Abstract:
An inking system is comprised of rollers. At least one roller has a barrel with at least two separate sections. One of these casing sections is arranged in a manner which permits it to be changed independently of the other casing section.

Description:
FIELD OF THE INVENTION 
   The present invention is directed to an inking unit with rollers. At least one of the rollers has a pad or barrel with two separated roll or casing sections. 
   BACKGROUND OF THE INVENTION 
   Inking units of the type, shown, for example in e.g. from DE 196 28 648 C1, can be employed, for example, but not exclusively, as inking units of rotary printing presses that can be switched between panorama printing and printing of multiple, separate pages, especially in different colors. Panorama printing refers to the printing of an image across two pages of a newspaper without interrupting the image. A printing press that, for example is four pages wide, is thus able, during panorama printing, to print two panorama images, each of which extends across two pages. When a printing unit is converted from panorama printing to printing multiple, separate, adjoining pages, or vice versa, conversion work of various kinds must be performed on the inking unit, since, in panorama printing, the space between two adjoining pages is printed and, consequently must be supplied with ink, whereas, when printing separate pages, this region between the pages must be maintained free of ink. 
   The conversion of the inking unit can, for example, be achieved, by exchanging the entire inking unit, but this represents a considerable conversion expense. To reduce the required expense of conversion, ink transport rollers are shown in DE 196 28 647 A1, that have a recess present between each set of adjoining, cylindrical sections. This recess can be selectively closed, for example, by the application of a covering strip. If a number of separate pages are to be printed alongside one another, and independently of one another, the recess between the different roll surface sections can prevent any running of the ink between the separate pages. In contract, when converting the inking unit to panorama printing, the recess is closed by the covering element, so that a continuous roll surface is obtained, with which an ink layer extending continuously over two pages can be transferred. 
   WO 98/28141 A1 discloses a roller for a printing press in which the recess between the separate roll surface sections is formed by accomplishing a shifting of the separate sections relative to one another. The separate sections can be formed, for example, in the manner of sleeves arranged on a common shaft. In a first mode of operation, that is suitable for panorama printing, the two sleeves are secured on the shaft such that their end surfaces bear against one another and thereby form a continuous roll surface. For the printing of separate, adjoining pages, the sleeves can be pushed apart, so that a recess is formed between the roll surface sections of the sleeves. 
   WO 98/28142 A1 discloses a roller for a rotary printing press. A roll surface, which is formed by a rubber-elastic cover, is selectively dividable by a ring-shaped constriction, whose diameter can be reversibly reduced. 
   Inking units which are suitable for use in printing presses that can be switched between panorama printing and printing of separate pages all have in common that for a surface to have a continuous print, thus either as a separate page or as a double page in panorama printing, separated ink supply paths are always provided. The separate ink supply paths or strands are separated from one another by recesses in the roll surface sections of the rollers being used. In converting between panorama printing and the printing of separate pages, or vice versa, as the case may be, the two separated ink supply paths or strands must either be separated, or must be joined together with one another, which joining together happens either by pushing neighboring roll surface sections together, or by covering of recesses situated between the surface sections. 
   DE 43 00 683 A1 discloses an inking unit. A second roller is displaceable together with a first roller. 
   DE 39 31 291 C1 describes a roller driven by a distribution cylinder. An oscillating movement of the roller can be turned off. 
   SUMMARY OF THE INVENTION 
   The present invention is directed to providing an inking unit with rollers. 
   The object is attained in accordance with the present invention, by the provision of an inking unit having rollers in which at least one roller has a pad or barrel that is formed with at least two separate roll sections. At least one of these roll sections is arranged for oscillation independently of the other roll section. 
   In the inking unit in accordance with the present invention, at least two rollers are engaged with one another, with a first roller of the at least two rollers being journaled such that it can be displaced in a longitudinal direction of the roller. A second roller is also journaled to be axially displaceable in a longitudinal direction of the roller. The second roller can also be axially fixed by the actuation of appropriate locking means. 
