EP1753621A1 - 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

 Printing machine with suction device, suction device and method for changing a printing pad

The invention relates to a suction device for a printing form used for ink transfer or another interchangeable covering of a printing substrate carrier.

USP 4,727,807 proposes the use of a robot for the assembly and disassembly of a printing form, which has suction cups on a robot arm for holding the printing form. The robot takes up a lot of space in the printing press. In addition, he can only handle one printing form at a time.

A suction device for the assembly and disassembly of printing forms is also known from USP 5,806,431 and USP 5,709,150. The suction device comprises a plurality of suction devices alongside one another along an axis and rollers arranged therebetween. To hold the printing forms, the suction cups are pressed against the printing forms, so that the suction cups form tight suction chambers with the printing forms. Vacuum is applied to the suction chambers, which generates the suction forces required to hold the printing plates. In order to be able to handle the individual printing forms independently of one another, the suction cups provided for each printing form can be set against the respective printing form independently of the suction cups for the other printing forms, and can be removed from the latter. An adjusting device is provided accordingly for each printing form in order to effect the inward and outward movement. Accordingly, a plurality of suction cup groups are each arranged alongside one another in the axial direction of the respective pressure cylinder, each with its own actuating device for the infeed and outfeed. For those with interchangeable Printing form carriers of the printing press equipped with printing forms each have their own suction device. Although the suction device allows the simultaneous handling of several printing forms arranged side by side on the printing form support, it is mechanically complex and still requires a comparatively large amount of space directly on the respective printing form support.

It is an object of the invention to provide a simple and inexpensive suction device for handling multiple pressure pads that takes up little space. By means of the suction device, it should be possible to economically change printing coverings serving the ink transfer in a printing press.

The invention relates to a printing press with at least one printing pad carrier, preferably an ink-transferring printing cylinder, on which a first printing pad and at least a second printing pad can be attached offset to one another in an axial direction. The at least two pressure pads can be attached directly next to one another in the axial direction. If a plurality of printing pads can be arranged next to one another transversely to the axial direction on the printing form carrier, the second printing pad can also be offset transversely to the axial direction, in the case of a printing cylinder in the circumferential direction, relative to the first printing pad. The printing press further comprises a suction device arranged opposite the printing lining carrier. The suction device extends in the axial direction. It comprises a first suction cup for the first pressure pad and a second suction cup for the second pressure pad which is arranged offset to the first suction cup in the axial direction. Furthermore, a fluidic device is provided, by means of which the suction cups for suctioning or holding the pressure linings can be subjected to a negative pressure or can be relieved of a negative pressure. The word "or" is used in the usual logical sense, i.e. 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 vacuum independently of one another or relieved of a vacuum by means of the fluidic device. The suction cups of the suction device are thus fluidly separated from each other per pressure pad. You therefore do not have to be mechanically separated by being mechanically independent of each other, although this should not be excluded 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 storing all suction cups associated with the pressure pad carrier in this way, a particularly space-saving suction device is obtained which, moreover, manages with a minimal number of actuating devices for switching the suction cups on and off.

In a preferred first embodiment, those suction cups which are intended to receive and hold a pressure coating 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, the pressure generators being able to be operated independently of one another. However, the vacuum per suction cup is more preferably generated by means of a common pressure generator, and the first suction cup and the second suction cup are separated from one another with fluidic control elements.

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 negative pressure itself. As is known from suction cups in other uses, such a suction cup is pressed against the pressure pad of the pressure pad carrier to be held and thereby elastic compressed. If the suction cup is relieved or a tensile force directed in the direction of the pressing is exerted, the suction cup expands again due to its elastic restoring forces or at least due to the tensile force. Its bowl volume increases accordingly. Since the suction cup is pressed tightly all around against the pressure pad, the cup volume increases when the widening takes place, but the enclosed air mass remains constant, so that the suction cup attaches itself to the pressure pad and can raise a weight corresponding to the suction force that is set. There is no need for active evacuation. The price of the suction device and the operating costs are reduced. Both when using the active suction cups working with an external negative pressure generator and when using the passive suction cups which generate the negative pressure themselves, the suction cup or the multiple suction cups which should or should not suck in a pressure coating, advantageously by connection with the surroundings or active ones Pressurized with excess pressure, while the suction cup or suction cups, which should or should suck in a pressure pad, are pressurized with the negative pressure generated by the pressure generator or generate or generate the required negative pressure by elastic compression and subsequent expansion.

