PRINTING SYSTEM AND METHOD FOR OPERATING A PRINTING SYSTEM

Description

[0001] The invention relates to a printing system for printing cup-shaped hollow bodies and a method for operating a printing system.

[0002] A known printing system is part of a production line for manufacturing aerosol cans, such as those manufactured and distributed by the applicant. An aerosol can can be used, for example, as packaging for cosmetics such as hairspray, deodorants, or other substances sprayed as an aerosol, in particular powders or liquids. Typically, a production line for manufacturing aerosol cans comprises all process stations necessary to produce a fillable aerosol can from a disc-shaped aluminum blank. For this purpose, process steps such as an extrusion process for producing a cup-shaped blank from the disc-shaped aluminum blank, a trimming process, a brushing process, and a printing process for the cup-shaped blank can be provided, so that it can then be formed into the desired geometry on a necking machine.Modern production lines now operate at cycle rates of more than 180 can blanks or hollow bodies per minute. In order to meet individual customer requirements, the number of aerosol cans to be produced with a specific print image is becoming increasingly smaller, so that the operation of the production line must often be interrupted in order to convert the printing press to the subsequent print motif, as is known, for example, from EP 1 468 827 A1. In order to prevent or largely avoid an interruption in operation for the other process stations of the production line, provision can be made for storage devices designed for the intermediate storage of aerosol can blanks to be arranged between the process stations. These storage devices represent an additional cost factor and require additional space.

[0003] FR 2748454 A1 discloses a printing press comprising a printing unit and a feed conveyor for containers. The feed conveyor transports the containers past a treatment station upstream of the printing unit. Furthermore, a discharge conveyor is provided for transporting the printed containers to a downstream treatment station. The printing press comprises at least two printing stations located between the feed conveyor and the discharge conveyor, each of which has its own conveyor section.

[0004] DE 1299298 A discloses a device for printing, varnishing and labeling hollow bodies, for example tubes, which device contains a workpiece carrier designed as a turret head and a tool designed as a printing or varnishing unit, which are coupled to one another in terms of drive and combined into a unit via a base, wherein the tool designed as a separate unit is designed to be exchangeable on the base and is displaceable relative to the turret head and pivotable about a vertical axis. The object of the invention is to provide a printing system with which the duration of an interruption in operation, such as can be carried out to carry out a print image change, can be reduced.

[0005] This object is achieved with the features of claim 1. Here, it is provided that the printing system comprises a first printing press with a first machine frame on which a first indexing star is mounted so as to be rotatable about a first indexing star axis and a first turret is mounted so as to be rotatable about a first turret axis aligned parallel to the first indexing star axis, wherein the first turret is assigned to a first printing unit and the first indexing star is designed to feed hollow bodies to the first turret, and a second printing press with a second machine frame on which a second indexing star is mounted so as to be rotatable about a second indexing star axis and a second turret is mounted so as to be rotatable about a second turret axis aligned parallel to the second indexing star axis,wherein the second turret is associated with a second printing unit and wherein the second switching star is designed for feeding hollow bodies to the second turret, wherein the first printing press and the second printing press are accommodated on a guide device which is designed for movement of the first printing press between a functional position relative to a conveyor device associated with the guide device and a setup position, also referred to as a maintenance position, away from the conveyor device, and for movement of the second printing press between the functional position relative to a conveyor device and the setup position or maintenance position away from the conveyor device.

[0006] It is assumed here that the inking units of the printing press, which are designed, for example, for carrying out a flexographic printing process, a screen printing process, or a hot press / dry offset process, are designed in a manner already known from EP 1 468 827 A1. However, according to the invention, a first printing press forms an assembly with a second printing press, which can preferably be equipped for carrying out the same printing process, but can also be equipped for carrying out a different printing process. Furthermore, it is provided that the assembly comprising the first printing press and the second printing press includes those transport components required for precise execution of the printing process.These are, in particular, the first turret, which interacts directly with the inking units of the first printing press, and the second turret, which interacts directly with the inking units of the second printing press. In addition, a first switching starwheel assigned to the first turret, and a second switching starwheel assigned to the second turret, form further essential transport components belonging to the first printing press and the second printing press, respectively. Provision is made here for a first sliding device to be assigned to the first switching starwheel, with the aid of which hollow bodies held on the first switching starwheel can be pushed, in particular using negative pressure, onto the oppositely arranged spindles of the first turret, also referred to as the spindle plate.In the same way, a second sliding device is assigned to the second switching star, with the aid of which hollow bodies held on the second switching star, in particular using negative pressure, can be pushed onto the spindles to be arranged opposite one another of the second turret head, also referred to as the spindle plate.

[0007] Thus, in addition to the first inking units, the first printing press also comprises the first turret, the first switching star and the first push-on device and forms an assembly with the second printing press, which in addition to the second inking units also comprises the second turret, the second switching star and the second push-on device.