   An advantage which is obtainable with the present invention resides, in particular, in that, in switching between panorama printing and the printing of separated pages, or vice versa, as the case may be, a conversion is required therefor, in which that the second roller, configured for a first mode of operation, in which separate pages are printed separately from one another, is journaled to be axially displaceable, and, in a second mode of operation, which is chosen for panorama printing, is axially fixed. The separation of the separate ink paths or strands which are transferred by the rollers and which are required for the printing of separate pages, is accomplished by having the two rollers each be axially displaceable in the first mode of operation and to thereby avoid a relative movement between the two rollers in the axial direction. Because of the absence of any relative movement in the axial direction, the ink applied on the roll surfaces is not rubbed or shifted in the longitudinal direction. Despite the presence of an uninterrupted roll surface, an errant running of the ink is essentially prevented. If it is then desired to execute a panorama print in the printing press, the second roller is fixed axially, so that the first roller now does execute an axial movement relative to the second roller. Through this axial or longitudinal shifting of the first roller relative to the second roller, the ink transferred in the contact zone between the rollers is rubbed or shifted on the roll surfaces, so that, by using a sufficient stroke or length of axial shifting, any ink-free zone on the roll surface can be covered with ink being brought into the zone incoming from the sides of the zone. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Preferred embodiments of the present invention are presented in the drawings and will be described in greater detail below. 
     The drawings show in: 
       FIG. 1  a schematic front view of a first preferred embodiment of an inking unit in accordance with the present invention in a first mode of operation; in 
       FIG. 2  a schematic front view of the inking unit of  FIG. 1  in a second mode of operation; in 
       FIG. 3  a schematic front view of a second preferred embodiment of an inking unit in accordance with the present invention; in 
       FIG. 4  a cross sectional view of a roller suitable for use in the inking units of  FIGS. 1 and 3 ; in 
       FIG. 5  a schematic front view of a third preferred embodiment of an inking unit in accordance with the present invention; in 
       FIG. 6  a schematic front view of a fourth preferred embodiment of an inking unit in accordance with the present invention; in 
       FIG. 7  a cross sectional view of a first roller suitable for use in the inking units of  FIGS. 5 and 6 ; and in 
       FIG. 8  a cross sectional view of a second roller suitable for use in the inking units of FIGS.  5  and  6 . 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Referring initially to  FIG. 1 , there may be seen generally at  01 , a first preferred embodiment of an inking unit with rollers in accordance with the present invention. The inking unit  01  is formed utilizing four rollers  02 ,  03 ,  04 ,  06 . The first roller  03  is configured in the manner of a distribution cylinder  03 , and exhibits an uninterrupted, or a continuous, roll surface. This first roller or distribution cylinder  03  is journaled rotatably on a shaft  07  and can be driven axially in a longitudinal direction of the shaft  07  by a drive mechanism which is not specifically shown and which causes roller  03  to oscillate longitudinally in its axial direction in the direction of arrow  8  about a middle or center position. The second roller  04  is formed in the manner of an ink forme roller, which is journaled rotatably on a shaft  10  and which likewise has a continuous roll surface. The journaling of the roller  04  on shaft  10  allows the roller  04  selectively to be fixed axially on the shaft  10  or to be displaced axially along shaft  10  between two end stops, which are not specifically shown. The third roller  02  is formed in the manner of an ink metering roller, and is journaled rotatably on a shaft  09 . The third roller  02  is configured having two separated roll sections  11 ,  12 , which are separated from one another by a centrally interposed, circumferential recess  13 . The fourth roller  06  of the inking unit  01  is formed in the manner of a plate cylinder, on which a printing plate  05 , that is suitable for panorama printing, is secured. The fourth roller or plate cylinder  06  is likewise journaled rotatably on a shaft  14 . 
