Abstract:
A printing unit, which is a part of a multi-color printing press, has a plurality of double printing units which are arranged vertically one above the other and consist of two printing groups forming a double print position. The printing group cylinders are mounted together in a central stand section. Inking units, which are associated with the printing groups, are mounted in outer stand sections. A distance between adjacent ones of these stand sections is adjustable. Printing and transfer cylinders of each printing group are coupled by a toothed gear wheel connection and are driven in pairs by a separate drive motor. The toothed gear wheels of all of the printing group cylinders are arranged in a common lubricant chamber which is formed by the central stand section and a cover. The inking systems have at least one separate drive motor, which is independent of the printing group cylinders.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This patent application is the U.S. national phase, under 35 USC 371, of PCT/EP2004/050623, filed Apr. 28, 2004 and published as WO 2005/115756 A1, the disclosures of which are expressly incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION  
       [0002]     The present invention is directed to a printing unit for a multicolor web-fed rotary printing press and to a method for operating such a printing unit. A plurality of blanket-to-blanket printing units are arranged vertically one above the other. Each printing unit includes two printing groups which form a blanket-to-blanket location. The printing group cylinders are all mounted in a center frame section. Inking units are mounted in outer frame sections.  
       BACKGROUND OF THE INVENTION  
       [0003]     A printing unit of this general type is discussed in WO 95/24314 A1. Four blanket-to-blanket printing units are arranged vertically, one above another, and can be moved horizontally relative to one another in the area of their blanket-to-blanket printing point. The blanket-to-blanket printing units that are on the same side of a web are each mounted in a shared frame. At least one of said frames can be moved horizontally.  
         [0004]     EP 12 64 686 A1 discloses a printing unit with blanket-to-blanket printing units arranged vertically, one above another The printing group cylinders are mounted in a center frame section and the two inking units are mounted in respective outer frame sections. These outer frame sections can be moved horizontally, relative to the center frame section, in order to introduce plate handling devices into the intermediate space, as may periodically be needed.  
         [0005]     EP 11 49 694 A1 discloses a printing unit having a multitude of arch-shaped blanket-to-blanket printing units, arranged vertically, one above another. Each such printing unit is comprised of two printing groups that form a blanket-to-blanket printing point. The printing group cylinders of the printing groups are all mounted in a center frame section while the inking units, which are assigned to the printing groups, are mounted in respective outer frame sections. The adjacent frame sections are structured such that their spacing relative to one another is adjustable.  
       SUMMARY OF THE INVENTION  
       [0006]     The object of the present invention is to provide a printing unit for a multicolor web-fed rotary printing press, and to provide methods for operating such a printing press.  
         [0007]     The object is attained, in accordance with the present invention with the provision of a printing unit for a multi-color web-fed rotary printing press having a plurality of blanket-to-blanket printing units which are arranged vertically. Each of these printing units is comprised of two printing groups that form a blanket-to-blanket printing location. The printing group cylinders of the printing units are all mounted in a center frame section. Inking units that are assigned to the printing groups are each mounted in outer frame sections. The adjacent frame sections can be adjusted, in terms of their spacing, with respect to each other. Forme and transfer cylinders of each printing group are coupled via a toothed gear connection and are actuated in pairs by their own drive motor. The inking units each have at least one separate drive motor mounted on its assigned outer frame section.  
         [0008]     The benefits to be achieved with the present invention consist especially in that in a first aspect, high printing quality is ensured at low cost using a rotary printing press having a compact construction. This is achieved, firstly, in that the printing group cylinders can remain in a fixed, such as, for example, a preset position relative to one another, even when the printing unit is opened, thus insuring excellent reproducibility. Secondly, the quality (doubling) is increased because a plane of connection for the rotational axes of the coordinating transfer cylinders forms an angle that is not equal to 90°, and which is preferably between 77 and 87°, with the plane of the web that is being fed into the respective blanket-to-blanket printing unit. Further, by using finite rubber blankets, which are structured as multipart printing blankets, a rigid mounting of the printing group cylinders in the frame walls can be effected, thereby providing rigidity to the printing press.  