[0008] This assembly is mounted on a guide device designed to move one of the two printing presses into a functional position relative to a conveyor device, with the conveyor device forming a component of the production line into which the respective printing press is integrated. Thus, the printing press in the functional position is an integral component of the production line, while the other printing press, which is arranged away from the conveyor device in a maintenance position, is not considered a component of the production line at this time and can, for example, be prepared (equipped) for use in the production line.Purely by way of example, it is provided that the printing press which is in the maintenance position can be prepared for its use in the production line in such a way that at the time of a desired change of the print image, only a movement of the assembly comprising the first printing press and the second printing press is carried out in such a way that the printing press which was previously in the maintenance position is transferred to the functional position, while the printing press which was previously arranged in the functional position is moved to the maintenance position.This measure allows a change of the print image to be carried out within a few minutes and the adjustment measures on the printing press that was prepared in the maintenance position and has now been transferred to the operating mode can be so advanced that either the further processing of hollow bodies can be continued directly or the further processing of hollow bodies can be resumed after a short time with minimal adjustment work.

[0009] It is particularly preferably provided that the functional position and the maintenance position are identical for the first printing machine and for the second printing machine, so that during the execution of printing processes one of the two printing machines is always arranged in the only functional position and the other of the two printing machines is always arranged in the only maintenance position.

[0010] According to the invention, it is further provided that the guide device has a pivot joint for pivotally mounting the first printing machine and the second printing machine about a common pivot axis aligned transversely to the first turret axis and the second turret axis, in particular aligned vertically.

[0011] This pivotable bearing enables a precise movement process to be carried out for transferring the respective printing press from the functional position to the maintenance position or from the maintenance position to the functional position. For this purpose, the first machine frame and the second machine frame are connected to the guide device in such a way that a common pivoting movement about the pivot axis of the pivot joint assigned to the guide device can be carried out. In order to ensure advantageous alignment of the first printing press and the second printing press with the conveyor device, which is designed both for providing hollow bodies and for removing hollow bodies to the printing press or from the machines, the pivot axis of the pivot joint and the first turret axis are aligned transversely to one another.Preferably, the pivot axis is oriented vertically, i.e., aligned in the direction of gravity or the center of the Earth. This ensures that for the pivoting movement of the first printing press and the second printing press, only the friction of the pivot joint and the inertia of the printing presses and the guide device need to be overcome, but no lifting work is required for the two printing presses.

[0012] It is preferably provided that the first printing press and the second printing press are aligned axially symmetrically to the pivot axis and that the pivot joint is designed for a pivoting movement of the first printing press and the second printing press with a pivot angle of 180 degrees. The axially symmetrical arrangement of the first printing press and the second printing press ensures that, during the pivoting movement about the pivot axis, one printing press can assume exactly the position previously occupied by the other printing press. This is of great importance, particularly with regard to the functioning of the supply of hollow bodies to the respective printing press in the production line, since a reliable supply of hollow bodies by a conveyor device and a reliable and precise removal of hollow bodies by the conveyor device must be guaranteed there.Given the axially symmetrical arrangement of the first printing press and the second printing press, and taking into account the need to supply the first printing press and the second printing press with energy, in particular electrical energy, it is advantageous if the pivot joint is designed for a pivot angle of 180 degrees. Accordingly, for each printing press to move from its functional position to its assigned maintenance position, it rotates 180 degrees clockwise or counterclockwise. A pivot angle of more than 180 degrees, in particular an unlimited pivot angle for the pivot joint, can be achieved if the energy supply, in particular the electrical supply, of the first printing press and the second printing press is implemented using an endless rotary feed.However, if the swivel angle is limited to 180 degrees, there is the advantage that an end stop for the swivel movement can be set individually for each of the two printing machines, thus ensuring particularly high precision for positioning the respective printing machine in the functional position.

[0013] In a further development of the invention, it is provided that the first machine frame is firmly connected to the second machine frame or that the first machine frame is formed integrally with the second machine frame and that the first turret axis is aligned parallel to the second turret axis. The firm coupling of the first machine frame to the second machine frame considerably facilitates the positioning of the first printing press and the second printing press in their respective functional positions. A firm connection between the first machine frame and the second machine frame can be provided by directly coupling the two machine frames.Alternatively, it can be provided that both the first machine frame and the second machine frame are each firmly connected to the guide device, without there being direct contact between the first machine frame and the second machine frame. In a further alternative for the design of the two printing presses, it is provided that the first printing press and the second printing press are implemented with a common machine frame. This can ensure particularly precise alignment of the two printing presses to one another. Furthermore, it is provided that the first turret axis is aligned parallel to the second turret axis and that the first turret axis and the second turret axis span a turret axis plane whose surface normal is aligned parallel to the pivot axis.

[0014] In a further embodiment of the invention, the guide device comprises a linear guide for linearly movable mounting of the first printing press and the second printing press along a movement path. Such a design of the guide device can be implemented in combination with a pivot bearing. A linear displacement of the guide device with the two printing presses attached to it is of particular interest when a displacement of the conveyor device, which is designed to supply and remove hollow bodies to and from the two printing presses, would pose considerable technical difficulties. In a guide device which, in addition to the pivot joint, also comprises a linear guide, a sequential sequence of a linear movement and a pivoting movement or an overlap between a linear movement and a pivoting movement can be provided.Depending on the design of the guide device, the movement path determined by the guide device is either a sequence of a straight line and a curve or a curve.

