinder has the task of transporting the glued labels under vacuum support to the transport path of the containers and passing them on to the transport path of the containers.

[0003] The vacuum cylinder is adapted to the specific size of the label and can be pulled upwards from the associated rotary drive in order to change the size. With regard to torque transmission and good concentricity accuracy, the combination of a drive shaft with a polygonal cross-section and a form-locking hub on the vacuum cylinder has proven successful. The polygonal shaft then extends essentially to the entire height of the vacuum cylinder, so that when the size is changed, it must be lifted over the entire length of the polygonal connection and thus pulled by the drive shaft. From an ergonomic point of view, this approach is very disadvantageous due to the relatively high weight of the vacuum cylinder and the often restricted access during the changeover process.

[0004] As a stopgap measure, DE 10 2011 090 190 A1, DE 10 2013 212 132 A1 and DE 202013 103 475 U1 propose universal vacuum cylinder units in which the polygonal shaft is replaced by a self-centering connection of a clamping pin to a clamping pot. Such a connection is also referred to as a zero-point clamping system. In these universal devices, the drive shaft has a relatively short shaft stub at its upper end for this purpose, and the corresponding vacuum cylinder has a corresponding clamping pot, which can be locked centeringly on the shaft stub.

[0005] This reduces the strokes to be overcome manually to remove the vacuum cylinder when changing dimensions, compared to devices with a polygonal axis. However, the clamping can and the associated actuation mechanism increase the weight of the vacuum cylinder, thereby partially offsetting the ergonomic advantage of lifting the vacuum cylinder. Furthermore, the clamping can and the associated actuation mechanism increase the equipment expenditure of the vacuum cylinder designed as an interchangeable part, thereby increasing its purchase cost to an undesirable extent.

[0006] As a result, zero-point clamping systems for universal vacuum cylinder units have not yet been accepted, so there is still a need to improve ergonomics when replacing vacuum cylinders while keeping the costs of a specific size of vacuum cylinder as low as possible. Summary of the invention

[0007] The proposed object is achieved with a vacuum cylinder unit according to claim 1. The vacuum cylinder unit is therefore used for transferring labels under vacuum support in a labeling device for containers and comprises a stationary lower part, a drive shaft annularly surrounded by the stationary lower part, and a vacuum cylinder centrally coupled to the drive shaft via a zero-point clamping system.

[0008] According to the invention, the zero-point clamping system comprises a clamping pin integrated in a vacuum cylinder and a clamping pot rigidly connected to the drive shaft, the clamping pot having a closing mechanism to be opened pneumatically by compressed air for clamping the clamping pin. In addition, elastically inflatable sealing rings are arranged in the lower part, which can be inflated by compressed air in order to seal the annular gap between the drive shaft and the lower part upward and downward, and thus an annular channel is formed between the sealing rings for supplying compressed air to the closing mechanism.

[0009] For this purpose, the sealing rings are designed as radial seals which are elastically expanded inwards by inflation and thus come to rest on the drive shaft to seal.

[0010] In the zero-point clamping system, the clamping pin is the passive component and the clamping pot is the active closing / opening component. Therefore, all components to be actuated to open / close the zero-point clamping system can be moved to the area of ​​the drive shaft, which is not replaceable when changing dimensions. Therefore, when replacing the vacuum cylinder, it is not necessary to lift / replace the relatively heavy and expensive clamping pot and its associated actuating elements, which improves ergonomics and makes it possible to have a relatively advantageous design of the vacuum cylinder.

[0011] In other words, the clamping pin mounted on the replaceable vacuum cylinder is relatively light and low in cost.

[0012] For example, a suitable zero-point clamping system is called Typically consists of a clamping pot housing made of hardened stainless steel, a steel cone for backlash-free clamping of the associated pin, the associated precision radial spring, a spring plate and, preferably, a locking device which closes by spring force and can be opened pneumatically.

[0013] Furthermore, the annular channel temporarily formed over the entire circumference for opening the zero-point clamping system enables the vacuum cylinder to be replaced in any rotational position. The arrangement of the sealing rings in the stationary lower part enables a simple supply of compressed air to these sealing rings and the annular channel.

[0014] Preferably, the sealing rings are designed and arranged in such a way that they do not contact the drive shaft when no compressed air is applied. This makes it possible to avoid undesired frictional contact of the sealing rings with the drive shaft during production operation.

[0015] Preferably, a groove opening inwards for accommodating the sealing ring is formed at the lower part. Preferably, the sealing ring without pressure relaxation is completely sunk into the groove at this time.