     FIG. 1  depicts the inking unit  01  in an operating configuration which is suited for panorama printing. For this purpose, the printing plate  05 , which is secured on the fourth roller  06 , is provided with a continuous roll surface. This printing plate  05  carries the image of two adjoining pages, and is thus suited for use in panorama printing where the intermediate space between the pages is to be printed without interruption. The ink required for such panorama printing is first supplied onto the two spaced roll sections  11 ,  12  of the third roller  02 , for example by application of such ink from two separated ink troughs, not specifically shown and each containing the same printing ink. Since the two roll sections  11 ,  12  are separated from one another by the recess  13 , the printing ink is transferred from the second roller  02 , in two separated contact zones, onto the surface of the first roller  03 . The transfer of the printing ink from the first roller  03  onto the second roller  04 , or from the second roller  04  onto the printing plate  05  which is carried on the fourth roller  06 , as the case may be, then proceeds always in continuous contact zones. In order to be able to achieve a uniform printed image over the entire width of the panorama page, the printing ink, which is transferred, separated at the third roller  02  by the roll sections  11 ,  12 , must be distributed or spread, so that the ink-free region caused by the recess  13  becomes filled with ink. This is effected by providing an oscillating stroke motion  08  of the first roller  03 , which is configured in the form of a distribution cylinder  03 . While the second roller  04  and the third roller  02  each rotate about their rotation axes, but remain axially fixed, the distribution cylinder  03  oscillates in a longitudinal direction with respect to its axis of rotation, as indicated by the motion arrow  08 , about a middle or central position. This longitudinal oscillation of the distribution cylinder  03  causes the printing ink, both in the contact zone between the first roller  03  and the third roller  02 , and in the contact zone between the first roller  03  and the second roller  04  to be rubbed or distributed evenly on the roll surfaces, so that, in the contact zone between the second roller  04  and the fourth roller  06 , an essentially uniform ink application occurs over the entire width of the printing plate  05 . 
   The ink application onto the fourth roller  06  and thus on the printing plate  05  will occur more uniformly, the stronger the printing ink is rubbed between the first roller  03  and the second roller  04  on the one side, and between the first roller  03  and the third roller  02  on the other side. The measure or the extent of the printing ink rubbing or distribution depends especially on the length of the longitudinal stroke  08  of the first roller  03  relative to the second roller  04  and relative to the third roller  02 . In order to be able to reliably fill the ink-free region formed by recess  13  with ink, the stroke distance or length  08  of the first roller  03  for panorama printing should equal at least half of the width of the recess  13 . In the first preferred embodiment depicted in  FIG. 1 , the recess  13  is fifteen millimeters wide and the first roller  03  can be axially displaced through a stroke distance or length  08  lying in the range of +/− 5 mm to +/− 10 mm, especially +/− 7.5 mm, out of a middle or central position, in both directions. 
     FIG. 2  shows the inking unit  01  in a second mode of operation, which is suited for use in the printing of two separated pages, especially with different inks. On the fourth roller  06 , which is formed as plate cylinder  06 , there are secured two separate printing plates  16 ,  17 , each of which plates  16 ,  17  is carrying the image of one page to be printed. The two printing plates  16 ,  17  are separated from one another by a plate spacing distance  18 , which spacing distance  18  defines an unprinted region on the paper web to be printed The first or distribution roller  03  oscillates longitudinally again in this second mode of operation with a stroke  08  lying in the range from +/− 5 mm to +/− 10 mm, and especially +/− 7.5 mm, around a middle or center position and receives the printing ink again from the separated roll sections  11 ,  12  of the axially fixed third roller  02 . In order to prevent the printing inks transferred separately from the third roller  02  from being too strongly rubbed, or distributed, the second roller  04  is no longer axially fixed on its shaft  10  in this second, illustrated mode of operation. Rather, the second roller  04  can be displaced in its axial direction. Due to the frictional forces between the first or distribution roller  03  and the second roller  04 , the second roller  04  executes essentially the same axial movement as that imparted to the first roller  03 . The result is there is essentially no relative movement between these two rollers  03 ,  04  and the printing ink in the contact area or zone between these two rollers  03 ,  04  is not vigorously rubbed or distributed. 