[0015] It is advantageous if a section of a chain conveyor and a withdrawal unit, in particular designed as a transfer drum or a transfer conveyor belt, are attached to the conveyor, wherein the withdrawal unit is designed for withdrawing hollow bodies from conveyor rods of the chain conveyor and transferring the hollow bodies to the adjacently arranged first switching star or second switching star. In this context, the conveyor has the task of providing hollow bodies from a preceding process station to the first printing press or the second printing press, respectively. It is assumed that the conveyor represents an integral component of a production line for the manufacture of hollow bodies, in particular aerosol can blanks.For example, it is provided that the conveyor device is connected to a storage device, which in turn is connected to a preceding process station, so that hollow bodies provided by the preceding process station can be temporarily used to receive hollow bodies in the event of a replacement of the first printing press with the second printing press or in the opposite direction, without the preceding process station having to be temporarily shut down. The storage device can in particular be designed as a chain storage device and is directly connected to the conveyor device of the printing system, so that the hollow bodies output from the storage device can subsequently be fed to the first printing press or the second printing press.

[0016] For this purpose, the hollow bodies pushed onto conveyor rods of a chain conveyor device are pulled off the respective conveyor rod by a take-off unit in the course of a linear movement aligned in the direction of a longitudinal axis of the respective hollow body and are transferred to the adjacently arranged first switching star or second switching star of the respective printing press.

[0017] For example, the withdrawal unit can be designed as a transfer drum, in which linearly movable vacuum shells are provided on an outer surface of a drum whose rotational axis is aligned parallel to the first switching star axis or second switching star axis, respectively, for adhering to the hollow bodies held on the conveyor rods. During a rotational relative movement of the transfer drum with respect to the chain conveyor, a synchronized linear movement of the vacuum shells occurs parallel to the rotational axis of the transfer drum in order to perform the desired withdrawal movement. Subsequently, the withdrawn hollow bodies can be transferred in a rolling motion with the respectively assigned first or second switching star.

[0018] In a transfer conveyor belt, it is provided that a conveying direction of the transfer conveyor belt runs at an acute angle to the conveying direction of the chain conveyor device and thus the hollow bodies coming into contact with the transfer conveyor belt are pulled off the conveyor bars of the chain conveyor device in the course of a superposition of two linear movements, the first of which is aligned parallel to the conveying direction of the chain conveyor device and the second of which is aligned transversely to the conveying direction of the chain conveyor device, and can be transferred to the respectively assigned first or second switching star.

[0019] It is expedient if the first printing press is assigned a first attachment device which is designed to transfer hollow bodies from the first turret to the conveyor rods of the chain conveyor device, and if the second printing press is assigned a second attachment device which is designed to transfer hollow bodies from the second turret to the conveyor rods of the chain conveyor device. It is assumed here that the first turret and the second turret, which can each also be referred to as spindle plates, each have a predetermined, in particular an identical, number of spindles aligned parallel to the first turret axis or the second turret axis and arranged on a pitch circle coaxial with the respective turret axis, which are each provided for receiving hollow bodies.These spindles can each be provided with an associated rotary drive in order to be able to carry out a rolling movement on a printing blanket bearing the motif to be printed during the printing process.

[0020] The task of the slip-on device is then to remove the freshly printed, preferably already dried, hollow bodies from the spindles precisely mounted on the turret without causing any damage, so that they can then be transferred to the chain conveyor device. For this purpose, it is advantageous if each of the two printing presses is assigned a separate slip-on device, as this ensures maximum precision for removing the hollow bodies from the spindles. The slip-on process onto the conveyor rods of the chain conveyor device is significantly less critical, although aging or wear of the conveyor chain must be taken into account here. In this respect, the first slip-on device is arranged on the first machine frame of the first printing press, while the second slip-on device is arranged on the second machine frame of the second printing press.

[0021] Preferably, the conveyor device is assigned a plug-in device designed to transfer hollow bodies from the first turret or the second turret to the conveyor rods of the chain conveyor device. In this alternative embodiment of the printing system, the (single) plug-in device is not assigned to the respective printing press, but rather is a component of the conveyor device. Accordingly, the plug-in device is not pivoted during the pivoting movement of the first printing press and the second printing press, but rather is fixedly arranged on a machine frame provided for the conveyor device.The advantage of such an arrangement is that only a single plug-in device is required, but it must be accepted that after the pivoting movement for the first printing machine and the second printing machine has been carried out, the plug-in device must first be adjusted relative to the respective first or second turret head, which entails a certain loss of time when carrying out a print image change.

[0022] In a further embodiment of the invention, it is provided that the conveyor device with the first printing press or with the second printing press determines a conveyor path for the hollow bodies, which extends along a first section of the chain conveyor device, the take-off unit, the first printing press with the first switching starwheel and the first turret or the second printing press with the second switching starwheel and the second turret as well as the respectively assigned attachment device up to a second section of the chain conveyor device. It is crucial that one of the two printing presses can be coupled into this conveyor path and for this purpose comprises at least the respective switching starwheel and the respective turret. The assignment of the attachment device can be selected depending on requirements either directly to the respective printing press or to the conveyor device.With regard to the printing system, the chain conveyor device may comprise a single conveyor chain or a combination of a first conveyor chain and a second conveyor chain.

