Vacuum drum for a labeling machine and labeling machine with such a vacuum drum

Description

[0001] The invention relates to a vacuum drum for a labeling unit. Furthermore, the present invention relates to a labeling unit with such a vacuum drum.

[0002] Vacuum drums for use in labeling units of labeling machines, for example for labeling machines designed for so-called all-around labeling, have long been known to those skilled in the art.

[0003] Basically, such vacuum drums serve, among other things, to apply the labels with a label end (label edge or side) that is ahead or leading in the direction of rotation or circulation of the vacuum drum during labeling to the respective container being moved past the labeling unit, to which the label is then subsequently fully applied, e.g. by rotating the container around its vertical container axis, and removed from the vacuum drum.

[0004] On the vacuum drum, the labels are held at their leading and trailing ends by vacuum holders or vacuum pads. The distance between the corresponding vacuum holders for the leading and trailing ends on the typically cylindrical surface of the vacuum drum essentially corresponds to the length of the labels being processed. Generally, several vacuum holders for the leading end of the label, each with a corresponding holder for the trailing end, are provided around the circumference of a vacuum drum, allowing multiple labels to be transferred to multiple containers during a complete rotation of the drum.

[0005] The vacuum holders are designed in a strip-like form and have a sub-area oriented in an axial direction parallel or essentially parallel to the drum axis, with a multitude of vacuum openings which are connected to drum-side vacuum channels via bores or channels provided in the vacuum pad.

[0006] It is also known from the prior art to design the vacuum holders on the vacuum drum, which are intended for suctioning the lateral beginning and end areas of the labels, to be switchable. For this purpose, the vacuum holders can then be selectively switched from an outer working position, in which the vacuum holders guide the label section they hold against a gluing unit provided in the periphery of the vacuum drum, to an inner waiting position, in which they do not touch the gluing unit, and vice versa.

[0007] From publication EP 0 261 861 A2, a method for applying a plastic label to a container using a rotatable label transport drum is known. In this method, a label separated from a strip of polymeric material is fed to the drum and then transferred to a container in such a way that its initial region adheres to the container and, after being wrapped around the container, its final region adheres to the initial region. The method described in this publication is particularly distinguished by the fact that the label is gripped by the drum using vacuum means, and while the label rotates on the drum, a hot-melt adhesive is applied to an area in the initial region of the label, and a solvent for the polymer is applied so that an adhesive solution forms in an area of ​​the final region.

[0008] Furthermore, a labeling unit is known from German patent application DE 10 2015 214011 A1, comprising a vacuum transfer cylinder with suction bars for picking up labels, a gluing unit located next to the vacuum transfer cylinder for applying glue to the labels, and a stationary switching unit with a movable control cam for switching the suction bars to an inner position in which the suction bars run along the gluing unit without contact. The labeling unit described in this patent application is particularly distinguished by the fact that the switching unit includes a toggle lever for actuating the control cam.

[0009] Particularly in production facilities where the individual processing machines are mechanically linked and equipped with precise container transport, errors upstream of the labeling machine inevitably result in gaps in the incoming container flow. Since the vacuum drum rotates continuously during operation, a corresponding gap must be created in the label flow at the conveyor position corresponding to the gap in the container flow by not loading the vacuum drum with a label at that point. Consequently, the unloaded vacuum holders are exposed as they pass the glue unit and must be moved to the inner waiting position to prevent unwanted gluing of the vacuum holders.

[0010] For switching the vacuum holders between the standby and working positions, a stationary switching unit with movable control cams is preferably provided below the vacuum drum, according to the prior art. These cams interact with control rollers coupled to the vacuum holders, switching them into the inner standby position. The switching unit typically includes a roller mechanism for switching the control cams. This mechanism must switch quickly and transmit comparatively high switching forces. This results in loud switching noises and undesirably high wear of the switching mechanism.

[0011] Based on this, the present invention aims to provide a vacuum drum for a labeling unit which avoids the aforementioned disadvantages and in particular enables a correspondingly improved machine operation when gaps occur in the container flow.

[0012] This problem is solved by the features of claim 1. The dependent claims relate to particularly preferred embodiments of the invention.

[0013] The essential aspect of the present invention is to provide a vacuum drum for a labeling unit of a labeling machine, in particular for labeling containers or the like, comprising at least one pair of vacuum holders rotatable in one direction of rotation about a drum axis of the vacuum drum, which includes at least two vacuum holders provided on a circumferential surface of the vacuum drum offset from one another in the direction of rotation about the drum axis. A vacuum holder located at the front, relative to the direction of rotation, is provided for holding a respective front label end of a corresponding label, and a vacuum holder located at the rear, relative to the direction of rotation, is provided for holding a corresponding rear label end on the circumferential surface of the vacuum drum.The front and rear vacuum holders of the at least one pair of vacuum holders each have a rotary switching device with at least one switching element that can be switched between two fixed stationary operating positions. Furthermore, the respective rotary switching device allows the front and rear vacuum holders to be switched between an inner waiting position (the first fixed operating position, in which the at least one pair of vacuum holders can be moved past a gluing unit located next to the vacuum drum without contact) and an outer working position (the second fixed operating position, in which the at least one pair of vacuum holders can be moved past the gluing unit with contact), by means of which the respective switching element of an associated rotary switching device with at least two stationary switching devices can be brought into operative engagement to initiate the switching movements.

