Abstract:
A printing machine utilizes several printing couples to produce at least one printed image on a printed material. Compensation for at least one of a longitudinal elongation and a transverse elongation of the printed material is accomplished. An anticipated elongation of the printed material is compensated for by matching of a printed image placement, with respect to length, width or position, with an imaging system generating the printed image placement on a printing forme.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This patent application is the U.S. national phase, under 35 USC 371, of PCT/EP2005/050261, filed Jan. 21, 2005; published as WO 2005/072966 A1 on Aug. 11, 2005 and claiming priority to DE 10 2004 004 263.2, filed Jan. 28, 2004, the disclosures of which are expressly incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention is directed to printing presses with several printing groups, which generate at least one printed image on a material to be imprinted, and to methods for compensating for a longitudinal elongation and/or a transverse elongation of a material to be imprinted. Each of the printing groups includes a forme cylinder and an ink transfer cylinder which form a portion of the printed image. The elongation of the material to be printed is a factor in the location of printing formes on the successive forme cylinders. 
       BACKGROUND OF THE INVENTION 
       [0003]    A method and a device for use in adapting the position of printing plates to a deformation of a paper web to be imprinted by printing rollers is known from DE 195 16 368 A1. The printing plate, or the holder receiving it in a punching and/or bending machine, is respectively displaced or is offset in the lateral direction, in the circumferential direction and/or in its angular position by those amounts which the printing plate requires on its printing roller because of the deformation of the paper web. This is done in order to provide an imprint which corresponds with a previous printing roller, in the feeding direction of the paper web, in spite of the deformation of the paper web which had taken place in the meantime. Bending and/or punching of the plate or holder is performed on this printing plate displaced from its zero position. A computer-controlled alignment device, in the punching and/or bending machine, is employed for this purpose, after the respective data regarding the paper web, the printing press and the production type have been entered in the computer. In this case, the deformation of the paper web, which is also known by the term “fan out”, is caused by moisture, by ink absorption and by mechanical stresses in the course of the passage of the paper web through several pairs of printing rollers which are arranged one after the other. 
         [0004]    Image regulation systems for counteracting the “fan out effect” are known from DE 295 01 373 U1, from DE 42 24 235 C2, from DE 43, 47 846 A1 and from EP 0 938 414 B2. In these systems the image regulators operate mechanically or pneumatically, for example. 
       SUMMARY OF THE INVENTION 
       [0005]    The object of the present invention is directed to providing printing presses with several printing groups, which several printing groups generate at least one printed image on a material to be imprinted, and to methods for the compensation of a longitudinal elongation and/or a transverse elongation of a material to be imprinted. 
         [0006]    In accordance with the present invention, this object is attained by the provision of the printing press with several printing groups, each of which includes a forme cylinder and an ink-transferring cylinder that transfers a portion of a common print image to a material to be printed as that material travels through the several printing groups which are arranged downstream in a production direction. The material to be imprinted has a longitudinal elongation and a transverse elongation, each expressed by an elongation factor. The locations of the printing formes on successive ones of the forme cylinders are different from those on prior ones of the forme cylinders by location factors. 
         [0007]    The advantages to be attained with the present invention lie, in particular, in that a longitudinal elongation and/or a transverse elongation of the material to be imprinted is compensated for. Factors affecting the longitudinal elongation and/or the transverse elongation are already being taken into consideration in the course of placing the images on the printing forme. A subsequent positional change of one or of several of the printing formes on a forme cylinder can be preferably omitted or is only necessary to a limited extent. It is thus possible to preferably omit devices for use in changing the position of one or of several printing formes on a forme cylinder, or at least to produce such devices very simply and cost-effectively. If factors of the printing press and the material to be imprinted, which affect the longitudinal elongation and/or transverse elongation of the material to be imprinted, are already known, such as, for example, from experience, their value can be determined and can be made available to the system for placing images on the printing forme. It is accordingly possible to match the size and the location of a print image location on each printing forme which is participating in the printing process at the time of producing the print image location on the printing form as needed as a function of the longitudinal elongation and/or the transverse elongation which is expected from experience. Because these systematic deviations, in particular between successive printing groups, are already compensated for, to the greatest extent, a change of the position of the printing forme having the print image location is preferably not required at all, or is only required for fine adjustment for updating in the course of an ongoing printing process. Print image locations, that are already matched to the expected longitudinal elongation and/or to the expected transverse elongation of the material to be imprinted, relieve the operators of the printing press of time-consuming checking of the correct position of the printing forme on the forme cylinder. This advantage becomes all the more important the more printing formes participate in the printing process. In a printing press which, for example, prints in four colors and which has twelve printing formes on each forme cylinder, for example, a considerable advantage arises from already performing the matching of the print image locations to the expected longitudinal elongation and/or to the expected transverse elongation of the material to be imprinted in the course of the placement of the images. Otherwise, the position of a total of forty-eight printing formes would have to be checked, and their positions would have to be aligned to compensate for the fan out effect on the four forme cylinders. In the case of simultaneous recto and verso printing, it is necessary, in the example mentioned, to align twice the number of printing formes, namely ninety-six, in relation to each other. An outlay for the checking of the position of the printing formes, as well as for their alignment, which could no longer be efficiently managed, is created for filling a printing order. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]    Preferred embodiments of the invention are represented in the drawings and will be described in greater detail in what follows. 