[0023] In an advantageous development of the invention, it is provided that the chain conveyor device comprises a first conveyor chain section which is assigned to the take-off unit and a second conveyor chain section which is assigned to the attachment device, wherein the first conveyor chain section belongs to a first conveyor chain and wherein the second conveyor chain section belongs to a second conveyor chain. For example, it is provided that the first conveyor chain extends as an endlessly circulating conveyor chain between the process station upstream of the printing system and the printing system, optionally with the interposition of a corresponding storage device. Furthermore, it is provided that the second conveyor chain is designed as an endlessly circulating conveyor chain between the printing system and a downstream process station, in particular with the interposition of a storage device.In principle, it is intended that a conveying speed of the first conveyor chain and a conveying speed of the second conveyor chain are identical with regard to the number of hollow bodies provided or removed per unit of time, whereby a spatial division of the conveyor bars of the first conveyor chain and the second conveyor chain does not necessarily have to be identical.

[0024] In a further embodiment of the invention, the guide device comprises a linear bearing device designed for movement of the conveyor device between a working position for interaction with the first printing press or the second printing press and a change position for carrying out the pivoting movement for the first printing press and the second printing press. Such a linear movement for the conveyor device is particularly important when the guide device for the first printing press and the second printing press only provides a pivot joint, so that a linear displacement of the conveyor device is necessary due to the spatial configuration of the first printing press and the second printing press and to avoid collisions with the conveyor device.For example, it is provided that the conveyor device can be removed from the first printing press and the second printing press in a horizontal direction that is aligned transversely to the first turret axis and the second turret axis, in order to enable the pivoting movement for the first printing press and the second printing press to be carried out in a changeover position. The conveyor device is then transferred back into the working position by a linear displacement with the aid of the linear bearing device, where it can ensure the desired supply and removal of hollow bodies. Typically, at least one conveyor chain is assigned to the conveyor device, with chain link axes of the chain links of the conveyor chain being aligned transversely to the linear movement axis determined by the linear bearing device.Accordingly, a linear displacement of the conveyor device in a spatial direction oriented transversely to the chain link axes of the chain links of the conveyor chain is to be provided. Alternatively, a pivoting movement of the conveyor device about a pivot axis, in particular a horizontal one, can also be provided, which is aligned parallel to the chain link axes of the chain links of the conveyor chain.

[0025] It is advantageous if the pivot joint comprises at least one bearing from the group: rolling bearing, plain bearing, hydrostatic plain bearing, and if a drive device for initiating a pivoting movement on the first printing press and the second printing press is assigned to the pivot joint. Preferably, the pivot joint comprises a combination of one or more rolling bearings, with which the precise spatial alignment of the first printing press and the second printing press can be ensured, with a plain bearing or a hydrostatic plain bearing, which are designed to absorb the considerable weight of the first printing press and the second printing press. It can be assumed that the combination of the first printing press and the second printing press has a weight in a range of 2000 kilograms to 6000 kilograms.In a hydrostatic plain bearing, it is provided that a fluid, in particular compressed air, is pressed into a bearing gap between a bearing surface assigned to the first and the second printing machine and a second bearing surface assigned to a machine foundation of the printing system in order to form a fluid film on which a relative movement of the first printing machine and the second printing machine can be carried out at least almost friction-free.

[0026] In a further embodiment of the invention, first supply lines for the first printing press and second supply lines for the second printing press are accommodated in a common line channel, preferably aligned coaxially with the pivot axis, which is designed for pivotal mounting of the first supply lines and the second supply lines. It is advantageous if the first supply lines and the second supply lines accommodated in the line channel perform only a rotational movement when performing the pivoting movement for the first printing press and the second printing press, which can be ensured by a coaxial arrangement of the line channel with the pivot axis.It is particularly advantageous if the first and second supply lines are routed at an end region facing away from the first printing press and the second printing press into a spiral-shaped, predeterminable drag chain, which is arranged, for example, on the ceiling of a machine room in which the printing system and the entire production line are installed. This ensures exclusive bending deformation of the first and second supply lines during the pivoting movement of the first printing press and the second printing press.

[0027] The object of the invention is achieved according to a further aspect by a method having the features of claim 13, namely a method for operating a printing system, in which the following steps are provided: Providing cup-shaped hollow bodies with a conveyor device to a first printing press and printing the hollow bodies in the first printing press with a first print image and transporting the printed hollow bodies away from the first printing press with the conveyor device; Providing cup-shaped hollow bodies, in particular with a feed device, to a second printing press and carrying out an adjustment process on the second printing press and printing the hollow bodies with a second print image and transporting the printed hollow bodies away from the second printing press, in particular with a removal device;Interrupting the provision of cup-shaped hollow bodies and performing a joint displacement movement as a pivoting movement of the first printing press and the second printing press relative to the conveyor device in order to remove the first printing press from a functional position relative to the conveyor device and to bring the second printing press into the functional position relative to the conveyor device; Providing cup-shaped hollow bodies with the conveyor device to the second printing press and printing the hollow bodies in the second printing press with a second print image, as well as transporting the printed hollow bodies away from the second printing press with the conveyor device.

[0028] In a further development of the method, it is provided that this is carried out with the printing system according to the invention.

[0029] An advantageous embodiment of the invention is illustrated in the drawing. Figure 1 is a strictly schematic front view of a printing system with a first printing machine and a conveyor device, which are accommodated on a guide device, wherein the first printing machine is arranged in a functional position opposite the conveyor device, Figure 2 is a strictly schematic plan view of the printing system according to the Figure 1 , showing that a second printing machine is arranged opposite the conveyor in a maintenance position, and Figure 3 shows the plan view according to the Figure 2 , wherein the conveying device is displaced linearly from a working position into a change position and wherein the first printing machine and the second printing machine are arranged in a pivoting movement between the respective functional position and the respective maintenance position.