Insofar as preferred features of the invention are described in the following only with reference to a single suction cup, the explanations advantageously also apply 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 bowl volume to a pressure reservoir, a pump or a compressor of the fluidic device in order to pressurize the bowl volume with an overpressure that is higher than atmospheric pressure. Instead, the bowl volume can alternatively be easily vented to the ambient pressure. A simple short-circuit with the surroundings is the simplest and cheapest, active pressurization is a particularly safe solution. A fluid line opening into the bowl volume and a fluidic control element assigned to the fluid line are provided for the fluidic deactivation. For the activation of the suction cup and the maintenance of the active state, the fluidic control element can assume a closed position in which it closes the fluid line, so that the suction cup can form the vacuum chamber with the pressure coating to be suctioned. The fluidic control element can in particular be a two-way control element which can be switched back and forth between the closed position and a flow position. However, it can also be a continuously adjustable fluidic control element or a multi-way control element with more than two different switching positions. In particular, it can be an electric or be a magnetically controllable control valve. The above applies to both an active and a passive suction cup. With an active suction cup, such a fluidic control element can be used to connect the suction cup to a vacuum generator for suction and to the environment or a pressure generator for inactivation. For the generation of the negative pressure and the ventilation, separate fluid lines can be provided per suction cup, in each of which one fluidic control element is arranged. Separate fluid lines are more preferably assigned a common fluidic control element which closes one of the fluid lines and opens the other in a first switching state and reverses the situation in another switching state. The fluidic control element or the plurality of fluidic control elements of the suction device is or are preferably arranged outside the axial section of the pressure lining carrier which can be occupied by pressure linings. It is even more preferred or they are arranged laterally, behind the casing of a machine frame, as seen from the pressure lining carrier.

In the case of an active suction cup, its negative pressure is preferably generated by means of a Venturi nozzle. The fluid line connects the bowl volume with a flow cross-section through which pressure fluid flows, i. H. it branches off from the flow cross-section through which it flows, preferably at a point with the narrowest cross-section. The pressurized fluid can advantageously be the pressurized fluid, in particular compressed air, normally present under the usual excess pressure at the location of the press. The negative pressure can thus be generated by means of a fluid which is under positive pressure, in that the static pressure of the venturi through which it flows forms the negative pressure.

The suction device preferably comprises at least two bearing structures, namely a crossbeam 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 crossbeam and can be moved in the feed and unloading directions relative to the crossbeam. The force required for the inward and outward movement can be generated mechanically, for example by means of an electric motor, or, more preferably, fluidly. Pneumatic force generation is then preferred over hydraulic force. 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 pad when the suction cups are switched off, which is particularly advantageous for attaching the pressure pad to the pressure pad carrier and when the pressure pad rolls off a cylindrical pressure pad 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 can each be moved relative to the crossmember and relative to one another in the feed and shutdown directions. Both the suction cup bearing structure and the roller bearing structure are preferably supported directly on the crossmember. In principle, however, it is also possible to connect one of the two bearing structures to the other, i.e. to support the other on the traverse. The roller bearing structure rotatably supports the roller about an axis pointing transversely to the feed and unloading direction. The suction cup is fastened to the suction cup bearing structure, wherein the fastening can be rigid or allow movements of the suction cup relative to the suction cup bearing structure, for example deflection or a pivoting movement, as long as however the fulfillment of the functions of sucking up and carrying the pressure pad is ensured.

All suction cups of the suction device are preferably supported on the suction cup bearing structure and can thus be adjusted and disengaged uniformly. The roller bearing structure preferably supports all the rollers of the suction device, so that they can be adjusted and removed uniformly.

For the handling of a single pressure coating, the suction device preferably comprises several of the suction cups and also several assigned rollers. If the suction power of a single suction cup is sufficient to safely lift the pressure pad, a single suction cup per pressure pad is sufficient, and basically a single roll is also sufficient.

In order to be able to handle a plurality of coverings which are stretched next to one another on the pressure pad carrier, the suction device comprises in preferred embodiments per print pad at least one suction cup. More preferably, it comprises a suction cup group consisting of at least two suction cups per pressure pad. Furthermore, it should have at least one roller per printing surface, it being preferred here for the application of a roller pressure evenly distributed over the printing surface if the suction device has a group of rollers per printing surface distributed over the surface width. 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 several suction cups are combined to form a suction cup group, a fluid line preferably opens into the cup volume of each of the group suction cups in order to be able to inactivate each of these suction cups. To loosen the suction connection, it may also be sufficient to vent only a portion of the suction cups per group or to apply an excess pressure. The fluid lines can be closed and opened for each suction cup group by means of individual fluidic control elements. More preferably, however, the fluid lines per suction cup group 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 fluidic control element is required per suction cup group.

