Abstract:
A drive for a rotary printing press makes a reliable transmission of high torques possible and, with low structural expenditure, setting of the phase in the main drive gear train. In the drive for a rotary printing press, two adjacent transfer drums are mounted with shaft journals in side walls, a gearwheel of the gearwheel mechanism is disposed fixedly in terms of rotation on the shaft journals and the gearwheels are not in direct engagement with one another. The gearwheels of the adjacent transfer drums are permanently in engagement in each case with one intermediate gear. The gearwheels of the adjacent transfer drums and the intermediate gears are kept at a spacing from one another in each case with one lever. The intermediate gears are kept at a spacing in each case from one another with a coupler. The coupler can be disconnected and the engagement of the teeth of the intermediate gears can be canceled.

Description:
CROSS-REFERENCE TO RELATED APPLICATION  
       [0001]    This application claims the priority, under 35 U.S.C. §119, of German application DE 10 2006 016 758.9, filed Apr. 10, 2006; the prior application is herewith incorporated by reference in its entirety. 
       BACKGROUND OF THE INVENTION  
     Field of the Invention  
       [0002]    The invention relates to a drive for a rotary printing press. The drive has a gearwheel mechanism for transmitting a rotational movement of transfer drums during transport of a printing material, a coupler in the gearwheel mechanism for producing and interrupting a transmission of torque, and at least one motor for feeding a torque into the gearwheel mechanism. 
         [0003]    Sheet-fed printing presses having a plurality of printing units in an inline construction are known, in which impression cylinders and drums which convey the sheets are driven by way of a gearwheel mechanism. The cylinders and drums are held rotatably in bearings by way of shaft journals in side walls. Gearwheels of the gearwheel mechanism are disposed fixedly in terms of rotation on the shaft journals. The gearwheels form a main drive gear train, into which a torque is fed by a motor during printing. During printing, the cylinders and drums have a defined rotational phase position, with the result that the sheets which are held in grippers can be transferred in register from a cylinder or a drum to a cylinder or an adjacent drum which lies downstream. 
         [0004]    Sheet-fed printing presses are known, the operating type of which can be set optionally to printing on only one side or to printing on both sides of the sheets. In order to set printing on both sides, a turner apparatus is actuated in the conveying path of the sheets. The rotational phase positions of the cylinders and drums differ during printing on only one side and in perfecter operation. Published, non-prosecuted German patent application DE 42 23 189 A1, corresponding to U.S. Pat. No. 5,398,606, discloses an apparatus which makes it possible to disengage the main drive gear train and to set the rotational phase of the cylinders and drums ahead of a turner apparatus with respect to the rotational phase position of the cylinders and drums after the turner apparatus to the desired operating type. The apparatus contains a coupling which can disconnect a gearwheel from the shaft journal of a turner drum. The coupling is configured as a friction coupling, friction faces of the gearwheel which can be disconnected and a gearwheel which is connected fixedly in terms of rotation to the shaft journal are pressed against one another during printing by a spring assembly. The gearwheel which can be disconnected and the gearwheel which is connected fixedly in terms of rotation to the shaft journal are permanently in engagement with the gearwheels of an adjacent storage drum and an impression cylinder. 
         [0005]    The torques which can be transmitted in the main drive gear train are limited by the construction of the gearwheels, the connection to the shaft journals and by couplings. In particular in machines with a large number of printing units and large sheet formats which are to be printed, static and dynamic torques occur which can lead to a failure of the coupling. If the coupling fails, the rotational phase position of the printing units changes, with the result that printing errors are produced or, in the extreme case, grippers collide with drum bodies. 
         [0006]    Published, non-prosecuted German patent application DE 102 02 385 A1 discloses a printing unit, in which intermediate gearwheels which are connected to a coupler are provided for changing the angular position between a printing form cylinder and a blanket cylinder, which intermediate gearwheels are in engagement with one another and with the drive gearwheels of the printing form cylinder and the blanket cylinder. The drive gearwheels of the printing form cylinder and the blanket cylinder are kept in each case at a spacing with respect to the respective intermediate gearwheel by a coupler. The coupler between the intermediate gearwheels can be moved by way of an actuator in order to set the angular position. The movement range of the coupler is limited, with the result that only small changes in the angular position can be set. 