   In this second mode of operation of the first preferred embodiment of the inking unit, the separately applied printing inks from the roll sections  11  and  12  are rubbed, or distributed by the oscillation of the first or distribution roller  03  thus only in the contact zone between the first roller  03  and the third roller  02 . Since, however, the width of the recess  13  corresponds to exactly twice the longitudinal stroke length  08  of the first roller  03 , and, additionally, since the plate spacing distance  18  between the printing places  16 ,  17 , is selected to be  23  mm, which plate spacing distance  18  is even greater than twice the stroke  08  of the first roller  03 , an undesired mixing of the separately applied printing inks can be prevented. 
     FIG. 3  shows a second preferred embodiment of an inking unit in accordance with the present invention, at  01   a , whose construction corresponds essentially to that of the printing unit  01  of the first preferred embodiment. The difference between the inking units  01  and  01   a  resides in that , the third roller  02   a  of the second inking unit  01   a  can selectively be journaled to be axially displaceable. In this way, in response to oscillation of the first, or distribution roller  03 , both the second roller  03  and also the third roller  02   a  are drawn along and caused to move in the axial, longitudinal direction, indicated by arrow  08 , so that the ink rubbing or the ink distribution in the contact zones between the rollers  02   a ,  04 ,  04  is lessened or eliminated, as the case may be. 
     FIG. 4  shows a cross-section through the second roller  04 . Roller  04  is composed essentially of the roller shaft  10 , which extends all the way across the roller and whose ends can be journaled in an inking unit frame, which is not specifically shown. A sleeve  22  is rotatably journaled on the shaft  10  by spaced bearings  23 ,  24 , which may be, for example deep groove ball bearings  23 ,  24 . Arranged between the inner rings of the ball bearings  23 ,  24  and the shaft  10  are bushings  26 ,  27 , which may be, for example ball bushings  26 ,  27 , so that roller sleeve  22  can be displaced axially in the longitudinal direction of the roller  04 . The movement of the roller sleeve  22 ; in the longitudinal direction relative to shaft  10  is limited by two end stops  28 ,  29 , which can be placed laterally spaced with respect to a sleeve bearing  31 , which may be, for example a deep groove ball bearing  31 , which is secured on the shaft  10  at the outboard ends of the roller sleeve  22 . In order to be able to axially fix the roller sleeve  22  relative to shaft  10 , there is provided a sleeve flange  32  at each end of sleeve  22 . Each sleeve flange  32 , as seen in  FIG. 4 , has a locking screw  33 , whose end surface can be tightened against an outer ring of the sleeve ball bearing  31 . If the locking screw  33  is released, the sleeve flange  32  can be displaced relative to the outer ring of the sleeve ball bearing  31 , whereby an axial movement of the sleeve  22  relative to the shaft  10  is made possible. Tightening of the locking screw  33  axially fixes the sleeve  22  relative to the shaft  10 , while the rotational movement of the sleeve  22  with respect to the shaft, as provided by the presence of sleeve ball bearing  31 , remains possible. 
