WO1989008027A1

WO1989008027A1 - Arrangement for dosing the supply of a liquid to the printing plate cylinder of a printer, for example for dosing the supply of damping solution to the printing plate cylinder of an offset printing press

Info

Publication number: WO1989008027A1
Application number: PCT/EP1989/000196
Authority: WO
Inventors: Niels Illum
Original assignee: Graphic Enterprises Inc.
Priority date: 1988-03-01
Filing date: 1989-02-28
Publication date: 1989-09-08
Also published as: EP0362319A1; DE3806466A1; DE3806466C2

Abstract

Arrangement for dosing the supply of a liquid, in particular damping solution or ink, to the printing plate cylinder of an offset printing press. Damping solution is conventionally supplied to the printing plate cylinder of an offset printing press either by film damping systems without ductors or by spray damping systems. The film damping systems do not permit selective, variable adjustment of the supply of solution to relatively narrow areas; in the case of spray damping systems, the image of the jet is often visible on the printed image. An adjustable supply of ink to individual areas is obtained using rollers subdivided into separately adjustable partial rollers. These damping systems are expensive andprone to failure. The new arrangement is simple and reliable and ensures a uniform, easily reproducible supply of damping solution or ink, even in small quantities and different from one area to another, to the printing plate cylinder. This is achieved by the use of a roller with an elastic casing, the diameter of which can be varied from inside the roller by a fluid or gaseous hydraulic medium supplied in a controlled manner from the exterior.

Description

Device for dosing the supply of a liquid to the printing plate cylinder of a printing press, for example for dosing the supply of dampening liquid to the printing plate cylinder of an offset printing press

State of the art

The invention relates to a device for dosing the supply of a liquid to the printing plate cylinder of a printing press, for example for dosing the supply of dampening liquid to the printing plate cylinder of an offset printing press, which device has a one-piece or multi-part roll with a lateral surface that determines the liquid supply to the printing plate cylinder. whose distance to the lateral surface of an adjacent roller, in particular zonal different, is adjustable and which device has control means for adjusting the distance of the lateral surface of this roller to the lateral surface of an adjacent roller. For use on offset printing machines, devices for metering the supply of dampening fluid to the printing plate cylinder of such printing machines are known, which are designed either as so-called film dampening units or as spray dampening units. Spray dampening systems, such as those from the Smith company. are known to have the advantage that the distribution of the dampening fluid in the axial direction - that is, zonally - can be adjusted quite precisely. In the event that, however, only relatively small amounts of liquid are to be supplied, the operation of such spray dampening systems can result in the spray image being seen in the printed image. This disadvantage is offset by the advantage that the nozzles of such spray dampening systems equipped with solenoid valves can each be remotely controlled in a simple manner. In the event that only relatively small amounts of dampening fluid are to be fed to the printing plate cylinder of the printing press, such spray dampening systems cannot be used with advantage because of the disadvantage mentioned in the distribution of the dampening fluid.

Especially when only relatively small amounts of dampening liquid are required for printing, the so-called film dampening units, which have been known for a long time, have proven themselves. Such film dampening units, known as so-called lifeless dampening units, are offered, for example, by the companies Miehle and Roland as Miehle-MATIC dampening units or Roland-MATIC dampening units. Lifterless dampening systems are also used for printing metal using the offset printing process. In contrast to the spray dampening systems, the known film dampening systems have the advantage that very small amounts of dampening fluid, and evenly distributed, can be fed to the printing plate cylinder of the printing press. A considerable disadvantage of these film dampening systems is, however, that the zonal or axial distribution can only be influenced very roughly. For the purpose of controlling the supply of dampening liquid to the printing plate cylinder, there are only three possible settings in these dampening units, namely on the one hand a uniform metering of the dampening liquid over the entire width of the roll, and on the other hand a metering which differs from one end of the metering roll End of this roller and finally a metering in the middle which differs from the metering at the ends. However, a precisely predeterminable, differentiated supply of dampening fluid to individual, selected zones of a plurality of zones lying one behind the other in the axial direction of the printing plate cylinder is not possible with the known film dampening systems.

Furthermore, lifter-free film dampening systems are known in which the printing plate is moistened on the printing plate cylinder by an ink roller (so-called "integrated dampening"). Such a film cigarette maker is offered, for example, by the Dahlgren company. These combined inking and film dampening units have essentially the same advantages and disadvantages with regard to plate moistening as the film dampening units mentioned above.

For metering the supply of ink to the printing plate cylinder of a printing press, it has long been known to meter the ink supply to the printing plate cylinder within wide limits to make, especially zonal different.

For example, CH-PS 169 362 already shows an inking unit for rotary printing presses with a plurality of individually adjustable and adjustable lifting rollers arranged side by side on a common shaft, the length of each corresponding approximately to the width of a printing plate. For the lifter rollers, a separate control disc with several adjacent, differently dimensioned cams is arranged on a common shaft that can be moved and adjusted on its own, = with the inking unit according to this publication, it should be possible to refer to the coloring of each individual page or for each printing plate width to be able to control the color stripe position during operation from a central point.

In the case of DD-PS 104 259, the object is to be able to program predetermined and / or calculated metered amounts of ink in a programmed manner, and to be able to eliminate inking problems during the printing process using control technology. This is to be achieved with a device for ink screwless and ink knife-free metering on offset or book printing machines in that a color layer thickness required for each ink-paper combination used is achieved in order to achieve a predetermined uniform coloration on the printing sheet when printing solid areas is achieved by a fine adjustment of a roll gap between the ductor and a counter roll and / or by a speed difference between these two rolls. The metering disk system provided for the transfer of the color and consisting of a plurality of zone disks oscillates under the action of an electromagnet and a spring between the ductor and a roller taking over the paint back and forth. The mentioned zone disks of the metering disk system are only supported on one side in the case of this device.

