EP1753621B1 - Printing press comprising a suction device, suction device, and method for replacing a printing film - Google Patents

Abstract

The printing press has a printing films support with first and second printing films. A suction device includes a suction cups (10) for each printing film. The second one is offset relative from the first one axially. A fluid apparatus (12, 14) causes negative pressure or relief of negative pressure to act independently on the suction cups.

Description

The invention relates to a suction device for a color transfer serving printing form or another interchangeable coating of a lining carrier of a printing press.

The USP 4,727,807 suggests for the assembly and disassembly of a printing forme the use of a robot having suction cups on a robot arm for holding the printing forme. The robot takes up a lot of space in the press. In addition, he can always handle only a single printing form.

A suction device for the assembly and disassembly of printing plates is further from the USP 5,806,431 and the USP 5,709,150 known. The suction device comprises along an axis side by side a plurality of suction cups and rollers arranged therebetween. To pick up the printing plates, the nipples are pressed against the printing plates so that the nipples form tight suction chambers with the printing plates. The suction chambers are subjected to negative pressure, whereby the suction forces required to hold the printing plates are generated. In order to be able to handle the individual printing forms independently of one another, the suction cups provided for each printing plate can each be delivered independently of the suction cups for the other printing forms against the respective printing form and arranged so that they can be shut off. For each printing form an adjusting device is provided in accordance to effect the supply and Abstellbewegung. Accordingly, a plurality of Saugnapfgruppen are each arranged with a separate adjusting device for the on and off next to each other along a traverse extending in the axial direction of the respective pressure cylinder. For those with interchangeable ones Compression molds equipped printing plate carrier of the printing machine is provided in each case a separate suction device. Although the suction device in each case allows simultaneous handling of a plurality of printing forms arranged side by side on the printing form carrier, it is however mechanically complex and still requires comparatively much space directly at the respective printing form carrier.

It is an object of the invention to provide a simple and inexpensive suction device for handling a plurality of printing pads, which requires little space. By means of the suction device, an economical change of the ink transfer serving printing pads should be possible in a printing press.

The invention relates to a printing press with at least one pressure pad carrier, preferably a color-transmitting printing cylinder, on which a first pressure pad and at least one second pressure pad in an axial direction offset from each other can be attached. The at least two pressure linings can be directly adjacent to one another in the axial direction. If a plurality of pressure linings can again be arranged next to one another on the printing form carrier transversely to the axial direction, the second pressure coating can also be offset transversely to the axial direction, in the case of a printing cylinder in the circumferential direction, relative to the first pressure coating. The printing press further comprises a suction device arranged opposite the pressure pad carrier. The suction device extends in the axial direction. It comprises a first suction cup for the first pressure pad and a first suction cup in the axial direction offset second suction cup for the second pressure pad. Furthermore, a Fluidikeinrichtung is provided, by means of which the suction cups for sucking or holding the pressure pads can be acted upon by a negative pressure or relieved of a negative pressure. The word "or" is used in the usual logical sense, i. including the meaning of "and" used.

According to the invention, the first suction cup and the second suction cup can be acted upon by the fluidic device independently of one another with the negative pressure or relieved of a negative pressure. The suction cups of the suction device are thus fluidly separated from one another per printing pad. They therefore do not have to be mechanically separated by being mechanically independent of each other and can be set off, although this should not be ruled out from the outset. However, a suction cup bearing structure common to the suction cups is preferred, on which the first suction cup and the second suction cup and, if present, preferably also further suction cups of the suction device are supported. By such storage of all the pressure lining carrier associated suction cups a particularly space-saving suction device is obtained, which also manages with a minimum number of adjusting devices for the supply and storage of the suction cups.

In a preferred first embodiment, those suction cups which are to receive and hold a pressure pad are evacuated by means of the fluidic device. For this purpose, the fluidic device can each be equipped with its own vacuum generator, for example a pump or a pressure reservoir, for the first suction cup and for the second suction cup, wherein the pressure generators can be operated independently of one another. More preferably, however, the negative pressure per suction cup is generated by means of a common pressure generator, and the first suction cup and the second suction cup with fluidic control members are separated from each other.

In a simplified second embodiment, the first suction cup and the second suction cup are each passively formed as an elastically deformable suction cup and generate the vacuum itself. As known from suction cups in other applications, such a suction cup is pressed against the pressure pad of the pressure pad carrier to be supported and thereby resilient compressed. If the suction cup relieved or exerted a direction opposite to the pressing direction tensile force, the suction cup expands due to its elastic restoring forces or at least due to the tensile force again. Its bowl volume increases again accordingly. Since the suction cup is pressed circumferentially close to the pressure pad, although the cup volume increases during the expansion, the trapped air mass remains constant, so that the suction cup adheres to the pressure pad and one of the self-adjusting suction force can raise corresponding weight. An active evacuation can be omitted. The price of the suction device and the operating costs are reduced.

Both with the use of active with an external vacuum generator active suction cups and the use of the negative pressure self-generating passive suction cups, the suction cup or the plurality of suction cups, or should suck the pressure pad or not, advantageously by connection with the environment or active Ventilation pressurized with an overpressure, while the suction cup or the suction cups, or should suck a pressure pad or should be acted upon by the negative pressure generated by the pressure generator or generated or generate the required negative pressure by elastic compression and subsequent expansion itself.