The suction device is preferably permanently installed in the printing press, i.e. an integral part of the printing press. However, this is not to say that the suction device cannot be dismantled from one place of attachment by means of quick assembly and re-assembled at another place. However, the invention also relates to a suction device provided for installation in a printing press, either for a new machine or a machine to be retrofitted with the suction device.

The pressure coating to be handled by means of the suction device can in particular be a printing form, preferably a printing plate, which is clamped on a forme cylinder or is provided for a forme cylinder. In principle, however, the suction device can also be used to handle other printing linings, for example a rubber blanket for or on a rubber blanket cylinder. Although the invention is primarily based on the Use for rotary printing presses and here especially for web printing presses, preferably in wet offset printing, is advantageous for use in printing presses in general and not only for rotations.

If all suction cups of the suction device are fastened to a common suction cup bearing structure or all rollers are fastened to a common roller bearing structure, an adjusting device for the in and out switching of the suction cups or an adjusting device for the in and out switching of the rollers can advantageously extend outside that in the axial direction Axial section of the pressure pad carrier may be arranged, preferably on said crossmember. The arrangement of the actuating device or actuating devices on the side next to the pressure pad carrier further reduces the space required within the axial section which can be covered with pressure pads. To the side of this axial section, the space requirement generally does not play such a critical role. This arrangement of the actuating device or actuating devices is particularly advantageous for rotary printing presses, because in this way the suction device can be arranged particularly close to the respective printing nip and in such an arrangement the other work on the respective printing unit is less impeded than the conventional suction devices.

In a preferred development, the suction device, the pressure linings and a clamping device of the pressure lining carrier, by means of which the pressure linings can be fastened on the pressure lining carrier, are coordinated with one another in such a way that the pressure linings can be released from the clamping device solely by means of a tensile force exerted by the suction device on a pressure lining end , The clamping device comprises at least one clamping piece per printing form, which has a clamping surface with which it clamps the end of the printing form in cooperation with a counter surface. The invention prefers clamping pieces which, in addition to the clamping surface, have a supporting surface on which the relevant clamping piece is supported in the radial direction of the printing cylinder, so that the clamping piece cannot wedge with the clamped printing form end when the printing form end is pulled out of the tensioning channel by means of the suction device , In this regard, it is also advantageous if the printing form end is angled flat and at right angles or even more obtuse, so that it only by means of the clamping device is held frictionally and not additionally also in a form-fitting manner in a rear grip and is also not bent. It is particularly advantageous if the direction in which the suction cups are brought in and out is at least substantially parallel to the clamped ends, so that when the printing forms are released, at least essentially only tensile forces act in their relevant ends. If the end of the printing form is angled, including a right angle, the in and out direction of the suction cups advantageously points 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 infeed and shutdown direction also has a direction component pointing tangentially to the pressure cylinder.

Preferred features of the invention are also described in the subclaims and their combinations.

An exemplary embodiment of the invention is explained below with reference to figures. Features that become apparent from the exemplary embodiment, each individually and in each combination of features, advantageously form the subject matter of the claims and also the embodiments described above. Show it:

1 shows a view of a printing unit of a printing press with built-in suction device, FIG. 2 shows an axial section of the suction device,

3 shows a circuit for deactivating a suction cup group of the suction device, FIG. 4 shows a tensioning channel with a clamping device for a clamping fastening of a printing form end, and FIG. 5 shows the suction device in a cross section.

FIG. 1 shows a view into a printing tower of a web-fed rotary printing press working in wet offset. Two printing form cylinders 1, in the exemplary embodiment plate cylinders, of two printing units can be seen, which are arranged one above the other in the printing tower and on the same side of a printing tower passing through the printing tower Print web work. The printing form cylinders 1 are each covered in a manner known per se with a plurality of printing forms 2 arranged axially next to one another, printing plates in the exemplary embodiment.

A suction device 5 is assigned to each of the printing form cylinders 1. A suction device 5 is individually assigned to the other printing form cylinders of the printing press in the same way. For example, in an 8-unit printing tower with four pressure bridges arranged one above the other for perfecting and equivalent printing and accordingly eight printing form cylinders 1, at least eight suction devices 5 are also arranged. Each of the suction devices 5 extends over the entire length of the assigned printing form cylinder 1 and is able to handle all printing forms 2 of the assigned printing form cylinder 1, namely to hold them in suction. Only one of the suction devices 5 is described below as representative of the others.