FR-PS 2 516 018 also shows a paint-transferring roller which is divided in the axial direction into a plurality of zone disks lying one behind the other, which are rotatably mounted eccentrically on the common core of the roller. The storage of the zone plate is thereby made such that the eccentric bearing is seen for the successive ^'Zone slices taken in the axial direction spirally vor¬. The transfer of the ink with the aid of this roller consisting of zone disks from a ink-dispensing roller to an ink-accepting roller will therefore take place more or less point-wise and in any case in accordance with the spirally offset arrangement of the zone disks on the roller mentioned.

DE-PS 31 43 781 describes a device for supplying a liquid to the cylinders of a rotary printing machine. This device is characterized in particular by the use of a plurality of contact elements which are arranged one behind the other in the axial direction and are provided in pairs. - in pairs - can be adjusted in approximately radial direction with the aid of separate control means. The contact elements mentioned take more or less liquid from a ductor referred to as a box roller in accordance with their pair-wise individual setting and pass the liquid on to a roller of the printing unit known as a friction roller. The device according to this document describes a construction which is intended to be suitable both for use on inking units and on dampening units of printing presses. DE-OS 29 24 635 shows an ink metering device for book and offset printing presses, in which ink lifter disk wheels are provided one behind the other for transmitting the ink in the axial direction and which oscillate at an individually adjustable frequency between a duct roller and an ink roller should. The device according to this document is intended to enable less susceptibility to faults against paper components and dampening water and, moreover, an ink supply which corresponds exactly to the printing form. It should also be mentioned that the mentioned color lifter wheels correspond to a certain color zone in their width.

The devices mentioned above for inking units divide the lifter roller into a plurality of transfer rollers which are arranged next to one another in the manner of disks and which. must be held laterally or must be controlled from the side by mechanical means for the purpose of their adjustment. In any case, there is a more or less large gap between adjacent transfer rollers of these devices, which can thus deposit color during the printing process, which later has to be removed in complex cleaning processes. To solve this problem, EP-A2 131 '' .10 proposes an ink metering device for book and offset printing presses, in which the ink lifter disks arranged side by side and which can be moved back and forth independently of one another between an ink fountain roller and a transfer roller each consist of a central part and an outer ring with a coating and are arranged side by side on a stationary support tube without gaps. Here, the outer ring is rotatably mounted on the middle part, the middle part is on the Carrier tube is mounted so as to be adjustable transversely to its longitudinal axis and a drive for adjusting the central part is provided within each of the disks mentioned. With the aid of the electrically or pneumatically operating drives provided in the disks, the mentioned outer rims can be driven in an oscillating manner individually between a box roller and a transfer roller.

Although the ink metering device according to EP-A2131 110 berei brings with it a considerable improvement in ink metering on printing presses, this improvement only affects the distribution of the ink in the axial direction of the rollers, apart from the fact that this ink metering device is suitable for assembly and cleaning is less problematic than previously known devices.

The image which the ink metering device according to EP-A2 131 110 generates on the transfer roller of the inking unit does not essentially differ from the images which are obtained at the relevant point in the other inking units described above. In all cases, these images correspond more or less to an image, as shown in DE PS 1 240 889 in FIG. 4. - It is clear that in the case of such a fashion ^{'arbdosierung} the F an inking unit alone must therefore have a plurality of rollers, which contribute to the dose in this way color to the extent necessary to discharge the paint on the printing plate cylinder in To distribute the circumferential direction of the rollers as evenly as possible. task

With the present invention it should be achieved that the dosing of wet liquid in offset printing machines working with a film dampener and the dosing of ink by inking units in offset or letterpress machines is substantially improved, in the sense that in one case, even the smallest amounts of wet liquid can be reproducibly dosed and, in particular, zonally individually fed to the pressure plate cylinder, and in the other case l color reproducibly dosed and in particular zona l indiv idue ll not already in the area of the ductor as in Fall l of the known metering devices intermittently, but is continuously removed.

solution

To achieve the above object, a device of the type mentioned in accordance with the invention is characterized in accordance with the features of claim 1 by the features that, on the one hand, the roller mentioned has a support tube rotatably mounted about its axis, that a sleeve-shaped support body is formed on the support tube porous and elastically deformable material, for example foam rubber or foam, the support body is closed to the outside by a liquid-tight jacket made of elastically deformable material, for example rubber, and that the support body is provided with a controllable pressure medium source via openings provided in the support tube a gaseous or liquid pressure medium, for example air or hydraulic fluid, is connected or connectable. Another possible solution to the stated object is characterized according to the invention by the mer male that the mentioned roller has a support tube rotatably mounted about its axis, that a support body consisting of one or more layers of a closed or lockable pipeline made of elastically deformable material, for example rubber, is that the support body is outwardly from a liquid-tight jacket made of likewise elastically deformable material, for example rubber,

is closed and that the pipe forming the support body with a controllable pressure medium source for a gaseous or liquid pressure medium, e.g. Air or hydraulic fluid ^ is connected.

