Forme cylinder for a rotary printing machine.

The foregoing invention relates to a pressure cylinder for a rotary printing press, wherein the printing plate in the form of a cylindrical coil plate is on the Aussenflaeche the impression cylinder, clamped by expanding a tube-like, elastic, thin jacket. The cylinder diameter is enlarge by inside an incompressible liquid Color applied to this coat, which by Verdraengungsvorrichtungen the liquid is controllable.

There are already cylinder for clamping rohrfoermigen printing plates rotary presses become known as gravure printing plates, matrices for flexographic printing or for other enveloping body of a rotary printing machine, such as gummy Huelsen for pressure cylinders, zylinderfoermige printing plates for anilox, coatings for power cylinder and similar facilities.

The known Verdraengungsvorrichtung used to increase the pressure in the Liquid and for expanding the outer jacket of the cylinder, have a Betaetigungsschraube for producing a compressive force that acts directly on clear fluid, like a piston, often through the interposition of a spring , Due to the machining tolerances of the screw or the threaded pin and the threaded hole in the discharge pipe, pressure loss can occur which lead to an alteration of Fluessigkeitsdruckes, thus causing a change in the outer circumference of the shell. Furthermore, the disadvantage may occur that the compression is not directly in the axial direction, which leads to further seal losses and / or a bigger wear of the components. The use of a spring due to the incorporation of three components, wherein the above drawbacks are not fixed together with a separately provided flask.

Further, it is required that the printing plate or may be positioned in the huelsenartige, rohrfoermige wrapping on the printing cylinder with high accuracy in the axial direction of the cylinder before an expansion of the cylinder takes place, thus avoiding any unwanted shifts in the transverse direction. Furthermore, it is to consider, that the edge portions of the known printing plate sharp edges or have 90 ° angled edges that would be affecting the operation of a squeegee in a disadvantageous manner, ie that component, which is intended to ablate the color excess, and with back and reciprocating motion moved in Laengsrichtung the printing cylinder.

Especially when the printing plate was produced from a flat plate, it is always difficult to avoid sharp edges on the Plattenraendern. Thus, the doctor interfered not only in its oscillating movement and in its operation, but it is also subject to a bigger wear.

When using a known printing cylinder in combination with a printing plate besthet of a flat, coated with photosensitive material metal plate, and is wound such that the printing plate takes a zylinderfoermige form, there occurs a further disadvantage. Since the shock takes a certain thickness between the ends of the printing plate, even if these thickeners can be partially mitigated, it is not possible to eliminate them completely.

When using a cylinder which undergoes a Vergroesserung the diameter, which is done in conventional gasoline type, a bead or extending in Laengsrichtung survey on the impact Telle the printing plate would result in what would lead to considerable difficulties in the use of this type of panel.

Alternatively, to avoid such a thickening at the junction Telle the printing plate has been proposed to provide a different type of cylinder, as well as a means of suitable pressure plate, the edges to be connected have a mutually complementary shape, which leads to a particularly complex form of empty margins, are not entirely without restrictions is.

The use of this known disc type is particularly advantageous as regards the production costs of the plate, this for both in terms of the necessary apparatuses and as regards the time required galvanic treatment and the etching of these plates. However, the known advantages can not be used completely, because the joint abutment, on the inside of zylinderfoermigen printing plate, forming a thickening due to the mentioned technical conditions that occur due to the interconnection of Plattenraender these printing plates.

The object of the above invention is to avoid the disadvantages of the prior art and the related restrictions.

The inventive object is solved in that a pressure cylinder reaches for a rotary printing machine is used, which has a rohrfoermigen, elastic, thin shell, which is fixed and sealed to the ends of the Zylinderkoerpers, and having peripheral chambers in which provided an incompressible liquid Color is, as well as with means for displacing the liquid, to cause an increase in the externals circumference of the printing cylinder and the pressure cylinder is characterized in that the Verdraengungsvorrichtung consists of a threaded pin which is screwed into a conduit which is in operative connection with the Fluessigkeitskammern and threaded pin having at its end a recording, which is in operative connection with a head-like thickening of the piston, and the piston has at its other end annular grooves for receiving sealing rings.

According to another feature of the invention, the ends of rohrfoermigen Mantelflaeche thickened material on, to thereby provide a seat or recess for the arrangement of the printing plate, wherein the thickness of the thickening is equal to the thickness of the printing plate, also are the auesseren edges of thickening with a rounding provided.

According to a farther aspect of the invention, has the Mantelflaeche the cylinder at least one longitudinal groove or a Laengssitz on to form a receiving and holding for the joint abutment of the printing plate, which consists of a wound and the end zusammengefuegten plate.

Further features and advantages of the invention, can the ensuing Beschriebung some Ausfuehrungsbeispiele that are not to be regarded as restrictive solutions, and the accompanying drawings are taken.