         [0009]     This configuration is supported or is made possible by a drive configuration that is specifically adapted to it. To prevent a drive train from extending beyond the point of separation between the printing group cylinders and the inking unit, each blanket-to-blanket printing unit is rotationally actuated by at least one drive motor of its own. This at least one drive motor for each blanket-to-blanket printing unit is independent from the other blanket-to-blanket printing units, and is also independent from the assigned inking units. Each inking unit also has its own independent drive motor for its rotational actuation. Transmission play, in the area of a separable transmission, and a transfer of impacts up to the printing point via the drive train, and resulting from reversal movements in the inking unit, are prevented. In one advantageous embodiment of the present invention, the printing group cylinders can each be separately driven by respective, independent drive motors. However, in order to minimize cost while achieving high quality and variability, in the preferred embodiment of the present invention, coordinating forme cylinders and transfer cylinders are actuated, in pairs, by drive motors that are independent from the motors of other pairs of forme cylinders and transfer cylinders. In this manner, a printing forme change for each individual printing point, using the drive motor that actuates the pair of cylinders, both during print operation and during maintenance and, if applicable, with longitudinal registration, is still possible. In this context, the frame section that accommodates all the printing group cylinders is also advantageous with respect to its simple construction. In this construction, a shared lubricant chamber can be formed for all of the drive trains of the various printing groups.  
         [0010]     Of particular advantage, with respect to quality and a compact construction, is the structuring of the printing groups or inking units as printing groups or inking units which are suitable for “waterless offset printing”. No dampening agent supply or dampening unit is provided. Instead, the inks and the printing formes are selected to have corresponding properties suitable for such waterless offset printing. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]     Preferred embodiments of the present invention are represented in the accompanying drawings and will be described in greater detail below.  
         [0012]     The drawings show:  
         [0013]      FIG. 1 a  schematic side elevation view of a printing unit in an operational position B; in  
         [0014]      FIG. 2 a  view similar to  FIG. 1  and showing the printing unit in a maintenance position A; in  
         [0015]      FIG. 3 a  frontal view of a drive configuration in accordance with the present invention; in  
         [0016]      FIGS. 4   a  and  4   b  top plan views of two drive configurations; and in  
         [0017]      FIGS. 5   a  and  5   b  two preferred embodiments of the inking unit in accordance with the present invention. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0018]     Referring initially primarily to  FIG. 1 , a printing machine, such as, for example, a web-fed rotary printing press, and especially a multicolor web-fed rotary printing press, has a printing unit  01 , in which a web of material  02 , referred to here as web  02 , can be printed multiple times in sequence, such as, for example, in this case the web  02  can be printed four times. Alternatively, multiple webs can be printed simultaneously a single time or multiple times. The printing unit  01  has multiple blanket-to-blanket printing units  03  arranged vertically, one above another with four such printing units  03  being depicted in  FIG. 1 , and which printing units  03  are operable, for double-sided printing in blanket-to-blanket operation. The blanket-to-blanket printing units  03  are each formed by two printing groups  04 , each of which printing groups  04  has cylinders  06 ;  07 . One cylinder is structured as a transfer cylinder  06  and one cylinder is structured as a forme cylinder  07 , as depicted by for example, printing group cylinders  06 ;  07 , and an inking unit  08 . In each case, a blanket-to-blanket printing point  05  is formed between the two transfer cylinders  06  when these two cylinders, in the engaged position depicted in  FIG. 1 . The above-described components are indicated with lead lines and only in the uppermost blanket-to-blanket printing unit  03  shown in  FIG. 1 . However, the several printing units  03 ;  04 , which are arranged one above another, are essentially identical in structure, especially in the embodiment of the features that are relevant to the present invention.  
         [0019]     The forme cylinders and transfer cylinders  07 ;  06  are preferably each structured with a barrel width of at least four vertical printed pages arranged side by side in newspaper format, and especially in broadsheet format. In this manner, a double-width web  02  can be printed with four pages positioned side by side. The forme cylinder  07  can be correspondingly loaded with four printing formes arranged side by side. Advantageously, both of the cylinders  06 ;  07  have a circumference that corresponds essentially to two printed pages in newspaper format, and which are arranged in tandem.  