[0014] The vacuum drum according to the invention thus represents a bistable system that forms a fixed, i.e., self-holding, stationary operating position in both the respective inner waiting position and the outer working position, without the need to hold or guide a switching roller of a roller switching device. Due to the design of the vacuum drum according to the invention, switching is therefore only necessary when changes in state occur, i.e., in particular when gaps in the container transport occur or when a continuous container flow re-establishes itself after a longer gap with several missing containers. This reduces the number of switching operations in the case of larger gaps in position with several missing containers.

[0015] Preferably, the respective switching element can be designed to be rotationally symmetrical, for example as a switching bolt, which is switched by means of the rotary switching device. Alternatively, the respective switching element can also be designed in the form of a switching flag, wherein the switching flag preferably has an external design such that the switching flag can be actuated by the associated actuating device with particularly low noise. For example, the switching flag can have an outer contour that is at least partially convex.

[0016] Preferably, however, the respective switching element is designed as a switching roller, and particularly preferably as a freely rotatable switching roller. The design as a switching roller enables particularly wear-free and / or quiet operation of a vacuum drum according to the invention, which is highly desirable in practice.

[0017] Furthermore, it is also possible that the respective switching element consists at least partially of a plastic material.

[0018] Furthermore, it is also possible that the respective switching element is designed as a pluggable, non-movable rotatable sleeve, preferably made of a particularly wear-resistant plastic or metal material.

[0019] According to an advantageous embodiment, the vacuum drum is designed in multiple parts with several segments arranged around the drum axis, each segment in turn having at least one pair of vacuum holders with a front and rear vacuum holder that can be switched separately into the first and / or second fixed stationary operating position by means of the associated rotary switching device.

[0020] According to a further advantageous embodiment, a front vacuum pad is provided on the front vacuum holder, which is switchable between the outer working position and the inner waiting position by means of the front rotary switching device assigned to the front vacuum holder, and a rear vacuum pad is provided on the rear vacuum holder, which is switchable between the outer working position and the inner waiting position by means of the rear rotary switching device of the rear vacuum holder.

[0021] According to a further advantageous embodiment, the corresponding rotary switching device has a substantially U-shaped support element, between the side legs of which a pivot axis oriented parallel or substantially parallel to the drum axis and rotatable extends, on which at least two rocker arms are fixedly arranged spaced apart along the pivot axis.

[0022] According to a further advantageous embodiment, the rocker arms have a first and second button, each of which interacts with a spring-loaded plunger that is axially displaceable in the base leg connecting the two side legs of the U-shaped support element, and wherein the respective plunger is firmly connected on its side opposite the rocker arms to a corresponding front or rear nozzle body on which the respective vacuum pads are arranged.

[0023] According to a further advantageous embodiment, it is provided that the at least two rocker arms fixedly arranged on the pivot axis are designed to pivot back and forth between the first and second fixed stationary operating positions, such that the first stationary operating position is formed at the first button and the second stationary operating position at the second button of the corresponding rocker arms.

[0024] According to a further advantageous embodiment, it is provided that the at least two rocker levers are designed to be switchable into the first fixed stationary operating position in such a way that the associated front or rear vacuum pad is held stationary in the waiting position, and that the at least two rocker levers are designed to be switchable into the second fixed stationary operating position in such a way that the associated front or rear vacuum pad is held stationary in the working position.

[0025] According to a further advantageous embodiment, it is provided that by initiating a pivoting movement via the respective switching element by means of the at least one stationary switching device, the associated pivot axis can be rotated and the associated plungers can be moved radially outwards or inwards from the drum axis via the buttons provided on the rocker lever, so that the respective front or rear rotary switching device is switched into its first or second fixed stationary operating position.

[0026] According to a further advantageous embodiment, it is provided that the respective front switching elements of the associated front vacuum holders are provided at free ends in a common height plane and the respective rear switching elements of the associated rear vacuum holders are provided at free ends in a common height plane, wherein the height plane is designed to be further spaced away from a base support than the height plane.

[0027] According to the invention, each stationary switching device has a pivotable lever with at least one control surface for initiating a switching movement of the respective front and / or rear rotary switching device via its respective switching element.

[0028] According to a further advantageous embodiment, a first, a second and a third stationary switching device are provided, wherein the first switching device has a first pivotable lever with a first control surface, the second switching device has a second pivotable lever with a second control surface, and the third switching device has a third pivotable lever with a third and fourth control surface.

[0029] According to a further advantageous embodiment, the first stationary switching device is designed to press the front switching element of a corresponding front vacuum holder, which rotates around the drum axis in the direction of rotation, from the outside inwards towards the drum axis by means of the first control surface, so that the front rotary switching device can be switched into the first stationary operating position, in which the front vacuum holder is in the waiting position.