In the drawings:<ul><li>FIG. 1 partially in section a pressure cylinder according to the above invention;</li><li>2 shows in section a detail of the printing cylinder, wherein the Verdraengungsvorrichtung and the receptacle are shown for the printing plate.</li><li>Figures 3 and 4 in detail the screw for Actuation of the piston;</li><li>Figure 4a shows the seat for receiving the Kopfstueckes the piston.</li><li>Figure 5 is a detail of a further embodiment of the receiving seat. and</li><li>Fig. 6 - 10, partly in section different Ausfuehrungsformen the cylinder jacket with slit-like recesses for receiving the connecting surge of pressure plate.</li></ul>

The inventive printing cylinder, which is shown in its broad outlines in Fig. 1 and is designated by the reference numeral 1, has two lateral bearing pins 2 and 3 for storage in the rotary printing press.

In the Umfangsflaeche of Zylinderkoerpers 4 peripheral chambers 5 are incorporated, which are relatively flat. These chambers 5 are filled with an incompressible liquid 11 and connected via a line 7 to the outside of the cylinder. inserted in the pipe 7 from the outer side 8 of the cylinder, Verdraengungseinrichtungen, which are schematically indicated by 9 and are described below in more detail. When printing cylinders with smaller length, it may be sufficient to provide a single circumferential chamber. 5

The body 4 of the cylinder is covered by a zylinderfoermigen, rohrfoermigen thin jacket 12, which for example is made of spring steel or is produced from plastic or other suitable materials. This elastic sheath 12 is fixed and sealed to the ends of the cylinder 1, for example by welding connection or other suitable connection possibilities, which are marked with. 13

About the Mantal 12 is pushed, the printing plate is not shown in FIG. 1. This plate can be moved freely on the rohrfoermigen jacket when the Liquid 11 is not pressurized. Is the rohrfoermige printing plate once positioned on the cylinder 1, the Liquid is 11 set by the Verdraengungsvorrichtung 9 under pressure, and the outside diameter of the cylinder enlarge due to the elasticity of the sheath 11. Thus, the printing plate in a predetermined position is evenly over the entire Zylinderflaeche tensioned.

The construction of the printing cylinder described so far is already substantially known, and will therefore not be explained in more detail.

With reference to the figures 2 - 4a, the Verdraengungseinrichtung 9 is now described the invention in more detail.

The Verdraengungseinrichtung 9 consists of a movable piston 20 which is slidably mounted in Laengsrichtung in line 7 and at one end a head having 25 and is provided at the other end with annular grooves 28 for receiving Dichtungsrignen 24th The piston 20 is connected to a drive member 21, advantageously a threaded pin 21 is operatively connected, but not rigidly connected thereto. The set screw 21 has a shape 22 for introduction of a key. Further, the pin has a thread 29, which is in operative connection with a thread 23, directed outwards, of the output line. 7

The Aunahmesitz 26 (Fig. 4 - 4a) of the threaded pin 20 is adapted to receive the head 25 of the piston 20. The head is led by a taper 27 of the piston in a tapered seat 30 of the threaded pin 21st As can be clearly seen, the head 25 of the piston is arranged with a certain play in the seat 26th Thereby, forces that do not exactly occur in the axial direction, balanced.

Thus, by functionally separating the piston chamber of the thread chamber Verdraengungseinrichtung is particularly accurate and efficient in its operation. Possibly occurring tolerances that occur in the production of the threaded pin 21 or the thread in the line 7, not affect the sealing effect of the device. Further, no stress due to axial deviation of the components will occur because no rigid connection between the piston head 25 and the threaded pin 21 is. The proposed design is particularly simple. The parts can be easily assembled, and there is the possibility to replace individual components easily.

Always with reference to FIG. 2, another feature of the invention is described.

As can be seen from this Drstellung, has the Aussenflaeche 35 of the jacket 12 at one end or both ends 32 (only the left tail is dargesellt in the figure) a thickening opposite the remaining material of the jacket 12. One thus creates a seat or receptacle for the printing plate. The recording consists of the casing 35 and from 31 attacks, which are formed by the thickening 32nd

the depth of the seat or the recording is equal to the thickness to be used printing plate that was not shown for reasons of clarity in the drawing. This is gewaehrleistet that when mounting a printing plate on the cylinder 1, in keeping with the receiving seat, the outer rim of the printing plate comes to lie flush with the Ausssenflaeche 32 of thickening.

Further, the edges of the auesseren thickening have 32 rounded 33rd The receptacle for the printing plate is not shown in Fig. 2 was prepared by mechanical processing of the shell 12 and has a circumferential groove 34 which however has no effect on the function of the cylinder. Alternatively, the material could be removed by a chemical or electrochemical method.

