Printing machine

A printing machine includes a roller which is hollow and through which a temperature control liquid flows. The roller is mounted in roller fittings constructed as quick-change devices or quick-acting closures, in such a way that the roller can be quickly removed from the roller fittings and the printing machine and quickly inserted into the roller fittings and the printing machine again, by the operator of the printing machine.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a printing machine, including a roller which is hollow and through which a temperature control liquid flows.

Such a printing machine is described in European Patent EP 0 733 478 B1. According to that prior art document, the roller is an oscillating distributor roller and is rotationally mounted by its journals in side walls of a machine frame. In that case, removal of the roller from the printing machine by the operator is neither required nor possible.

German Published, Non-Prosecuted Patent Application DE 103 15 191 A1, corresponding to U.S. Pat. No. 6,941,861, describes a printing machine having anilox or engraved or screen rollers which, replacing one another, are inserted into a pair of roller fittings, that are constructed as quick-acting closures. In that case, there is no provision to control the temperature of the anilox rollers through the use of a temperature control liquid.

SUMMARY OF INVENTION

It is accordingly an object of the invention to provide a printing machine which overcomes the hereinafore-mentioned disadvantages of the heretofore-known devices of this general type and in which favorable conditions for constructing the roller as an anilox roller are provided.

With the foregoing and other objects in view there is provided, in accordance with the invention, a printing machine, comprising roller fittings constructed as quick-change devices or quick-acting closures, and a hollow roller through which a temperature control liquid flows. The roller is mounted in the roller fittings. The roller fittings permit the roller to be quickly removed from the roller fittings and the printing machine and permit the roller to be quickly inserted into the roller fittings and the printing machine again, by an operator of the printing machine.

The printing machine according to the invention is advantageously constructed with regard to maintenance of the roller carried out outside the printing machine. For instance, the roller can be an anilox roller having an engraved structure which can in principle be cleaned only outside the printing machine. In addition, the construction of the printing machine according to the invention is advantageous with regard to a change of the roller carried out from print job to print job. For instance, in the case of the construction already mentioned of the roller as an anilox roller, its engraved structure can be suitable for a specific print job and the engraved structure of another anilox roller can be suitable for a following print job, so that one anilox roller is replaced by the other between the two print jobs. The fact that the roller fittings are constructed as quick-change devices or quick-acting closures means that the operator can quickly remove the anilox roller used during the preceding print job from the roller fittings and insert the other anilox roller into the roller fittings.

In accordance with another feature of the invention, the roller and a feed line for conducting the temperature control liquid into the roller are connected fluidically to each other through a line coupling, having a first coupling half and a second coupling half, when the roller is inserted into the printing machine. The roller and the feed line are separated fluidically from each other when the roller is removed from the printing machine.

In accordance with a further feature of the invention, the first coupling half is a first shutoff valve and the second coupling half is a second shutoff valve. The shutoff valves can, for example, be shutoff cocks that can be operated by hand.

In accordance with an added feature of the invention, the first shutoff valve and the second shutoff valve are constructed as self-closing shutoff valves which close automatically when the roller is removed from the printing machine. Therefore, when the roller is removed from the printing machine, one of the shutoff valves substantially prevents the temperature control liquid from emerging from the feed line, and the other of the shutoff valves substantially prevents the temperature control liquid from emerging from the roller.

In accordance with an additional feature of the invention, the first shutoff valve has a sprung, first valve body and the second shutoff valve has a sprung, second valve body. The first coupling half is displaceably mounted in such a way that, when the first coupling half is displaced toward the second coupling half, the first valve body and the second valve body are displaced mutually in order to open the shutoff valves.

In accordance with yet another feature of the invention, the first coupling half is disposed on the feed line and the second coupling half is disposed on the roller. In this case, the feed line can be mounted through at least one rotary bearing in a slide for displacing the feed line and the first coupling half.

In accordance with yet a further feature of the invention, the first coupling half is disposed on the roller and the second coupling half is disposed on the feed line. In this case, the feed line can be a hollow shaft, through which the temperature control liquid flows, for driving the roller in rotation, and a gear can be seated on this hollow shaft. The hollow shaft and the roller can be associated with a driver coupling for transmitting a torque from the hollow shaft to the roller.