           [0009]    Shown are in: 
           [0010]      FIG. 1 , a schematic side elevation representation of a printing press, suitable for multi-color printing, and having four printing units, each with two printing groups, in 
           [0011]      FIG. 2 , a schematic top plan view representation of four forme cylinders, arranged downstream of each other, and with printing formes with print image locations, in 
           [0012]      FIG. 3 , a perspective view of a printing group with print images formed on a material to be imprinted, and in 
           [0013]      FIG. 4 , a holding device arranged in a channel of a forme cylinder. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0014]    In a greatly simplified form,  FIG. 1  schematically shows a printing press  01 , preferably a printing press  01  which imprints a web  03  in several different colors, such as, for example, a printing press  01  for newspapers, and having four printing units  02  which are arranged vertically on top of each other, for example. A material  03  to be imprinted, such as, for example, a web  03  of material, and in particular a paper web  03 , passes vertically through the successive printing units  02 . A production flow or direction P of the material  03  to be imprinted passing through the printing press  01  is assumed to substantially move from the bottom to the top, as indicated by the arrow in  FIG. 1 . 
         [0015]    In the configuration represented schematically in  FIG. 1 , a respective printing group  04 , including a cylinder  06  for transferring ink and a forme cylinder  07 , which rolls off on the transfer cylinder  06  which is transferring the ink image from the forme cylinder  07 , is arranged on each of the two sides of the paper web  03  in each printing unit  02 , for accomplishing recto and verso printing. The specific representation of an associated inking system, a dampening system and further components, which are typically part of the printing group  04 , for example, has been omitted here, since they are not necessary for an understanding of the invention. The cylinders  06  transferring ink are preferably embodied as transfer cylinders  06  which are operating by the offset printing method. The transfer cylinders  06  preferably each have an elastic surface. That elastic surface is constituted, for example, by at least one printing blanket which is made of an elastomeric material and which is arranged on the shell face of the transfer cylinder  06 . 
         [0016]    In the preferred embodiment of  FIG. 1 , the transfer cylinders  06 , which are arranged on both sides of the paper web  03  in each printing unit  02 , have been placed against each other in a so-called rubber-to-rubber arrangement. The two transfer cylinders  06 , which are arranged in the same printing unit  02 , alternatingly each function as a counter-pressure cylinder. Alternatively, two adjoining printing units  02  can be combined into a satellite printing unit. The printing groups  04  of these printing units  02  are then arranged around a common counter-pressure cylinder, which is separate from the remaining cylinders  06 ,  07 . The paper web  03  is conducted between the counter-pressure cylinder and at least one transfer cylinder  06  which is placed against the counter-pressure cylinder in such a satellite printing unit. 
         [0017]    A further alternative for the configuration of the printing press  01  can provide if the printing press  01  is to be configured as a job-printing press  01 , and preferably as such a printing press  01  with a substantially horizontal guidance of the material  03  to be imprinted. Several successive printing groups  04  are typically provided in the printing press  01  along the production flow or travel direction P of the material  03  to be imprinted, and are preferably located on both sides of the material  03 , i.e. both underneath and on top of the material  03  to be imprinted. The transfer cylinders  06  of two printing groups  04 , which are arranged in a printing unit  02 , are again placed against each other in a rubber-to-rubber arrangement. The material  03  to be imprinted is conducted between the two transfer cylinders  06  which are placed against each other, so that the material  03  to be imprinted passes through the area in which the two transfer cylinders  03  roll off on each other. 
         [0018]    The forme cylinders  07  which are assigned to the transfer cylinders  06  each have at least one printing forme  08 , as seen in  FIG. 2  on their shell faces. In their axial direction X and/or in their circumferential direction Y, the forme cylinders  07  are each preferably covered by several printing formes  08 . For example, in a newspaper printing press  01 , the forme cylinders  07  are each covered, in their axial direction X, with six printing formes  08 , and are each covered, in their circumferential direction Y, with two printing formes  08 . This results in twelve printing formes  08  being arranged on each forme cylinder  07 . A developed view of such forme cylinders  07 , each with twelve printing formes  08 , is represented schematically in  FIG. 2 . The directional arrows X, Y, which are part of  FIG. 2 , and which extend at right angles to each other, show the axial direction X of the forme cylinder  07  and the circumferential direction Y of the forme cylinder  07 . 