         [0020]     The printing group cylinders  06 ;  07  of the multiple, such as the depicted four blanket-to-blanket printing units  03 , which are arranged one above another, are rotatably mounted in a center frame or panel section  11 , which is, in turn, preferably arranged fixed in its location such as, for example, being secured in plate on a floor  09  of the printing shop, on a stationary support  09 , on a mounting plate  09  or on a mounting frame  09  for the printing unit  01 . The inking units  08 , which are situated on both sides of the blanket-to-blanket printing units  03 , as may also be seen in  FIG. 1 , are each mounted in separate frame or panel sections  12 ;  13 , which are, in turn, mounted vertically opposite the center frame section  11 . The frame or panel sections  12 ,  13  are movable relative to the floor  09  or the support  09  or the mounting plate  09  or the mounting frame  09 , which is hereinafter referred to as the support  09 . For this purpose, the outer frame sections  12 ;  13  are each mounted in bearing elements  14 ;  16  of the frame sections  12 ;  13  and of the support  09 , which bearing elements  14 ;  16  correspond with one another. These bearing elements  14 ;  16  can be structured as rollers  14  that run on rails  16 , as illustrated in  FIG. 1 , or can be configured as sliding or as roller-mounted linear guide elements  14 ;  16  that are allocated to one another.  
         [0021]     Preferably, the fixed central frame or panel section  11 , and the movable, outer frame or panel sections  12 ;  13  are structured such that in their operational position B, as depicted in  FIG. 1 , they are structured in pairs, the shapes of which pairs essentially complement one another on their facing sides. When these pairs are pushed together, at their lines of separation or their lines of abutment  17 ;  18  they nevertheless form an essentially closed side configuration, as shown in  FIGS. 1 and 2 . In this manner, on both the cylinder side and the inking unit side, the greatest possible area for accommodating the bearing can be achieved in the corresponding frame section  11 ;  12 ;  13 . Additionally, requirements with respect to noise, personnel safety and containment of contamination can be met. In order to achieve the most stable mounting possible, with cylinder journals of corresponding strength, the center frame section  11  deviates from a vertical alignment in the area of the cylinder bearing, which is not specifically shown in  FIGS. 1 and 2 , and is equipped with corresponding protrusions  19 , as is shown in  FIG. 2 , and that accommodate the bearing. The outer frame sections  12 ;  13  have recesses  21  whose shape complements these protrusions  19 , as may also be seen in  FIG. 2 . The recesses  21  and the protrusions  19  are formed on the bearing arrangements in the inking unit  08  and the printing group  04  with respect to provision of sufficient or even the greatest possible strength of the enclosure, i.e. at least a minimum strength, through the respective frame.  
         [0022]      FIG. 2  shows a maintenance position A of the printing unit in accordance with the present invention on both sides of the printing points  05  The relative position of the inking units  08 , with respect to the printing group cylinders  06 ;  07 , is achieved by moving the frame sections  12 ;  13  that accommodate the inking units  08  laterally. It is also possible to adjust only one side of the assembly to the depicted maintenance position A, while the other side of the printing unit  01  is in the operational position B depicted in  FIG. 1 . In principle, the relative positions can also be achieved in another embodiment, in which one outer frame section,  12  or  13  is mounted so as to be fixed in space, while the center section  11  and the other outer frame section  11   13  or  12  or even all three frame sections  11 ;  12 ;  13  are mounted so as to be movable with respect to each other.  