[0016] Preferably, the sealing ring is not only elastically deformable toward the drive shaft but also elastically deformable at its outer circumference and, in the case of pressure-free relaxation, has an interference of 0.1% to 3%, in particular 0.5% to 1%, with respect to the groove bottom formed in each case in the form of a sealing seat in the groove. In this case, the sealing ring is always under slight tension in the groove, so that the sealing ring reliably retracts into the groove after it has been vented.

[0017] Preferably, the sealing ring has a profile with an outer clamping foot. In addition, a corresponding anchoring profile is formed in the region of the groove bottom formed in the groove for radially anchoring the clamping foot in a form-fitting and / or force-fitting manner. For example, the anchoring profile can be a C-profile or T-profile or a shaped groove that is produced, for example, as a negative mold for the clamping foot. This type of fixing is relatively flexible, space-saving and reliable.

[0018] Preferably, in the stationary lower part, axially guided and removable screws are arranged in the region of the groove bottom formed in each case in the groove for radial locking of the sealing ring. This fastening variant is particularly suitable if the sealing ring needs to be removed from the groove bottom, for example, for cleaning or to simplify the replacement of worn sealing rings and thus reduce machine downtimes.

[0019] Preferably, the sealing ring is bonded to the groove bottom formed separately in the groove in a radially fixed manner. Here, the sealing element is only fixed in the groove bottom with a suitable adhesive, which is particularly reliable and makes higher load-bearing capacity possible.

[0020] Preferably, at least one first supply channel leading between the grooves for supplying compressed air to the annular channel and a second supply channel leading into the groove for supplying compressed air to the sealing ring are also formed in the lower part, thereby making it possible to have a sealing seat with an easily guided fixed compressed air supply.

[0021] Preferably, separate external compressed air connections are assigned to the first supply channel on the one hand and the second supply channel on the other hand. This makes it possible to apply compressed air to the sealing ring first and then to the clamping pot separately and in a coordinated manner, and to release the pressure in the reverse order.

[0022] Preferably, the lower part is an annular part produced by 3D printing, which is mainly made of plastic. As a result, grooves and supply channels with relatively complex cross sections and directions can be formed in the lower part in a flexible and optimizable manner in terms of design. In addition, cost-effective production is possible.

[0023] Preferably, at least one of the grooves and in particular each groove has a cross section which narrows from the groove bottom to the annular channel. This facilitates the automatic retraction of the pressureless sealing ring into the groove to avoid frictional contact with the drive shaft. In this case, the sealing ring can have an outer cross section which widens correspondingly toward the groove bottom. For example, it is conceivable that the sealing ring and the associated groove have mutually corresponding trapezoidal cross sections.

[0024] Preferably, the clamping can comprises a spring-preloaded closing mechanism which can be opened pneumatically, i.e. by applying compressed air. The spring force enables the connection to be reliably closed even in the event of a missing / failure of the compressed air supply. This means that when compressed air is applied, the clamping pin is inserted into the clamping can and a force-locking connection is established by cutting off the compressed air supply, thereby maintaining the mechanical connection until compressed air is applied again. Thus, an ergonomic opening is provided by a temporary compressed air supply when the vacuum cylinder is stationary.

[0025] Preferably, the clamping pot is designed to be opened by applying compressed air at a pressure of 4-8 bar. This makes it possible to open the zero-point clamping system relatively easily and ergonomically using a conventional central compressed air supply.

[0026] Preferably, the clamping pin has an engagement length of 10 to 50 mm relative to the clamping pot. This means that the engagement length when the vacuum cylinder is lifted off the drive must be overcome by a manual stroke. This makes the removal of the vacuum cylinder relatively ergonomic.

[0027] The stated object is also achieved by a labelling device according to claim 13 and a labelling machine according to claim 15. According to the definition, the labelling device is used for labelling containers, in particular bottles, and for this purpose comprises a vacuum cylinder unit which is arranged to transfer the label directly to the container according to at least one of the described embodiments. For example, the labelling device is configured for all-round labelling of the container by transferring the label provided on a roller and coated with hot glue. Then, the labelling device is a hot glue labelling device. It can also be a cold glue labelling device for the container.