[0030] According to a further advantageous embodiment, the second stationary switching device is designed to press the rear switching element of a corresponding rear vacuum holder, which rotates around the drum axis in the direction of rotation past the second switching device, from the outside inwards towards the drum axis by means of the second control surface, so that the rear rotary switching device can be switched into the first stationary operating position, in which the rear vacuum holder is in the waiting position.

[0031] According to a further advantageous embodiment, the third stationary switching device is designed to press the front and rear switching elements of a corresponding front and rear vacuum holder, which rotate around the drum axis in the direction of rotation past the third switching device, radially away from the drum axis by means of the third and fourth control surfaces, so that the front and rear rotary switching device can each be switched into the second stationary operating position, in which the front and rear vacuum holder is in the working position.

[0032] The expression "essentially" or "approximately" means, within the meaning of the invention, deviations from the respective exact value by + / - 10%, preferably by + / - 5% and / or deviations in the form of changes that are insignificant for the function.

[0033] Further developments, advantages, and possible applications of the invention will also become apparent from the following description of exemplary embodiments and from the figures. All features described and / or illustrated are, individually or in any combination, fundamentally the subject matter of the invention, irrespective of their compilation in the claims or their cross-reference. The content of the claims is also incorporated into the description.

[0034] Although some aspects have been described in connection with a device, it is understood that these aspects also constitute a description of the corresponding process, so that a block or component of a device is also to be understood as a corresponding process step or as a feature of a process step. Similarly, aspects described in connection with or as a process step also constitute a description of a corresponding block, detail, or feature of a corresponding device. Some or all of the process steps may be performed by (or using) a hardware apparatus such as a microprocessor, a programmable computer, or an electronic circuit. In some embodiments, some or more of the main process steps may be performed by such an apparatus.

[0035] The invention will be explained in more detail below with reference to exemplary embodiments shown in the figures. The figures show: Fig. 1 in schematic representation and top view of a labeling unit of a labeling machine for labeling containers, Fig. 2 in schematic perspective view from a top oblique angle, a vacuum drum according to the invention, Fig. 3 in schematic perspective view from a bottom oblique angle, a vacuum drum partially shown, a vacuum drum, Fig. 4 in schematic representation, a top view of the support plate of a vacuum drum, Fig. 5 in schematic side view, a vacuum drum according to the invention, Fig. 6 in schematic perspective view, a segment with a vacuum holder pair of a vacuum drum, Fig. 7 in partially cut-away side view, the segment according to Fig. 6, Fig. 8 in schematic top view, the segment according to Figure 6 or 7, with the front vacuum holder in its working position, and Fig. 9 in schematic top view the segment according to Figure 6 or 7 , wherein the front vacuum holder is in its waiting position, and Fig.10 in schematic perspective view from obliquely below, a freestanding vacuum drum according to the invention in which the switching elements 31.1, 31.2 are designed as switching rollers.

[0036] For identical or similarly functioning elements of the invention, identical reference numerals are used in the figures. Furthermore, for the sake of clarity, only those reference numerals necessary for describing the respective figure are shown in the individual figures. The invention is also presented in the figures only as a schematic view to illustrate its operation. In particular, the illustrations in the figures serve only to explain the fundamental principle of the invention. For the sake of clarity, not all components of the device are shown.

[0037] In the figures, 1 is a labeling unit of a labeling machine for labeling bottles or similar containers 2 with so-called roll-fed labels 3. These labels are pulled from a supply roll 4 of endless, ribbon-like label material 3a and cut to the required length for each label 3 in a cutting unit 5 of the labeling unit 1. The resulting labels 3 are transferred via a vacuum drum 6, which is designed as a labeling and transfer drum, to the containers 2. The containers are moved past the labeling unit 1 on a rotor 7 of the labeling machine, which rotates about a vertical machine axis. The labels are then applied to the containers 2, as will be explained in more detail below. The directions of rotation of the rotor 7 and the vacuum drum 6 are indicated by arrows A and B, respectively.

[0038] The label material 3a is taken from a supply roll 4 by means of conveyor rollers in accordance with the rotational movement of the rotor 7 and fed to the cutting unit 5.

[0039] The cutting unit 5 includes in particular a cutting drum 12 which is driven around its vertical drum axis during labeling, for example in the opposite direction to the direction of rotation B of the vacuum drum 6 (arrow C).

[0040] In more detail, the labeling machine consists, in the known manner, of a rotor 7 driven around a vertical machine axis in the direction of arrow A, with a plurality of support surfaces formed by turntables 8 around the circumference of the rotor 7, each for a container 2. The containers 2 to be labeled are fed to the rotor 7 via a conveyor (not shown) at a bottle inlet such that each container 2 is arranged upright on a turntable 8, i.e., with its vertical axis oriented in the vertical direction. The rotor 7 moves the containers 2 past a labeling unit 1, where a label, provided with adhesive on its reverse side and held on the circumference of the vacuum drum 6, is applied with a leading label end 3.1 is transferred to each passing container 2 and then applied to the container 2 by winding or rolling it on while rotating the container 2 and peeling the label 3 off the vacuum drum 6. The labeled containers 2 are then passed back to the conveyor for removal at a container or bottle outlet.