         [0019]    To generate a print image  11 , as seen in  FIG. 3  on the material  03  to be imprinted, each printing forme  08  has at least one print image location  09 , as shown in  FIG. 2 . It can alternatively be provided that the printing formes  08  have several print image locations  09  in the axial direction X with respect to the forme cylinder  07 , and/or in the circumferential direction Y of the forme cylinder  07 . By way of example,  FIG. 3  shows the generation of six print images  11  on the material  03  to be imprinted in the axial direction X, with respect to the forme cylinder  07 . The production flow or direction P of the material  03  to be imprinted, as well as a production direction of rotation R of the forme cylinder  07  and of the transfer cylinder  06  working together with the forme cylinder  07 , are indicated. Instead of providing, for example, six printing formes  08  in the axial direction on a forme cylinder  07 , and of providing two printing formes  08  in its circumferential direction Y, the forme cylinders  07  can, for example, each be covered by only one printing forme  08 , wherein this printing forme  08  has, for example, six print image locations  09  in the axial direction X, with respect to the forme cylinder  07  and/or has, for example, two print image locations  09  in the circumferential direction Y of the forme cylinder  07 . Also, every printing forme  07  can have only a single print image location  09 . 
         [0020]    The printing groups  04 , which are arranged one behind, or after, the other, in the production direction P, on the same side of the material  03  to be imprinted, preferably each print inks of colors that are different from each other. For example, ink dots of the colors black, cyan, magenta and yellow, which are the customary colors used in four-color printing, are printed in four successive printing groups  04 . Specifically, color dots of one of these colors are printed in each one of these four successive printing groups  04 . Print image locations, which correlate with the same resultant print image  11 , are located on the forme cylinder  07  of the four successive printing groups  04 . Each such print image location constitutes a color separation of the resultant multi-color print image to be created. Each such color separation is assigned to one of the color tones to be printed. A multi-color print image  11  is formed in that several color separations, such as, for example, the four color separations, which correspond to the four respective colors, black, cyan, magenta and yellow, are printed on top of each other onto the material  03  to be imprinted. The color dots of the individual color separations relating to the same resultant print image  11  are arranged either next to each other or on top of each other on the material  03  to be imprinted. The resultant multi-color print image  11  is formed by a color mixture of the color dots resulting from the different color separations. 
         [0021]    Each print image location  09  has a width B in the axial direction X with respect to the forme cylinder  07  and a print image location length L in the circumferential direction Y of the forme cylinder  07 . Print image locations  09  that each constitute a color separation, for forming a resultant common print image  11 , must be printed, or located so that they fit exactly on top of each other, by the utilization of the successive printing groups  04  which are arranged following each other in the production flow or direction P of the material  03  to be imprinted. These print image locations  09  are imprinted on the material  03  by their respective cylinders  06  which transfer the ink from the forme cylinder  07 . Adherence to this requirement, which is necessary for a good printing result, is made difficult since the material  03  to be imprinted customarily has a longitudinal elongation along the production flow or direction P, and/or has a transverse elongation crosswise to the production flow or direction P, which elongation occurs on the web&#39;s way from one ink-transferring cylinder  06  to a successive ink-transferring cylinder  06 , which follows in the production flow or direction P. The longitudinal elongation and/or the transverse elongation of the material  03  to be imprinted results, for example, from the material  03  to be imprinted absorbing moisture that is transported to it by the dampening system of the printing press  01 , and/or moisture from the ink, and/or moisture from the air surrounding the material  03  to be imprinted, and/or from a mechanical elongation of the material  03  to be imprinted when that material  03  is passing through several successively arranged printing groups  04 . Such a longitudinal elongation and/or a transverse elongation of the material  03  to be imprinted is described by the term “fan out”. 
         [0022]    If, in connection with a printing press  01 , the distances A 1 , A 2 , A 3 , as shown in  FIG. 1 , between ink-transferring cylinders  06  of successive printing groups  09 , which are arranged one behind the other in the production flow or direction P, and a mechanical elongation of the material  03  to be imprinted, and which is possibly occurring between these successive cylinders  06 , as well as the moisture-caused elongation of the material  03  to be imprinted, which moisture-caused elongation has been determined, for example, in accordance with DIN 53130, are known, it is possible to determine what changes in the length L and/or in the width B of the print image locations  09 , which create a common resultant print image  11  and which print image locations  09  are located in different printing groups  04 , are to be expected. Therefore, a defined dimensional change is to be expected for each print image location  09 , as a function of its position on the forme cylinder  07  and as a function of the intensity of the several above-mentioned influencing values, in comparison with another print image location  09  which is arranged on another forme cylinder  07  at the same relative position. The dimensional change indicates that the length L of two print image locations  09 , following each other in the production flow or direction P of the material  03  to be imprinted, differs by a factor FL. The width B of two print image locations  09  following each other in the production flow or direction P of the material  03  to be imprinted, on successive forme cylinders  07 , differs by a factor FB. In this case, the factors FL, FB can express a relative dimensional change, such as, for example, in percent, with respect to an original length L or an original width B, or can express an absolute dimensional change, such as, for example, in the form of an amount of change which is based on an original length L or width B. 