[0028] The labelling machine comprises the labelling device described and a continuously rotating container conveyor belt for positioning the containers during labelling transfer. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] A preferred embodiment of the present invention is shown in the accompanying drawings. In the accompanying drawings:

[0030] Figure 1 A cross-sectional view of the vacuum cylinder unit is shown;

[0031] Figure 2 A section of the vacuum cylinder unit is shown when the sealing ring is relaxed;

[0032] Figure 3 A portion of the vacuum cylinder unit is shown when the sealing ring is inflated;

[0033] Figure 4 Shows the basis on another aspect Figure 3 Arrangement;

[0034] Figure 5 An oblique view of the fixed lower portion is shown;

[0035] Figure 6 An oblique view showing a drive assembly of a vacuum cylinder unit; and

[0036] Figure 7 A schematic top view of a labeling device with a vacuum cylinder unit is shown. DETAILED DESCRIPTION

[0037] For example, from Figure 1 and Figure 2 It can be seen that in a preferred embodiment the vacuum cylinder unit 1 comprises a drive shaft 2 (with an adapter 2a included therein) and a vacuum cylinder 3 which are centered relative to the vertical rotation axis 1a via a zero-point clamping system 4 and coupled to each other for torque transmission.

[0038] The zero-point clamping system 4 comprises a clamping pin 5 which is fixed to the vacuum cylinder 3 and which points downwards during working operation, and a clamping pot 6 which is rigidly connected to the drive shaft 2 and is used to engage and clamp the clamping pin 5 .

[0039] The connection between the drive shaft 2 and the clamping cup 6 is established, for example, by an adapter 2 a arranged at the end of the drive shaft 2 , which adapter is considered to be a component of the drive shaft 2 for the sake of simplicity.

[0040] The clamping tank 6 comprises a spring pre-clamping closing mechanism 7 which can be opened by applying a first compressed air 8a ( Figure 3 ) Pneumatic opening, e.g. from known in the system.

[0041] The vacuum cylinder unit 1 further comprises a fixed lower part 9 which surrounds the drive shaft 2 in an annular manner. An annular gap 10 ( Figure 2 ).

[0042] The lower part 9 comprises two inwardly opening grooves 11, in each of which there is an elastically inflatable sealing ring 12. By applying the second compressed air 8b ( Figure 4) can inflate the sealing rings 12 so as to seal the portion of the annular gap 10 located between the sealing rings 12 upward and downward, and thereby temporarily form an annular channel 10a at the clamping pot 6 for the first compressed air 8a required to open the closing mechanism 7. Here, the terms "first" and "second" do not indicate a sequence, but are only used for functional allocation.

[0043] The (pneumatically) pressure-free relaxed sealing ring 12 is preferably completely sunk into the groove 11 .

[0044] Figure 2 The annular gap 10 is shown when the sealing ring 12 is relaxed / pressure-free during the working operation of the vacuum cylinder 3, and Figure 3 and Figure 4 The vacuum cylinder 3 is shown in a static state, wherein the sealing rings 12 are inflated and an annular channel 10 a is temporarily formed between the sealing rings.

[0045] The annular channel 10a is only temporarily generated when the vacuum cylinder 3 is stationary, and is here defined over the entire circumference by the sealing ring 12, the drive shaft 2 or the adapter 2a and the lower part 9. Thus, it is possible to supply the clamping pot 6 with compressed air regardless of the rotational position of the vacuum cylinder 3.

[0046] As from Figure 2 It can be seen that the sealing rings 12 are anchored in the grooves 11 in such a way that they do not touch the drive shaft 2 without the second compressed air 8b being applied to the seals 12. This prevents undesired frictional contact of the sealing rings 12 during operating operation.

[0047] To this end, the sealing ring 12 can, for example, be adhesively bonded and / or mechanically fixed to (the outward wall region of) the groove bottom 11a of the groove 11, in particular by form-fitting and / or force-fitting clamping and / or by a screw locking mechanism (not shown) in a (non-destructive) removable manner, as described above.

[0048] In addition or alternatively, the sealing ring 12 can have a circumferential interference relative to the associated groove bottom 11a in the unpressurized relaxed state, for example 0.1% to 3%, in particular 0.5% to 1% (not shown). As a result, even in the unpressurized state, the sealing ring 12 is compressed circumferentially, and these sealing rings avoid the resulting stress by returning to the groove bottom 11a again when appropriate and remaining there, so that these sealing rings are arranged to reliably maintain a certain distance from the drive shaft 2 / adapter 2a during working operation, thereby avoiding friction contact.