In this way, from the doctor to the decrease of about scatterbrained vinegars printing ink and moves back and forth parallel to the cylinder 1, found no interruption in the Zylinderoberflaeche. Especially the doctor no longer meets a 90 ° sharp deflected edge which is unsocial at usual winding plates.

is shown an alternative, as shown in FIG. 5, the seat the Abeckteile 40 can be formed on the basis of two laterally arranged thickened, have 42, which rest on the cylinder end, having the smaller diameter to form a projection relative to the surface 45 of the jacket which corresponds to the thickness of the printing plate.

The outer edge 43 is rounded here, and the component 40 can be attached to the shell by means of screws, adhesive bonding, welding or similar Verbindnungsmittel.

There are also other alternative Ausfuehrungsformen possible, such as the provision of the thickening on only one side of the cylinder jacket.

In a preferred manner, when the receiving seat is achieved by means of lateral thickening, this thickening are made of a material whose characteristics are similar to the characteristics of the photo sensitive coating material, which forms the outer surface of the printing plate. Features that would be similar to affect the coefficient of friction and the hardness of the material, so as to avoid any interruption in the continuity of the squeegee movement.

Thanks to the above-described Merkmales to provide a peripheral recess for receiving the printing plate, in which the entire Wall Thickness of printing plate is to accommodate and, by providing a rounded edge, an outer diameter over the entire width of the cylinder is achieved, gewaehrleistet of continuity over the entire Zylinderlaenge what the squeegee process much easier. In an alternative solution can be provided that only one end of the cylinder has a thickening.

In the case in which the printing plate is designed as a closed Case or Case zusammengefuegte continuous profile, both in the circumferential direction and in the radial direction, the surface appears (35, 45) of the sheath continuously.

In the case where the use of a printing plate is carried out, which is present in the form of a zusammengefuegten shell to achieve a continuous suture winding panel, wherein the butt joint forming an interior bend, has erfindungsgemaess the jacket 12 of the cylinder at least one recess or longitudinal groove to as this in various Ausfuehrungsbiespielen in figures 6 - is shown 10th The recess 50 shown in Fig. 6 extends in Laengsrichtung along a surface line of the jacket 12 and has a depth which is greater than its width. This recess is slightly kept wider than the width dimension of the angled portion so as to allow their easy insertion in dei recess. The groove-like recess are ersteckt radially.

In alternative, the groove could 50 also extend inclined to the generating line of the mantle 12, this for the case where the butt joint of the printing plate would be provided inclined opposite the shell, usually along a slightly inclined angle to an excessive reduction in the usable area for the take printing in purchase to have to.

In the embodiment shown in Fig. 7, the slot-like opening 51 on small depth, but their width is substantially greater than their depth. This type of recess is adapted to receive and determine when the shock Telle was bent, so as to limit the thickness of the shock Telle to a minimum, a printing plate. This groove shallower recording is required, and thus there is a very slight weakening of the jacket.

Fig. 8 shows an embodiment in which the groove-like recess 52 is angled relative to the radial direction of the cylinder is disposed, and a shock Telle corresponds, wherein the Plattenstoesse are not arranged at 90 ° relative to the Druckplattenflaeche and are not bent completely. In this way, a depth for the recess is achieved, which is less than the actual amount of shock Telle, without the had to resort to a complete turn of changing collisions. The selection of the groove type is tacked on various factors, among others can reach the strength of the cylinder jacket, starch up to 10 mm.

In Fig. 9 a further embodiment is shown, wherein at least one slot 53 for receiving the joint, and a further number of slots or incisions 54 which are distributed over the Aussenflaeche of shell 12, is provided. These latter have slots compensation function and serve mainly to prevent the formation of an oval panel circumference and / or reduce peak loads. The cuts can be covered as required by elastic Cases made of steel or plastic. In Fig. 10, a further embodiment is shown in which the groove is marked to receive the connecting surge 56.

Another notch 57 is arranged in an inclined position relative to the first groove and a third groove 58 is provided on the opposite side on the inside of the jacket 12th With this embodiment, a so-called clamping effect over the edges of the groove is achieved due to their elongation, elongation, which then undergoes the jacket, when the liquid is placed in the compartments 5 under pressure. One gets in this way a beneficial effect for clamping the printing plate on the mantle 12th

As already described for the embodiment of Fig. 6, may also be provided a plurality of grooves for receiving the connection stroke of the pressure plate, and the groove or grooves may be disposed inclined relative to the generating lines of the circumferential skirt when the junction of the pressure plate is disposed inclined.

With the invention, the object described above is solved. By providing a separately arranged piston which is operatively connected to a threaded rod, essentially is the possibility of leakage and pressure losses created due to Bearbeitstolleranzen and lack of alignment of the threaded pipe and the piston accommodating chamber. The provision of a recess or a seat in the circumferential direction of the pressure plate makes it possible to provide a smooth Advertising surface without interruptions, which the doctor blade process much simplified, thanks to the rounding of the outer edges. Finally, the possibility is created by the provision of one or more longitudinal grooves to also use printing plates, which are designed as winding plates, in which the thickness of the shock Telle is not negligible.