         [0023]    Each print image location  09  is limited by its length L and width B and defines an area, as seen in  FIG. 2 , wherein the area of a print image location  09 , which is arranged on a forme cylinder  07 , is curved or arched. Its curvature is matched to the curvature of the shell face of the forme cylinder  07 , in its circumferential direction Y. At the intersection of that area&#39;s diagonal lines as represented in dashed lines in  FIG. 2 , the area has a center point S. Alternatively to, or in addition to the dimensional change of a print image location  09 , a position, X 1 , Y 1 , of the center point S of a first print image location  09  can also differ, in comparison with a position, X 2 , Y 2 , of a second print image location  09 , which is also correlated with the resultant common print image  11 , on a subsequent forme cylinder  07  which follows in the production flow P of the material  03  to be imprinted. These print image locations  09  are preferably each arranged on a printing forme  08 . The printing formes  08 , with the first and second print image locations  09 , which differ in the position X 1 , Y 1 , X 2 , Y 2  of their center points S, are arranged in the same respective position on the respective forme cylinders  07 . Thus, the printing formes  08 , with their respective print image locations  09 , remain fixed in place on their respective forme cylinders  07 . Only the position X 1 , Y 1 , X 2 , Y 2  of at least one of the center points S of two successive print image locations  09 , which are following each other in the production flow or direction P of the material  03  to be imprinted, is displaced. Only the positions X 1 , Y 1 ,X 2 , Y 2  of the center points S of these respective print image locations  09  are changed in relation to each other, by a distance W, as seen in  FIG. 2 , without changing the position of a printing forme  08  on its respective forme cylinder  07 . The distance W is located in the same plane as is the area defined by the length L and the width B of the print image location  09 , and can show the displacement of the center point S in this plane in any arbitrary direction, in comparison with the position X 1 , X 2  of the center point S of the related print image location  09 . 
         [0024]    Since the longitudinal elongation and/or the transverse elongation of the material  03  to be imprinted can have different effects, depending on the position of a printing forme  08  on the forme cylinder  07 , the lengths L of two print image locations  09 , which are arranged side-by-side on the same forme cylinder  07 , in its axial direction X, can differ from each other by a factor FL. The width B of two print image locations  09 , which are arranged side-by-side on the same forme cylinder  07  in its axial direction X, can differ from each other by a factor FB. In this case, in a manner that is the same as in the previously described dimensional change, the factor FL, relating to the length L of the print image location  09 , is a function of a factor DL of the web longitudinal elongation. The factor FB, relating to the width B of the print image location  09 , is a function of a factor DQ of the web transverse elongation. The factor DL of the web longitudinal elongation and the factor DQ of the web transverse elongation take into consideration, for example, the distances A 1 , A 2 , A 3  between the ink-transferring cylinders  06  of the printing press  01 , and which are arranged following each other in the production flow or direction P, as well as the mechanical elongation of the material  03  to be imprinted possibly occurring between these cylinders  06 , as well as the moisture-caused elongation of the material  03  to be imprinted. In the course of this consideration, the length L of the print image location  09  is preferably increased by the factor DL of the web longitudinal elongation, and the width B of the print image location  09  is preferably increased by the factor DQ of the web transverse elongation. The factor DL of the web longitudinal elongation and the factor DQ of the web transverse elongation can be changeable. This change can be related to further parameters, and in particular to parameters relating to operating conditions of the printing press  01  and to properties of the material  03  to be imprinted, such as, for example, the production speed of the printing press  01  or the temperature of the air surrounding the material  03  to be imprinted, and, in particular, to the moisture content of this air. 
         [0025]    Furthermore, the factor DL of the web or material longitudinal elongation and/or the factor DQ of the web or material transverse elongation can take into consideration that, for example, the transverse elongation, with respect to the print image locations  09  which are “on the outside”, with respect to the end of the forme cylinder  07  has a greater effect than a transverse elongation with respect to “inner” print image locations  09 , which are arranged close to the center of the forme cylinder  07 , provided a center line M, which, for example, halves the cylinder length, serves as a reference, or as a reference marker M for the transverse elongation, as seen in  FIG. 2 . Also, the factor FL, which differentiates the length L of two print image locations  09  following each other in the production flow or direction P of the material  03  to be imprinted, and/or the factor FB, which differentiates the width B of two print image locations  09  following each other in the production flow or direction P of the material  03  to be imprinted, can depend on the arrangement of that printing group  04  in the production flow or direction P of the material to be imprinted, in which the forme cylinder  07  with the printing form  08  having the print image location  09  whose length L and/or width B changed by the factor LB, FB is located. This is because there is an effect on the value of the factors FL, FB whether the print image locations  09  of printing groups  04 , which directly follow each other, or those of printing groups  04  lying farther apart, are being compared to each other. 