[0049] Additionally or alternatively, the groove 11 may have a cross section that at least partially narrows inwards from the groove bottom 11 a (not shown). For example, the groove 11 and the sealing ring 12 may have a trapezoidal cross section that tapers toward the annular gap 10 .

[0050] The above-mentioned measures each enable the sealing rings 12 , which have been relaxed without pressure, to be reliably retracted back into the grooves 11 , so that they are then kept at a distance from the drive shaft 2 / adapter 2 a which rotates during working operation.

[0051] In order to supply the annular channel 10 a with first compressed air 8 a from the outside, at least one first supply channel 13 is formed in the stationary lower part 9 .

[0052] In order to supply the sealing ring 12 with the second compressed air 8 b from the outside, a second supply channel 14 is formed in the stationary lower part 9 .

[0053] Furthermore, at least one connecting channel 15 is formed in the drive shaft 2 or the adapter 2 a , for example in the form of a bore, at the level of the temporary annular channel 10 a , which connects to the annular gap 10 and leads to the clamping cup 6 of the closing mechanism 7 .

[0054] After the sealing ring 12 is inflated by applying the second compressed air 8b, the first compressed air 8a can therefore be applied to the clamping pot 6 through the first supply channel 13, the temporary annular channel 10a and the connecting line 15 to pneumatically open the closing mechanism 7, thereby making it possible to remove the vacuum cylinder 3 by releasing the clamping pin 5.

[0055] The groove 11 and the sealing ring 12 are configured over the entire circumference so that it is possible to apply the first compressed air 8a to the clamping pot 6 regardless of the rotational position of the vacuum cylinder 3 relative to the lower part 9. That is, when compressed air is appropriately applied to the clamping pot 6, the vacuum cylinder 3 can be pulled out upward at any rotational position relative to the lower part 9. This allows ergonomic handling of the vacuum cylinder 3 during the replacement of a specific size.

[0056] The fixed lower part 9 is preferably an annular component which is produced in a manner known in principle, for example, by a 3D printing process. Figure 5 By way of example, it can be seen that the groove 11 and the supply channels 13 , 14 can be produced with a relatively complex shape design and optimized in a particularly practical manner.

[0057] For example, the first compressed air 8a can be supplied from the outside to the first supply line 13 via an input-side compressed air connection 13a, and the second compressed air 8b can be supplied from the outside to the second supply line 14 via a separate compressed air connection 14a, see for example Figure 3 and Figure 4 .

[0058] The first compressed air 8 a and the second compressed air 8 b can then be mechanically connected separately from one another in a manner known in principle.

[0059] The first compressed air 8 a and the second compressed air 8 b can be provided in a manner known in principle at different pressure levels, or can also have the same pressure level.

[0060] In particular, the first compressed air 8 a can also be provided by manual connection via a hose with a pressure gun or a similar valve.

[0061] In the area of ​​the zero-point clamping system 4, for example at the vacuum cylinder 3, there can be indexing pins and / or indexing holes (not shown) around the clamping pin 5 in order to determine the rotational position of the vacuum cylinder 3 relative to the drive shaft 2. Therefore, there are corresponding openings and / or pins in the area of ​​the clamping pot 6. Such indexing can not only be used to determine the relative rotational position to one another, but can also supplement the transmission of torque from the drive shaft 2 to the vacuum cylinder 3 via the zero-point clamping system 4, i.e. the force-locking connection between the clamping pin 5 and the clamping pot 6.

[0062] The indexing pins and the associated holes can be provided in the clamping pot 6 and in the adapter for the clamping pin 5 and can be based on conventional anti-twist devices for other uses of such clamping pots. In order to ensure the correct engagement of the vacuum cylinder 3, visual, optoelectronic, contact electrical checks and / or vacuum tests are possible in a manner known in principle.

[0063] The zero-point clamping system 4 is preferably automatically closed by spring pre-tensioning, but can in principle also be mechanically tightened. To separate and join the zero-point clamping system 4, it is pneumatically opened, for example, by applying first compressed air 8a at a pressure of 4 bar to 8 bar to the temporary annular channel 10a. By releasing the pressure, the zero-point clamping system 4 is automatically locked in a centering and force-locking manner and remains permanently locked without the need to reapply pressure.

[0064] The clamping pin 5 preferably has an engagement length 16 of no more than 50 mm in the clamping pot 6 , which must be overcome when the vacuum cylinder 3 is lifted in order to enable an ergonomic replacement of the vacuum cylinder 3 .