[0030] In the Figure 1A printing system 1 is shown, such as can be used in a production line (not shown in detail) for the manufacture of packaging tubes or packaging cans, in particular aerosol cans. By way of example, such a production line comprises all process steps from the provision of a tube or can material blank, which can be provided, for example, in the form of a coin-shaped aluminum blank, to the fillable packaging designed as a tube or can.

[0031] The task of the printing system integrated into the production line is to provide the outer surface of the packaging tube or packaging can with a visually appealing decoration, typically using printing processes such as screen printing, flexographic printing or letterpress / dry offset.

[0032] For the decoration of the packaging tubes or packaging cans, the printing system 1 comprises a first printing machine 10 and a Figures 2 and 3 visible second printing press 20. By way of example, it is provided that the first printing press 10 and the second printing press 20 are designed completely identically, so that in the following description, in order to avoid repetition, only the first printing press 10 is described and the relevant statements apply equally to the printing press 20, wherein the same designations with reference numerals increased by 10 are used for the second printing press 20. Furthermore, the printing system comprises a conveyor device 30, which according to the illustrations of the Figures 1 and 2It is designed for supplying unprinted hollow bodies 2, i.e., tube blanks or can blanks to be printed, to the first printing machine 10 and for removing printed hollow bodies 2, and is part of a transport system of the production line (not shown in detail). The conveyor device enables, for example, the supply of unprinted hollow bodies from a preceding process station in the production line and the further transport of the printed hollow bodies to a downstream process station.

[0033] The first printing press 10 comprises a printing unit 11, which is provided with a plurality of inking units 12, which are designed depending on the printing process to be carried out (in particular screen printing or flexographic printing or letterpress / dry offset). Furthermore, the first printing press 10 comprises a first turret 13, which is also referred to as a spindle plate and which has a plurality of spindles 16 arranged on a carrier plate 55, which are circularly cylindrical and rotatably mounted on the carrier plate 55. By way of example, each of the spindles 16 is assigned a drive device (not shown), so that each of the spindles 16 can be rotated by a rotational speed transverse to the plane of the illustration of the Figure 1 Furthermore, it is provided that the first turret 13 can be rotated about an axis parallel to the center axes of the spindles 16 and thus also transverse to the plane of representation of the Figure 1aligned first turret axis 18 is rotatably mounted on a first machine frame 61. To initiate a rotary movement on the first turret head 13, a drive device (not shown) is provided, which can be designed, for example, as an electric server motor. The first turret head 13 is arranged on the first printing unit 11 in such a way that it overlaps with the first printing unit 11. This makes it possible for one of the first spindles 16 to be fed to the first printing unit 11 in such a way that an application of ink to the outer surface of the hollow body can be carried out and, if necessary, drying of this application of ink can be ensured before the printed hollow body leaves the first printing unit 11.

[0034] The first turret head 13 is assigned a first indexing star 14, which is rotatably mounted on the first machine frame 61 and is provided with a drive device (not shown in detail) to enable a rotational movement of the first indexing star 14 about a first indexing star axis 19 aligned parallel to the first turret axis 18. On an outer surface of the indexing star 14, trough-like receiving shells 57 are provided at regular angular pitches along the first indexing star axis 19 and are constantly formed with an arcuate profile. The receiving shells 57 are provided with vacuum bores in a manner not shown in detail, so that a hollow body 2 fed into the area of ​​the respective receiving shell 57 can be adhered to the respective receiving shell 57 by the action of a vacuum.As a result, the first switching star 14 enables the receiving of hollow bodies 2, for example, at an end region 32 of a transfer conveyor belt 31 belonging to the conveying device 30, and the feeding of the hollow bodies 2 to the first turret 13. A first push-on device 15 is provided for transferring the hollow bodies 2 received in the respective receiving shells 57 of the first switching star 14 to the first turret 13. The push-on device 15 comprises a push-on housing 58, which is fixed to the first machine frame 61 and in which a linear drive device (not shown in detail) is accommodated.The linear drive device is designed to initiate movement onto a slider 59 mounted on the slider housing 58 for linear movement parallel to the first turret axis 18 and the first indexing star axis 19. The slider 59 is designed to bear against a base region of the hollow body 2 in order to slide this hollow body 2 onto the oppositely arranged spindle 16 of the turret head 13. The position of the spindle 16 at which the sliding process for the hollow body 2 is carried out by the first indexing star 14 can also be referred to as the loading position.

[0035] After the still unprinted hollow body 2 has been pushed onto the spindle 16, the hollow body 2 is first fed to the printing unit 11 in the course of several successive rotary step movements, which are carried out purely clockwise for example, where the decoration of the hollow body 2 takes place. The now printed hollow body 2 is transported further in the course of further rotary step movements of the first turret 13 to an unloading position at which a first attachment device 17 is arranged. The task of the first attachment device 17 is to grip the hollow bodies 2 at the base area or to suck them in using a vacuum and, in a subsequent step, to pull them off the respective spindle 16 initially by a linear movement aligned parallel to the first turret axis 18.In a subsequent step, the attachment device 17 pivots about a pivot axis 60 in order to attach the hollow bodies 2 onto second conveyor bars 38 of a second conveyor chain section 36 of a second conveyor chain 34. For example, the attachment device 17 is provided for simultaneously gripping two hollow bodies 2, which are attached to the second conveyor bars 38 of the second conveyor chain section 36; alternatively, only one hollow body 2 or three hollow bodies 3 can be gripped using an attachment device (not shown).