         [0007]    In a printing press according to published, non-prosecuted German patent application DE 39 03 093 A1, a storage drum and a turner drum are disposed parallel to the sheet feed during printing on only one side of the sheets, for turning of sheets. The storage drum and the turner drum are connected to a coupler. The storage drum and the turner drum are connected in each case by way of a swinging arm to a transfer drum and an impression cylinder. During printing on only one side of the sheets, the storage drum and the turner drum are thrown off. The swinging arms and the coupler are disposed pivotably in order to set different sheet formats and in order to adjust the gripper opening cams. As a result of the parallel configuration of the turner apparatus, it is not necessary to decouple the sheet-guiding cylinders which are disposed behind the turner apparatus and to adjust their rotary position. 
       SUMMARY OF THE INVENTION  
       [0008]    It is accordingly an object of the invention to provide a drive for a rotary printing press that overcomes the above-mentioned disadvantages of the prior art device of this general type, which drive makes reliable transmission of high torques possible and, with low structural expenditure, sets the phase in the main drive gear train. 
         [0009]    With the foregoing and other objects in view there is provided, in accordance with the invention, a drive for a rotary printing press. The rotary printing press has side walls, two adjacent transfer drums, and shaft journals mounting the two adjacent transfer drums in the side walls. The drive contains a gearwheel mechanism for transmitting a rotational movement of the transfer drums during transport of a printing material, a coupler disposed in the gearwheel mechanism for producing and interrupting a transmission of torque, at least one motor for feeding the torque into the gearwheel mechanism, levers, and intermediate gears having teeth. The gearwheel mechanism has gearwheels, each of the gearwheels is disposed fixedly in terms of rotation on one of the shaft journals and the gearwheels are not in direct engagement with one another. Each of the gearwheels for the adjacent transfer drums are permanently in engagement in each case with one of the intermediate gears. The gearwheels for the adjacent transfer drums and the intermediate gears are kept at a spacing from one another in each case with one of the levers. The intermediate gears are kept at a spacing in each case from one another with the coupler. The coupler can be disconnected and an engagement of the teeth of the intermediate gears can be canceled. 
         [0010]    According to the invention, gearwheels of adjacent transfer drums are not in engagement with one another, but are in engagement permanently with intermediate gears. The intermediate gears are in engagement with one another permanently. The gearwheels of the transfer drums and those of the intermediate gears are kept at a spacing by way of levers. The intermediate gears are kept at a spacing by way of a coupler. The coupler can be disengaged, with the result that the teeth of the gearwheels of the intermediate gears can be moved out of engagement and the rotational angle position of the transfer drums with respect to one another can be set. When the coupler is active between the intermediate gears, the levers and the coupler can be moved by way of a positioning apparatus, with the result that precision setting is possible of the rotational phase between the transfer drums. 
         [0011]    The invention can be used, in particular, in sheet-fed rotary printing presses, where a storage drum and a turner drum are driven in a main drive gear train and, for changing over between printing on one side to printing on both sides of the sheets, the main drive gear train has to be disengaged temporarily for setting of the phase. A transmission of torque via the intermediate gears is reliable. The disconnection of the main drive gear train between the intermediate gears can be implemented inexpensively and requires a small amount of installation space. 
         [0012]    Other features which are considered as characteristic for the invention are set forth in the appended claims. 
         [0013]    Although the invention is illustrated and described herein as embodied in a drive for a rotary printing press, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims. 