     FIG. 5  shows a third preferred embodiment of an inking unit  41 , in accordance with the present invention, that is suitable for use in a four page wide printing press. In such a four page wide printing press, one has the choice of arranging on the fourth roller  06   b , which is in the form of a plate cylinder  06   b , separate printing plates  16 , and  17 , which may be used for example, to print four separated pages, or printing plates  05 , of which is adapted each for two pages of panorama printing. In the operating state illustrated in  FIG. 5 , the fourth roller  06   b  has one continuous printing plate  05  for panorama printing and two separate printing plates  16 ,  17  for printing with decorative inks. The first or distribution roller  03 b, which is formed in the manner of a distribution cylinder  03   b , has a width essentially equalling that of the fourth roller  06   b  and is configured having a continuous roll surface. The second roller  04   b  is formed having two adjoining roll sections  42 ,  43 . The roll section  43 , which interacts with the fourth roller  06   b  in the region of the printing plate  05  for panorama printing, is fixed on the shaft  10   b  in the operating configuration illustrated in  FIG. 5 , in order to achieve, from the oscillatory movement  08  of the distribution roller  03   b , a maximum rubbing or distribution of the printing inks which are applied separately from the third roller  02   b . Roll section  42 , in contrast, is journaled to be axially displaceable on shaft  10   b , so that it follows the oscillatory movement  08  of the first roller  03   b , and essentially no rubbing or distribution of the ink occurs in the contact zone between the first roller  03   b  and the roll section  42 . The result is that inking unit  41  can print either two panorama print pages, each having two single pages which are printed continuously between one another, four single pages, especially with separate colors, or one panorama page combined with two single pages. Depending on whether the printing plate  05  for the panorama print is located to the left or to the right of the two single print pages, or whether either none or all of the pages are printed in panorama print, conversion simply requires that the two roll sections  42 ,  43  be axially fixed, or released, as the case may require. 
     FIG. 6  shows a fourth preferred embodiment of an inking unit  41   a , whose construction corresponds essentially to the construction of the third preferred embodiment of the inking unit  41 . In contrast to the third inking unit  41 , for the fourth inking unit  41   a  the third roller  02   c , which is in form of an ink metering roller, also has two separated roll sections  46 ,  47 . The two roll sections  46 ,  47  can, in a similar to the journalling of the two roll sections  42 ,  43 , each be selectively fixed axially on the shaft  09   c  or can be axially displaceable relative thereto. If the two roll sections  46  and  47  are both released, so that they can both axially displace or shift, then the rubbing or distribution of the printing ink in the region of the contact zone between the first roller  03   b  and the third roller  02   c  can be lessened or can be eliminated, as the case may be. Each roll section  46 ,  47 , in turn, is configured having two separated roll surface sections  51 ,  52  as one set,  53 ,  54  as the other set, respectively, which roll surface sections  51 ,  52  and  53 ,  54  are each separated by an annular groove  13 . The two roll surface sections  51 ,  52 , and  53 ,  54  can be both axially fixed as well as being oscillatory. 
     FIG. 7  shows a cross-section through the second roller  04   b , in accordance with the third and fourth preferred embodiments, with a shaft  10   b  extending from one end to the other. The two roll sections  42 ,  43  are each formed by a sleeve  22 , which, in a manner the same as was discussed for roller  04  of  FIG. 4 , are journaled on the shaft  10   b  by the use of the deep groove ball bearings  23 ,  24 , and the use of the ball bushings  26 , to be rotatable and axially displaceable. Tightening of the locking screws  33  permit the two roll sections  42 ,  43  of roller  04   b  to each be axially fixed on the shaft  10   b  independently of one another. 
     FIG. 8  shows a cross-section of a further configuration of a second roller  04   c  that can be used in an inking unit  41  or  41  a for a four page wide printing press. Instead of combining one deep groove ball bearing  23 ,  24  with one ball bushing  26 ,  27 , for each sleeve  22 , as depicted in  FIGS. 4 and 7 , in the configuration of  FIG. 8  the sleeves  22  of the roll sections  42 ,  43  are each journaled with two bearings  49 , for example with needle bearings  49 , on the shaft  10   c . The needle bearings  49  permit both a rotational and an axial relative movement of the sleeves  22  relative to the shaft  10   c . Again, sleeve flanges  32  contain locking screws  33  for use in fixing the roll sections  42 ,  42 , at the locations of the deep groove ball bearings  31 , on the shaft  10   c.    
   While preferred embodiments of an inking unit with rollers, 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 specific type of printing ink being used, the overall press structure, 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 following claims.