The suction device 5 comprises a traverse 6 which extends over the entire length of the associated printing form cylinder 1 and is fixedly mounted on side frame parts 4 at its two axial ends. The cross member 6 forms a slender, elongated, fixed on both sides bearing beam. The crossbeam 6 serves as a carrier for a plurality of suction cups 10 and rollers 11. The suction cups 10 and rollers 11 are lined up alongside the crossbeam 6, parallel to the printing form cylinder 1, one of the suction cups 10 between two of the rolls 11. The suction device 5 is per printing form 2 equipped with two suction cups 10 and three rollers 11. The suction cups 10 and rollers 11 form a suction cup / roller group 10, 11 for each printing form 2. The suction device 5 forms the same suction cup / roller groups 10, 11 axially next to one another in a number corresponding to the number of printing forms 2 arranged side by side on the printing form cylinder 1 , The suction cup / roller groups 10, 11 can be moved in and against a pressing direction directed at the respective printing form 2, that is to say they can be moved in and out. The suction cups 10 can be moved in and against the pressing direction relative to the rollers 11 and the rollers 11 relative to the suction cups 10. The pressing direction points at least essentially radially to the axis of rotation of the assigned printing form cylinder 1. FIG. 2 shows an axial end section of the suction device 5 detached from the machine, for example in a state intended for installation. The suction cups 10 are axially elongated, and each form a corresponding axially elongated cup volume. In the exemplary embodiment, they are oval, each with a straight central section and semicircular ends. The suction cups 10 are resilient in terms of shape and material. By pressing on the printing form 1, the suction cups 10 are elastically compressed. If the pressing force is removed, the suction cups 10 expand again elastically. 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 vacuum occurs in the enclosed cup volume because of the airtight contacting of the cup form 2 and therefore a certain suction force between the suction cups 10 and the printing form 2 , If a tensile force directed away from the printing form 1, preferably a tensile 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 size, shape and material of the suction cups 10 are designed such that the sum of the suction forces of the suction cups 10 per group is sufficient to hold a single printing form 2 securely. The suction force per group is also so great that the respective printing form 2 can be sucked in at one end by means of the suction device 5 and can be pulled out of a clamping channel of the printing form cylinder 1 without further tools or manual support. If the suction device 5 per printing plate 2 had only one suction cup, this suction cup would of course be dimensioned in such a way that its suction power is sufficient for this. If there are more than two suction cups per group, the individual suction cup can be made correspondingly weaker and / or smaller.

Each of the suction cups 10 is connected to the immediate vicinity of the suction device 5 via a fluid line 12. The mouths of the fluid lines 12 in the bowl volumes can be seen in FIG. The fluid lines 12 each open centrally and extend from their mouths in the cup volumes in the shortest possible way through the fastening area of each of the suction cups 10. The fluid lines 12 are closed for sucking in and holding the printing form 2. The bowl volumes can be short-circuited to the environment via the fluid lines 12 and thereby deactivated or switched inactive beforehand. The axes of rotation of the rollers 11 are parallel to the axis of rotation of the associated printing form cylinder 1, so that they can roll in the assembled state of the suction device 5 in the circumferential direction of the associated printing form cylinder 1 on its printing forms 2, as is the case for rolling over a printing form 2 for fastening it and one 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 crossmember 6 already mentioned and also a roller bearing structure 7 and a suction cup bearing structure 8. The cross member 6 is used to fasten the suction device 5 in the machine frame. The rollers 11 are attached to the common roller bearing structure 7, which is supported on the cross member 6. The roller bearing structure 7 extends over the entire axial length of the printing forme cylinder 1 which can be occupied by printing formes 2. It is formed as a stiff bar from which the stands protrude in the pressing direction, 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 jointly supported on the suction cup bearing structure 8, which extends over the entire axial length of the printing form cylinder 1, which can be occupied by the printing formes 2. The suction cup bearing structure 8 is supported directly on the cross member 6 and can be advanced relative to the latter against the printing form cylinder 1 and can be disengaged 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 cross member 6, as preferred, one of the two bearing structures 7 and 8 could also be supported on the cross member 6 only via the other. Although less preferred, it should not be ruled out that a separate bearing structure 8 or a separate bearing structure 7 is provided for each suction cup group or per roller group and that 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 to suck up and hold one of the printing forms 2, the suction cup groups assigned to each of the printing forms 2 are pneumatically separated. For the pneumatic separation, those suction cups 10, which are not intended to suck in printing form 2, are short-circuited with the environment A (FIG. 3) and thereby set to inactive, while the other suction cups 10 are fluidically separated from the environment A for the purpose of sucking and holding the printing form 2 or the plurality of printing forms 2.