[0041] To hold the labels 3 on the circular cylindrical circumferential surface of the vacuum drum 6, which is driven about a vertical drum axis TA synchronously with the rotor 7 but in the opposite direction of rotation, i.e., in the direction of arrow B, at least two vacuum holders 9.1 and 9.2 with vacuum openings 10 are provided, offset in the direction of rotation B of the vacuum drum 6. Specifically, a front vacuum holder 9.1 holds the respective label 3 at its front label end 3.1, which leads the direction of rotation B of the vacuum drum 6, and a rear vacuum holder 9.2 holds each label 3 at its rear label end 3.2, which lags behind the direction of rotation B of the vacuum drum 6. The front and rear vacuum holders 9.1 and 9.2 form a vacuum holder pair 9 and are offset from each other about the drum axis TA in the direction of rotation B by an arc distance equal to the length of a label 3.In other words, a front vacuum holder 9.1, relative to the direction of rotation B, is provided for holding a respective front label end 3.1 of a corresponding label 3, and a rear vacuum holder 9.2, relative to the direction of rotation B, is provided for holding a corresponding rear label end 3.2 on the circumferential surface of the vacuum drum 6.

[0042] In the illustrated embodiment, the labels 3 are produced from a web-like label material 3a by cutting or separating. In more detail, the label material 3a is wound as a continuous strip on a supply spool 4 and is unwound from this spool 4 as needed for further processing. For this purpose, the label material 3a is fed to the labeling unit 1 via several rollers and by means of the motor-driven feed rollers and then reaches the cutting unit 5, where the length forming the respective label 3 is cut from the label material 3a and transferred to the vacuum drum 6.

[0043] According to the invention, the front and rear vacuum holders 9.1, 9.2 of the at least one pair of vacuum holders 9 each have a rotary switching device 30.1, 30.2, switchable into two fixed stationary operating positions BS1, BS2, with at least one switching element 31.1, 31.2. In more detail, a front rotary switching device 30.1 is assigned to the front vacuum holder 9.1 and a rear rotary switching device 30.2 to the rear vacuum holder 9.2. The switching element 31.1, 31.2 can preferably be a component or element extending along an axis and designed to be rotationally symmetrical. In particular, the switching element 31.1, 31.2 can be designed to be rotationally symmetrical, for example as a switching bolt, which is switched by means of the rotary switching device 30.1, 30.2.

[0044] The front and rear vacuum holders 9.1 and 9.2 are switchable between an inner waiting position (WP) and an outer working position (AP) by means of the respective rotary switching device 30.1 and 30.2. In more detail, the respective vacuum holder 9.1 and 9.2 are switched to the inner waiting position (WP) in the first stationary operating position (BS1) of the respective rotary switching device 30.1 and 30.2, and to the outer working position (AP) in the second stationary operating position (BS2).

[0045] The corresponding vacuum holder 9.1, 9.2 of the corresponding vacuum holder pair 9 can be moved past a gluing unit 11 located next to the vacuum drum 6 without contact in the waiting position WP, and in the outer working position AP it is in contact with the gluing unit 11. The outer working position AP can be understood as the proper working position of the vacuum holder pair 9. In particular, in the working position AP, the vacuum holder pair 9 guides the suctioned label areas against a glue roller located on the gluing unit 11. The waiting position WP, which is radially inner compared to the outer working position AP, can be understood as a fallback position of the vacuum holder pair 9. Empty vacuum holders 9.1, 9.2, i.e., those not carrying a label, are temporarily switched to the fallback position.

[0046] In more detail, in the second fixed operating position BS2 of the rotary switching device 30.1, 30.2, the front and rear vacuum holders 9.1, 9.2 are each switched to the working position AP, thus holding a label 3 with the front and rear vacuum holders 9.1, 9.2 of a respective pair of vacuum holders 9 on the vacuum drum 6 and moving it past the gluing unit 11, i.e. the gluing station, to generate a glue application at the front and rear label ends 3.1, 3.2.

[0047] The vacuum drum 6, designed as a transfer drum, is multi-part in the embodiments shown in the figures and comprises several segments 17 arranged around the drum axis TA, preferably identical to each other, wherein each segment 17 in turn has at least one pair of vacuum holders 9 with a front and rear vacuum holder 9.1, 9.2 that can be switched separately to the first and / or second fixed stationary operating position BS1, BS2 by means of the associated rotary switching device 30.1, 30.2.

[0048] Each segment 17 provides a lower, semicircular segment-shaped support plate 15, which, together with the other semicircular segment-shaped support plates 15 of the further segments 17, is arranged on a vertical shaft 16 that drives the vacuum drum 6 and coincides with the drum axis TA. The shaft 16 can pass through a base support 40 of the vacuum drum 6 and be driven in the direction of rotation B by a drive unit 18 located below, but attached to, the base support 40. The drive unit 18 can be designed, in particular, as an electric motor, and especially advantageously as a servo motor. Finally, the base support 40 is designed to be stationary and has at least the drive unit 40 on its underside and the respective segments 17 above it.

