Abstract:
A printing unit is comprised of a pair of cylinders, such as a forme cylinder and a transfer cylinder. These two cylinders, together with a third cylinder, form a printing site. The third cylinder is in contact with the transfer cylinder. The forme cylinder and the transfer cylinder are coupled together and form a drive system which is driven by a common drive motor during the printing process. Power is transmitted from the transfer cylinder to the forme cylinder. The drive system for the cylinder pair and a drive for the third cylinder are coupled to each other by a mechanical coupling for selective coupling and decoupling.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention is directed to a printing unit including at least first and second printing pairs or couples. A satellite cylinder cooperates with a transfer cylinder of the first pair. A drive assembly is provided for the cylinders.  
         BACKGROUND OF THE INVENTION  
         [0002]    A printing press is known from EP 0 644 048 B1 in which pairs of cylinders, each consisting of a forme cylinder and a transfer cylinder, are mechanically fixedly coupled. Each cylinder pair has its own drive motor. The cylinder pairs themselves cannot be coupled to each other.  
           [0003]    DE 44 30 693 A1 discloses printing units of a printing press with separate configurations of cylinders which are driven individually, or in groups. Cylinders, or groups of cylinders, are not in a driven connection with each other.  
           [0004]    A four-cylinder printing unit is known from DE 196 03 663 A1. The two transfer cylinders which cooperate with each other are fixedly coupled to each other and can be selectively driven by the drive mechanism of one or of both associated forme cylinders. In one embodiment, a pair of cylinders, consisting of a forme cylinder and a transfer cylinder, which can be driven at the forme cylinder, can be placed against this four-cylinder printing unit, and can be coupled into the drive linkage between the two first mentioned transfer cylinders for synchronization, or to attain correctly registered printing.  
           [0005]    EP 0 997 273 A2 discloses a four-cylinder printing unit, in which the four cylinders can be driven by two drive motors. Two couplings at the journals of the two forme cylinders, and two gear wheels, which can be axially displaced on the journals of the two transfer cylinders, facilitate the formation of different drive linkages.  
           [0006]    WO 00/06384 A1 discloses printing units with satellite cylinders in a modular construction which make possible a multitude of production possibilities by use of flexible arrangements. Each satellite cylinder has its own drive motor or can be coupled to one of the cooperating cylinder pairs.  
         SUMMARY OF THE INVENTION  
         [0007]    The object of the present invention is directed to providing a printing unit.  
           [0008]    In accordance with the present invention, this object is attained by the provision of a printing unit having a first cylinder pair comprised of a first forme cylinder and a first transfer cylinder. A second cylinder pair is also provided and is comprised of a second forme cylinder and a second transfer cylinder. A satellite cylinder, together with the transfer cylinders, forms a printing location. A drive for the first forme cylinder, and a drive for the first transfer cylinder form a coupled drive linkage which, during printing is driven by a common drive motor on the transfer cylinder. A drive mechanism for the satellite cylinder can be selectively switched and coupled, through a first coupling, with the drive linkage of the first cylinder pair. With the coupling engaged, the drive is taken off the drive motor and transferred to the satellite cylinder.  
           [0009]    The advantages which can be gained by the present invention lie, in particular, in that a large operational diversity and variability of a printing unit or of compound cylinders, together with a high degree of operational dependability, is provided by redundancy, without each cylinder being provided with its own drive mechanism. The present invention unites the advantages of the high degree of flexibility provided by the expensive and elaborate single drive technology with the advantages of coupled cylinder groups, namely the savings of motors and the mechanical synchronization of the connected cylinders.  
           [0010]    As a rule, by the optimized arrangement of switchable couplings and motors as many of the desired operating modes are possible as would be provided with the embodiment where all cylinders are provided with separate motors. Thus, with the coupling released, it is possible to move cylinders, or groups of cylinders, independently of each other, which is required, for example, when the printing formes or rubber blankets are exchanged, when a paper web is drawn in, or when rollers and cylinders are independently inked or washed. In many cases, an auxiliary drive mechanism can therefore be omitted, since the function of this auxiliary drive mechanism can be taken over by the main drive mechanisms, if the couplings are appropriately switched. In the same way, is it possible to perform the switching of individual cylinders or cylinder groups of connected larger cylinders, in that new drive linkages are formed by releasing couplings and activating other couplings.  
           [0011]    Moreover, a substantial advantage lies in the option of standardizing individual small groups, for example a pair of cylinders consisting of a forme cylinder and a transfer cylinder with an appropriate coupling, and of combining them in any desired way, in response to a request made in a purchase order, into larger units. An above discussed pair of cylinders can also represent a standard group, together with a counter-pressure cylinder. The journals of the cylinders can be embodied as needed, for example selectively, with or without coupling, with a gear wheel which is fixed against relative rotation or can be fixed in place, matching a first or second drive level.  