         [0026]    In the same way, it can be provided that the position X 1 , Y 1  of the center point S of a first print image location  09  differs, in comparison with the position X 2 , Y 2  of the center point S of another, second print image location  09  that is arranged on the same forme cylinder  07  in the axial direction X of the latter. These print image locations  09  being compared have the same length L and width B. The print image locations  09 , which are arranged side-by-side on the same forme cylinder  07 , are each arranged on one printing forme  08 . The printing formes  08 , which are arranged on the same forme cylinder  07  and which have print image locations  09  whose position X 1 , Y 1 , X 2 , Y 2  of their center points S differ, have been placed in alignment with each other in the axial direction X of the respective forme cylinder  07 . Even in the case of the displacement of the position X 1 , Y 1 , X 2 , Y 2  of the center point S of print image locations  09 , which are different, but which form a common print image  11 , the distance W of the displacement can be a function of the factor DL of the longitudinal web or material elongation and of the factor DQ of the transverse web or material elongation, regardless of the arrangement of the print image locations  09  on the same, or on forme cylinders  07  which follow each other in sequence in the production flow P. 
         [0027]    A channel  13 , which is extending in the axial direction X underneath the shell face  12  of the forme cylinder  03 , and which is provided with a preferably slit-shaped opening  14 , for use in holding one or several printing formes  08  on the shell face  12  of a forme cylinder  07  is, for example, provided, as can be seen in  FIG. 4 . Plate end legs  18 ,  19 , which are beveled or angled off the ends  16 ,  17  of the printing forme or formes  08 , are placed against channel walls  23 ,  24 , which channel walls  23 ,  24  extend from edges  21 ,  22  on the shell face  12  of the opening  14  toward the interior of the channel  13 . One of the plate ends  16  has been hooked, by means of the plate end leg  18 , which leads in the production direction R of the printing forme or formes  08 , on the wall  23 , which wall  23  extends, in relation to an imaginary tangential line T resting on the opening  14 , at a preferably acute opening angle α in respect to the channel  13 . The other plate end leg  19  at the end  17  of the printing forme or formes  08  which trails, in the production direction P of the forme cylinder  07 , is held by an outer end  26 , which is oriented toward the opening  14  by the use of a preferably strip-like holding member  27 , against a wall  24  which wall  24 , in relation to a tangential line T resting on the opening  14 , extends at a preferably approximately right-angled opening angle β in respect to the channel  13 . An inner end  28  of the holding member  27  that is facing away from the channel opening  14 , is pivotably seated, for example in a groove  29 , which is situated on, or close to, the bottom of the channel  13 . An actuating element  32 , such as, for example, a pneumatically actuable actuating element  32 , and in particular a hollow body  32  which can be charged with a pressure medium, such as, for example, compressed air, and which is reversibly elastically deformable, and which is preferably a hose  32  is arranged in the channel  13 . Hose  32 , is, for example, supported on a counter-thrust element  31  which is arranged in the channel  13 . If the hose  32  is actuated, it pivots the at least one holding member  27  against the force of at least one spring element  33 , that is also preferably arranged in the channel  13 . The at least one spring element  33  performs a controlled lift, such as, for example, by the use of a guide element  34  that is assigned to it, which is substantially directed in the circumferential direction Y of the forme cylinder  07 . The guide element  34  can be arranged on a support element  37 , which itself is supported on an interior, arcuate wall  36  of the channel  13 . The opening  14  has a slit width V of preferably less than 5 mm at the shell face  12  of the forme cylinder  07 . The slit width V lies between 1 mm and 3 mm in particular. In the embodiment represented in  FIG. 4 , the holding member  27 , the actuating element  32  and the spring element  33  constitute essential elements of a holding device for use in holding one or several printing forms  08  on the shell face  12  of a forme cylinder  07 . 
         [0028]    It is also possible, for example, to provide at least one register pin, which is not specifically represented in at least one forme cylinder  07 . The register pin aligns at least one printing forme  08 , arranged on the forme cylinder  07 , in an axial direction X, with regard to the forme cylinder  07 . The holding device, or the register pin, is configured for working together with at least one printing forme  08  and can be shifted in the channel  13  in the axial direction X of the forme cylinder  07 , such as, for example, as a function of the factor DQ of the transverse web elongation, and preferably at a ratio that is proportional to the behavior of the factor DQ of the transverse web elongation. To perform the shifting of the printing forme  08 , which shifting is directed particularly in the axial direction X of the forme cylinder  07 , preferably at least one controllable actuator, which is not specifically represented, is arranged in the forme cylinder  07 , for example in its channel  13 . The actuator shifts the holding device or the register pin. The actuator can be configured as a piezo element or as a linear motor, for example. At least one holding device or at least one register pin is preferably assigned to the printing forme  08  on each forme cylinder  07 . It is advantageous if each printing forme  08  can be individually shifted in the axial direction X, with respect to the forme cylinder  07 . 