Insofar as preferred features of the invention are described below with reference to a single suction cup, the embodiments also apply advantageously to the at least one further suction cup and more preferably to each further suction cup of the suction device.

The suction connection is fluidly released by increasing the pressure in the bowl volume. This can be accomplished by connecting the cup volume to a pressure reservoir, a pump or a compressor of the fluidic device to pressurize the well volume with an overpressure that is greater than atmospheric pressure. Instead, however, the alternative size of the bowl volume can easily be vented to ambient pressure. A simple short circuit with the environment is the simplest and most cost-effective, an active pressurization is a particularly safe solution. For the fluidic inactivation, a fluid conduit opening into the well volume and a fluidic control member associated with the fluid conduit are provided. For the activation of the suction cup and the maintenance of the active state, the fluidic control member can assume a closed position in which it closes the fluid line, so that the suction cup with the pressure pad to be sucked can form the vacuum chamber. In particular, the fluidic control member may be a two-way control member which is switchable between the closed position and a flow-through position. However, it may also be a continuously variable fluidic control member or a Mehrwegesteuerglied with more than two different switching positions. In particular, it can be an electric or be magnetically controllable control valve. The above applies to both an active and a passive suction cup. In an active suction cup, such a fluidic control member can be used to connect the suction cup for suction with a vacuum generator and for inactivation with the environment or a pressure generator. For generating the negative pressure and the ventilation, separate fluid lines may be provided per suction cup, in each of which a fluidic control element is arranged. Separate fluid lines is more preferably associated with a common fluidic control member which closes one of the fluid lines in a first switching state and the other opens, and in another switching state reverses the conditions. The fluidic control member or the plurality of fluidic control members of the suction device is or are preferably arranged outside of the pressurizable coverable axial portion of the pressure pad carrier. Even more preferably, they are arranged laterally, viewed from the pressure lining carrier, behind a casing of a machine frame.

In an active suction cup whose negative pressure is preferably generated by means of a Venturi nozzle. The fluid conduit connects the bowl volume to a flow area through which pressure fluid flows, i. H. it branches off from the flow cross-section through, preferably at a point narrowest cross-section. The pressurized fluid may advantageously be the pressurized fluid normally present under the usual overpressure at the location of the printing press, in particular compressed air. The negative pressure can thus be generated by means of a pressurized fluid by the static pressure of the traversed venturi forms the negative pressure.

The suction device preferably comprises at least two bearing structures, namely a traverse, which supports the entire suction device, preferably on a frame part of the printing press, and a further bearing structure, which is supported on the traverse and is movable relative to the traverse in the supply and Abstellrichtung. The force required for the closing and stopping movement can be generated mechanically, for example by means of an electric motor, or more preferably fluidically. A pneumatic power generation is then again preferred over a hydraulic one.

In a preferred embodiment, the suction device comprises a roller assigned to the suction cup, with which the suction device can be rolled over the pressure lining when the suction cups are parked, which is advantageous in particular for attaching the pressure lining to the pressure lining carrier and for unrolling the pressure lining from a cylindrical pressure lining carrier.

For the storage of the suction cup and the roller, the further bearing structure in a preferred embodiment is subdivided into a suction cup bearing structure and a roller bearing structure. The suction cup bearing structure and the roller bearing structure are each movable relative to the traverse and relative to each other in the supply and Abstellrichtung. Preferably, both the suction cup bearing structure and the roller bearing structure are supported directly on the traverse. In principle, however, it is also possible to have one of the two bearing structures at the other, i. to support the crossbeam over the other. The roller bearing structure rotatably supports the roller about an axis which is transverse to the direction of engagement and disengagement. The sucker is attached to the sucker bearing structure, which attachment may be rigid or allow movements of the sucker relative to the sucker bearing structure, such as compression or pivotal movement, as long as the function of sealing and supporting the pressure pad is backfilled.

Preferably, all the suction cups of the suction device are supported on the suction cup bearing structure and thus can be switched on and off uniformly. The roller bearing structure preferably supports all the rollers of the suction device, so that they are uniformly switched on and off.

The suction device preferably comprises a plurality of suction cups and also a plurality of associated rollers for handling a single pressure pad. If the suction force of a single suction cup is sufficient to safely lift the pressure pad, however, a single suction cup suffices per pressure pad, and a single roller is generally sufficient.

In order to be able to handle a plurality of coverings spanned adjacent to one another on the pressure-lining carrier, the suction device comprises in preferred embodiments per pressure-covering at least one sucker. More preferably, it comprises per pressure pad a suction cup group consisting of at least two suction cups. Furthermore, it should have at least one roller per printing pad, wherein for the application of a uniformly distributed over the pressure pad roller pressure, it is also preferred here, when the suction device per pressure pad distributed over the pad width has a group of roles. The suction cup groups and / or roller groups can advantageously be controlled separately from one another in order to be able to move them in or against the pressing direction.