           [0012]    In a preferred embodiment, the transfer cylinder of the pair is driven. In this way, it is possible to definitely define a flow of moments up to an inking unit, which aids in improving the printing quality.  
           [0013]    In particular, in connection with printing units which can be switched from rubber-on-rubber to rubber-on steel operation, i.e. in which at least one of the transfer cylinders can be selectively placed against a counter-pressure cylinder or against a second transfer cylinder, a reversal of the direction of rotation of one or several cylinders is necessary, depending on the printing unit, and thus requires the release of drive linkages and the formation of new drive linkages. With a five-cylinder printing unit, an embodiment with one drive motor for each pair of forme and transfer cylinders is advantageous, and in which the counter-pressure cylinder can be coupled with one of the two drive motors, or with both drive motors, or with cylinder pairs, depending on the paper guidance and the mode of operation.  
           [0014]    In such embodiments, a flying plate exchange is possible for a five-cylinder printing unit by use of only two drive motors and only two couplings. This can be accomplished without the need for auxiliary drives for subsequent cylinder acceleration or for appropriate devices for circumferential registration changes and/or for finding the register, which are typically necessary prior to recoupling.  
           [0015]    A one-sided printing forme change is possible in an embodiment with only one drive motor and with only two couplings, for example, for preparing an imprint.  
           [0016]    An embodiment, in the form of a four-cylinder printing unit expanded by a further cylinder pair, for example, is advantageous for a six-cylinder y- or lambda-printing unit, which can be flexibly employed, for example, for a 2/1 production run, for the flying one-sided plate change, or during the imprint function in the course of 1/1 printing.  
           [0017]    The present invention can also be employed particularly advantageously and efficiently in seven-cylinder, nine-cylinder or ten-cylinder printing units, when maximum flexibility, together with a minimal number of motors, is required.  
           [0018]    In the situation of several pairs of cylinders working together directly or via a counter-pressure cylinder, there is the possibility of changing the relative rotational position of the forme cylinders to each other, for example for the adjustment of the circumferential or ink registration, by uncoupling.  
           [0019]    The great operational dependability provided by the present invention, because of the redundancy in the number of usable drive motors, which provides a so-called back-up function, is also partially advantageous in the situation of several drive mechanisms which can by connected by couplings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0020]    Preferred embodiments of the present invention are represented in the drawings and will be described in greater detail in what follows.  
         [0021]    Shown are in:  
         [0022]    [0022]FIG. 1, a schematic representation of a first preferred embodiment of a printing unit in accordance with the present invention with three cylinders,  
         [0023]    [0023]FIG. 2, a schematic representation of a second preferred embodiment of a printing unit with three cylinders,  
         [0024]    [0024]FIG. 3, a schematic representation of a third preferred embodiment of a printing unit with three cylinders,  
         [0025]    [0025]FIG. 4, a schematic representation of a fourth preferred embodiment of a printing unit with three cylinders,  
         [0026]    [0026]FIG. 5, a schematic representation of a fifth preferred embodiment of a printing unit with four cylinders,  
         [0027]    [0027]FIG. 6, a schematic representation of a sixth preferred embodiment of a printing unit with four cylinders,  
         [0028]    [0028]FIG. 7, a schematic representation of a seventh preferred embodiment of a printing unit with five cylinders,  
         [0029]    [0029]FIG. 8, a schematic representation of an eighth preferred embodiment of a printing unit with five cylinders, and in  
         [0030]    [0030]FIG. 9, a schematic representation of a ninth preferred embodiment of a printing unit with five cylinders.  
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0031]    A printing unit  01  of a printing press, in particular a printing unit  01  of a web-fed rotary printing press, has a first pair  02  of cooperating cylinders  03 ,  04 , for example a first forme cylinder  03  and a first transfer cylinder  04  cooperating with it, as may be seen in FIG. 1. For all of the preferred embodiments, the first pair of cooperating cylinders  02  can also be fixedly or switchably mechanically connected with an ink and/or a damping unit, not specifically shown. The drive of the first cylinder pair  02  is mechanically coupled and is provided by a common drive motor  06  during printing production or operation of the web-fed rotary printing press. The common drive motor  06  drives the first transfer cylinder  04 , which drives the first forme cylinder  03  by friction or via a mechanical coupling, for example a positive coupling through gear wheels.  