         [0029]    Alternatively, or in addition to the displacement of one or of several printing formes  08  on a forme cylinder  07 , it is possible to provide the entire forme cylinder  07  to be shiftable in its axial direction X, so that all of the printing formes  08  arranged on it are identically shifted. When shifting one or several printing formes  08  on the forme cylinder  07 , as well as when axially displacing the entire forme cylinder  07 , shifting takes place transversely with respect to the production flow or direction P of the material  03  to be imprinted and relative to the location of the material  03  to be imprinted, i.e. relative to a reference marker M of the material  03  to be imprinted. The reference marker M can be, for example, the center line M of the material  03  to be imprinted, as seen in  FIG. 2 . However, the reference marker M can also be located at a different spot on the material  03  to be imprinted, such as, for example, at one of its lateral edges. The displacement of the printing formes  08 , which is oriented transversely with respect to the production flow P of the material  03  to be imprinted, can also be related to a stationary frame of the printing press  01  instead of to the material  03  to be imprinted. 
         [0030]    The forme cylinder  07  and/or the transfer cylinder  06 , which transfers ink, of at least one of the two printing groups  04  that are arranged one after or behind the other in the production direction P is preferably driven by a controllable drive mechanism, which is not specifically represented, such as, for example, by an electric motor, and in particular by a frequency-controlled motor. However, each one of the forme cylinders  07  and/or the ink-transferring cylinders  06  of all printing groups  04 , which are arranged one behind the other, may be individually driven. When using controllable drive mechanisms, a phase relation, which is assumed with respect to each other of the forme cylinders  07  and/or of the ink-transferring cylinders  06  of at least two printing groups  04 , can preferably be controlled as a function of the factor DL of the longitudinal extension. Because of the controllable phase relation of the forme cylinders  07  and/or of the ink-transferring cylinders  06 , it is possible, in particular, to affect a circumferential register of the forme cylinders  07 . 
         [0031]    The actuator, and/or the phase relation of the forme cylinders  07  and/or the phase relation of the ink-transferring cylinders  06 , are preferably continuously controllable. The actuator, and/or the phase relation of the forme cylinders  07  and/or of the ink-transferring cylinders  06 , are preferably controllable in the running production flow or direction P of the material  03  to be imprinted. In particular, the actuator, and/or the phase relation of the forme cylinders  07  and/or of the ink-transferring cylinders  06 , are controllable, such as, for example, from a control console that is assigned to the printing press  01  or from another central control unit, i.e. they can be remotely controlled. 
         [0032]    It is advantageous to provide a memory unit which is connected with the control unit for at least one of the printing groups  04 . The memory unit contains at least one value for the factor FL of the length L of two print image locations  09  which are located behind each other in the production flow or direction P of the material  03  to be imprinted and/or at least one value for the factor FB of the width B of two print image locations  09  which are located behind each other in the production flow or direction P of the material  03  to be imprinted. Alternatively, or additionally, the memory unit can contain at least one value for the factor FL of the length L of two print image locations  09  which are located side-by-side on the same forme cylinder  07  and/or can contain at least one value for the factor FB of the width B of two print image locations  09  which are located side-by-side on the same forme cylinder  07 . Furthermore, the memory unit can contain at least one value for the different positions X 1 , Y 1 , X 2 , Y 2  of the center point S of two print image locations  09  which are located side-by-side on the same forme cylinder  07 . 
         [0033]    The control unit can track the center point S of at least one print image location  09 , which tracked center point follows a different print image location  09  in the production flow or direction P of the material  03  to be imprinted, with respect to the center point SB of the print image  11  to be imprinted, which center point was displaced during a running printing process, such as, for example, by the longitudinal elongation and/or by the transverse elongation of the material  03  to be imprinted, as seen in  FIG. 3 . In the process, the control unit controls at least the actuator and/or the phase relation of the forme cylinder  07  and/or of the ink-transferring cylinders  06 , preferably as a function of the value for the factor FL and/or the factor FB and/or the positions X 1 , Y 1 , X 2 , Y 2  of the center point S which is stored in the memory unit. For example, the center point S of the print image  11  to be imprinted is detected by a detector unit which is connected with the control unit, such as, for example, a device which optically detects and digitally evaluates the print image  11 , and which may be, for example, a semiconductor camera with a CCD sensor. For example, the control unit can operate devices, which are connected with it, with the result that the center points S of the print image locations  09  which print a common print image  11  are brought into agreement with the center point SB of the common print image  11  to be imprinted. 