If a plurality of suction cups are combined to form a suction cup group, preferably one fluid line each opens into the cup volume of each of the suction cups of the group in order to be able to inactivate each of these suction cups. It may also be sufficient to release the suction connection, only to vent a portion of the suction cups per group or to apply an overpressure. The fluid lines can be closed and opened per Saugnapfgruppe means of individual Fluidiksteuerglieder. However, the fluid lines per suction cup group preferably lead to a common group line, which can be closed and opened by means of a fluidic control element provided for the group, so that only one single fluidic control element is required per suction cup group.

The suction device is preferably fixedly mounted in the printing machine, i. integral part of the printing press. However, this is not to say that the suction device can not be dismantled from a location of attachment by means of quick assembly and remounted at another location. However, the invention also relates to a first provided for installation in a printing machine suction device, either for a new or a retrofitted to the suction machine.

The pressure pad to be handled by means of the suction device can in particular be a printing plate, preferably a printing plate, which is stretched on a forme cylinder or provided for a forme cylinder. In principle, however, the suction device can also be used to handle other pressure linings, for example a blanket for or on a blanket cylinder. Although the invention is directed primarily to the Used for rotary printing machines and especially for web presses, preferably in wet offset printing, it is for use in printing machines in general and not only for rotations advantage.

If all the suction cups of the suction device are fastened to a common suction cup bearing structure or all the rollers are mounted on a common roller bearing structure, an adjusting device for switching on and off the suction cups or an adjusting device for the loading and unloading of the rollers can advantageously be located outside of the axial direction Axialabschnitts of Druckbelagträgers be arranged, preferably on said traverse. The arrangement of the adjusting device or adjusting devices laterally adjacent to the pressure lining carrier reduces the space requirement within the axial section which can be assigned with pressure linings. On the side next to this axial section, the space requirement generally does not play such a critical role. This arrangement of the adjusting device or adjusting devices is advantageous, in particular for rotary printing presses, because in this way the suction device can be arranged particularly close to the respective printing gap and obstructs the other work on the respective printing unit less than the conventional suction devices in such an arrangement.

In a preferred embodiment, the suction device, the pressure pads and a clamping device of Druckbelagträgers, by means of which the pressure pads are fastened to the pressure pad carrier, matched to one another, that the pressure pads can be solved by means of a force exerted by the suction device on a Druckbelagende tensile force of the clamping device , The clamping device comprises per printing forme at least one clamping piece, which has a clamping surface, with which it clamps the pressure forming end in cooperation with a counter-surface. The invention preferably provides clamping pieces which, in addition to the clamping surface, have a supporting surface on which the clamping piece in question is supported in the radial direction of the printing cylinder, so that the clamping piece can not become wedged with the clamped printing plate end when the printing plate end is pulled out of the clamping channel by means of the suction device , In this regard, it is also advantageous if the printing plate end is angled flat and at right angles or even more obtuse, so that it by means of the clamping device only frictionally engaged and not additionally also positively held in a rear grip and is not bent. It is particularly advantageous if the direction in which the suction cups are turned on and off is at least substantially parallel to the clamped ends, so that at least essentially only tensile forces act upon release of the printing plates in their respective ends. If the printing plate end is angled at the inclusion of a right angle, the feeding and Abstellrichtung the suction cups advantageously radially to the axis of rotation of the printing cylinder. If the end is angled at an angle greater than 90 °, it is advantageous if the supply and Abstellrichtung also has a direction tangential to the printing cylinder directional component.

Also in the subclaims and their combinations preferred features of the invention are described.

Figur 1

einen Blick auf ein Druckwerk einer Druckmaschine mit eingebauter Saugvorrichtung,

Figur 2

einen Axialabschnitt der Saugvorrichtung,

Figur 3

eine Schaltung für die Deaktivierung einer Saugnapfgruppe der Saugvorrichtung,

Figur 4

einen Spannkanal mit einer Klemmeinrichtung für eine klemmende Befestigung eines Druckformendes und

Figur 5

die Saugvorrichtung in einem Querschnitt.

Hereinafter, an embodiment of the invention will be explained with reference to figures. The features disclosed in the exemplary embodiment advantageously each individually and in each combination of features form the subject matter of the claims and also the embodiments described above. Show it:

FIG. 1

a view of a printing unit of a printing machine with built-in suction device,

FIG. 2

an axial section of the suction device,

FIG. 3

a circuit for deactivating a suction cup group of the suction device,

FIG. 4

a clamping channel with a clamping device for a clamping attachment of a pressure forming end and

FIG. 5

the suction device in a cross section.

FIG. 1 shows a view into a printing tower of a wet offset web-fed rotary printing press. Evident are two printing form cylinder 1, in the exemplary embodiment plate cylinder, two printing units, which are arranged one above the other in the printing tower and on the same side of a printing tower passing Bedruckbahn work. The printing form cylinder 1 are each in a conventional manner with a plurality of axially juxtaposed printing plates 2, in the embodiment printing plates, covered.

The printing forme cylinders 1 are each assigned a suction device 5. The further printing forme cylinders of the printing machine is assigned in the same way individually to a suction device 5. For example, in an eight-printing tower with four printing bridges arranged one above the other for perfecting and correspondingly eight printing cylinders 1, at least eight suction devices 5 are likewise arranged. Each of the suction devices 5 extends over the entire length of the associated printing form cylinder 1 and is able to handle all the printing plates 2 of the associated printing form cylinder 1, namely to keep it sucking. In the following, only one of the suction devices 5 will be described as representative of the others.