In accordance with yet an added feature of the invention, the feed line is a rotary leadthrough, which is located in the printing machine when the roller is removed from the printing machine.

In accordance with a concomitant feature of the invention, the roller is an anilox, engraved or screen roller.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now initially to the common features of the exemplary embodiments shown in the drawings and first, particularly, toFIGS. 1A and 1Bthereof, in which mutually corresponding components and elements are designated by the same designations, there is seen a printing machine1including a roller2which is mounted in roller fittings3in such a way that it can be released by an operator. The printing machine1is an offset printing machine and the roller2is an anilox or engraved or screen roller of an anilox inking unit.

Only one of the roller fittings3is illustrated in the drawing. The other roller fitting is constructed mirror-symmetrically with respect to that which is illustrated. The illustrated roller fitting3is fitted to a side wall18of a machine frame and has a clamping eccentric23to secure the roller2radially in the roller fitting3. The clamping eccentric23is rotatably mounted in the roller fitting3and is rotated by the operator through the use of a socket wrench into a rotary position to secure it. In this rotary position, the clamping eccentric23presses an antifriction bearing24against two stops of the roller fitting3, so that the antifriction bearing24is clamped in between the clamping eccentric23and the stops as in a three-point mounting. The antifriction bearing24is seated firmly on an axle journal of the shaft2.

A rotary leadthrough17is a constituent part of a feed line4, through which a temperature control liquid, preferably water, is pumped into a hollow space25inside the roller2. A line coupling5having a first coupling half6and a second coupling half7is disposed between the feed line4and the roller2. Through the use of the line coupling5, the roller2is connected to a temperature control liquid circuit as desired during roller installation and separated from the circuit again during roller de-installation.

In the following text, the exemplary embodiments will be described separately from one other with a view toward their special features.

In the first exemplary embodiment illustrated inFIGS. 1A and 1B, the feed line4is rotatably mounted in a slide13by rotary bearings12. The slide13is displaceably mounted in the side wall18through a bush-like sliding bearing. A pipe22of the rotary leadthrough17is plugged into a first shutoff valve8, which is a constituent part of the first coupling half6. The first shutoff valve8is disposed within the feed line4. A second shutoff valve9is a constituent part of the second coupling half7, which is formed on the roller2. Each shutoff valve8,9includes a respective valve body10,11, which is mounted in such a way that it can be displaced into a valve position in which the shutoff valve8,9is open, counter to a restoring action of a valve spring26.

The first exemplary embodiment is based on the following function: After the roller2has been inserted into the roller fitting3and secured, the slide13together with the first coupling half6and the first shutoff valve8is displaced toward the roller2, so that the first valve body10of the first shutoff valve8strikes and presses the second valve body11of the second shutoff valve9, and the valve bodies10,11are displaced mutually into the aforesaid valve position, in which the shutoff valves8,9are open.

Each valve body10,11is constructed as a substantially M-shaped profiled ring and has at least one valve opening27in the form of a transverse bore introduced into the inner side or flank of the respective valve body10,11. In the valve position provided in order to open the shutoff valve8or9(seeFIG. 1B), the valve body10,11is pressed so deeply into the shutoff valve8or9that an outer side or flank of the valve body10,11is lifted off a valve seat28and the valve opening27is no longer separated fluidically from its interior by an edge of the pipe of the shutoff valve8or9.

In the aforesaid valve position, the temperature control liquid flows out of an annular gap29of the rotary leadthrough17and between the outer sides or flanks of the valve bodies10,11resting on each other and the bead-like valve seats28and, subsequently, into the hollow space25of the roller2. The temperature control liquid then flows through the hollow space25and flows out of the latter into the interior of the second shutoff valve9. The temperature control liquid flows through the valve opening27in the second valve body11, out of the interior of the second shutoff valve9into an internal space formed jointly by the two valve bodies10,11resting on each other. The temperature control liquid flows from this internal space through the valve opening27introduced into the first valve body10into the interior of the first shutoff valve8and, from the latter, through the pipe22, back into the rotary leadthrough17. The flow path of the temperature control liquid is illustrated symbolically through the use of arrows inFIG. 1B.