[0036] In the Figures 1 to 3In the illustrated embodiment of a printing system 1, the first attachment device 17 is fixed to the first machine frame 61 of the first printing press 10 and thus belongs to the first printing press 10. Accordingly, a second attachment device 27 is also assigned to the second printing press 20. In an embodiment of a printing system not illustrated, the attachment device can be provided as a component of the conveying device, so that in this case only a single attachment device is required.

[0037] The first machine frame 61 of the first printing press 10 and the second machine frame 62 of the second printing press 20 are rigidly coupled to one another and mounted on a guide device 3 on a pivot joint 63 (illustrated only schematically and designed, for example, as a roller bearing arrangement), for rotation about a pivot axis 64, which is preferably oriented vertically. The guide device 3 forms the machine foundation for the printing system 1 and is therefore designed to absorb all weight forces caused by the mass of the first printing press 10, the second printing press 20, and the conveyor device 30. By way of example, it is provided that a hydrostatic plain bearing 4 is formed between the guide device 3 and the assembly formed from the first machine frame 61 and the second machine frame 62, in which two bearing surfaces 5, 6, each oriented transversely to the pivot axis 64, lie opposite one another.A pressurized fluid, in particular compressed air, can be introduced between the two bearing surfaces 5, 6 in order to form a fluid film with which a virtually friction-free relative movement between the two bearing surfaces 5, 6 is enabled in order to enable a pivoting movement of the first printing press 10 and the second printing press 20 about the pivot axis 64.

[0038] To ensure an advantageous supply of the first printing press 10 and the second printing press 20, the assembly comprising the first machine frame 61 and the second machine frame 62 is assigned a cable duct 7 aligned coaxially with the pivot axis 64. This cable duct 7 is intended to accommodate electrical supply lines and electrical communication lines (not shown), as well as, if necessary, compressed air lines and / or hydraulic lines. For example, it is provided that the lines accommodated in the cable duct 7 are suspended from a ceiling of the factory hall in which the production line is installed, so that during the intended pivoting movement of the assembly comprising the first printing press 10 and the second printing press 20, only a slight torsion of the respective supply lines occurs. This assumes that the pivoting movement is carried out within an angular range of 180 degrees.

[0039] The conveyor device 30 is also accommodated on the guide device 3, wherein the guide device 3 comprises a linear bearing for the conveyor device 30. Thus, the conveyor device 30 can be moved from the Figures 1 and 2 shown working position into a change position arranged at a distance from the first printing press 10 and the second printing press 20. This provides the pivoting space required for the pivoting movement of the first printing press 10 and the second printing press 20 about the pivot axis 64.

[0040] In addition to the components described above, the conveyor device 30 comprises a first conveyor chain section 35 of a first conveyor chain 33. The first conveyor chain 33 can be coupled, as shown in more detail, to a preceding process station (also not shown) arranged upstream in the production line, from which hollow bodies 2 are provided, which are processed in a preceding process step and transported by the first conveyor chain 33 to the printing system 1. As can be seen from the illustration in the figure, the first conveyor chain section 35 extends in sections parallel to a horizontally oriented upper side 39 of the transfer conveyor belt 31.Here, a distance between the first conveyor bars 37 of the first conveyor chain section 35 and the upper side 39 is selected such that the hollow bodies 2 rest on the transfer conveyor belt 31 and can be removed from the first conveyor bars 37 during a transfer movement oriented obliquely to the conveying plane of the first conveyor chain 33. The hollow bodies 2, completely removed from the conveyor bars 37, can then be transferred to the first switching star 14 at the end region 32 of the transfer conveyor belt 31.

[0041] An operating mode for the printing system 1 can be described as follows: at a given time, it is assumed that the printing system 1, which is integrated into a production line (not shown), is supplied with hollow bodies 2 to be printed from a process station arranged upstream in the process direction and transport direction of the hollow bodies 2, using the first conveyor chain 33 in the course of a continuous circular movement. These hollow bodies 2 are placed by the first conveyor chain section 35 onto the upper side 39 of the transfer conveyor belt 31 and, by the transport movement of the transfer conveyor belt 31, which is aligned at an acute angle to the conveying plane of the first conveyor chain section, are pulled off the first conveyor rods 37 and transferred to the first switching star 14 at the end region 32 of the transfer conveyor belt 31.The first switching star 14 transports the hollow bodies 2, whose outer surfaces adhere to the receiving shells 57, in a sequence of rotary incremental movements into a detection area of ​​the pusher 59, which pushes the hollow body 2, each located exactly opposite a spindle 16, onto the respective spindle 16 of the first turret 13 in a linear pushing movement. Through a sequence of rotary incremental movements, the hollow bodies 2 are fed to the first printing unit 11 and provided with the intended decoration, which can also be referred to as the first printed image. The hollow bodies 2 are then moved into the detection area of ​​the first push-on device 17 by further rotary incremental movements of the first turret 13.There, it is provided that two hollow bodies 2 are grasped by the attachment device 17 and placed onto second conveyor rods 38 of the second conveyor chain section 36, whereby it is assumed that the second conveyor chain 34 performs a continuous circulating movement in the same way as the first conveyor chain 33. For example, it is provided that the second conveyor chain 34 is coupled to a process station (not shown) arranged downstream in the production line, to which the printed hollow bodies 2 are fed for the execution of further work processes.