         [0032]    It is advantageous in regard to the driving of the transfer cylinder  04  that, in this way, there is a definite flow of torque or moments from the drive motor  06  to the transfer cylinder  04 , to the forme cylinder  03  and to the drive linkage for an ink unit, which may optionally be provided.  
         [0033]    Together with a third cylinder  08  or  09 , which may be, for example a satellite cylinder  08 , such as, for example a steel cylinder  08 , or a second transfer cylinder  09 , the first transfer cylinder  04  of the first cylinder pair  02  constitutes a printing location  11 , where the two cylinders  04  and  08 , or  09 , act together in a print-on position through a web that is running between the cylinders  04  and  08 , or  04  and  09 , for example a web of material to be imprinted such as a paper web. In a print-on position, this third cylinder  08  serves as a backstop and vice versa. The drive mechanism of the first pair of cooperating cylinders  02  and a drive for the third cylinder  08 , or  09  can be connected with each other by use of a switchable mechanical coupling  12 , for example by use of a switchable connector  12 .  
         [0034]    In a first group of preferred embodiments, in each three-cylinder group, as depicted in FIGS. 1, 2,  3  and  4 , the third cylinder  08 ,  09  is embodied as a satellite cylinder  08 . In the first case, the printing unit  01  represents, for example, a three-cylinder color deck, or a part of a larger printing system with counter-pressure cylinders  08  embodied as satellite cylinders.  
         [0035]    In the first preferred exemplary embodiment of FIG. 1, the third cylinder  08  is embodied without its own drive mechanism. The drive motor  06  of the first cylinder pair  02  drives the transfer cylinder  03 , which drives the forme cylinder  04  by friction.  
         [0036]    The cylinders  03 ,  04 , and  08  or  09  each have journals  13 ,  14 , 16  or  17  arranged on the drive side, which journals are seated on both faces of a frame wall  18 , for example a housing wall  18 . Gear wheels  19  and  21  are respectively arranged, fixed against relative rotation, on the drive side end of the journal  13  of the forme cylinder  03 , as well as of the journal  14  of the transfer cylinder  04 . These gear wheels  19  and  21  are in engagement in such a way that a solid mechanical coupling between the cooperating forme cylinder  03  and transfer cylinder  04  exists.  
         [0037]    The gear wheel  21  of the transfer cylinder  04  can be driven directly, or via a gear  22 , such as, for example a pinion gear  22  of the drive motor  06  and, together with the gear wheel  19 , constitutes a fixed drive linkage  23  for the first pair of cooperating cylinders  02 . A second gear wheel  24  is rotatably seated on the journal  14  of the transfer cylinder  04 . By use of the switchable coupling  12  gear wheel  21  can be selectively connected, fixed against relative rotation, with the journal  14 . This gear wheel  24  positively engages a gear wheel  26  or  27  which is arranged, fixed against relative rotation, on the journal  16  or  17  of the third cylinder  08 ,  09 , respectively. The common drive motor  06  preferably is arranged, fixed in place in respect to the frame wall  18 , for example on a housing wall  28 , or its own frame. If the cylinder  04  is pivotably seated, for example by the use of eccentric bushings, the common drive motor  06  can also be arranged fixed in place in relation to the transfer cylinder  04  to be driven, or the pinion gear  22  and gear wheel  21 , which are in engagement with each other, can be provided with sufficient play. The third cylinder  08 ,  09  can be stopped independently of the first pair  02  by releasing the coupling  12 , or is movable in a further drive linkage, not represented, while the pair  02  is movable, and can be braked or accelerated again, for example to accomplish for a printing forme or rubber blanket change, for pre-inking or for washing, independently of the third cylinder  08 ,  09 . With the coupling  12  engaged, the third cylinder  08 ,  09  can be driven mechanically and synchronously with respect to the pair of cooperating cylinders  02 . With a drawn-in web in particular, it is possible to set up one of the cylinders  03 ,  04 , or the inking unit, without the web being conveyed.  
         [0038]    In the second preferred embodiment of FIG. 2, the arrangement in FIG. 1 has an additional, second drive motor  29 , which meshes, via a third gear  31 , which is, for example a pinion gear  31 , with the second gear wheel  24 , which can be selectively connected, fixed against relative rotation, on the journal  14 . In comparison with the first preferred embodiment, the third cylinder  08 , 09  of the second embodiment can additionally be independently driven when the coupling  12  is released. With the coupling  12  engaged, a common, redundant, drive by both drive motors  06  and  29  is possible.  