[0049] In more detail, the following can also be provided, in particular arranged, on the respective carrier plate 15 of a corresponding segment 17: a) a vacuum holder 9.1, located at the front (with respect to the direction of rotation B), for holding a respective front label end 3.1 of an associated label 3, and b) a vacuum holder 9.2, located at the rear (with respect to the direction of rotation B), for holding this rear label end 3.2 on the circumferential surface of the vacuum drum 6. Between the respective front vacuum holder 9.1 and the rear vacuum holder 9.2, a circular arc segment 19, forming the circumferential surface of the vacuum drum 6, is provided.

[0050] In the respective segment surface section 19 of a corresponding segment 17, several intake openings 20 for air can be formed. Radially behind these intake openings 20, i.e., on the side of the segment surface section 19 facing the drum axis TA, a vacuum chamber 21 is provided for several of these intake openings 20, which are connected via suction lines 22 and a rotary connection (not shown) to a central intake device (also not shown), in particular a central vacuum generating device.

[0051] The vacuum holder pair 9 assigned to the respective segment 17 has a strip-like vacuum pad 35.1, 35.2 on the front and rear vacuum holders 9.1 and 9.2, respectively. The vacuum pad has several vacuum openings 10 and is oriented in its longitudinal extent parallel to the drum axis TA of the vacuum drum 6. The front and rear label ends 3.1, 3.2 can be drawn onto the vacuum pad via the vacuum openings 10. In particular, a front vacuum pad 35.1 is provided on the front vacuum holder 9.1. This front vacuum pad can be switched between the outer working position AP and the inner waiting position WP by means of the rotary switching device 30.1 assigned to the front vacuum holder 9.1. Similarly, a rear vacuum pad 35.2 is provided on the rear vacuum holder 9.2. This rear vacuum pad can also be switched between the outer working position AP and the inner waiting position WP by means of the rotary switching device 30.2 of the rear vacuum holder 9.2.

[0052] To ensure that the adhesive is applied only to the front and rear label ends 3.1, 3.2 of each label 3, the strip-like vacuum pads 35.1, 35.2, which are oriented with their longitudinal extent parallel to the drum axis TA of the vacuum drum 6, protrude slightly beyond the circumferential surface of the vacuum drum 6 formed by the circular arc-shaped segment surface sections 19 in their respective working position AP.

[0053] The front and rear vacuum pads 35.1, 35.2 are each hermetically sealed to a corresponding front and rear nozzle body 36.1, 36.2, such that the vacuum openings 10 provided on the respective vacuum pads 35.1, 35.2 can be connected via suction lines 22 and the rotary connection (not shown) to the central suction device (also not shown), in particular a central vacuum generating device.

[0054] Furthermore, the front and rear vacuum holders 9.1, 9.2 of the at least one pair of vacuum holders 9 each have the rotary switching device 30.1, 30.2 which can be switched between the two fixed stationary operating positions BS1, BS2, by means of which the front and / or rear vacuum holder 9.1, 9.2 can be switched between the inner waiting position WP and the outer working position AP.

[0055] The respective rotary switching device 30.1, 30.2 has a substantially U-shaped support element 32, between whose side legs a pivot axis 33 oriented parallel or substantially parallel to the drum axis TA and rotatable extends, on which at least two rocker levers 34.1, 34.2 are fixedly arranged spaced apart along the pivot axis 33.

[0056] Each rocker arm 34.1, 34.2 in turn has a first and second button SF1, SF2, each of which interacts with a spring-loaded plunger 37, which is axially displaceable in the base leg connecting the two side legs of the U-shaped support element 32 and which (plunger 37) is firmly connected on its side opposite the rocker arms 34.1, 34.2 to the corresponding front or rear nozzle body 36.1, 36.2.

[0057] In more detail, the at least two rocker arms 34.1, 34.2, which are fixedly arranged on the pivot axis 33, are designed to pivot back and forth between the first and second fixed stationary operating positions BS1, BS2, such that the first stationary operating position BS1 is formed at the first button SF1 and the second stationary operating position BS2 is formed at the second button SF1 of the rocker arms 34.1, 34.2. If at least two rocker levers 34.1, 34.2 are switched to the first fixed stationary operating position BS1, the associated front or rear vacuum pad 35.1, 35.2 is held stationary in the waiting position WP, while the associated front or rear vacuum pad 35.1, 35.2 is held stationary in the working position AP when the two rocker levers 34.1, 34.2 are switched to the second fixed stationary operating position BS2.

[0058] Furthermore, the respective pivot axis 33 is connected to the corresponding switching element 31.1, 31.2 via a lever element 39. By initiating a pivoting movement via the respective switching element 31.1, 31.2 by means of the at least one stationary switching device 41.1...41.3, the pivot axis 33 is rotated and, via the buttons SF1, SF2 provided on the rocker lever 34.1, 34.2, the associated pistons 37 are moved radially outwards or inwards from the drum axis TA, and in this way the respective front or rear rotary switching device 30.1, 30.2 is switched to its first or second fixed stationary operating position BS1, BS2. The rotary switching device 30.1, 30.2 remains in its respective first or second operating position BS1, BS2, without any action being taken via the associated switching elements 31.1, 31.2 by means of the buttons SF1, SF2 provided on the rocker levers 34.1, 34.2, which interact with the axially guided punches 36 under preload.2. A switching or holding force must be exerted by means of a stationary switching device 40.1...40.3. The front and rear rotary switching device 30.1, 30.2 is thus designed to be virtually "self-holding" in its first and second operating positions BS1, BS2.