The suction device 5 comprises a traverse 6, which extends over the entire length of the associated printing forme cylinder 1 and is fixedly mounted at its two axial ends on side frame parts 4. The traverse 6 forms a slender, elongated, on both sides firmly clamped bearing bar. The traverse 6 serves as a carrier for a plurality of suction cups 10 and rollers 11. The suction cups 10 and rollers 11 are juxtaposed parallel to the printing form cylinder 1 along the traverse 6, one of the suction cups 10 between two of the rollers 11. The suction device 5 is per printing plate 2 equipped with two suction cups 10 and three rollers 11. The suction cups 10 and rollers 11 form per printing plate 2 a suction cup / roller group 10, 11. The suction device 5 forms axially adjacent suction cup / roller groups 10, 11 in a number of juxtaposed on the plate cylinder 1 printing plates 2 corresponding number , The suction cup / roller groups 10, 11 are movable in and against a directed to the respective printing plate 2 pressing direction, ie, switched on and off. The suction cups 10 are movable relative to the rollers 11 and the rollers 11 relative to the suction cups 10 in and against the pressing direction. The pressing direction has at least substantially radially on the axis of rotation of the associated printing forme cylinder 1.

FIG. 2 shows an axial end portion of the suction device 5 detached from the machine, for example, in a state intended for installation. The suction cups 10 are axially stretched, and each form a correspondingly axially elongated bowl volume. In the embodiment, they are oval, each with a straight central portion and semi-circular ends. The suction cups 10 are dimensionally and materially elastic. By pressing against the printing plate 1, the suction cups 10 are elastically compressed. If the pressing force is removed, the suction cups 10 expand elastically again. As a result of the widening, the cup volume enclosed between the printing form 2 and the wall of the suction cups 10 is expanded so that a negative pressure and thus between the suction cups 10 and the printing plate 2 each set a certain suction force due to the cup edge contacting the printing plate 2 in the enclosed bowl volume , If a pulling force directed away from the printing form 1, preferably a pulling force directed against the pressing direction, is exerted on the suction cups 10, this can lead to a further increase in volume and thus to an increasing suction force. The suction cups 10 are designed according to size, shape and material so that the sum of the suction forces of the suction cups 10 per group sufficient for secure holding a single printing plate 2. The suction force per group is further so great that by means of the suction device 5, the respective printing forme 2 can be sucked in at one end and pulled without further tools or manual support from a clamping channel of the plate cylinder 1. If the suction device 5 per printing plate 2 only have a single suction cup, this suction cup would of course be sized so that its suction sufficient for this purpose. With more than two suction cups per group, the individual suction cup may be correspondingly weaker and / or smaller in size.

Each of the suction cups 10 is connected via a fluid line 12 with the immediate vicinity of the suction device 5. In FIG. 2 the openings of the fluid lines 12 can be seen in the Napfvolumina. The fluid lines 12 each open centrally and extend from their mouths in the cup volumes on the shortest path through the attachment region of each of the suction cups 10. For sucking and holding the printing plate 2, the fluid lines 12 are closed. The Napfvolumina can be short-circuited via the fluid lines 12 to the environment and thereby deactivated or switched inactive in advance.

The axes of rotation of the rollers 11 are parallel to the axis of rotation of the associated printing forme cylinder 1, so that they can roll in the mounted state of the suction device 5 in the circumferential direction of the associated printing forme cylinder 1 on the printing plates 2, as for a roll over a printing plate 2 to its attachment and a Transport of the printing form 2 when rolling from the printing form cylinder 1 is desirable.

The suction device 5 forms a multi-part bearing structure, which consists of the already mentioned traverse 6 and further comprising a roller bearing structure 7 and a suction cup bearing structure 8. The traverse 6 is used to attach the suction device 5 in the machine frame. The rollers 11 are fixed to the common roller-bearing structure 7, which is supported on the cross member 6. The roller-bearing structure 7 extends over the entire, assignable with printing plates 2 axial length of the plate cylinder 1. It is formed as a rigid beam from which protrude in the pressing direction stator on which the rollers 11 are rotatably mounted. Within the suction cup / roller groups 10, 11, the suction cups 10 form a suction cup group. The suction cups 10 are supported together on the suction cup bearing structure 8, which extends over the entire axial length of the plate cylinder 1, which is assignable to the printing plates 2. The suction cup bearing structure 8 is supported directly on the traverse 6 and relative to this against the printing form cylinder 1 undeliverable and offset from the printing form cylinder 1. The same applies to the roller bearing structure 7. Instead of supporting the two bearing structures 7 and 8 directly on the traverse 6 as preferred, one of the two bearing structures 7 and 8 could also be supported on the traverse 6 only via the other. Although less preferred, it should nevertheless not be ruled out that a separate bearing structure 8 or a separate bearing structure 7 is provided per suction pad group or per roller group, and each of the bearing structures 7 or 8 can be switched on and off independently of the others.