FR-PS 486 283 already describes a roller which, under a rubber cover surrounding the roller cylinder, has a pressurized, gas-filled hollow chamber. Egg-like roller is also shown in DE-OS 1 460 775. This roller, equipped with an egg-shaped, gas-filled chamber, is used in the case of both publications as a transfer roller for a wallpaper printing machine. With the roller mentioned, the disadvantages that are encountered in wallpaper printing machines are to be eliminated.

otherwise result when using a known, also made of rubber printing blanket. - Apart from a different type of construction and a different mode of operation of the rollers according to these two documents, there should also be • one compared to

Subject to registration completely different task can be solved.

benefits

The device according to the invention enables the reproducibly metered supply of liquid, namely moist liquid or ink to the printing plate cylinder of a printing machine, whereby in the case of the supply of wet liquid even the smallest amounts of liquid or even ink already ^' during the actual metering process in the form of a uniform, related film. It follows that it is possible at least in part to dispense with rollers which, in the case of the known dyeing or dampening units, have hitherto been provided in large numbers to distribute or even out the liquid. Furthermore, a particular advantage of the invention is to be seen in the fact that smooth transitions from one zone to the next are obtained in the liquid supply when the metering of the liquid is set at different zones. Finally, another noteworthy advantage of the invention is that the cleaning effort of a roller used according to the invention is considerably less compared to known metering devices.

The special construction of the roller used in the context of the invention results, in addition to avoiding abrupt transitions between adjacent zones, as in the case of the known devices which are intended in particular for inking units, as well as the further advantages of a very precise and in particular reproducible delivery of the feed of Areas of this roller which determine the liquid to the printing plate cylinder and the adjacent roller or rollers of the dampening and / or inking unit concerned and - because of the continuous metering possible by the device according to the invention already at the point where the liquid is taken up by a ductor - a possible input Saving of the necessary distribution rollers in the case of the known devices.

The advantages with regard to a dosing of the liquid which corresponds as exactly as possible to the requirements are particularly evident when the invention is applied to film dampening units if the smallest amounts of dampening liquid are to be dosed.

Of course, the device according to the invention is also suitable for inking units or combined inking / dampening units (so-called "integrated inking units").

Another advantage of the device according to the invention is the - compared to known devices of the type mentioned - lower manufacturing costs. This is in particular the fact that no technically complicated and manufacturing complex "multi-part" rolls are necessary as in the known devices, the plate cylinder pressure liquid to be supplied to be able to zonal dosing indi¬ vidually ι ^«m.

In addition, the device according to the invention also has few moving parts, which, in addition to the manufacturing costs, has a particularly positive effect on the susceptibility to faults.

Finally, it should again be pointed out that a roller, as in the case of the invention, is easy to clean because of the end of the roller, which is preferably one-piece in the axial direction, that is to say continuous. The operation of the device according to the invention or each of the possible embodiments according to claims 1 and 2 ^"of the invention consists essentially in that the corresponding support of the mentioned support body of the roll essential for the invention of the jacket covering the support body is more or less strong is deflected evenly over the entire circumference, which means that the invention creates a roller whose diameter, in particular also zonally different, can be varied to a predeterminable extent using one or more energies belonging to the object of the invention Sources, in particular pneumatic or hydraulic pressure medium sources, can accordingly, by correspondingly controlling the roller forming the essential feature of the invention, a more or less large proportion of liquid, for example dampening liquid, if the invention is used on one Film dampening system from which the roller opposite this roller, in particular the doctor roller, is "squeezed". The new roller enables reproducible infeeds of the jacket of this roller compared to the adjacent roller or rollers in the order of 1/10 mm

Further advantageous or expedient refinements of the devices according to the invention according to claims 1 and 2 result from subclaims 3 to 30.

A possible further embodiment of the device according to the invention according to claim 2, according to the proposal according to claim 3, consists in that the pipeline consists of airtight or liquid-tight material. Under the action of the pressure medium, therefore, the volume occupied by this pipeline will change and adjust according to the respective pressure of the pressure medium, so that the jacket of the roller covering the pipeline to the outside in its distance from or to the adjacent rollers of the printing unit of the printing press, if necessary can be adjusted. In addition to the proposal according to claim 3, it is further expedient according to claim 4 to embed the pipeline in elastically deformable material such as foamed or non-foamed rubber or in foam. As a result, the support body for the jacket of the roll formed by the pipeline is made more uniform and also the position of the individual turns of the pipeline is secured.

According to a further possible embodiment of the device according to the invention according to claim 2, the pipeline can consist of air-permeable or liquid-permeable material and can be embedded in porous and elastically deformable material such as, in particular, foam or foam rubber. In this case, the support body for the jacket of the roller is essentially formed by the aforementioned porous and elastically deformable material, while the air-permeable or liquid-permeable pipeline practically forms only one channel, through which the pressure medium used may get faster into the support body mentioned arrives than in the case of the support body in the device according to claim 1. As a result, the support body can then bring about necessary changes in the setting of the jacket of the roller relative to the adjacent rollers or more quickly.

Further advantageous embodiments of the solution according to claim 2 are specified in claims 6 to 12. - According to claim 6, the pipeline is continuous in the axial direction of the support tube. Of course, it is also possible - albeit with a view to the production costs and the mode of operation less favorable - to provide the pipeline in a zonal manner in the axial direction of the carrier tube.

In a further expedient embodiment of the proposal according to claim 6, the pipeline is connected to a pressure medium source at predetermined intervals. The distances between the connections to a pressure medium source are selected such that one of the zones of the roller is formed in the axial direction between adjacent connections of the pipeline. In the case of the solution according to claim 7, the device can be operated in such a way that the individually mentioned connections to a pressure medium source are supplied with separately controllable compressed air or pressurized liquid, so that in the case of different pressures the pressure medium in question passes through this part of the pipeline flows in the corresponding direction and, as a result of the flow resistance of the pipeline, there is a pressure drop along the pipeline and thus also in the axial direction of the carrier pipe. Accordingly, the jacket of the roller according to the invention will be deflected to a greater or lesser extent in the radial direction in accordance with the respective pressure in the pipeline. This ensures that between pipeline areas - that is, zones - with different pressure conditions there are smooth transitions from one zone to the next on the surface of the jacket.