[0042] Simultaneously with the productive printing operation performed by the first printing press 10, a print image change can be performed on the second printing press 20. For this purpose, it may be possible, for example, to equip the individual second inking units 22 of the second printing unit 21 with new printing plates or printing screens and subsequently perform adjustment work for the respective second inking units 22. This adjustment work can be performed for a certain number of hollow bodies 2 under production conditions.For this purpose, a feed conveyor belt 45 (shown only symbolically) is assigned to the second switching star 24, onto which, for example, 10 to 20 hollow bodies 2 can be placed. These hollow bodies 2 can then be pushed onto the second spindles 26 of the second turret 23 by the second switching star 24 in the same way as if the second printing press 20 were integrated into the production line, using the second pushing-on device 25, and can then be printed in the second printing unit 21. The printed hollow bodies 2 are pulled off the second spindles 26 of the second turret 23 by the second pushing-on device 27 and pushed onto conveyor rods of a removal conveyor chain 46 (shown only symbolically). This removal process also takes place under the same conditions as if the second printing press 20 were integrated into the production line in production mode.Accordingly, during the period in which the first printing machine 10 is in production mode in the production line, the second printing machine 20 can be set up as if it were in the production line and is thus prepared to immediately take over the printing of hollow bodies 2 in the production line.

[0043] Accordingly, for the replacement of the print image to be applied to the hollow bodies 2, provision is made for stopping the conveying movement of the first conveyor chain 33 in a first step in order to interrupt further supply of hollow bodies 2 to the transfer conveyor belt 31 and the first printing press 10. For this purpose, it can be provided, for example, that the hollow bodies 2 provided by the preceding process station are stored in a storage device (not shown) until the conveying movement of the first conveyor chain 33 can be resumed.

[0044] The first printing press 10 continues to operate until all hollow bodies 2 provided by the first conveyor chain 33 have been printed and transferred to the second conveyor chain section 36 of the second conveyor chain 34 via the first attachment device 17. Subsequently, the conveying movement for the second conveyor chain 33 is also interrupted, and the first printing unit 11 of the first printing press 10 and the second printing unit 21 of the second printing press 20 are stopped.

[0045] In a further step, the conveyor device 30 is displaced linearly along the guide device 3 in order to increase the distance from the assembly comprising the first printing press 10 and the second printing press 20. In this case, the conveyor device 30 is moved from its working position into a change position, as shown in the Figure 3 is shown.

[0046] Compressed air is then supplied to the hydrostatic plain bearing 4 in order to form a fluid film between the first bearing surface 5 and the second bearing surface 6. The pivoting movement for the assembly comprising the first printing press 10 and the second printing press 20 can then be carried out about the pivot axis 64, wherein the first printing press 10 is moved from the functional position relative to the conveyor device 30 to a maintenance position away from the conveyor device 30 during this pivoting movement, and wherein the second printing press 20 is moved from the maintenance position away from the conveyor device 30 to the functional position relative to the conveyor device 30.

[0047] Subsequently, the conveyor device 30 is displaced linearly along the guide device 3 from the change position into the working position, wherein the distance from the assembly comprising the first printing press 10 and the second printing press 20 is reduced and the interaction between the conveyor device 30 and the second printing press 20 is enabled.

[0048] Subsequently, the conveying movements for the first conveyor chain 33 and the second conveyor chain 34 are resumed and the printing unit 21 of the second printing machine 20 is put into operation, so that hollow bodies 2 conveyed via the first conveyor chain 33 can now be provided with the print image for which the second printing machine 20 was set up and accordingly printed hollow bodies 2 can be transferred to the second conveyor chain 34.

[0049] With the commissioning of the second printing press 20, the first printing press 10 can be converted without disrupting the production process on the production line. The printing press 10 can be converted to a new print image during the time period within which the second printing press 20 is processing the print job with the second print image. In this case, the first printing press 10 can be completely or at least almost completely adjusted to the production conditions, so that after a further pivoting process for the first printing press 10 and the second printing press 20, virtually uninterrupted production on the production line can be carried out with the now new print image from the first printing press 10.

Claims

1. Printing system (1) for printing cup-shaped hollow bodies (2), having a first printing machine (10) which has a first machine frame (61) on which a first switching star wheel (14) is mounted such that it can rotate about a first switching star wheel axis (19) and a first turret head (13) is mounted such that it can rotate about a first turret axis (18) aligned parallel to the first switching star wheel axis (19), the first turret head (13) being assigned to a first printing unit (11) and the first switching star wheel (14) being designed to supply hollow bodies (2) to the first turret head (13), and with a second printing machine (20) which has a second machine frame (62), on which a second switching star wheel (24) is mounted such that it can rotate about a second switching star wheel axis (29) and a second turret head (23) is mounted such that it can rotate about a second turret axis (28) aligned parallel to the second switching star wheel axis (29), the second turret head (23) being assigned to a second printing unit (21) and the second switching star wheel (24) being designed to supply hollow bodies (2) to the second turret head (23), characterized in that the first printing machine (10) and the second printing machine (20) are held on a guide device (3) which is designed for a movement of the first printing machine (10) between an operating position opposite a conveying device (30) associated with the guide device (3) and a maintenance position away from the conveying device (30) and for a movement of the second printing machine (20) between an operating position opposite the conveying device (30) and a maintenance position away from the conveying device (30), the guide device (30) having a pivot joint (63) for a pivotally movable mounting of the first printing machine (10) and of the second printing machine (20) about a common pivot axis (64) aligned transversely to the first turret axis (18) and to the second turret axis (28).