         [0023]      FIGS. 3 and 4  schematically depict an advantageous drive configuration for the printing group cylinders  06 ;  07  of the printing unit  01 . The journals for the forme cylinders and of the transfer cylinders  07 ;  06  are each non-rotatably connected, at their end surfaces, to toothed gears  22 ;  23 , respectively, and particularly, spur gears  22 ;  23 . These gears, in pairs, form a drive connection. The paired drive is advantageously accomplished by the use of a drive motor  24  via a transmission, and particularly by a speed-reduction transmission, which is situated on one of the two cylinders  06 ;  07 , and particularly on the forme cylinder  07 . Due to its shorter adjustment path, the location of the drive on the forme cylinder  07  contributes to a simple and sturdy construction of the printing unit. In the depicted example, the drive is accomplished via a sprocket wheel  26  on the spur gear  22 , as seen in  FIG. 4   a.  In another embodiment, as seen in  FIG. 4   b,  in addition to the spur gear  22 , a second toothed gear  27  can be non-rotatably connected to the forme cylinder journal, and on which second toothed gear  27  the sprocket wheel  26  is actuated. In this embodiment, the spur gears  22 ;  23 , that form the drive connection, can be structured to be evenly toothed to favor the accomplishment an axial relative shiftability to accomplish lateral register, and the second toothed gear  27  and the sprocket gear  26  can be structured to be helically toothed in order to provide rigidity. In principle, it is also possible, with the above-described configurations, to effect the drive first on the transfer cylinder  06  and from there on the forme cylinder  07 . Reference symbols  06  and  07  would then need to be transposed. In a preferred embodiment which is not shown here, and for the purpose of improved attenuation, the output from the drive motor  24  to one of the cylinders  06 ;  07  can take place not via a toothed gear connection, such as a sprocket but instead can take place via a belt and chain drive, such as, for example, via a belt, and especially a toothed belt which meshes with corresponding pulleys. If the drive motor  24  is sufficiently heavy, is large in dimension and/or has an adapter transmission, typically for speed reduction, then the drive motor  24  can also drive coaxially on one of the cylinders  06 ;  07  of each of the pairs of cylinders.  
         [0024]     As may be seen by again referring to  FIG. 4 , the frame section  11 , together with a cover  28 , preferably forms a lubricant chamber  29  that conceals the cylinder end surfaces, and also conceals the toothed gears  22 ;  23 ;  27 ; or the sprockets  26 . This lubricant chamber  29  preferably extends over the four spur gars  22 ;  23  of a blanket-to-blanket printing unit  03  in its width, and over all four of the vertically arranged blanket-to-blanket printing units  03  in its height. In other words, one shared lubricant chamber  29  exists for all of the printing group cylinders  06 ;  07  of the printing unit  01 .  
         [0025]     The blanket-to-blanket printing units  03  are each structured, relative to the intended vertical web path, such that a plane of connection, which is defined by the rotational axes of the coordinating transfer cylinders  06  of each printing unit  03 , in their engaged position, forms an angle α that is not equal to 90°, and which is preferably between 77° and 87°, with respect to the plane of the web  02  that is being fed into the respective blanket-to-blanket printing unit  03 , as is shown by way of example in  FIG. 1 . In the engaged position of each printing unit  03 , the rotational axes of the forme cylinders  07  do not lie in the same plane as those of the transfer cylinders  06 . In other words, the blanket-to-blanket printing units  03  are not linear in structure. Instead, they are angular and preferably are arch-shaped. To accomplish this purpose, the cylinders  06 ;  07  are correspondingly mounted in the frame section  11 . As is schematically indicated in  FIG. 4   a,  by the use of double lines, the journals of the transfer cylinder  06  are mounted in radial bearings  32 , which radial bearings  32  are, in turn, mounted in eccentric bushings  33  to thereby allow adjustment of the transfer cylinder  06 . This mounting can have a overall structure, such as, for example, a three-ring or as a four-ring bearing  32 ,  33 . In one preferred embodiment, only one of the transfer cylinders  06  is mounted in this manner, so as to be adjustable, while the other transfer cylinder  06  is fixed. The mounting of the forme cylinders  07  can also be structured in this manner. However, in  FIG. 4   a  only the radial bearings  31  are shown.  
         [0026]     In one preferred embodiment of the present invention, the printing unit  01  is structured as a printing unit  01  for use in dry offset printing, or in other words for waterless or for dampening agent-free offset printing. In this preferred embodiment, the printing unit  01  has no dampening units, and thus is even more compact. In  FIG. 1 , the inking units  08  are illustrated in schematic fashion, and can be structured differently in accordance with the demands of the specific printing unit.  