In the second exemplary embodiment illustrated inFIGS. 2A and 2B, a hollow shaft14is rotatably mounted in the side wall18through rotary bearings19. A gear15is firmly seated on the hollow shaft14in order to drive the roller2in rotation.

The hollow shaft14is subdivided by a dividing wall34into a first liquid channel35and a second liquid channel36. The pipe22of the rotary leadthrough17extends into an inlet of the first liquid channel35, and the second shutoff valve9is disposed in an outlet of the first liquid channel35. The first shutoff valve8is disposed in an extension of the first liquid channel35formed in the roller2. A third shutoff valve30is disposed in an extension of the second liquid channel36, likewise formed in the roller2. A fourth shutoff valve31is disposed in an inlet of the second liquid channel36, and the annular gap29of the rotary leadthrough17is connected to an outlet of the second liquid channel36. The third shutoff valve30has a third valve body32, and the fourth shutoff valve31has a fourth valve body33. The four shutoff valves8,9,30,31are identical and the valve bodies32,33are conical or tapered and spring-loaded through the use of valve springs26, so that the shutoff valves are self-closing. The first coupling half6of the line coupling5is provided with blind holes, in the bases of which the first valve body10and the third valve body30are seated in the closed valve position. The second coupling half7is provided with hollow plug pins, in the tops of which the second valve body11and the fourth valve body33are seated in the closed valve position.

When the coupling halves6,7are coupled to each other (seeFIG. 2B), the plug pins are plugged with an accurate fit into the blind holes, which are equipped with sealing rings37, and the first valve body10and the second valve body11are pressed mutually away from their respective valve seat (blind hole base, plug pin top), so that the temperature control liquid flowing toward the roller2can flow out of the second shutoff valve9into the first shutoff valve8. In addition, when the coupling halves6,7are coupled to each other, the third shutoff valve30and the fourth shutoff valve31are mutually held in the open state, so that the temperature control liquid flowing away from the roller2can flow over from the third shutoff valve30into the fourth shutoff valve31. The flow path of the temperature control liquid is illustrated symbolically through the use of arrows inFIG. 2B.

The line coupling5is coupled due to the roller2with the first coupling half6disposed thereon being displaced in the axial direction. This displacement of the roller2together with the first coupling half6toward the second coupling half7on the frame side is carried out at the time at which the antifriction bearing24of the roller has already been inserted loosely into the roller fitting3but has not yet been secured therein through the use of the clamping eccentric23. In order to guide the aforesaid axial displacement of the roller2, a linear guide38, along which the antifriction bearing24slides as far as the clamping eccentric23, is formed on the roller fitting3.

As the line coupling5is coupled, at the same time a driver coupling16is also coupled. In the coupled state, the driver coupling16transmits the rotational drive movement from the hollow shaft14to the roller2. The driver coupling16is what is known as a shaft-hub connection and includes one or more axial grooves20on the outer side of the axle journal of the roller2and sliding springs21complimentary to the groove or grooves20on the inner side of the hollow shaft20or, preferably, a ring connected to the hollow shaft20. When the driver coupling16is engaged, the grooves20are brought into engagement with the sliding springs21. A mutually interchanged configuration of the grooves20and of the sliding springs21is equally possible, as is the construction of the driver coupling16as a claw coupling of a different configuration having coupling halves which can be released from each other.

An important advantage possessed by both exemplary embodiments described previously is to be seen in the fact that the temperature control liquid can run neither out of the roller2nor out of the feed line4when the roller2is removed from the roller fitting3. Without any action on the part of the operator, the shutoff valves prevent any leakage of the temperature control liquid, so that not only is contamination otherwise caused by the temperature control liquid avoided but the volume of the temperature control liquid in the temperature control liquid circuit is also kept constant and frequent topping-off or replenishment of the temperature control liquid is not necessary. From this point of view, the printing machine1is therefore very easy to maintain.

This application claims the priority, under 35 U.S.C. § 119, of German Patent Application DE 10 2004 054 388.7, filed Nov. 11, 2004; the entire disclosure of the prior application is herewith incorporated by reference.