In accordance with the proposal according to claim 8, the pipeline is designed in several parts in the axial direction. In the case of this configuration, the pipeline or ^" the pipelines can be operated as in the case of the device according to claims 6 and 7), that is to say using a pressure medium that constantly flows through the pipeline during operation. However, a solution according to claim 9 is also possible, in which the pipeline is closed at one end, so that operation with a static pressure in the pipeline is made possible.

According to claim 10, the pipeline can be formed by a channel which is embedded in an otherwise sleeve-shaped support body made of elastically deformable material. This type of configuration can provide advantages in terms seen in the axial direction as possible kontinuier Liche deflection of the mantle of Walze.- According to the invention the material proposed according to ^* claim 11 and 12, a support body designed according to claim 10 made of foam-rubber or consist of foam, which can also be porous. It is then also possible to have such a support body perform the double function, namely on the one hand support function and on the other hand control function for the casing of the roller, as in the case of the solution according to the invention according to claim 1. In this respect, the solution according to claims 10 to 12 a combination of the two solutions according to claim 1 and 2.

A possible and, in various respects, particularly advantageous further configuration of a device according to the invention according to claims 1 or 2 is characterized according to claim 13 in that the roller, which is divided into zones in the axial direction, has a jacket which is common to all zones. "This solution offers lum iintn - Which does not need to be explained further - special advantages with regard to cleaning the roller, on the other hand, the continuous jacket in the axial direction ensures a "smooth" transition from one zone to the next. - Of course, a separate jacket (as well as a separate support body and a separate carrier tube) can be provided for each individual zone (for example for production reasons or with regard to an inexpensive modular system). In such a case, however, there are more or less abrupt transitions between the adjacent zones in spite of the close succession of adjacent shells in accordance with the respective setting of the relevant supporting body or supporting body part. Otherwise would be in

Λv

In the case of such a solution, cleaning is also difficult for the same reason.

In a further preferred embodiment of the devices according to claims 1 and 2, the roller, which is divided into zones in the axial direction, has a support body common to all zones. The advantages of this solution arise in part from what has been said above regarding a common shell. Inexpensive production can also be advantageous, «

Furthermore, according to claim 15, the roller divided in the axial direction into zones can have a support tube common to all zones. This solution can also be offered for reasons of economical production and satisfactory functioning.

A preferred embodiment of a device according to the invention consists, according to the proposal of claim 16, in that the roller which is divided into zones in the axial direction has a common feature in all zones. Carrier tube, a common support body and a common jacket.

The support body for the jacket of the roller provides an actuator which acts uniformly in the radial direction and over the circumference for adjusting the jacket, more precisely for adjusting the diameter of the jacket since, in the case of the device according to claim 1, the jacket forms part of this actuator, namely, on the one hand, due to the fact that it is directed in the radial direction onto the support body and is superimposed on the spring force of the support body Spring action and on the other hand by the air or liquid-tight closure of the support body made of porous material formed from it towards the outside, in the event that this support body does not have an air- or liquid-tight layer on the side facing the jacket or with such a shift is complete. When carrying out the invention, of course, first of all, there is a solution in which, if the porous material mentioned is used for the support body, the - sleeve-shaped - support body at the ends, that is to say at the end faces of the roller, is air or liquid is tightly sealed, as indicated in claim 17. But it is also quite conceivable a solution in which in the case of the use of air as a pressure medium, the support body or the support body at the ends are air-permeable to a predetermined extent. Such a solution would then result in constant movement or consumption of air, but it can offer advantages in terms of precise control or regulation of the liquid dosage

In the case of the embodiment according to claim 4 or claim 1, in which a common support body is provided for all zones of the roller, the pressure medium between the individual zones of the support body will act differently in the event of the individual zones being acted upon by the pressure medium associated areas result in a more or less strong compensation of the pressure medium. This can be quite desirable with regard to smooth transitions of the corresponding areas of the jacket lying on the support body. With the help of suitable control devices, it is easily possible, despite the pressure equalization that may occur between adjacent zones, to have a certain pressure difference, for example between the respective centers. areas of the relevant zones of the support body.

In order to provide a separation between the individual zones of an otherwise continuous or one-piece support body - which can bring advantages with regard to the regulation of the desired setting state of the jacket - it is proposed according to claim 19 that the roller which is divided into zones in the axial direction has a plurality of ₈ partial adjoining bodies lying one behind the other in the axial direction, of which adjacent sub-supporting bodies are each connected to one another by an air or liquid barrier which is elastically deformable like the material of the partial supporting body . This air or liquid barrier then deforms in the radial direction together with the porous, elastic material.

For a further possible embodiment of the devices according to claims 1 and 2, it is proposed according to claim 20 that the carrier tube is designed on a hollow by means of a separating and closing disc and by means of at least essentially gas or liquid-tightly encapsulated slide or ball bearings , fixed bearing axis is rotatably mounted so that chambers are formed between the support tube, separating or closing disks and bearing axis, which are connected or connectable to the pressure medium source via openings in the bearing axis and pressure medium lines adjoining these openings.

Another possible embodiment of the devices according to claims 1 and 2 is characterized according to claim \

C 'in that the porous, elastically deformable Material existing support body or the pipeline is connected to the pressure medium source via at least one opening provided in the support tube and a pressure medium distribution unit.

Furthermore, it is possible according to claim ²² , for further configuration of the devices according to claim 1 or 2, to firmly connect the support tube via separating or end disks to a layer shaft, so that cavities are formed between the support tube, separating or end disks and bearing shaft are connected or connectable to a pressure medium source via connections located on one or both end faces of the roller with associated sliding seals. According to claim 23, it is expedient for this that the carrier tube and bearing shaft are formed by a single component.