The movements of the bearing structures 7 and 8 are effected fluidically, preferably pneumatically as in the exemplary embodiment. An actuating device 15 is provided for the delivery and disengagement of the bearing structure 7 and an actuation device 16 is provided for the delivery and disengagement of the bearing structure 8. The actuating devices 15 and 16 are connected to a compressed air reservoir, as is usually the case with printing machines on site. The bearing structures 7 and 8 are each moved individually by means of actuators, in the exemplary embodiment pneumatic cylinders, the actuating devices 15 and 16. The control elements of the actuating devices 15 and 16 are preferably two-way valves, the switching states of which are controlled by a suitably electronic control. The electronic control offers the possibility of manual operability directly at the location of the suction device 5 in question.

In order to keep the suction device 5 flat in the pressing direction, the cross-bar 6, which extends in the form of a bar in the axial direction, and the roller bearing structure 7 are U-profiles which are open in the direction of the assigned printing form cylinder 1. In a retracted state, the U-profile of the cross member 6 at least essentially accommodates the roller bearing structure 7. The suction cup bearing structure 8 is accommodated in the U-profile of the roller bearing structure 7 at least in the retracted state. Alternatively, instead of the roller bearing structure 7, the suction cup bearing structure 8 can be formed as a U-profile and accommodate the bearing structure 7. All three bearing structures 6, 7 and 8 can also be shaped as U-profiles. The term "U-profile" is also intended to encompass other trough-shaped profiles, for example a V-profile or an H-profile, although the latter is less preferred because it requires more height. In principle, at least two of the bearing structures 6, 7 and 8 or possibly also all three bearing structures 6, 7 and 8 could each be formed as simply elongated plates that are thin radially to the printing form cylinder 1. The side legs of the U-profile advantageously have a stiffening effect. In principle, the cross member 6 does not have to be one of the two other bearing structures 7 and accommodate 8 or both other bearing structures 7 and 8. Rather, the traverse 6 can in principle also be received by one of the other bearing structures 7 and 8 or two other bearing structures 7 and 8. The nested arrangement with at least partial overlap enables a particularly flat construction of the suction device 5 radially to the printing form cylinder 1.

Figure 3 shows a pneumatic circuit for inactivating a single group of suction cups 10. The suction cups 10 are short-circuited to the environment A, i.e. the surrounding atmosphere, vented, more precisely: 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. Arranged in the group fluid line 13 as a fluidic control element 14 is a two-way solenoid valve 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 fluidly separated from the environment A, and which opens in its other switching state, so that the short circuit with the environment A is established. The fluidic control element 14 is controlled by the electronic control mentioned in connection with the actuating devices 15 and 16 in coordination with the actuating and control elements for the bearing structures 7 and 8. The moving actuator of the fluidic control element 14 is preloaded into the closed position by an installed spring.

By means of the suction device 5, the change of a printing form 2 is carried out semi-automatically, namely partly manually by an operator and partly automatically by the suction device 5 assigned to the printing form 2 in accordance with the operation by the operator on site.

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

For the removal of the printing form 2, the printing form cylinder 1 is rotated into a position in which one of the two ends of the printing form 2 comes to lie radially under the suction device 5, preferably the end of the printing form 2 trailing in printing operation. With the printing form cylinder 1 in position the operator of the operator presses the group of suction cups 10 assigned to the printing form 2 to be removed against the printing form 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 suction cups 10 of the suction device 5 extend together, those suction cup groups which are to suck up a printing form 2 are set to active and the others to inactive by means of the fluidic control elements 14. The previously pressed suction cups 10 are then moved back against the pressing direction again by pressing a button or by automatic sequence control, so that the sucked-in end of the printing form 2 is lifted out of the clamping channel. The sucked-in printing plate end now hangs on the suction device 5. The operator takes over the sucked-in end and deactivates the suction cups 10 at the push of a button and thus causes ventilation. The printing form cylinder 1 is turned back while the operator holds the printing form 2 until the leading end of the printing form 2 is the operator can be gripped and pulled out of his tensioning channel.