         [0027]     In a first embodiment of the present invention, and which is particularly advantageous in terms of its compact construction, the inking units  08  are structured as short inking units  08 , as seen at the top right of  FIG. 2 . Such short inking units  08  each have an anilox roller  34 , which dips into an ink tray  36  where it absorbs ink. Excess ink is scraped off the anilox roller  34  by a blade device  37 , such as, for example, by a fountain blade or a fountain sheet. The ink tray  36  and the blade device  37  can preferably be structured as a single component as an ink chamber blade  36 ,  37 , which receives its ink from an ink supply by the operation a pump that is not shown in  FIG. 2 . The anilox roller  34  preferably has a drive motor  35  that is mechanically independent from the printing group cylinders  06 ;  07 . The ink is taken from the anilox roller  34  by at least one forme roller  38 , and advantageously by two such rollers  38 , as seen in  FIG. 2  or by even three such forme rollers  38 , and is transferred to the forme cylinder  07 . Because the cells on the anilox roller  34  essentially define the quantity of ink to be taken up, for each rotation of the anilox roller  34  the overall quantity of ink removed from the ink tray  36  can result either from a relative speed of two rollers or advantageously from the temperature of the ink and/or the temperature of ink-transporting components, such as, for example, the temperature of at least the anilox roller  34 . The anilox roller  34  is rotationally actuated by its own drive motor  35 , which motor  35  is mechanically independent from the printing group cylinders  06 ;  07 , and especially from the forme rollers  38 . With a substantial change in the quantity of ink needed, the anilox roller  34  must, if applicable, be exchanged for another.  
         [0028]     In one embodiment of the present invention, that is advantageous in terms of the variability of the quantity of ink, the inking units  08  are structured according to the depictions of  FIGS. 5   a  and  5   b,  for example, as roller inking units  08 . The ink is again applied by multiple forme rollers  38 , such as the two forme rollers  38  depicted in  FIGS. 5   a  and  5   b,  to the printing forme of the forme cylinder  07 . However, in this embodiment the forme rollers  38  do not receive the ink from an anilox roller  34 , but instead receive ink by way of a roller train, which has at least one oscillating roller  39  that is provided with a hard surface, and is a so-called distribution roller  39 . A roller train that has two distribution rollers  39  with hard surfaces and with one intermediate roller  41  between them, and which is provided with a soft surface, is advantageous. The distribution cylinder  39  that is distant from the forme cylinder receives the ink, through another intermediate roller  41 , from a film roller  42  which has a hard surface. In accordance with the partitionable printing unit  01  of the present invention, it is provided that the two distribution cylinders  39  are mechanically coupled to one another via a transmission, such as, for example, a wheel train or a belt and chain drive, and are rotationally actuated by a shared drive motor  43  that is mechanically independent from the printing group cylinders  06 ;  07 . Such a drive train is indicated by a dashed line. In one simple embodiment of the present invention, an oscillating axial movement of the two distribution cylinders  39  can be accomplished, from the rotational movement of the two distribution cylinders  39  by the provision of a corresponding transmission which is not specifically shown. However, in one advantageous embodiment of the present invention, the axial movement of the distribution cylinders  39  is produced by the use of at least one other drive motor that is not shown here. The intermediate rollers  41 , and the forme rollers  41  are preferably driven only by friction. The film roller  42  receives ink from a fountain roller  44 , with which it forms a contact gap or point. The fountain roller  44  is rotationally actuated via its own drive motor  46 . The metering of the ink onto the fountain roller  44  can be accomplished in various ways which are not specifically depicted.  
         [0029]     In one simple embodiment of the present invention, as seen in  FIG. 5   a,  the fountain roller is configured as a dipping roller  44 , which roller  44  dips into the ink reservoir of an ink tray  47 . With proper control of the speed of the drive motor  46 , and hence the speed of the fountain roller  44 , the quantity of ink to be transported from the fountain roller, through the gap, to the film roller  42 , can be adjusted.  