2. Printing system (1) according to claim 1, characterized in that the first printing machine (10) and the second printing machine (20) are aligned axially symmetrically with respect to the pivot axis (64), and in that the pivot joint (63) is designed for a pivoting movement of the first printing machine (10) and the second printing machine (20) with a pivot angle of 180 degrees.

3. Printing system (1) according to claim 1 or 2, characterized in that the first machine frame (61) is fixedly connected to the second machine frame (62) or in that the first machine frame (61) is formed integrally with the second machine frame (62) and in that the first turret axis (18) is aligned parallel to the second turret axis (28).

4. Printing system (1) according to one of claims 1 to 3, characterized in that the guide device (3) has a linear guide (65) for a linearly movable mounting of the first printing machine (10) and of the second printing machine (20) along a movement path (66).

5. Printing system (1) according to one of claims 1 to 4, characterized in that a section (35) of a chain conveyor (33) and a removal unit (31) are attached to the conveying device (30), the removal unit (31) being designed to remove hollow bodies (2) from conveyor rods (37) of the chain conveying device (33) and to transfer them to the adjacently arranged first switching star wheel (14) or second switching star wheel (24).

6. Printing system (1) according to claim 5, characterized in that the first printing machine (10) is assigned a first mounting device (17) which is designed to transfer hollow bodies (2) from the first revolving head (13) to the conveying rods (38) of the chain conveying device (34), and that the second printing machine (20) is assigned a second mounting device (27) which is designed to transfer hollow bodies (2) from the second turret head (23) to the conveying rods (38) of the chain conveying device (34).

7. Printing system (1) according to claim 5, characterized in that the conveying device is assigned a push-on device which is designed to transfer hollow bodies (2) from the first turret (13) or from the second turret (23) to the conveying rods of the chain conveying device.

8. Printing system (1) according to claim 6 or 7, characterized in that the conveying device (30) defines with the first printing machine (10) or with the second printing machine (20) a conveying path for the hollow bodies (2), which extends along a first section (35) of the chain conveying device (33), the removal unit (31), the first printing machine (10) with the first switching star wheel (14) and the first turret head (13) or the second printing machine (20) with the second switching star wheel (24) and the second turret head (23) and the respectively associated mounting device (17, 27) as far as a second section (36) of the chain conveyor (34).

9. Printing system (1) according to claim 5, 6 or 7, characterized in that the chain conveying device (33, 34) comprises a first conveying chain section (35) which is associated with the removal unit (31) and comprises a second conveying chain section (36) which is associated with the mounting device (17, 27), the first conveying chain section (35) belonging to a first conveying chain (33) and the second conveying chain section (36) belonging to a second conveying chain (34).

10. Printing system (1) according to one of claims 5 to 9, characterized in that the guiding device (3) comprises a linear bearing device (65) which is designed for movement of the conveying device (30) between an operating position for interacting with the first printing machine (10) or the second printing machine (20) and a changing position for performing the pivoting movement for the first printing machine (10) and the second printing machine (20).

11. Printing system (1) according to one of the preceding claims, characterized in that the pivot joint (63) comprises at least one bearing from the group: roller bearing, sliding bearing, hydrostatic sliding bearing (4), and that a drive device for initiating a pivoting movement of the first printing machine (10) and the second printing machine (20) is assigned to the pivot joint (63).

12. Printing system (1) according to one of the preceding claims, characterized in that first supply lines for the first printing machine (10) and second supply lines for the second printing machine (20) are accommodated in a common conduit duct (7), preferably aligned coaxially with the pivot axis (64), which is designed for a pivot bearing of the first supply lines and the second supply lines.

13. Method for operating a printing system (1) comprising the steps of: providing cup-shaped hollow bodies (2) to a first printing machine (10) by means of a conveying device (30) and printing a first print image on the hollow bodies (2) in the first printing machine (10) and transporting the printed hollow bodies (2) away from the first printing machine (10) by means of the conveying device (30); providing cup-shaped hollow bodies (2) to a second printing machine (20) and carrying out a setting operation on the second printing machine (20) and printing a second print image on the hollow bodies (2) and removing the printed hollow bodies (2) from the second printing machine (20); interrupting the provision of cup-shaped hollow bodies (2) and carrying out a joint displacement movement as a pivoting movement of the first printing machine (10) and the second printing machine (20) with respect to the conveying device (30), in order to remove the first printing machine (10) from an operating position with respect to the conveyor device (30) and in order to bring the second printing machine (20) into the operating position with respect to the conveyor device (30); providing cup-shaped hollow bodies (2) to the second printing machine by means of the conveying device (30) and printing the second print image on the hollow bodies (2) in the second printing machine (20) and removing the printed hollow bodies (2) from the second printing machine (20) by means of the conveying device (30).

14. A method according to claim 13, characterized in that the printing system (1) is designed according to one of claims 1 to 12.