It is an essential concern of the present invention to carry out the liquid metering as continuously as possible at the location of the actual metering element - namely with., Uniform distribution of the liquid over the circumference of a roller (and this also in particular zonally different). In addition to this possibility, the invention also opens up the possibility of performing the metering differently, also viewed over the circumference of the roller or rollers. With an appropriate dimensioning of the diameters of the individual rollers up to the printing plate cylinder, an even better adaptation of the liquid requirement to the respective printing plate can be achieved. With regard to the aforementioned, additional possibility of metering in the direction of the roller train to the printing plate cylinder, the roller or the zones of the roller can be divided into separately controllable segments.

According to claim 25, it is also expedient if, in the devices according to claim 1 or 2, the support body is under a certain pretension on the carrier tube. Likewise, the jacket may lie on the support body under a certain pretension.

With an appropriate choice of materials and with a certain preload, no special measures need to be taken to keep the jacket on the support body and the support body on the support tube in a predetermined position. However, it is also possible to connect the support body to the jacket and / or to the support tube by gluing, independently of any pre-tensioning of the jacket and / or support body, as stated in claim 27.

An advantageous further embodiment of the device according to claim 1 or 2 consists in claim 28 that the support body and the jacket are made in one piece, in particular from so-called integral foam.

Finally, in a further embodiment of the solution according to the invention, either the pipeline can wrap around the support tube in a helical shape, or else it can be laid in a meandering manner on the outer surface of the support tube, as specified in claim 29 and claim 30, respectively. 40-

The device according to the invention is explained in more detail below with the aid of FIGS. 1 to 9 of the drawing.

Show it

1 shows a dampening unit of an offset printing press, which is known per se from the basic structure, in a schematic representation and using the device ₉ according to the invention

2 shows another dampening unit, known per se from the basic structure, for printing on metal in a schematic representation and using the device according to the invention,

FIG. 3 shows a preferred embodiment for a roller which can be used in connection with the device according to the invention in a dampening unit and / or inking unit,

FIG. 4 shows a section through the roller according to FIG. 3 according to section line 1V-IV in FIG. 3

5 shows a variant of the embodiment of the device according to the invention according to FIG. 3 in an Ansic in section,

6 shows a further embodiment of a roller corresponding to the roller according to FIG. 3 in terms of its basic structure, in a side view in section and with the roller being divided into segments, FIG. FIG. 7 shows a further possible embodiment of a roller used in connection with the device according to the invention in a view partly in section and partly broken away,

FIG. 8 shows the roller according to FIG. 7 in a side view in section along section line VIII-VIII in FIG. 7,

Figure 9 shows a variant of the embodiment according to the

Figures 7 and 8 in a view partially in section and partially broken

44

FIG. 1 schematically shows an offset printing machine with a printing plate cylinder 1 to which a dampening unit 2 is assigned. The dampening unit 2 consists of a duct roller 5 immersed in a container 3 with dampening liquid 4, a metering roller 6, a dampening application roller 7 and a distribution roller 8. The function of such a dampening unit is known per se and therefore does not need to be explained further here become.

Figure 2 shows a further ₈ schematically shown offset printing machine, which is provided in particular for printing on metal sheet. This printing press has a printing plate cylinder 9, on which the roller train of a dampening unit, denoted overall by 10, ends. The dampening unit 10 consists of a container 11 for dampening liquid 12, a ductor roller 13 immersed in the dampening liquid 12 or the container 11, a transfer roller 14, a friction roller 15 and adjoining it in the roller train. finally, dampening rollers 16 and 17.

The roller proposed below according to various embodiments and exemplary embodiments and proposed according to the invention can be used at different points in the two dampening units according to FIGS. 1 and 2, which are only shown by way of example, for example as a metering roller 6 in the case of the dampening unit according to FIG. 1 or as a transfer roller 14 in FIG Case of the dampening unit according to Figure 2.

A possible embodiment of a roller provided according to the invention is shown in FIGS. 3 and 4. The roller shown in these figures, generally designated 18, essentially consists of a support tube 20, which is rotatably mounted on a stationary, hollow axis 19, and a support body 21 made of porous and elastically deformable material, in particular, located on the support tube 20 IS

Foam or foam rubber, and a jacket 22 made of elastically deformable material, in particular rubber, covering the sleeve-shaped support body 21 on the side facing away from the carrier tube 20.

The carrier tube 20 is held on the end faces of the roller 18 and the end disks 23 and 24 and between the end disks 23, 24 provided disks 25 and 26 and airtight encapsulated rotary bearings 27 to 30 on the axis 19 and rotatably supported. The closing disks 23 and 24 and the cutting disks 25 and 26 form, with the respective areas of the axis 19 and the support tube 20 in question, hollow chambers 31 to 33, the corresponding chambers lying one behind the other in the axial direction 31 to 33 are connected on the one hand via openings 34 in the support tube 20 to the support body 21 and on the other hand via openings 36 in the wall 35 of the axis 19 and pressure medium lines 37 adjoining these openings 36 with a controllable one which is not shown Pressure medium source (compressed air source) connected or connectable. The sleeve-shaped support body 21 is expediently closed off in the region of the end faces of the roller 18 by an annular, air-impermeable lock 38. The lock 38 can e.g. consist of approximately the same amount of elasticity of the material of the support body 21 as elastic material such as rubber. to 30 As a result of the airtight encapsulation of the rotary bearings 27 /, the chambers 31 to 33 are essentially airtight against one another or against the external atmosphere. Via the pressure medium lines 37, the

* Define zones. mentioned compressed air source, the air pressure in the chambers 31 to 33 can be set independently of one another.