         [0039]    In contrast to FIGS. 1 and 2 a third preferred embodiment, as seen in FIG. 3, has the switchable coupling  12  and the cooperating, rotatably seated second gear wheel  24  on the journal  16 ,  17  of the third cylinder  08 ,  09 , respectively. Via the associated drive motor pinion gear  22 , the drive motor  06  drives the second gear wheel  24 , which is seated so it can selectively be fixed in place and is in engagement with the gear wheel  21  of the transfer cylinder  04  which, in turn, is in engagement with the gear wheel  19  of the forme cylinder  03 . With the coupling  12  released, the drive motor  06 , together with the gear wheels  24 ,  21  and  19 , constitutes the fixed drive linkage  23 . By engaging the coupling  13 , the satellite cylinder  08  can also be driven. As indicated in dashed lines in FIG. 3, the journal  16 ,  17  can have a further or fourth gear wheel  33 , which is arranged fixed against relative rotation and which meshes, for example, with a gear wheel, that is not specifically represented, of a further cylinder or drive linkage.  
         [0040]    [0040]FIG. 4 shows a fourth preferred embodiment of the present invention which is a further development of the third preferred embodiment represented in FIG. 3. Besides the rotatably seated second gear wheel  24 , the journal  16 ,  17  of the third cylinder  08 ,  09  has a fifth, rotatably seated gear wheel  34 . This can be selectively connected, fixed against relative rotation, with the journal  16 ,  17  by use of a switchable coupling  36 , for example a second connector  36 , arranged on the journal  16 ,  17 . As also represented in FIG. 4, the gear wheel  34  can be driven via the pinion or third gear  31  by the second drive motor  29 , similar to the second preferred embodiment. The fifth, rotatably seated gear wheel  34  for example also meshes with a gear wheel  37 , shown in dashed lines, of a further cylinder or drive linkage, not specifically represented. By use of the two couplings  12 ,  36  it is selectively possible to independently drive all cylinders  03 ,  04 ,  08  or  02  by both drive motors  06 ,  29  together, or the first pair of cooperating cylinders  02  and the third cylinder  08 ,  09  if required, together with a further drive linkage.  
         [0041]    In a second group of preferred embodiments, which are shown in FIGS. 5 and 6, the third cylinder  08 ,  09 , which cooperates with the first pair of cooperating cylinders  02 , is embodied as a second transfer cylinder  09  and cooperates, in turn, with a second cylinder  38 , for example a second forme cylinder  38 . By way of example and differing from the preferred first to fourth embodiments for the three-cylinder printing unit  01 , FIGS. 5 and 6 show two advantageous embodiments for linking the drive from the second transfer cylinder  09  to the cooperating second forme cylinder  38  of a four-cylinder printing unit  39 .  
         [0042]    In the fifth preferred embodiment, as shown in FIG. 5, the second forme cylinder  38  has a gear wheel  42  seated, fixed against relative rotation, on its journal  41 , which second forme cylinder gear wheel  42  meshes with the gear wheel  27  of the second transfer cylinder  09  and is in a fixed drive linkage with it.  
         [0043]    Referring now to FIG. 6, in the sixth preferred embodiment of the present invention, the journal  41  of the second transfer cylinder has a rotatably seated gear wheel  43 , which can be selectively coupled, fixed against relative rotation, on the journal  41  via a switchable coupling  44 , for example a connector  44 , arranged on the journal  41 .  
         [0044]    The embodiments represented in FIGS. 3 and 4 are also possible for the drive configuration of the first pair of cooperating cylinders  02 , together with the second transfer cylinder  09 .  
         [0045]    In a third group of preferred embodiments which are shown in FIGS.  7  to  9  for a five-cylinder printing unit  46 , for example as a semi-satellite, the third cylinder  08 , which cooperates with the first cylinder pair  02 , is embodied, the same as in the first group, as a satellite cylinder  08  which, however, cooperates with a second pair  47  of cylinders  48 ,  49 , for example a second transfer cylinder  48  and a second forme cylinder  49 .  
         [0046]    For the two cylinder pairs  02 ,  47 , the arrangement represented in FIG. 7 results, with the second cylinder pair  47  being laterally reversed in respect to the satellite cylinder  08 , from the arrangement in accordance with the first preferred embodiment, as shown in FIG. 1. The cylinders  48 ,  49  of the second cylinder pair  47  also have journals  51 ,  52 , respectively assigned to the drive side and seated in the frame wall  18 . Gear wheels  54 ,  53  are arranged, fixed against relative rotation, on the drive side of the journal  52  of the second forme cylinder  49 , as well as the drive side of the journal  51  of the second transfer cylinder  48 , and are in engagement with each other in such a way that a solid coupling exists between the cooperating second forme cylinder  49  and the second transfer cylinder  48 . The gear wheel  53  of the second transfer cylinder  48  is driven via a gear  56 , for example a pinion gear  56  of the second cylinder pair drive motor  57 , and constitutes a fixed drive linkage  58  for the second cylinder pair  47 . A second gear wheel  59 , analogous to the second gear wheel  24 , is rotatably seated on the journal  51  of the second transfer cylinder  48  which, however, can be selectively connected, fixed against relative rotation, with the second transfer cylinder journal  51  by operation of a switchable coupling  61 , for example a connector  61 . The same as the gear wheel  24  of the first pair of cooperating cylinders  02 , this gear wheel  59  positively engages the satellite cylinder gear wheel  27 , which gear wheel  27  is arranged, fixed against relative rotation, on the journal  16  of the satellite cylinder  08 . The drive motor  57  is also preferably arranged to be stationary in respect to the frame wall  18  or  28 .  