In an alternative embodiment, the suction device 5 does not have passive, but rather active suction cups 10 and a vacuum generator, by means of which the cup volumes are sucked off in order to suck in and hold the printing formes 2. The Vacuum generator can be connected to the individual suction cups 10 via the group fluid lines 13 and fluid lines 12. Alternatively, suction lines 12 and 13 can be provided in addition to the ventilation lines. Furthermore, as an alternative to a simple short circuit with the surroundings, the suction cups 10 can be subjected to an overpressure relative to the ambient pressure. It is particularly preferred if those suction cups 10 which are to receive and hold a printing form 2 are suctioned off, and those suction cups 10 which are not also supposed to also perform a holding function are subjected to an overpressure in order to suck a printing form 2 through the to prevent particularly relevant suction cups 10.

Figure 4 shows one of the clamping channels of the printing form cylinder 1 in a cross section. A clamping device is arranged in the clamping channel, by means of which a leading end 2v of a printing form 2 and a trailing end 2n of the same or a different printing form 2 are clamped in the clamping channel. The clamping device is described in German patent application No. 10 2004 042 342.3, which is referred to in this regard. The trailing end 2n is angled at an angle of slightly more than 90 ° and at least essentially protrudes with the angled flange, i.e. with a deviation of not more than 20 ° to the radial on the axis of rotation of the printing form cylinder 1 in the clamping channel. The angled flange of the printing form end 2n is flat and is not deformed by the clamping device, but only clamped by friction. The suction cup bearing structure 8 can be advanced at least substantially parallel to the angled flange against the printing form cylinder 1 and can be supported by the printing form cylinder 1 on the crossmember 6. After the suction cups 10, which are associated with the printing form 2 with the printing form end 2n, have been firmly sucked in, the angled flange is therefore at least essentially only subjected to tension when the suction cups 10 are turned off.

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

The trailing printing form end 2n can be pulled out of the clamping 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 on the suction cups 10. The actuating device 15 is shown for the roller bearing structure 7. The pneumatic actuator of the actuating device 16 is not shown for the suction cup bearing structure 8; the connection to its actuator is only indicated at 18.

The suction device 5, in particular the suction cup 10 representative of the other illustrated, is shown for a printing form 2 in its delivered position after the trailing end 2n has been sucked in. The suction force S acting on the printing form 2 along the axis PS of the feed and shutdown movement acts as close as possible to the angled, trailing end 2n of the printing form 2. The distance between the axis PS and the edge of the trailing end 2n is chosen to be as small as possible. The suction cup 10 is designed in a special way for this. The contact surface of the suction cup 10 facing the printing form 2 is at its greatest distance a from the movement axis PS on its side facing the angled end 2n, measured between the movement axis PS and the outer peripheral edge of the suction cup 10, which is at most 20 mm, preferably at most 15 mm. Apart from a small distance, the suction cup 10 on its outer peripheral edge from the edge of the trailing End 2n, the suction force S acts 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 form cylinder 1 should not be more than 8 mm, preferably no more than 5 mm, at least in the area of the suction cup 10 which is closest to the edge of the trailing end 2n.

The removability of the printing form 2 solely by means of the suction device 5 is also required if the angled flange has the smallest possible length e. The flange length e should not be more than 14 mm and is preferably at most 10 mm. The angled flange forms a right angle with printing plate 2, which is flat in the unloaded state. The suction force S, which coincides with the direction of the shut-off movement, points parallel to the angled flange. If the trailing end 2n is pulled out of the clamping channel of the printing form cylinder 1, tensile forces therefore act at least essentially, ideally exclusively, in the angled flange.

The pulling out of the printing form end 2n is also conducive to the fact that when the pulling out is first carried out, the roller bearing structure 7 is accelerated in the direction S by means of the adjusting device 15 and during this movement by means of a stop element 17 into a stop contact with the suction cup which is not yet in motion at this time Bearing structure 8 arrives so that an impact force acting in the direction S acts on the suction cup bearing structure 8. The impact force is advantageous in order to overcome the static friction acting on the clamped flange of the printing form end 2n. FIG. 5 shows the stop element 17 as an additional element, which can be attributed to the fact that the suction cup bearing structure 8 is accommodated in whole or in part in the roller bearing structure 7, at least in the retracted state. If this arrangement is reversed, ie the at least partial inclusion 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 U-section forming the roller bearing structure 7 replace the stop element 17.