The jacket 22 located on the support body 21 can be brought onto the support body 21 with a certain pretension ("be pulled up"); regardless of this, it may be appropriate to firmly connect the jacket 22 to the support body 21 by gluing. Furthermore, the support body 21 can also be connected to the support tube 20 by adhesive bonding. However, such an adhesive connection must ensure the free supply and removal of air into and from the support body 21 through the openings 34.

The mode of operation of the roller 18 is described below.

By controlling the air pressure in the chambers 31 to 33, the support body is in terms of its Aus¬ expansion in the radial direction and accordingly ^* be¬ züglich its outer diameter against the from the own elasticity of the supporting body, and in addition, the elasticity of the sheath 22 resulting spring action? to change. Accordingly, in addition to the support body 21 ^" , the outer diameter of the jacket 22 is also changed, for example, increased in diameter, as the dashed line indicated at 39 for example in the region of the chamber 32 indicates - to an exaggerated extent -. Of course an air pressure which is present in the area of a chamber in the porous support body 21 and which is higher than an adjacent chamber will endeavor to balance itself out to the sides - that is to say in the direction of the areas of the adjacent chambers or zones Material for the support body more or less slowly instead, so that a corresponding deflection state of the jacket located on the support body can nevertheless be maintained by correspondingly controlling the individual chambers via the pressure medium source

It is readily apparent that in the case of an embodiment as shown in FIGS. 3 and 4, a smooth transition between possibly different outer diameters of the jacket 22 in the area of the various chambers is achieved. The individual chambers correspond to different zones or are assigned to different zones of the printing plate cylinder and, of course, the number of which can be adapted to the requirements.

Corresponding to the more or less strong deflection of the jacket 22 in the radial direction in accordance with the air pressure in the various chambers of the roller 18, the jacket 22 is b.zw. Approaching the respectively adjacent roller or the respectively adjacent rollers - for example as a metering roller 6 to the duct roller 5 in the case of the dampening unit 2 according to FIG. 1 or as a transfer roller 14 to the duct roller 13 and the ^* distribution roller 15 of the dampening unit 10 according to FIG. 2 - for ensure a zone-controlled supply of damp liquid to the printing plate of the printing press. If, for example, the middle chamber 32, as previously assumed, has an air pressure that is more or less than that of the two adjacent chambers 31 or 33, the support body 21 with the jacket 22 will to a certain extent relative to the support tube 20 in expand in the radial direction so that the gap between the outer surface of the shell 22 and the surface or surfaces neighboring rolls are changed accordingly or, if the roll according to the invention is used in a inking unit, the contact pressure on the relevant opposite roll is changed.

With the aid of the roller used in accordance with the invention, the deflections of the elastic roller shell which occur in the radial direction can be controlled reproducibly in the order of magnitude of approximately 1/10 mm.

FIG. 5 shows a sectional view of a roller 40, which essentially corresponds to the roller 18 according to FIGS. 3 and 4. In the case of the roller 40, however, the support body located on a support tube 41 is composed of a plurality of partial support bodies 42. The partial support bodies 42 are connected to one another via air locks 43 made of elastic material, in particular rubber, which are elastic in the radial direction approximately to the extent of the elasticity of the material of the partial support bodies 42. With the help of these air locks 43, a compensation of the pressure medium - that is to say the compressed air used in this case - between adjacent partial support bodies 42 can be prevented. A jacket 40a closes the partial support body 42 from the outside.

FIG. 6 shows a further embodiment of an embodiment of the roller according to the invention as shown in FIGS. 3 and 4. The roller shown in FIG. 6, designated 44, has a support body located on a support tube 45, which consists of support body segments 46 arranged one behind the other in the circumferential direction. The support body segments 46 are - similar to the case of the support body in the roller according to FIG. 5 - in each case closed off from one another by an air lock 47. Furthermore, the carrier tube 45 has dividing walls 48 which are continuous in the axial direction, the chambers 49 form. The partitions 48 run out at their end facing away from the carrier tube 45 in seals 50 which are rotatably mounted on a fixed, hollow bearing shaft 51. Openings 52 are provided in the bearing axis 51, which are connected to the compressed air source via separate pressure medium lines (not specified in any more detail) and via which compressed air can be supplied to the chambers 49 to different degrees. Assuming a relatively low speed of rotation of the roller 44, it is possible to partially deflect the shell of the roller 44, designated 53, in the radial direction in the radial direction in the circumferential direction of the roller in the course of the rotation of the roller by a corresponding change in the air pressure . - For higher speeds of such a further embodiment of a roller according to the invention, however, other, more suitable constructions are also conceivable, which are obvious to a person skilled in the art in terms of their structural design.

FIGS. 7 and 8 show a variant of a further, fundamentally possible embodiment of a roller used in the context of the invention on a dampening unit and / or an inking unit: The roller shown in FIGS. 7 and 8, generally designated by 54, essentially exists from a support tube 55, on the support tube 55 meandering pipelines 56 made of an elastically deformable material, in particular rubber, and a _. the side of the pipelines 56 facing away from the carrier tube 55, the jacket 57, which closes the roller 54 to the outside, and also made of elastically deformable material, in particular rubber. In order to equalize the forces exerted by the pipelines 56 on the jacket 57, as will be explained later, a compensating body 58 is provided between the pipelines 56 and the jacket 57. The compensating body 58 ^• So

suitably consists of a likewise elastically deformable material, in particular foam or foam rubber. However, the use of, for example, felt or similar materials is also possible.