[0065] For the sake of completeness, it should be mentioned that suction elements 3a for label accommodation / delivery, which are known in principle, are arranged extensively and evenly at the vacuum cylinder 3. The associated vacuum distribution ring 17 surrounds the fixed lower part 9, see Figure 1 The vacuum distribution ring 17 is pressed by a compression spring against the corresponding sealing surface of the vacuum cylinder 3 in order to enable its vacuum supply. Via pneumatic connections and hoses (not shown), the vacuum can then be conveyed to the suction element 3a in a manner known in principle.

[0066] Figure 6The clamping pot 6 and the lower part 9 are shown by way of example as components of a drive assembly 18 for a vacuum cylinder 3, with a fixed support plate 19 (see also for example Figures 2 to 4 ) and a drive motor 20.

[0067] exist Figure 7 In the figure, a labeling device 21 for labeling containers 22 (only one is shown), in particular bottles, is shown by way of example and schematically, the labeling device having a vacuum cylinder unit 1 arranged to transfer a label 23 (only one is shown) directly to the container 22, the vacuum cylinder unit having a replaceable vacuum cylinder 3.

[0068] The label 23 is provided, for example, by a roller 24 and is applied with hot glue by a gluer 25. Therefore, the labelling device 21 shown is preferably a hot glue labelling device.

[0069] Alternatively, a corresponding docking of the vacuum cylinder unit 1 is also conceivable for cold glue labeling devices (not shown) and / or for gripper cylinders, transfer cylinders or similar rotary units which have to be completely replaced on the labeling device depending on the size.

[0070] The labelling device 21 is then preferably part of a labelling machine 31 comprising a continuously rotating container conveyor 32 for positioning the containers 22 during labelling transfers and the labelling device 21 parked at least at the periphery of the container conveyor 32 in a substantially known manner.

[0071] The above-described arrangement of the zero-point clamping system 4 with its clamping pin 5 arranged on the vacuum cylinder 3 and the clamping pot 6 arranged on the drive shaft 2 allows an ergonomic replacement of the vacuum cylinder 3 in the event of size changes and also reduces the costs for individual size-specific vacuum cylinders 3.

[0072] Furthermore, the temporary annular channel 10 a makes it possible to replace the vacuum cylinder 3 regardless of its rotational position.

[0073] To replace the vacuum cylinder 3, the electric motor connected to the drive shaft 2 is switched off and the vacuum cylinder unit 1 is brought to a standstill, ie without an operating rotary drive.

[0074] As soon as the vacuum cylinder 3 is no longer rotating, the second compressed air 8b can be connected, for example, at the external compressed air connection 13a. This inflates the sealing ring 12 and temporarily forms an annular channel 10a in the annular gap 10. The first compressed air 8a can then be connected and applied to the clamping pot 6 via the annular channel 10a, so that the clamping pot opens in such a way that the clamping pin 5 can be released and the vacuum cylinder 3 can be lifted upward from the drive shaft 2.

[0075] While continuing to apply the first compressed air 8 a and the second compressed air 8 b , the vacuum cylinder 3 suitable for another label size can be installed by inserting the clamping pin 5 of the vacuum cylinder into the clamping pot 6 .

[0076] Then, by shutting off the first compressed air 8a and introducing air into the annular channel 10a, the clamping pin 5 is mechanically clamped in the clamping pot by the spring preload of the clamping pot 6 and is thereby locked in a torsionally rigid manner. The indexing pin used for anti-twist when the clamping pot 6 is used alone can support the torque transmission in this case.

[0077] This means that when the clamping pin 5 is inserted into the clamping pot 6, the clamping pot is applied with the first compressed air 8a and is therefore opened. By closing the compressed air supply and passing air into the annular channel 10a, the clamping pot 6 is automatically closed around the clamping pin 5 by the spring preload.

[0078] Subsequently, the second compressed air 8 b can also be switched off, so that air is introduced into the sealing ring 12 , the latter is loosened and retracts again into the groove 11 .

[0079] In order to correctly assign the rotational position of the vacuum cylinder 3 to the drive shaft 2, indexing pins and / or indexing holes present on the vacuum cylinder 3 are preferably engaged with corresponding structures in the region of the clamping pot 6. The torque required in the working operation is then transmitted from the drive shaft 2 to the vacuum cylinder 3, for example by means of the adapter 2a, primarily by the force lock of the zero-point clamping system 4.

[0080] Since the pressure coupling is achieved in the entire circumferential direction by the temporarily formed annular channel 10 a , the absolute rotational position of the drive shaft 2 / clamping pot 6 can be arbitrary.