         [0047]    In contrast to FIG. 7, the eighth preferred embodiment in accordance with FIG. 8 has the arrangement represented in FIG. 3, but without a gear wheel  33 , arranged fixed against relative rotation, and with the second cooperating pair of cylinders  47  laterally reversed in respect to the satellite cylinder  08 , but on a second drive level. The journal  16  of the satellite cylinder  08  has both switchable couplings  12  and  61 , as well as the cooperating gear wheel  24  and  59 , which are rotatably seated on the journal  16 . With the coupling  12  or  61  released, the drive motor  06 ,  57 , together with the gear wheels  19  and  21 , or  54  and  53 , as well as the pinion gears  22  or  56 , constitutes the fixed drive linkage  23  or  58 . The satellite cylinder  08  can be driven by engaging the coupling  12  and/or  61 . In the two preferred embodiments in accordance with FIGS. 7 and 8, it is also possible to drive all cylinders  03 ,  04 ,  08 ,  48 ,  49  by operation of one or both drive motors  06 ,  57 .  
         [0048]    The variation which is indicated in dashed lines in FIG. 8 is one wherein, instead of the drive motor  57  with associated pinion gear  56 , a drive motor  62  directly drives the journal  16  of the satellite cylinder  08 . This leads to a further possibility for the realization a fixed coupling of a pair  02  with a drive motor  06 , wherein the pair  02  can be selectively coupled to the third cylinder  08 .  
         [0049]    A five-cylinder printing unit  46  is represented in FIG. 9, in which the drive of the first forme cylinder  03 , the first transfer cylinder  04  and the satellite cylinder  08  takes place by use of the two drive motors  06 ,  57  and the coupling  12  in accordance with FIGS.  2  or  5 . The gear wheel  27 , which is seated, fixed against relative rotation, on the journal  16  of the satellite cylinder  08 , meshes with a gear wheel  53 , which is also arranged, fixed against relative rotation, on the journal  51  of the second transfer cylinder  48  and which itself meshes with the gear wheel  54  arranged on the journal  52  of the second forme cylinder  49 . With this configuration the coupling  61  from FIGS.  7  or  8  is omitted and results in a fixed drive linkage  58  between the satellite cylinder  08 , the second transfer cylinder  48  and the second forme cylinder  49 . As shown by way of example in FIGS. 8 and 9, the drive linkages  23  and  58  must be arranged on different levels.  
         [0050]    The solutions represented in the preferred nine exemplary embodiments depict basic configurations, which can be standardized, also for the flexible configuration of larger cylinder connections, such as Y or lambda embodied six- or seven-cylinder printing units, or configurations of nine- or ten-cylinder printing units that may be embodied as a satellite unit or satellite system.  
         [0051]    The driving of the gear wheels  21 ,  24 ,  53 ,  59 , disclosed in the preferred embodiments and as represented in FIGS.  1  to  9 , by the use of drive motors  06 ,  57  via associated gears  22 ,  31  or  56 , embodied as pinion gears  22 ,  32  or  56 , can also take place in a different way. For example, the gear wheels  21 ,  24 ,  53 ,  59  can also be driven by the respective drive motors  06 ,  57  by drive belts. It is also possible to drive the journal  14 ,  16 ,  17 ,  51 , which, in the drawings, is driven respectively via the pinion gears  22 ,  31  or  56  and the cooperating gear wheel  21 ,  24 ,  53 ,  59 , directly by use of the rotor of a drive motor  06 ,  57 , possibly coupled by the interposition of a joint. Such a direct drive can take place, by way of example, in the variation represented in dashed lines in FIG. 8 by operation of the drive motor  62  for the journal  16 .  
         [0052]    While preferred embodiments of a printing unit comprising a drive system that is coupled in a fixed manner 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 sizes of the cylinders, the specific nature of the couplings 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.