         [0034]    Methods for compensating for the longitudinal elongation and/or for the transverse elongation, in accordance with the present invention, provide, preferably in advance of a shifting of at least one printing forme  08  on a forme cylinder  07 , and wherein that shifting takes place in relation to a reference marker M on the material  03  to be imprinted, that the length L of at least one print image location  09  of a printing forme  08 , compared with the length L of a print image location  09 , which correlates with the same print image  11 , of a different printing forme  08  arranged on another forme cylinder  07 , is changed by the factor FL. The width B of at least one print image location  09  of a printing forme  08 , as compared with the width B of a print image location  09 , correlating with the same print image  11  of another printing forme  08  that is arranged on another forme cylinder  07 , is changed by the factor FB. Alternatively, or additionally, the position X 1 , Y 1  of a center point S of at least a first print image location  09  of a printing forme  08 , compared with the position X 2 , Y 2  of the center point S of a second print image location  09 , correlating with the same print image  11 , of another printing forme  08 , that is arranged on another forme cylinder  07  at the same position of the forme cylinder  07 , is changed. In the process, the length L and/or the width B and/or the position X 1 , Y 1 , X 2 , Y 2  of the center point S of the print image location  09  is preferably changed by using the factor DL of the longitudinal web elongation and/or the factor DQ of the transverse web elongation. Also, a change of the length L and/or the width B and/or the position X 1 , Y 1 , X 2 , Y 2  of the center point S of the print image location  09  is preferably accomplished as a function of the position of the printing forme  08  on the forme cylinder  07 , and namely of that forme cylinder  07 , on which the printing forme  08 , with the changed print image location  09 , is arranged. 
         [0035]    A value for the factor FL, which changes the length L, is preferably determined as a function of the factor DL of the longitudinal web elongation. A value for the factor FB, which changes the width B, is preferably determined as a function of the factor DQ of the transverse web elongation. The value for the factor FL, which changes the length L, and/or the value for the factor FB, which changes the width B, and/or which changes the coordinates for a new position of the X 1 , Y 1 , X 2 , Y 2  of the center point S of the print image location  09  on the printing forme  08  on one of the forme cylinders  07  can also be determined as a function of the print image location  09  of a different printing forme  08 , that is arranged in the same position on the forme cylinder  07 , on a different forme cylinder  07 . 
         [0036]    A change of the position L and/or of the width B of a print image location  09 , or a change of the position X 1 , Y 1 , X 2 , Y 2  of its center point S, for compensating for a portion of the longitudinal elongation and/or of the transverse elongation, which is known at the time the image was applied to the printing forme  08 , is preferably performed wherein a printing forme  08 , with a print image location  09  which was changed in its above-mentioned parameters, is arranged on a forme cylinder  07  in the same position of a forme cylinder  07  having a printing forme  08  with a print image location  09  which is to be changed. In this way, at least a part of the compensation of the “fan out effect” takes place in connection with the provision of an image on the printing forme  08 , i.e. in the course of determining the print image location  09 . A print image location  09  which, in comparison with the print image location  09  of another printing forme  08 , has already been changed, with respect to its dimensions, and/or with respect to the position X 1 , Y 1 , X 2 , Y 2  of its center point S, is arranged at the position on a forme cylinder  07  that is intended for it. In this case, the change is performed to the extent that the change of the dimension and/or of the position X 1 , Y 1 , X 2 , Y 2  of its center point S of the print image location  09  is to be expected, such as, for example, as a function of the factor DL of the longitudinal web elongation, and/or the factor DQ of the transverse web elongation of the material web  03  to be imprinted, and/or as a function of the position of the print image location  09  on one of the forme cylinders  07 , as well as possibly as a function also of further previously known or determinable parameters. Thus, the change relates to a change of the dimension and/or of the position of the print image location  09  on a printing forme  08 , so that systematic deviations, which are to be expected between at least two print image locations  09 , are compensated for. Because of this, a change of the position of the printing forme  08  on the forme cylinder  09  is often no longer required, or is only required for fine adjustment or for updating in the course of an ongoing printing process. 