In order to activate only those suction cups 10 which are intended to suck in and hold one of the printing plates 2, the suction cup groups each associated with one of the printing plates 2 are separated pneumatically. For pneumatic separation, those suction cups 10, which are not supposed to suck in printing form 2 with the environment A ( Fig. 3 ) and thereby set inactive, while the other suction cups 10 are fluidly separated from the environment A for the purpose of sucking and holding the printing form 2 or the plurality of printing plates 2.

The movements of the bearing structures 7 and 8 are fluidly, preferably pneumatically effected as in the embodiment. For the switching on and off of the bearing structure 7, an adjusting device 15 and for the switching on and off of the bearing structure 8, an adjusting device 16 is provided. The adjusting devices 15 and 16 are connected to a compressed air reservoir, as is usually the case in printing presses. The bearing structures 7 and 8 are each individually by means of actuators, in the embodiment of the pneumatic cylinder, the adjusting means 15 and 16 moves. The control members of the adjusting devices 15 and 16 are preferably two-way valves whose switching states are controlled by a suitably electronic control. The electronic control offers the possibility of manual operation directly at the location of the relevant suction device. 5

In order to keep the suction device 5 flat in the pressing direction, the beam-shaped traverse 6 extending in the axial direction and the roller bearing structure 7 are U-profiles which are open in the direction of the associated printing-plate cylinder 1. In a retracted state, the U-profile of the traverse 6 takes up the roller bearing structure 7 at least substantially. The suction cup bearing structure 8 is accommodated at least in the retracted state in the U-profile of the roller bearing structure 7. Alternatively, instead of the roller bearing structure 7, the suction cup bearing structure 8 may be formed as a U-profile and receive the bearing structure 7. It can also be formed as U-profiles all three bearing structures 6, 7 and 8. The term "U-profile" should also encompass other trough-shaped profiles, for example a V-profile or an H-profile, although the latter is less preferred since it requires more height. In principle, at least two of the bearing structures 6, 7 and 8 or, if appropriate, also all three bearing structures 6, 7 and 8 could each be formed as simply elongated plates which are thin radially to the printing form cylinder 1. The side legs of the U-profile act advantageously but stiffening. In principle, it is not necessary for the traverse 6 to have one of the two other bearing structures 7 and 8 or both other bearing structures 7 and 8. Rather, the traverse 6 can in principle also be taken up by one of the other bearing structures 7 and 8 or both other bearing structures 7 and 8. The nested arrangement with at least partial overlap allows radially to the printing form cylinder 1 a particularly flat construction of the suction device. 5

FIG. 3 shows a pneumatic circuit for inactivating a single group of suction cups 10. The suction cups 10 are vented by shorting to the environment A, ie the surrounding atmosphere, more specifically vented to ambient pressure. The fluid lines 12 branch off from a common group fluid line 13 to the individual suction cups 10 of the group and each open into one of the cup volumes. In the group fluid line 13, a two-way solenoid valve is arranged as the fluidic control member 14, which closes the group fluid line 13 in one of its two switching states, so that the cup volumes of the suction cup group are fluidically separated from the environment A, and opens in its other switching state, so that the short circuit to the environment A is made. The fluidic control member 14 is controlled by the electronic control mentioned in connection with the adjusting devices 15 and 16 in coordination with the adjusting and control members for the bearing structures 7 and 8. The moving actuator of the fluidic control member 14 is biased by a built-in spring in the closed position.

By means of the suction device 5, the change of a printing plate 2 is semi-automatically performed, namely partially manually by an operator and partially automatically by the printing plate 2 associated suction 5 according to the operation by the operator on site.

After the printing form cylinder 1 has been rotated by pressing a button with its single clamping channel or one of several distributed over the cylinder circumference provided clamping channels in a favorable position for manual access, the operator preferably places the leading end of the printing plate 2 in the clamping channel of the plate cylinder 1. The further clamping operation that is, the winding of the printing form 2 and the placement of the other printing form end by means of the suction device. 5 automatically. For this purpose, the rollers 11 of the associated suction cup / roller group 10, 11 are pressed against the printing plate 2 by the group for this group 10, 11 or all groups 10, 11 jointly provided roller bearing structure 7 is extended by pressing the operator. Furthermore, the printing form cylinder 1 is also rotated forward by pressing a button. During the forward rotation, the rollers 11 roll over the printing form 2 and apply them to the surface of the plate cylinder 1. The rollers 11 roll over the trailing end of the printing plate 2, so that it is pressed into the clamping channel or another clamping channel of the printing form cylinder 1 and thereby automatically fixed, preferably by clamping.

For the expansion of the printing form 2, the printing form cylinder 1 is rotated to a position in which one of the two ends of the printing form 2 comes to lie radially below the suction device 5, preferably the trailing end in printing operation end of the printing plate 2. With the printing forme cylinder in position. 1 is pressed by pressing the operator of the abzunehmenden printing form 2 associated group of suction cups 10 against the printing plate 2. The suction cups 10 of the group in question or in the preferred storage variant all suction cups 10 are elastically compressed by the pressure of the pressing force. If all the suction cups 10 of the suction device 5 extend together, by means of the fluidic control members 14 those suction cup groups which are to suck in a printing plate 2 are set to active and the others to inactive. Subsequently, the previously pressed-on suction cups 10 are moved back against pressing direction again by pressing a button or by automatic sequence control, so that the sucked end of the printing plate 2 is lifted out of the clamping channel. The operator takes over the suctioned end and deactivated by pressing a button and thereby effected venting the suction cups 10. The printing form cylinder 1 is rotated back while the operator holds the printing form 2 until the leading end of the printing form 2 of the operator can be gripped and pulled out of its clamping channel.