The pipes 56, which are provided separately for several zones 59 in the case of the embodiment shown in FIGS. 7 and 8, form a support body in the sense of the present invention similar to the support body 21 in the case of the roller 18 according to FIGS. 3 and 4.

The pipelines 56, which are closed at one end, are connected at the other end to a pressure medium source, not shown, in particular a compressed air source, via a connection 60 and pressure medium lines 61 penetrating the carrier tube 55. For this purpose, the pressure medium lines 61 are guided through at least one of the two shaft ends 62 provided for the roller 54 and rotatably mounted in the printing unit in a manner not shown in more detail and end in a pressure medium transmission unit 63. The pressure medium transmission unit 63 consists of a stationary part 64 and one adjoining the stub shaft 62, 65. the rotatable ^"" member has with the stub shaft rotatable part connected 65 - one behind the other in the axial direction - not shown in detail, each one of the Druckmittel¬ lines 61 associated openings, circumferential grooves or the like, which with. Correspondingly provided openings, grooves or the like correspond in the stationary part 64, so that via the stationary part 64 with lines 6.5a connecting the pressure medium source, not shown, each of the pipes 56 independently of the other pipes with a predetermined pressure by the Pressure medium can be controlled. Accordingly, the jacket 57 of the roller 54 will adjust its diameter individually, as in the case of the above-described embodiment according to FIGS. 3 and 4.

It goes without saying that instead of the structural details chosen for the roller according to FIGS. 7 and 8, the mounting of the support tube 55, which in each case is rotatably mounted, and the transmission of the pressure medium, also in other ways, e.g. The purpose of the invention can be achieved via a fixed, hollow bearing axis and corresponding pressure medium transmissions, without the need for special inventive efforts.

FIG. 9 shows a further variant of the embodiment of the invention according to FIG. 2. The roller shown in FIG. 9, identified by 66, essentially consists of a carrier tube 67, a plurality of pipelines 68 located on the carrier tube 67 and winding around the carrier tube 67 in a helical manner and a jacket 69 provided on the side of the pipes 68 facing away from the carrier pipe 67 and supported on the pipes 68. The pipes 68 and the jacket 69 exist as in the case of FIGS. Variant according to FIGS. 7 and 8 made of elastically deformable material, in particular rubber. - Between the pipes 68 and the jacket 69, a sleeve-shaped compensating body 70 is also provided, similar to the previous embodiment, also made of elastic material, such as foam or foam rubber. While the pipelines 68 are also closed at one end in this exemplary embodiment, the other end of the pipelines 68 is connected to the one, movable part 72 of a pressure medium transmission unit 73 via connections (not specified) in the region of the carrier pipe 67 and lines 71 . Lines 75 connect to the other, stationary and designated 74 part of the pressure medium transmission unit 73 which, as in the case of the flow lines 56 in the exemplary embodiment according to FIGS. 7 and 8, individually control the pipes 68 with the pressure medium used = not shown Dru mittelςuelle connect ,, ^■ = ^■ after explaining the variant according to figures 7 and 8 gives rise to further the understanding of the embodiment of Figure 9 possibly more important details readily apparent from the Dar¬ position in the drawing, so that then not in individual needs to be discussed further.

At this point it should be pointed out again that a preferred mode of operation of a device according to the invention is provided such that the individual zones of the support body in the device according to claim 1 or 2 are separately connected to a pressure medium source for a gaseous or liquid pressure medium and that the arrangement is made so that pressure equalization between adjacent zones is possible. This may be associated with a more or less strong, constant transport of pressure medium between adjacent zones; with appropriate design or dimensioning of the support body or the pipeline serving as support body in the case of the device according to claim 2 and However, due to their variation possibilities, the pressure medium consumption or pressure medium transport can be kept at a relatively low level. In any case, such an operating mode has the advantage over the other possible operating mode with static pressure in the individual zones that relatively large transitions between the zones can nevertheless be achieved in the event of larger pressure differences and correspondingly larger diameter differences of the roll mantle between adjacent zones. This then has a positive effect on the liquid supply - be it damp liquid or paint.

In addition to the solutions shown in the exemplary embodiments on the one hand according to FIGS. 7 and 8 and on the other hand according to FIG. 9 with separately provided pipes made of elastic material, these pipes can also be formed in such a way that the (outer) lateral surface of the support pipe 67 of the embodiment, for example 9 according to FIG. 9 has a correspondingly spiral ^" channel running in the jacket surface, which is then covered, for example, by a sleeve-shaped support or compensation body 70 made of elastically deformable and porous foam or foam rubber.

An essential feature of the invention in all of its embodiments is that the outer, liquid-tight jacket by means of a support body which can be controlled in terms of its volume or its extent in the radial direction of the roller at any point on the circumference and in the axial direction of the carrier tube the roller is fixed. This is the only way to achieve the purpose of the invention to vary the diameter of the roll in a reproducible manner, with different zones, with extremely small deviations from the nominal value. It is clear that this is not just an operation with a variable distance between lateral surfaces ^

mutually adjacent rolls is possible, but also - or overlapping to this - an operating mode such that the pressure exerted on the lateral surface of an adjacent roller from the lateral surface of the roller according to the invention can be varied in a controlled manner.