         [0014]    The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0015]      FIG. 1  is a diagrammatic, side sectional view of a multiple-color sheet-fed printing press having a turner apparatus according to the invention; 
           [0016]      FIG. 2  is a diagrammatic, plan view of a gear mechanism for driving a storage drum and a turner drum; 
           [0017]      FIGS. 3-5  are diagrammatic illustrations for showing a setting of a phase between a storage drum and a turner drum; 
           [0018]      FIG. 6  is a diagrammatic illustration of a gearwheel mechanism for precision setting of the phase; 
           [0019]      FIG. 7  is a diagrammatic illustration of a cam mechanism for precision setting of the phase; and 
           [0020]      FIG. 8  is a diagrammatic illustration of a coupler which is divided in two for disengaging intermediate gears. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0021]    Referring now to the figures of the drawing in detail and first, particularly, to  FIG. 1  thereof, there is shown a perfector printing press having eight printing units  1 - 8  and a varnishing unit  9  for printing on sheets  10 . A feeder  12  having a suction head  13 , a creeper table  14  and swinging grippers  15  is provided for separating sheets  10  from a stack  11  and for conveying them to the first printing unit  1 . Transfer drums  16 - 49  are provided for conveying the sheets  10  through the printing press. The transfer drums  17 ,  21 ,  25 ,  29 ,  33 ,  37 ,  41 ,  45 ,  49  are configured as impression cylinders and interact with transfer cylinders  50 - 57 . The transfer cylinders  50 - 57  interact with form cylinders  58 - 65 . In the varnishing unit, the transfer drum  49  interacts directly with a form cylinder  66 . During passage through a press nip between a transfer cylinder  50  to  57  and an impression cylinder  17 ,  21 ,  25 ,  29 ,  37 ,  41 ,  45 ,  49 , the sheets  10  are printed with color separation. The color separation of a color separation image is transferred from the respective form cylinder  58 - 65  onto a transfer cylinder  50 - 57 . The color separation image is transferred from the respective transfer cylinder  50 - 57  to a surface of the sheet  10 . In the varnishing unit, the sheets  10  are given in each case a final varnish coat on that side of the sheet  10  which was printed last. All transfer drums  16 - 49  which guide sheets  10  have gripper configurations  67  for gripping a leading edge of the sheets  10 . The transfer drum  31  has additional gripper configurations  68  for holding a trailing edge of the sheet  10 . The transfer drums  16 - 49 , the transfer cylinders  50 - 57  and the form cylinders  58 - 66  are coupled to one another in a gearwheel mechanism. In order to drive the printing press, a motor  69  is provided which feeds a torque to a shaft of the transfer drum  38  via a gear mechanism  70 . The completely printed sheets  10  are conveyed onto a stack  73  in a deliverer  71  having a chain gripper system  72 . 
         [0022]    The printing press can be changed over from printing on only one side of the sheets  10  to printing on both sides. In perfecter operation, the printing units  1 - 4  serve for printing on the front side and the printing units  5 - 8  and the varnishing unit  9  serve for printing on the rear side of the sheets  10 . The transfer drums  31 ,  32  are configured between the printing units  4  and  5  as a storage drum and a turner drum. During printing on both sides, the phase positions of the gripper configurations  67 ,  68  are set in such a way that the edge which trails in the printing units  1  to  4  is conveyed further as the leading edge from the printing unit  5 . 
         [0023]    There is no direct drive connection between the drive gearwheel of the storage drum  31  and the turner drum  32 , but rather via intermediate gears  74 ,  75  which are kept at a spacing by way of a coupler  76 . The intermediate gears  74 ,  75  are assigned a coupling configuration  77  which disengages or closes the coupler  76  in order to set the phase position of the gripper configurations  67 ,  68  and brings the intermediate gears  74 ,  75  out of or into engagement. The intermediate gear  74  and the intermediate gear  75  are kept at a spacing with respect to the storage drum  31  and with respect to the turner drum  32  by swinging arms  78  and  79 . The remote-controlled coupling configuration  77  is connected to a control device  80 . Setting of the phase is carried out by way of the motor  69  or an additional adjusting motor and is monitored on the shaft of the transfer drum  46  by way of a rotary encoder  81 . The rotary encoder  81  and the motor  69  are likewise connected to the control device  80 . 
         [0024]    In printing operation, the coupling configuration  77  is closed, with the result that, starting from the motor  69  via the coupling configuration  77 , a torque is transmitted to the elements which are to be driven in the printing units  1  to  4 . 
         [0025]    In the following text, the method of operation of the intermediate gears  74 ,  75  and the coupling configuration  77  is to be described using  FIGS. 2 to 6 . If designations which have already been introduced are used in the following description, they are elements with an equivalent function. 
         [0026]    As shown in plan view in  FIG. 2 , the storage drum  31 , the turner drum  32  and the impression cylinder  33  having shaft journals  82  to  87  are mounted rotatably in side walls  88 ,  89  of the printing press. Helically toothed gearwheels  90  to  92  are disposed fixedly in terms of rotation on the shaft journals  83 ,  85 ,  87 . The gearwheels  90 ,  92  are connected to further gearwheels  93 ,  94  of the main drive gear train. The gearwheels  90 ,  91  lie in different planes and are not in engagement with one another. The gearwheel  90  is in engagement with an intermediate gear  95 , which is shown symbolically by a dashed line. The intermediate gear  95  has the diameter of the intermediate gear  91 . The intermediate gear  95  is mounted on an axle pin  96 . The shaft journal  83  and the axle pin  96  are kept at a spacing by way of the swinging arm  78 . The gearwheel  91  is in engagement with an intermediate gear  97  and is mounted on an axle pin  98 . The shaft journal  85  and the axle pin  98  are kept at a spacing by way of a swinging arm  79 . The axle pins  96 ,  98  are kept at a spacing by way of the coupler  76 . The coupler  76  is assigned the coupling configuration  77 . The axle pin  98  is coupled to a hydraulic actuator  99  which is connected to the control device  80 . 