In an alternative embodiment, the suction device 5 does not have passive, but via active suction cups 10 and a vacuum generator, by means of which the Napfvolumina be sucked to suck the printing plates 2 and hold. Of the Vacuum generator can be connected via the group fluid lines 13 and fluid lines 12 to the individual suction cups 10. Alternatively, in addition to the vent lines 12 and 13 suction lines may be provided. Furthermore, as an alternative to a simple short circuit with the environment, it is also possible to provide the suction cups 10 with an overpressure relative to the ambient pressure. It is particularly preferred if those suction cups 10, which are to receive and hold a printing plate 2, are sucked off, and those suction cups 10, which are not also to exercise a holding function, are acted upon by an overpressure to a suction of a printing plate 2 through the To prevent particular suction cups 10 particularly safe.

FIG. 4 shows one of the clamping channels of the plate cylinder 1 in a cross section. In the clamping channel, a clamping device is arranged, by means of which a leading end 2v of a printing plate 2 and a trailing end 2n of the same or another printing plate 2 are clamped in the clamping channel. The trailing end 2n is angled at an angle of slightly more than 90 ° and protrudes with the angled flange at least substantially, ie with a deviation of not more than 20 ° to the radial on the axis of rotation of the plate cylinder 1 in the clamping channel. The angled flange of the pressure forming end 2n is flat and is not deformed by the clamping device, but merely clamped frictionally. The suction cup bearing structure 8 is deliverable at least substantially parallel to the angled flange against the printing form cylinder 1 and supported by the printing form cylinder 1 abstellbar on the cross member 6. After the suction of the suction cups 10, which are assigned to the printing plate 2 with the pressure forming end 2n, the angled flange is therefore at least essentially claimed in the Abstellbewegung the suction cups 10 only to train.

The angled flange of the pressure forming end 2n is clamped by means of a clamping piece 20 movably mounted in the clamping channel of the clamping device, which has a flange contacting clamping surface for linear contact and additionally a support surface and on the support surface radially to the axis of rotation of Printing forme cylinder 1 is supported. More precisely, the clamping piece 20 is guided in a guide 21 of the printing form cylinder 1 at least substantially in the tangential direction. As a result, the clamping piece exerts on the clamped flange of the pressure forming end 2n only one determined by the strength of a spring 22 clamping force. The spring 22 acts in the direction of the guide 21. The guide 21 has obliquely to the radial R of the plate cylinder 1 to the outside and includes with the radial R an acute angle a of more than 45 °; In this sense, the guide extends at least substantially tangentially to the axis of rotation of the plate cylinder 1, so that when pulling out of the flange, an inhibition is prevented.

The trailing pressure-forming end 2n can be pulled out of the tensioning channel, in particular, solely on account of the suction effect of the suction device 5 and without additional actuation of the clamping device.

FIG. 5 shows the nested arrangement of the bearing structures 6, 7 and 8 and further details of the suction cups 10. For the roller bearing structure 7 whose actuator 15 is shown. For the suction cup bearing structure 8 of the pneumatic actuator of the adjusting device 16 is not shown, the connection with the actuator is only indicated at 18.

The suction device 5, in particular the suction cup 10 shown as representative of the other, is shown to a printing plate 2 in its delivered position after sucking the trailing end 2n. The suction force S acting on the printing form 2 along the axis PS of the feeding and stopping movement engages in the greatest possible proximity on the angled, trailing end 2n of the printing form 2. The distance of the axis PS to the edge of the trailing end 2n is chosen to be as small as possible. The suction cup 10 is designed for this purpose in a special way. The pressure surface 2 facing contact surface of the suction cup 10 has at its the angled end 2n facing side of the movement axis PS a maximum distance a, measured between the movement axis PS and the outer peripheral edge of the suction cup 10, which is at most 20mm, preferably at most 15mm. Apart from a small distance, the suction cup 10 at its outer peripheral edge of the edge of the trailing End 2n, the suction force S attacks at a distance a from the edge of the trailing end 2n. The thickness d of the contact surface measured transversely to the axial direction PS of the printing plate cylinder 1 should not be more than 8 mm, preferably not more than 5 mm, at least in the region of the suction cup 10 which is closest to the edge of the trailing end 2n.

The removability of the printing plate 2 alone by means of the suction device 5 is further beneficial if the angled flange e has the shortest possible length. The flange length e should not be more than 14 mm and is preferably at most 10 mm. The angled flange closes with the planning in the unloaded state printing form 2 a right angle. The suction force S, which coincides with the direction of the Abstellbewegung, has parallel to the angled flange. When the trailing end 2n is pulled out of the clamping channel of the plate cylinder 1, tensile forces therefore at least essentially, in the ideal case exclusively, act in the angled flange.