[0059] Advantageously, the vacuum drum 6 represents a bistable system that, in both the inner waiting position WP and the outer working position AP, forms a fixed, i.e., self-holding, stationary operating position BS1, BS2, without the switching elements 31.1, 31.2 needing to be held or guided by the switching device 41.1...41.3. Therefore, switching is only required when changes in state occur, particularly when gaps in the container transport occur or when a continuous container flow resumes after a longer gap with several missing containers. This reduces the number of switching operations in the case of larger gaps with several missing containers.

[0060] Furthermore, it is provided that the respective free end of a front switching element 31.1 of a front vacuum holder 9.1 is arranged in a different height plane relative to the base support 40 compared to the respective free end of a rear switching element 31.2 of a rear vacuum holder 9.2. Specifically, the respective free ends of the front switching elements 31.1 of the associated front vacuum holders 9.1 are arranged in a common height plane H1, and the free ends of the respective rear switching elements 31.2 of the associated rear vacuum holders 9.2 are arranged in a common height plane H2, wherein the height plane H1 is positioned further away from the base support 40 than the height plane H2. In other words, the free ends of the front switching elements 31.1 are located above the free ends of the rear switching elements 31.2.

[0061] To initiate a switching movement of the front and / or rear rotary switching device 30.1, 30.2 of a vacuum holder pair 9 between the first and / or second stationary operating position BS1, BS2, the respective switching elements 31.1, 31.2 can be brought into active engagement with at least two switching devices 41.1...41.3.

[0062] Each stationary switching device 41.1...41.3 has a pivotable lever 42.1...42.3 with at least one control surface 43.1...43.4 for initiating a switching movement of the respective front and / or rear rotary switching device 30.1, 30.2 via its respective switching element 31.1, 31.2. In particular, the respective lever 42.1...42.3 is pivotable relative to the respective switching element 31.1, 31.2 such that a switching movement between the first and / or second stationary operating position BS1, BS2 can be initiated on the front and / or rear rotary switching device 30.1, 30.2 by means of its control surface 43.1...43.4.

[0063] Advantageously, a first, a second and a third stationary switching device 41.1...41.3 are provided, wherein the first switching device 41.1 has a first pivotable lever 42.1 with a first control surface 43.1, the second switching device 41.2 has a second pivotable lever 42.2 with a second control surface 43.2, and the third switching device 41.3 has a third pivotable lever 42.3 with a third and fourth control surface 43.3, 43.4.

[0064] The first stationary switching device 41.1 is configured to press the front switching element 31.1 of a corresponding front vacuum holder 9.1, which rotates past the first switching device 41.1 around the drum axis TA in the direction of rotation B, from the outside inwards towards the drum axis TA by means of the first control surface 43.1, so that the front rotary switching device 30.1 is switched into the first stationary operating position BS1, in which the front vacuum holder 9.1 is in the standby position WP. If the front switching element 31.1 now disengages from the first control surface 43.1 of the first switching device 41.1 by continuing to rotate around the drum axis TA, the front vacuum holder 9.1 remains self-locking in the first stationary operating position BS1. In particular, the first control surface 43.1 of the first switching device 41.1 is provided in the first height level H1.

[0065] The second stationary switching device 41.2 is configured to press the rear switching element 31.2 of a corresponding rear vacuum holder 9.2, which rotates around the drum axis TA in the direction of rotation B, from the outside inwards towards the drum axis TA by means of the second control surface 43.2, so that the rear rotary switching device 30.2 is switched into the first stationary operating position BS1, in which the rear vacuum holder 9.2 is in the standby position WP. If the rear switching element 31.2 now disengages from the second control surface 43.2 of the second switching device 41.2 by continuing to rotate around the drum axis TA, the rear vacuum holder 9.2 remains self-locking in the first stationary operating position BS1. In particular, the second control surface 43.2 of the second switching device 41.2 is provided in the second height level H2.

[0066] The third stationary switching device 41.3 is designed to push the front and rear switching elements 31.1, 31.2 of a corresponding front and rear vacuum holder 9.1, 9.2, which rotate around the drum axis TA in the direction of rotation B past the third switching device 41.3, radially away from the drum axis TA from the inside to the outside by means of the third and fourth control surfaces 43.3, 43.4, so that the front and rear rotary switching device 30.1, 30.2 is each switched into the second stationary operating position BS2, in which the front and rear vacuum holder 9.1, 9.2 is in the working position AP. If the front and rear switching element 31.1, 31.2 is now disengaged from the third and fourth control surfaces 43.3, 43.4 of the third switching device 41.2 by further rotation about the drum axis TA, the front and rear vacuum holder 9.1, 9.2 self-holding in the second stationary operating position BS2. In particular, the third control surface 43.3 is provided in the first height level H1 and the fourth control surface 43.4 of the third switching device 41.3 in the second height level H2.