The embodiments of the invention explained in the drawing using exemplary embodiments can of course be supplemented by further exemplary embodiments without further inventive activity being necessary for this

Claims

1P claims

1. Device for dosing the supply of a liquid to the printing plate cylinder of a printing press, for example for dosing the supply of dampening liquid to the printing plate cylinder of an offset printing press,

a) with a one-piece or multi-piece roller which determines the liquid supply to the printing plate cylinder and has a lateral surface whose distance from the lateral surface of an adjacent roller, in particular zonally different, is adjustable, and

b) with control means for adjusting the distance between the outer surface of this roller and the outer surface of an adjacent roller,

characterized by the following features:

c) the roller (18) mentioned has a support tube (20) which can be rotated about its axis,

d) on the support tube (20) there is a sleeve-shaped support body (21) made of porous and elastically deformable material, e.g. Foam rubber or foam,

e) the support body (21) is closed to the outside by a liquid-tight jacket (22) made of an elastically deformable material, such as rubber, and f) the support body (21) is connected or connectable to a controllable pressure medium source for a gaseous or liquid pressure medium, for example air or hydraulic fluid, via openings (34) provided in the support tube (20).

2. Device for dosing the supply of a liquid to the printing plate cylinder of a printing press, for example for dosing the supply of dampening liquid to the printing plate cylinder of an offset printing press,

characterized by the following features:

c) the roller (54) mentioned has a support tube (55) which is rotatably mounted about its axis,

d) on the support tube (55) there is a support body consisting of one or more layers of a tube line (56) made of elastically deformable material, e.g. Rubber,

e) the support body is also elastic towards the outside from a liquid-tight jacket (57) deformable material, such as rubber, closed, and

f) the pipeline (56) forming the support body is connected to a controllable pressure medium source for a gaseous or liquid pressure medium, e.g. Air or hydraulic fluid connected or connectable.

3. Device according to claim 2, characterized in that the pipe (56) made of airtight or liquid-tight material, e.g. Rubber.

4. Device according to claim 3, characterized in that the pipe (56) in elastically deformable material such as e.g. foamed or non-foamed rubber or embedded in foam.

5. Device according to claim 2, characterized in that the pipeline (56) consists of air-permeable or liquid-permeable material and is embedded in porous and elastically deformable material such as, in particular, foam material or foam rubber.

6. Device according to claim 2, characterized in that the pipeline is carried out continuously in the axial direction of the carrier tube.

7. Device according to claim 6, characterized in that the pipeline is connected to a pressure medium source at predetermined intervals.

8. Device according to claim 2, characterized in that the pipeline is made in several parts in the axial direction.

9. Device according to claim 6 or 8, characterized in that the pipeline is closed at one end.

10. Device according to claim 2, characterized in. that the pipeline is formed by a channel which is embedded in an otherwise sleeve-shaped support body made of elastically deformable material.

11. The device according to claim 10, characterized in that the support body consists of foam or foam rubber.

12. The device according to claim 11, characterized in that the foam or foam rubber is porous.

13. The device according to claim 1 or 2, characterized gekenn¬ characterized in that the axially divided into zones roller (18) has a common to all zones jacket (22).

14. Device according to claim 1 or 2, characterized in that the roller (18) divided into zones in the axial direction has a supporting body (21) common to all zones.

15. Device according to claim 1 or 2, characterized in that the roller (18) divided into zones in the axial direction has a support tube (20) common to all zones.

16. Device according to claim 1 or 2, characterized in that the roller (18) divided in the axial direction into zones has a support tube (20) common to all zones, a common support body (21) and a common jacket (22).

17. The device according to claim 1 or 5, characterized in that the support body (21) are airtight or liquid-tight at the ends.

18. Device according to claim 1 or 5, characterized in that when using air as pressure medium, the support bodies (21) are air-permeably closed at the ends to a predetermined extent.

19. Device according to claim 1, characterized in that the roller (40) divided in the axial direction into zones has a plurality of partial support bodies (42) lying one behind the other in the axial direction, closely adjoining one another, of which adjacent partial support bodies (42 ) are connected to each other via a similarly to the material of a partial support body (42) elastically deformable air or liquid barrier (43) to a one-piece support body.

20. Device according to claim 1 or 2, characterized in that the carrier tube (20) is rotatably mounted on a hollow, stationary bearing axis, and that chambers (31 to 33) between the carrier tube (20), separating or closing disks (23, 24 or 25, 26) and Lager¬ axis (19) are formed, which in the bearing axis

(19) located openings (34) and pressure medium lines (37) adjoining these openings (34) are or can be connected to a pressure medium source.

21. The device according to claim 1 or 2, characterized in that the support body made of porous, elastically deformable material or the pipeline (56) is connected to the pressure medium source via at least one opening provided in the carrier tube (55) and a pressure medium distribution unit (63).

22. The device according to claim 1 or 2, characterized in that the carrier tube is fixedly connected to a bearing shaft via separating or closing disks, so that cavities are formed between the carrier tube, separating or closing disk and the bearing shaft, which are on one or both end faces Connections located on the roller with associated sliding seals (pressure medium distribution unit 73) are connected or can be connected to a pressure medium source.

23. The device according to claim 22, characterized in that the carrier tube and bearing shaft are formed by a single component.

24. Device according to claim 1 or 2, characterized in that the roller (44) or zones of the roller (44) are divided into separately controllable segments.

25. The device according to claim 1 or 2, characterized gekenn¬ characterized in that the support body (21) is under a certain bias on the support tube (20).

26. Device according to claim 1 or 2, characterized gekenn¬ characterized in that the jacket (22) is under a certain Vor¬ tension on the support body (21).

27. The device according to claim 1 or 2, characterized in that the support body (21) with the jacket (22) and / or with the support tube (20) is firmly connected by gluing.

28. Device according to claim 1 or 2, characterized gekenn¬ characterized in that the support body and the jacket are made in one piece, in particular from so-called integral foam.

29. The device according to claim 2, characterized in that the pipeline (68) wraps around the support tube (67) helically.

30. The device according to claim 2, characterized in that the pipeline (56) is laid in a meandering shape on the support tube (55).