         [0030]     In one advantageous embodiment of the present invention, as shown in, the inking unit  08  is structured as an ink injector system  08  and receives the necessary quantity of ink in a controlled manner through the use of a pump device  48 , which allows a quantity of ink to be applied to the fountain roller  44  in a targeted fashion through the use one or more pumps. Advantageously, the quantity of ink to be applied can be controlled, in zones, for sections of the fountain roller  44 , which fountain roller  44  is divided in an axial direction, which quantity of ink applied to the various zones is achieved with multiple pumps or with multiple, individually controllable valves, or preferably with a combination of the two. In this manner, an ink requirement that differs over a web to be printed can be taken into consideration. The pump or pumps  48  can be structured as piston pumps or as continuously running gear pumps.  
         [0031]     As indicated primarily in  FIG. 5 , the transfer cylinders  06  each preferably have at least one axially extending opening  49  on their periphery, and especially have a channeled opening  49 , into which the ends of a resilient dressing or packing  51 , which is schematically depicted in  FIG. 5   b,  can be inserted and which, if applicable, can be fastened in an interior channel. The resilient dressing or packing  51  is advantageously structured as a multipart printing blanket  51  which includes a dimensionally stable base plate, such as, for example, of metal and an elastic layer, such as, for example, of rubber, and which thus may be, for example, a so-called metal printing blanket  51 . Preferably, on the transfer cylinder  06 , which has the width of four printed pages, two such printing blankets  51  are arranged axially side by side. In an advantageous further development, these two axially arranged printing blankets  51  are arranged offset in a circumferential direction with respect to each other, such as, for example offset by 180°. In this manner, and in contrast to rubber sleeves, an exchange of the resilient dressing or packing  51  is possible, without requiring an opening in the panel  11  and without the requirement of corresponding removable radial bearings, also in the panel section  11 . In the operational position B depicted in  FIG. 1 , the resilient dressing or packing  51  can be conveniently exchanged from the intermediate space that is formed between the inking units  08  and the printing group cylinders  06 ;  07 . The same applies to accessing a web  02  in the event of problems during threading of the web  02  or following a web tear.  
         [0032]     Although it is advantageous for the maintenance position A of the printing unit, as depicted in  FIG. 2 , to be assumed in the aforementioned circumstances, such a positioning is not advantageous during routine printing forme changes. As is shown in the lower left corner of  FIG. 1  as an example for all of the printing groups  04 , in an advantageous further development of the present invention all the printing groups  04  are assigned printing forme exchange devices  52  or printing forme handling devices  52 . These printing forme exchange devices  52  can advantageously have two guides, on one of which guides the printing forme, and especially the printing plate, can be advanced to the forme cylinder  07 , guided between the inking units  08 . On the other guide, the printing forme to be removed can be withdrawn from the forme cylinder  07 . The guides can also be structured as closed shafts. The printing forme exchange devices  52  or their guides/shafts are connected to the outer frame sections  12 ;  13  and are moved together with the movement of the inking units  08 . For the advancement and the withdrawal of the printing plates, at least one transport element for the printing forme is expediently provided. This at least one transport element has, for example, a drive element, such as, for example, a motor and has an actuated holding element, such as, for example, a frictional surface, a stop, or a suction foot. Thus to accomplish routine printing forme changes, it is not necessary for the printing unit  01  to be placed in its maintenance position A, which would, in turn, require time and, if applicable, would also require an adjustment of settings and a realignment. The printing group cylinders  06 ;  07 , and especially the transfer cylinders  06  that form the printing point  05 , can remain in their positions relative to one another.  
         [0033]     Preferably, the printing forme handling device  52  is structured for this purpose such that, when viewed in an axial direction of the forme cylinder  07 , a printing forme can be handled on four sections side by side. This can be accomplished by using correspondingly wide, continuous guides or shafts and by also using at least four transport elements for the sections, or with four guides/shafts, which are arranged side by side, each of which is provided with assigned transport elements.  
         [0034]     Everything which has been discussed in the above-description with respect to cylinders  06 ;  07  that have been recited as being four printed pages wide and/or printing forme handling devices  52  can be applied accordingly for cylinders  06 ;  07  which have a width of six printed pages which are arranged axially side by side.  
         [0035]     While preferred embodiments of a printing unit for a multicolor web-fed rotary printing press, and a method for operating such a press, 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 overall structure of the printing press, the types of webs being printed, 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.