[0081] After shutting down the zero-point clamping system 4 by cutting off the supply of the first compressed air 8a and the second compressed air 8b, the vacuum cylinder unit 1 and the labeling device 21 / labeling machine 31 associated therewith can resume working operation.

Claims

1. A vacuum cylinder unit (1) for transferring labels under vacuum support in a labeling device for containers (22), the vacuum cylinder unit having a fixed lower part (9), a drive shaft (2) surrounded by the lower part (9) in an annular manner, and a vacuum cylinder (3) coupled to the drive shaft (2) in a centrally linked manner via a zero-point clamping system (4), characterized in that The zero-point clamping system (4) comprises a clamping pin (5) integrated in the vacuum cylinder (3) and a clamping pot (6) rigidly connected to the drive shaft (2), the clamping pot having a closing mechanism (7) to be opened pneumatically for clamping the clamping pin (5), and a sealing ring (12) arranged in the lower part (9), the sealing ring being able to be inflated so as to seal the annular gap (10) between the drive shaft (2) and the lower part (9), so as to form an annular channel (10a) between the sealing ring (12) for supplying compressed air to the closing mechanism (7).

2. The vacuum cylinder unit according to claim 1, wherein an inwardly opening groove (11) for accommodating the sealing ring (12) is formed in the lower part (9), and wherein the sealing ring (12) is designed and arranged so that the sealing ring does not contact the drive shaft (2) when compressed air (8b) is not applied.

3. The vacuum cylinder unit according to claim 2, wherein the sealing ring (12) is also capable of elastic deformation at its outer circumference and has a circumferential interference of 0.1% to 3%, in particular 0.5% to 1%, relative to the groove bottom (11a) respectively formed in the groove (11).

4. A vacuum cylinder unit according to claim 2 or 3, wherein the sealing ring (12) has a profile with an external clamping foot, and wherein a corresponding anchoring profile is formed in the area of ​​the groove bottom (11a) formed in each case in the groove (11) for radially anchoring the clamping foot in a form-locking and / or force-locking manner.

5. The vacuum cylinder unit according to one of claims 2 to 4, wherein axially removable bolts are arranged in the region of the groove bottom (11a) formed in each case in the groove (11) for radially locking the sealing ring (12).

6. The vacuum cylinder unit according to one of claims 2 to 5, wherein the sealing ring (12) is bonded in a radially fixed manner to a groove bottom (11a) formed in each case in the groove (11).

7. The vacuum cylinder unit according to at least one of claims 2 to 6, wherein at least one and in particular each of the grooves (11) has a cross section which narrows from the respective groove bottom (11a) to the annular channel (10a).

8. The vacuum cylinder unit according to claim 2 , wherein at least one first supply channel ( 13 ) opening between the grooves ( 11 ) for supplying compressed air ( 8 a ) to the annular channel ( 10 a ) and a second supply channel ( 14 ) opening into the groove ( 11 ) for supplying compressed air ( 8 b ) to the sealing ring ( 12 ) are formed in the lower part ( 9 ), and wherein in particular separate external compressed air connections ( 13 a , 14 a ) are assigned to the first supply channel ( 13 ) on the one hand and to the second supply channel ( 14 ) on the other hand.

9. The vacuum cylinder unit according to one of the preceding claims, wherein the lower part (9) is an annular plastic part produced by 3D printing.

10. The vacuum cylinder unit according to at least one of the preceding claims, wherein the closing mechanism (7) of the clamping pot (5) is designed to be closed by elastic preload.

11. The vacuum cylinder unit according to at least one of the preceding claims, wherein the clamping pot (6) is designed for pneumatically opening the zero-point clamping system (4) by applying compressed air at a pressure of 4 bar to 8 bar. 12 . The vacuum cylinder unit according to claim 1 , wherein the clamping pin ( 5 ) has an engagement length ( 17 ) of 10 mm to 50 mm relative to the clamping pot ( 6 ).

13. A labelling device (21) for containers (22) having a vacuum cylinder unit (1) according to at least one of the preceding claims for transferring a label (23) directly to the container, in particular a bottle.

14. The labelling device according to claim 13, which is configured to deliver labels (23) provided on a reel (24) and coated with hot glue.

15. A labelling machine (31) having a labelling device (21) according to claim 13 or 14 and having a continuously rotatable container conveyor belt (32) for positioning the containers (22) during the transfer of the labels.

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