[0067] The switching devices 41.1...41.3 are each designed to be pivotable separately relative to each other.

[0068] The invention has been described above using exemplary embodiments. It is understood that numerous modifications and adaptations are possible without departing from the underlying inventive concept.

[0069] The patent claims become part of the description. Reference symbol list

[0070] 1 Labeling unit 2 Container 3 Label 3a Label material 3.1 Front label end 3.2 Back label end 4 Supply roll 5 Cutting unit 6 Vacuum drum 7 Rotor 8 Turntable 9 Vacuum holder pair 9.1 Front vacuum holder 9.2 Rear vacuum holder 10 Vacuum openings 11 Gluing unit 12 Cutting drum 15 Carrier plate 16 Shaft 17 Segment 18 Drive unit 19 Segment surface section 20 Suction openings 21 Vacuum chamber 22 Suction lines 30.1 Front rotary switching device 30.2 Rear rotary switching device 31.1 Front switching element 31.2 Rear switching element 32 Support element 33 Swivel axis 34.1 First rocker arm 34.2 Second rocker arm 35.1 Front vacuum pad 35.2 Rear vacuum pad 36.1 Front nozzle body 36.2 Rear nozzle body 37 Stamp 39 Lever element 40 Base support 41.1 First switching device 41.2 Second switching device 41.3 Third switching device 42.1 First lever 42.2 Second lever 42.3 Third lever 43.1 First control surface 43.2 Second control surface 43.3 Third control surface 43.4 Fourth control surface A Rotor rotation direction AP Working position B Vacuum drum rotation direction BS1 First operating position BS2 Second operating position C Cutting drum rotation direction H1 First height level H2 Second height level WP Waiting position T A Drum axis SF1 First button SF2 Second button

Claims

1. Vacuum drum for a labelling unit of a labelling machine, in particular for labelling containers (2) or the like, comprising at least one vacuum holder pair (9) rotatable about a drum axis (TA) of the vacuum drum (6) in a direction of rotation (B) which comprises at least two vacuum holders (9.1, 9.2) provided on a peripheral surface of the vacuum drum (6) around the drum axis (TA) at an offset to one another in the direction of rotation (B), wherein a vacuum holder (9.1) located at the front with respect to the direction of rotation (B) is provided for holding a front label end (3.1) of a corresponding label (3), and a vacuum holder (9.2) located at the rear with respect to the direction of rotation (B) is provided for holding an associated rear label end (3.2) on the peripheral surface of the vacuum drum (6), wherein the front and rear vacuum holders (9.1, 9.2) of the at least one vacuum holder pair (9) each has a rotational switching device (30.1, 30.2) with at least one switching element (31.1, 31.2) which can be switched into two fixed stationary operating positions (BS1, BS2), wherein, by means of the respective rotational switching device (30.1, 30.2), the front and rear vacuum holders (9.1, 9.2) are switched between an inner maintenance position (WP) as a first fixed operating position (BS1), in which the at least one vacuum holder pair (9) can be guided past a gluing unit (11) provided adjacent to the vacuum drum (6) without contact, and an outer working position (AP) as a second fixed operating position (BS2), in which the at least one vacuum holder pair (9) can be guided past the gluing unit (11) with contact, in that the respective switching elements (31.1, 31.2) of an associated rotational switching device (30.1, 30.2) can be brought into active engagement with at least two stationary switching devices (41.1 ...41.3) in order to initiate the switching movements, characterised in that the respective stationary switching device (41.1 ... 41.3) each comprises a pivotable lever (42.1 ...42.3) with at least one control surface (43.1 ... 43.4) for initiating a switching movement of the associated front and / or rear rotational switching device (30.1, 30.2) via its respective switching element (31.1, 31.2).

2. Vacuum drum according to claim 1, characterised in that the vacuum drum (6) is constructed in a multi-part design comprising a plurality of segments (17) arranged around the drum axis (TA), wherein each segment (17) in turn comprises at least one vacuum holder pair (9) with front and rear vacuum holders (9.1, 9.2) that can be switched separately from one another into the first and / or second fixed stationary operating positions (BS1, BS2) by means of the associated rotational switching device (30.1, 30.2).

3. Vacuum drum according to claim 1 or 2, characterised in that a front vacuum pad (35.1) is provided on the front vacuum holder (9.1) which is designed to be switchable by means of the front rotational switching device (30.1) associated with the front vacuum holder (9.1) between the outer working position (AP) and the inner maintenance position (WP), and in that a rear vacuum pad (35.2) is provided on the rear vacuum holder (9.2) which is designed to be switchable by means of the rear rotational switching device (30.2) of the rear vacuum holder (9.2) between the outer working position (AP) and the inner maintenance position (WP).

4. Vacuum drum according to any of the preceding claims, characterised in that the corresponding rotational switching device (30.1, 30.2) each comprises a substantially U-shaped carrier element (32), between the side legs of which extends a pivot axis (33) oriented parallel or substantially parallel to the drum axis (TA) and capable of rotation, on which at least two rocker levers (34.1, 34.2) are fixedly arranged at intervals along the pivot axis (33).