The extraction of the pressure forming end 2n is further beneficial that when pulling out first the roller bearing structure 7 in direction S by means of the adjusting device 15 is accelerated and in this movement by means of a stop member 17 in a stop contact with the suction cup not yet in motion at this time Bearing structure 8 passes, so that acts on the suction cup bearing structure 8 acting in the direction S impact force. The impact force is advantageous for overcoming the static friction acting on the clamped flange of the pressure forming end 2n. In FIG. 5 is the stop member 17 shown as an additional element, which is due to the fact that the suction cup bearing structure 8 is wholly or partially received in the roller bearing structure 7, at least in the retracted state. Upon reversal of this arrangement, ie the at least partial reception of the roller bearing structure 7 in the suction cup bearing structure 8 surrounding in such a case, the bottom of the U-profile forming the roller bearing structure 7 would replace the stop element 17. the bottom of the roller bearing structure 7 forming U-profile replace the stop element 17.

In the FIGS. 1 and 2 the adjusting devices 15 and 16 are arranged on the side of the traverse 6, which faces the bearing structures 7 and 8. Instead, the adjusting devices 15 and 16 or at least one of these adjusting devices 15 and 16 can also be arranged to save space on the same side as the bearing structures 7 and 8 and protrude in the direction of the supply and Abstellbewegung the suction cups 10 and rollers 11 of the traverse 6.

The suction device 5 is equipped both for the roller bearing structure 7 and for the suction cup bearing structure 8, each with two pneumatic actuators. Depending on one of the actuators is outside of the assignable with printing plates 2 axial section of the plate cylinder 1 in the two axial end portions of the cross member 6 is attached. In the exemplary embodiment, the two pairs of actuators are arranged on both sides of the plate cylinder 1 in the two pin areas. If the printing form cylinders 1 are equipped with bearer rings, as in the exemplary embodiment, the actuators and preferably the further fluidic members of the actuators 15 and 16 are each arranged on the outside of the bearer rings so that they do not overlap the cylinder peripheral surface, in particular in their axial section that can be set with printing plates 2 Take up space. The Fluidiksteuerglieder 14 and optionally further Fluidiksteuerglieder are arranged behind the casing of the machine frame 4. Between the arranged on both sides of the pressure range actuators 15 and 16 extend only the fluid lines.

When using active instead of passive suction cups 10 10 Venturi nozzles are formed directly to the suction cups to produce the negative pressure by means of the usual air pressure of the existing local air pressure system, either a Venturi nozzle per suction cup 10 or per Saugnapfgruppe. Otherwise, for suction devices with active suction cups preferably the above statements apply to the passive suction cups. It takes the place of suction by elastic expansion of the Napfvolumina only the active suction by applying a negative pressure, ie by evacuation.

Claims (24)

1. Printing machine with a printing plate carrier (1) to which a first printing plate (2) and a second printing plate (2) can be applied offset from one another in the axial direction, and with a suction device (5) comprising:

   a) a first suction cup (10) for the first printing plate (2),

   b) a second suction cup (10) for the second printing plate (2) disposed offset from the first suction cup (10) in the axial direction,

   c) and a fluid system (12-14) by means of which the suction cups can be placed at a negative pressure or relieved of a negative pressure independently of one another,