In FIGS. 1 and 2, the adjusting devices 15 and 16 are arranged on the side of the crossmember 6, which is opposite the bearing structures 7 and 8. Instead, the actuating devices 15 and 16 or at least one of these actuating devices 15 and 16 can also be arranged in a space-saving manner on the same side as the bearing structures 7 and 8 and protrude from the cross member 6 in the direction of the inward and outward movement of the suction cups 10 and rollers 11.

The suction device 5 is equipped with two pneumatic actuators each for the roller bearing structure 7 and for the suction cup bearing structure 8. One of the actuators is attached outside the axial section of the printing form cylinder 1 which can be occupied by printing formes 2 in the two axial end regions of the crossmember 6. In the exemplary embodiment, the two pairs of actuators are arranged on both sides of the printing form cylinder 1 in its two journal areas. If the printing form cylinders 1 are equipped with bearer rings, as in the exemplary embodiment, then the actuators and preferably the further fluidic elements of the actuating devices 15 and 16 are each arranged on the outside of the bearer rings, so that they do not have any over the cylinder circumferential surface, in particular in its axial section which can be occupied with printing formes 2 Take up space. The fluidic control elements 14 and possibly further fluidic control elements are arranged behind the casing of the machine frame 4. Only the fluid lines run between the adjusting devices 15 and 16 arranged on both sides of the pressure area.

When using active instead of passive suction cups 10, Venturi nozzles are formed directly at the suction cups in order to generate the negative pressure by means of the usual air pressure of the on-site air pressure system, either one Venturi nozzle per suction cup 10 or per suction cup group. Otherwise, the above statements regarding passive suction cups preferably apply to suction devices with active suction cups. It takes the place of suction by elastic expansion of the