5. Vacuum drum according to claim 4, characterised in that the rocker levers (34.1, 34.2) have a first and second switching surface (SF1, SF2), each of which interacts with a plunger (37) preloaded by spring force, which is guided so as to be axially displaceable in the base leg connecting the two side legs of the U-shaped support element (32), and wherein the respective plunger (37) is fixedly connected on its side facing the rocker levers (34.1, 34.2) to a corresponding front or rear nozzle body (36.1, 36.2) on which the respective vacuum pads (35.1, 35.2) are arranged.

6. Vacuum drum according to claim 4 or 5, characterised in that the at least two rocker levers (34.1, 34.2) fixedly arranged on the pivot axis (33) are designed to be pivotable back and forth between the first and second fixed stationary operating positions (BS1, BS2), such that the first stationary operating position (BS1) is formed at the first switching surface (SF1) and the second stationary operating position (BS2) is formed at the second switching surface (SF1) of the corresponding rocker levers (34.1, 34.2).

7. Vacuum drum according to any of claims 4 to 6, characterised in that the at least two rocker levers (34.1, 34.2) are designed to be switchable into the first fixed stationary operating position (BS1), such that the associated front or rear vacuum pad (35.1, 35.2) is held stationary in the maintenance position (WP), and in that the at least two rocker levers (34.1, 34.2) are designed to be switchable into the second fixed stationary operating position (BS2), such that the associated front or rear vacuum pad (35.1, 35.2) is held stationary in the working position (AP).

8. Vacuum drum according to any of claims 4 to 7, characterised in that the associated pivot axis (33) is rotatable through the initiation of a pivoting movement via the respective switching elements (31.1, 31.2) by means of the at least one stationary switching device (41.1 ...41.3), and that, via the switching surfaces (SF1, SF2) provided on the rocker lever (34.1, 34.2), the associated plungers (37) can be moved radially outwards or inwards, as viewed from the drum axis (TA), so that the respective front or rear rotational switching device (30.1, 30.2) is switched into its first or second fixed stationary operating position (BS1, BS2).

9. Vacuum drum according to any of the preceding claims, characterised in that the respective front switching elements (31.1) of the associated front vacuum holders (9.1) are provided on the free-end side in a common first height plane (H1), and the respective rear switching elements (31.2) of the associated rear vacuum holders (9.2) are provided on the free-end side in a common second height plane (H2), wherein the first height plane (H1) is formed further away from a base support (40) than the second height plane (H2).

10. Vacuum drum according to any of the preceding claims, characterised in that a first, a second and a third stationary switching device (41.1 ...41.3) are provided, wherein the first switching device (41.1) comprises a first pivotable lever (42.1) with a first control surface (43.1), the second switching device (41.2) comprises a second pivotable lever (42.2) with a second control surface (43.2), and the third switching device (41.3) comprises a third pivotable lever (42.3) with a third and fourth control surface (43.3, 43.4).

11. Vacuum drum according to any of the preceding claims, characterised in that the first stationary switching device (41.1) is designed to press the front switching element (31.1) of a corresponding front vacuum holder (9.1), which rotates past the first switching device (41.1) in the direction of rotation (B) about the drum axis (TA), by means of the first control surface (43.1) from the outside inwards towards the drum axis (TA), so that the front rotational switching device (30.1) can be switched into the first stationary operating position (BS1) in which the front vacuum holder (9.1) is in the maintenance position (WP).

12. Vacuum drum according to any of the preceding claims, characterised in that the second stationary switching device (41.2) is designed to press the rear switching element (31.2) of a corresponding rear vacuum holder (9.2), which rotates past the second switching device (41.2) in the direction of rotation (B) about the drum axis (TA), by means of the second control surface (43.2) from the outside inwards towards the drum axis (TA), so that the rear rotational switching device (30.2) can be switched into the first stationary operating position (BS1), in which the rear vacuum holder (9.2) is in the maintenance position (WP).

13. Vacuum drum according to claim 10, characterised in that the third stationary switching device (41.3) is designed to press the front and rear switching elements (31.1, 31.2) of a corresponding front and rear vacuum holder (9.1, 9.2), which rotate past the third switching device (41.3) in the direction of rotation (B) about the drum axis (TA), by means of the third and fourth control surfaces (43.3, 43.4) from the inside outwards radially away from the drum axis (TA), so that the front and rear rotational switching devices (30.1, 30.2) can each be switched into the second stationary operating position (BS2), in which the front and rear vacuum holders (9.1, 9.2) are in the working position (AP).

14. Vacuum drum according to any of the preceding claims, characterised in that at least one of the switching elements (31.1, 31.2) is designed as a switching pin, a switching tab, a switching roller, a freely rotatable switching roller or a sleeve.

15. Labelling unit for a labelling machine for labelling containers (2) with a roll-fed label, at least comprising a vacuum drum (6), characterised in that the vacuum drum (6) is designed according to any of the preceding claims.