   characterised by

   d) a common suction cup bearing structure (8) for the suction cups (10) on which the first suction cup (10) and the second suction cup (10) are supported and can therefore be advanced and retracted as a unit.
2. Printing machine as claimed in the preceding claim, further comprising a crossbar (6) extending in the axial direction, and the suction cup bearing structure (8), supported by the crossbar (6), on which the first and second suction cups (10) are supported can be moved relative to the crossbar (6) towards the printing plate carrier (1) and away from the printing plate carrier (1).
3. Printing machine as claimed in the preceding claim, characterised in that the crossbar (6) has an open profile towards the printing plate carrier (1) as viewed in cross-section, preferably a trough-shaped profile, in which the suction cup bearing structure (8) is accommodated across at least a major part of its height as measured in the advancing and retracting direction (P, S) in a position retracted from the printing plate carrier (1).
4. Printing machine as claimed in one of the two preceding claims, further comprising a suction cup actuator unit (16) for advancing and retracting the suction cup bearing structure (8).
5. Printing machine as claimed in the preceding claim, characterised in that the suction cup actuator unit (16) is disposed in the axial direction outside of an axial portion of the printing plate carrier (1) accommodating the printing plates (2).
6. Printing machine as claimed in one of the two preceding claims, further comprising a control system which controls the suction cup actuator unit (16) and the fluid system (12-14) for removing the first printing plate (2) so that the suction cups (10) are jointly moved forward and, of the first suction cup (10) and the second suction cup (10), only the first suction cup (10) is placed at a negative pressure.
7. Printing machine as claimed in one of the three preceding claims, further comprising a control system which controls the suction cup actuator unit (16) and the fluid system (12-14) for removing the first printing plate (2) so that the suction cups (10) are jointly moved forward and the second suction cup (10) is connected to the ambient environment (A) or is placed at a positive pressure, whilst the first suction cup (10) applies suction to the first printing plate (2).
8. Printing machine as claimed in one of the six preceding claims, characterised in that the suction cups (10) are jointly retained on the suction cup bearing structure (8) and can be advanced and retracted with the suction cup bearing structure (8) as a unit.
9. Printing machine as claimed in one of the preceding claims, further comprising a first roller (11) for the first printing plate (2), a second roller (11) for the second printing plate (2), a crossbar (6) extending in the axial direction and a roller bearing structure (7) supported on the crossbar (6) on which at least one of the rollers (11) is retained, and which can be advanced relative to the crossbar (6) towards the printing plate carrier (1) and retracted from the printing plate carrier (1).
10. Printing machine as claimed in the preceding claim, further comprising a roller actuator unit (15) for advancing and retracting the roller bearing structure (7).
11. Printing machine as claimed in the preceding claim, characterised in that the roller actuator unit (15) is disposed in the axial direction outside of an axial portion of the printing plate carrier (1) accommodating the printing plates (2).
12. Printing machine as claimed in one of the three preceding claims, characterised in that the crossbar (6) has an open profile towards the printing plate carrier (1) as viewed in cross-section, preferably a trough-shaped profile, in which the roller bearing structure (7) is accommodated across at least a major part of its height as measured in the advancing and retracting direction (P, S) in a position retracted from the printing plate carrier (1).
13. Printing machine as claimed in one of the preceding claims in combination with claim 2 and claim 9, characterised in that the roller bearing structure (7) has a stop element (17) by means of which, when the suction cup bearing structure (8) is advanced, it moves against the still advanced suction cup bearing structure (8) in an abutting contact during a retracting movement.
14. Printing machine as claimed in one of the preceding claims in combination with claim 2 and claim 9, characterised in that at least one of the roller bearing structure (7) and suction cup bearing structure (8) has an open profile towards the printing plate carrier (1) in which the other of the roller bearing structure (7) and suction cup bearing structure (8) is accommodated across at least a major part of its height as measured in the advancing and retracting direction (P, S) in a position retracted from the printing plate carrier (1).
15. Printing machine as claimed in one of the preceding claims in combination with claim 2 and claim 9, characterised in that the crossbar (6), the roller bearing structure (7) and the suction cup bearing structure (8) nest one inside the other when the roller bearing structure (7) and the suction cup bearing structure (8) are in a position retraced from the printing plate carrier (1) and at least mutually overlap across a major part of their heights as measured in the advancing and retracting directions (P, S).
16. Printing machine as claimed in one of the preceding claims in combination with one of claims 2 and 9, characterised in that the crossbar (6) is mounted so that it is not able to move.
17. Printing machine as claimed in one of the preceding claims, characterised in that each of the printing plates (2) has a downwardly angled flat flange at one end (2n), at least in a non-biased state, by means of which the respective printing plate (2) can be secured in a tensing passage of the printing plate carrier (1) clamped to the printing plate carrier (1), and the suction cups (10) can be retracted in a direction (S) pointing at least substantially parallel with the flange so that when the respective printing plate (2) is released, at least essentially tensile forces only act in its flange.
18. Printing machine as claimed in the preceding claim, characterised in that the flange is clamped in the tensing passage solely due to a friction lock.
19. Printing machine as claimed in one of the preceding claims, characterised in that the printing plate carrier (1) is a printing plate cylinder and each of the printing plates (2) has a downwardly angled flange by means of which it can be secured in a tensing passage of the printing plate carrier (1) clamped to the printing plate carrier (1), and a clamping mechanism is disposed in the tensing passage which has at least one clamping piece (20) each for the printing plates (2) which can be clamped in the tensing passage, which has a clamp contact surface acting on the flange of the respective printing plate (2) as well as a support surface, and is supported against the support surface in the radial direction of the printing plate carrier (1) in order to prevent the clamped flange from becoming blocked when the respective printing plate (2) is being removed.
20. Printing machine as claimed in one of the preceding claims, characterised in that the suction cups (10) are elastically deformable and, once the respective suction volume has been reduced due to deformation, suck firmly on the co-operating printing plate (2) due to elastic expansion.
21. Printing machine as claimed in one of the preceding claims, characterised in that the fluid system (12-14) has fluid lines (12, 13) opening into the suction cups (10) and fluid control elements (14) for the fluid lines (12, 13), and the fluid control elements (14) close the fluid lines (12, 13) or connect them to a negative pressure generator for applying suction to the printing plates (2) and open in order to reduce the suction force.
22. Printing machine as claimed in the preceding claim, characterised in that the fluid lines (12, 13) connect the suction cups (10) to a pressure generator or the ambient environment (A) in order to reduce the negative pressure.
23. Printing machine as claimed in one of the two preceding claims, characterised in that the fluid control elements (14) are magnetically or electrically operable multi-way valves respectively.
24. Method of removing a printing plate (2) from a printing plate carrier (1) of a printing machine by means of a suction device (5) as claimed in one of the preceding claims, whereby a) a clamped end (2n) of the printing plate (2) is released from a clamped connection to the printing plate carrier (1) by means of a co-operating suction cup (10), b) an oppositely lying end of the printing plate (2) is then released by hand, c) and the printing plate (2) is removed from the printing plate carrier (1) by hand.

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