Claims

Expectations 1. Printing machine with a printing pad carrier (1) on which a first printing pad (2) and a second printing pad (2) can be attached offset in one axial direction, and with a suction device (5) comprising: a) a first suction cup (10) for the first pressure pad (2), b) a second suction cup (10) for the second pressure pad (2) c) which is offset in the axial direction from the first suction cup (10) and a fluidic device (12-14) by means of which the suction cups ( 10) can be acted upon independently of one another by a vacuum or can be relieved of a vacuum. 2. Printing machine according to the preceding claim, further comprising an axially extending traverse (6) and a on the traverse (6) supported suction cup bearing structure (8) on which at least one of the suction cups (10) is held and which is relative to the Traverse (6) against the pressure pad carrier (1) can be adjusted and can be removed from the pressure pad carrier (1). 3. Printing machine according to the preceding claim, characterized in that the crossmember (6) has a profile open to the printing lining carrier (1) in cross section, preferably a trough-shaped profile in which the suction cup bearing structure (8) in one of the printing lining carrier (1 ) parked position is recorded at least over a larger part of its height measured in the in and out direction (P, S). 4. Printing machine according to one of the two preceding claims, further comprising a suction cup actuating device (16) for the delivery and removal of the suction cup bearing structure (8). 5. Printing machine according to the preceding claim, characterized in that the suction cup adjusting device (16) is arranged in the axial direction outside of an axial section of the pressure pad carrier (1) receiving the pressure pads (2). 6. Printing machine according to one of the two preceding claims, further comprising a control which controls the suction cup actuating device (16) and the fluidic device (12-14) for removing the first pressure coating (2) in such a way that the suction cups (10) together are delivered and from the first suction cup (10) and the second suction cup (10) only the first suction cup (10) is subjected to negative pressure. 7. Pressure machine according to one of the three preceding claims, further comprising a control which controls the suction cup actuating device (16) and the fluidic device (12-14) for removing the first pressure coating (2) so that the suction cups (10) together are delivered and the second suction cup (10) is connected to the surroundings (A) or an excess pressure is applied while the first suction cup (10) sucks in the first pressure coating (2). 8. Printing machine according to one of the six preceding claims, characterized in that the suction cups (10) are held together on the suction cup bearing structure (8) and can be adjusted and removed uniformly with the suction cup bearing structure (8). 9. Printing machine according to one of the preceding claims, further comprising a first roller (11) for the first printing surface (2), a second roller (11) for the second printing surface (2), an axially extending cross member (6) and one the crossbeam (6) supported roller bearing structure (7), on which at least one of the rollers (11) is held and which can be advanced relative to the crossbeam (6) against the pressure lining carrier (1) and can be removed from the pressure lining carrier (1). 10. Printing machine according to the preceding claim, further comprising a roller actuating device (15) for the infeed and out of the roller bearing structure (7). 11. Printing machine according to the preceding claim, characterized in that the roller actuating device (15) is arranged in the axial direction outside of an axial section of the pressure pad carrier (1) receiving the pressure pads (2). 12. Printing machine according to one of the three preceding claims, characterized in that the crossmember (6) has in cross section a profile open to the pressure lining carrier (1), preferably a trough-shaped profile, in which the roller bearing structure (7) in one of the pressure lining carriers (1) parked position is recorded at least over a larger part of its height measured in the in and out direction (P, S). 13. Dmck machine according to one of the preceding claims in combination with Anspmch 2 and Anspmch 9, characterized in that the roller bearing structure (7) has a stop element (17) with which it stops during a shutdown movement in the case of a closed suction cup bearing structure (8 ) comes into abutment contact against the suction cup bearing structure (8) that is still being delivered. 14. Printing machine according to one of the preceding claims in combination with Anspmch 2 and Anspmch 9, characterized in that at least one of the roller bearing structure (7) and suction cup bearing structure (8) has an open to the pressure lining carrier (1) profile in which the another of the roller bearing structure (7) and suction cup bearing structure (8) is accommodated in a position parked by the pressure lining carrier (1) at least over a larger part of its height measured in the feed and shutdown direction (P, S). 15. Dmck machine according to one of the preceding claims in combination with Anspmch 2 and Anspmch 9, characterized in that the crossmember (6), the roller bearing structure (7) and the suction cup bearing structure (8) in one of the pressure pad carrier (1) parked position of the roller bearing structure (7) and the suction cup bearing structure (8) are nested one inside the other and overlap at least over a larger part of their heights measured in the feed and shutdown direction (P, S). 16. Printing machine according to one of the preceding claims in combination with one of claims 2 and 9, characterized in that the crossmember (6) is installed so that it cannot move. 17. Printing machine according to one of the preceding claims, characterized in that each of the pressure pads (2) has at one end (2n) an angled, at least in an unloaded state flat flange with which the respective pressure pad (2) in a tensioning channel of the pressure pad carrier (1) can be clamped on the pressure pad carrier, and that the suction cups (10) can be set down in a direction (S) that is at least substantially parallel to the flange, so that when the respective pressure pad (2) is loosened in its flange at least essentially only act tensile forces. 18. Printing machine according to the preceding claim, characterized in that the flange is clamped in the clamping channel only by friction. 19. Printing machine according to one of the preceding claims, characterized in that the printing pad carrier (1) is a printing form cylinder and each of the printing pads (2) has an angled flange, with which it is clamped in a tensioning channel of the printing pad carrier (1) on the printing pad carrier (1 ) can be fastened, and that a clamping device is arranged in the tensioning channel, which comprises at least one clamping piece (20) for the pressure coating (2) that can be clamped in the tensioning channel, which has a clamping contact surface that acts against the flange of the respective pressure coating (2) and an additional one Has support surface and is supported on the support surface in the radial direction of the pressure lining carrier (1) in order to prevent the clamped flange from wedging when the respective pressure lining (2) is removed. 20. Printing machine according to one of the preceding claims, characterized in that the suction cups (10) are elastically deformable and according to the respective Tighten the bowl volume-reducing deformation by elastic widening on the assigned pressure coating (2). 21. Printing machine according to one of the preceding claims, characterized in that the fluidic device (12-14) comprises fluid lines (12, 13) and fluidic control elements (14) for the fluid lines (12, 13) opening into the suction cups (10) and in that the Fluidic control elements (14) close the fluid lines (12, 13) for sucking in the pressure deposits (2) or connect them to an underpressure generator and open them to reduce the suction force. 22. Pressure machine according to the preceding claim, characterized in that the fluid lines (12, 13) connect the suction cups (10) with a pressure generator or the environment (A) to reduce the vacuum. 23. Printing machine according to one of the two preceding claims, characterized in that the fluidic control elements (14) are each magnetically or electrically actuable multi-way valves. 24. A method for removing a pressure coating (2) from a pressure coating carrier (1) of a printing machine, preferably by means of a suction device (5) according to one of the preceding claims, in which a) a clamped end (2n) of the pressure coating (2) by means of an associated Suction cups (10) are released from a clamping connection with the pressure pad carrier (1), b) an opposite end of the pressure pad (2) is then released by hand c) and the pressure pad (2) is removed from the pressure pad carrier (1) by hand.