         [0027]    During printing, the torque flow leads from the gearwheel  90  of the storage drum  31  to the intermediate gear  95 , from the intermediate gear  95  to the intermediate gear  97  and from the intermediate gear  97  to the gearwheel  91  of the turner drum  32 . The gearwheel  91  is the first gearwheel in the gearwheel train of that part of the printing press which lies behind the turner apparatus. In order that the torque can be transmitted in the gearwheel train from the plane of the gearwheel  90  into the plane of the gearwheel  91 , one of the intermediate gears  95 ,  97  has double the width. During printing, the coupler  76  is fixed on the side wall  89 . The connection of the coupler  76  to the side wall  89  can be released for a phase adjustment between the gearwheels  90  and  91 . 
         [0028]      FIGS. 3 and 4  show two different positions of the swinging arms  78 ,  79  and of the coupler  76 . The phase positions of the gearwheels  90 ,  91  and the intermediate gears  95 ,  97  are identified in each case with a phase arrow  100 . In  FIG. 3 , the phase positions are in an initial position. If the swinging arms  78 ,  79  and the coupler  76  are pivoted or pushed into the positions which are shown in  FIG. 4  by the actuator  99 , the phase positions of the gearwheel  91  and the intermediate gears  95 ,  97  are changed by an angle α with respect to the initial position. The phase position can also be set in an infinitely variable manner during printing. 
         [0029]    If the printing press is changed over from printing on one side to printing on both sides of the sheets, the phase position of the gearwheels after the turner drum  38  has to be adjusted with respect to the phase position of the gearwheels before the turner drum  32  by a relatively great amount. This relatively great amount cannot be achieved solely by pivoting of the swinging arms  78 ,  79  and by displacement of the coupler  76 . A mechanism, in particular a threaded spindle  101 , with which the length  1  of the coupler  76  can be increased, is situated on the coupler  76 . If, as shown in  FIG. 5 , the coupler  76  is extended to such an extent that the intermediate gears  95 ,  97  are out of engagement, the main drive gear train is disconnected and the phase position can be adjusted by the abovementioned relatively great amount. After the adjustment of the phase position, the length l of the coupler  76  is again reduced by way of the threaded spindle  101  to such an extent that the intermediate gears  95 ,  97  are in engagement again. In order that the intermediate gears  95 ,  97  can be brought into engagement again, the adjustment of the phase position is performed in such a way that the rotated intermediate gear  95  or  97  is rotated only by a multiple of the tooth pitch. 
         [0030]      FIGS. 6 and 7  show variants of how a precision adjustment of the phase position of the gearwheels  90 ,  91  and the intermediate gears  95 ,  97  can be performed. 
         [0031]    According to  FIG. 6 , a gearwheel mechanism is provided, containing a gearwheel  102  and a rack  103 . The rack  103  is in engagement with the gearwheel  102 . One end of the rack  103  is connected to the axle pin  98  in an articulated manner. If the gearwheel  102  is rotated, the positions of the swinging arms  78 ,  79  and the coupler  76  are changed. 
         [0032]    In the variant which is shown in  FIG. 7 , a cam mechanism having a cam  104  and a cam roller  105  is used. The cam roller  105  is mounted on the swinging arm  98 . If the cam  104  is rotated about an axle  106 , the cam roller  105  then follows the profile of the cam  104  and the swinging arm  79  is deflected. As a result of the coupling to the axle pins  96 ,  98 , the coupler  76  and the swinging arm  78  are also moved, so that a change in the rotational phase position of the intermediate gears  95 ,  96  and the gearwheels  90 ,  91  results. 
         [0033]      FIG. 8  shows one variant of how the coupler  76  can be extended or shortened. The coupler  76  contains a first coupler rod  76 . 1  and a shorter second coupler rod  76 . 2 , which are connected to a joint  107 . In each case that end of a coupler rod  76 . 1 ,  76 . 2  which faces away from the joint  107  is connected to the axle pins  98 ,  96  in an articulated manner. In order to change the coupler length l, the coupler rod  76 . 2  is rotated about the axle pin  96 . If the angle β between the coupler rods  76 . 1 ,  76 . 2  is 180°, this results in a maximum coupler length l max , at which the intermediate gears  95 ,  97  are reliably out of engagement.