         [0037]    To begin with, known or determinable parameters, for taking into consideration the required change of the dimension and/or position of the print image location  09  on a printing forme  08 , such as, for example, the factor DL of the longitudinal web elongation, and/or the factor DQ of the transverse web elongation of the material  03  to be imprinted, are supplied to an image application system. That image application system applies the print image location  09 , such as, for example, by the use of a laser, to the printing forme  08 , and is preferably controlled by a computer and on the basis of a digital data set. Therefore, the image application system forms the print image location  09  on a printing forme  08  in accordance with predetermined conditions and, in this way, compensates for the results of the “fan out effect” which are to be expected. In the image application process, the image application system applies the images to the printing forme  08 , in particular as a function of the color tone of the cylinder  06  which is transferring the ink, and/or as a function of the arrangement of the printing group  04 , with respect to the forme cylinder  07  that is carrying the printing forme  08  in the production flow P of the material  03  to be imprinted, and/or as a function of the position of the printing forme  08  which is arranged on the forme cylinder  07 . Thus, in the course of forming a print image location  09 , the image application system takes into consideration its position on the forme cylinder  08 . This position is customarily determined by an occupation plan that is conceived in a pre-printing stage. Based on the position of the printing forme  08 , in accordance with the occupation plan, on one of the forme cylinders  07 , the image application system then matches at least some print image locations  09 , and preferably matches each print image location  09  in a further printing group  04  that is following a first printing group  04 , in its length L, and/or width B, and/or in the position of its center point S, as a function of the above-mentioned influencing values, which were taken into consideration during the formation of the same print image  11 . This is done in order to counteract systematic deviations, which are to be expected in the course of the ongoing printing process, and to compensate for these deviations, as much as possible, by a suitable arrangement, or positioning of the print image location  09 . 
         [0038]    In a further development of the method in accordance with the present invention, a desired value of the factor FL for changing the length L, and/or a desired value of the factor FB for changing the width B, and/or a desired value of the position of the center point S of a print image location  09  of a printing forme  08  to be changed, are continuously determined. Parameters, which are relevant to the above-mentioned changes, are detected and their values are matched, in the course of the ongoing printing process. It is then possible to arrange a printing forme  08 , containing the changed print image location  09 , on at least one forme cylinder  07 , if an actual value of the factor FL for changing the length L, and/or a actual value of the factor FB for changing the width B, and/or an actual value of the position X 1 , Y 1 , X 2 , Y 2  of the center point S of the print image location  09  of a printing forme  08  exceeds a permissible deviation from the determined desired values. However, to attain this end, the preparation of a printing forme  08  with a changed print image location  09 , and its exchange on the forme cylinder  07  which is involved is required. This can require an interruption of the printing process. 
         [0039]    The desired values may be determined for each color tone which is transferred by an ink-transferring cylinder  06 . Alternatively, the desired values may be determined for each forme cylinder  07  of the printing groups  04  that are following each other in the production flow or direction P of the material  03  to be imprinted, and/or for each position of a printing forme  08  which is arranged on one of the forme cylinders  07 . The determined desired values are preferably stored in a memory and are made available to the image application system as required. 
         [0040]    It is furthermore possible, in accordance with the present invention, to counteract at least a part of the transverse elongation of the material  03  to be imprinted by employing an image regulator  38 , as depicted schematically in  FIG. 1  wherein, prior to its entry into a subsequent or following printing group  04 , the material  03  to be imprinted is deformed, preferable in a wave shape, by the image regulator  38  transversely to its production direction R. In this way, the material  03  is reduced, in its width B 03 , in a manner which counteracts the transverse elongation, as seen in  FIG. 3 . Preferably, the intensity or the extent of the width reduction takes place at a reverse ratio with respect to the factor DQ of the transverse web elongation, and can preferably also be changed in the course of the ongoing printing process. The deformation of the material  03  to be imprinted can take place, for example, mechanically by the use of rollers which are preferably placed against both sides of the material  03  to be deformed. To prevent the occurrence of negative effects on the quality, these rollers preferably act outside of the print image  11  on the material  03  to be imprinted and are preferably individually rotatorily driven. Another embodiment of the image regulator  38  provides at least one air nozzle that is directed onto the surface of the material  03  to be imprinted. This at least one air nozzle, for example, permits compressed air to flow against the material  03  to be imprinted. In this way the air nozzle deforms the material  03  to be imprinted in a contactless manner. Preferably, several such air nozzles are provided in connection with this pneumatic image regulator  38 , which air nozzles are spaced apart from each other. Preferably at least three air nozzles are provided, wherein the air flow of an air nozzle, which is arranged between two other air nozzles is preferably directed counter to the air flow direction of its adjoining air nozzles. The result is that the material  03  to be imprinted, which is charged with the air flow, is deformed in a wave shape. With use of the mechanical, as well as with use of the pneumatic image regulator  38 , the deformation of the material  03  to be imprinted can preferably be continuously controlled within defined limits by a control unit which controls the image regulator  38 . In particular, this deformation can be controlled remotely from a control console which is part of the printing press  01 . The control unit can change the center point SB of the print image  11  by actuating the image regulator  38 . 
         [0041]    While preferred embodiments of a printing machine with a device and a method for compensation of a longitudinal elongation and a transverse elongation of a printed web printed in differing printing couples, in accordance with the present invention, have been set forth fully and completely hereinabove, it will be apparent to one of skill in the art that various changes in, for example, the sizes of the cylinders, the specific inking and dampening units, and the like could be made without departing from the true spirit and scope of the present invention which is accordingly to be limited only by the appended claims.