Patent Publication Number: US-2002002916-A1

Title: Printing press

Description:
BACKGROUND OF THE INVENTION  
       [0001] 1. Field of the Invention  
       [0002] This invention relates to a printing press which can efficiently perform both of offset printing and screen printing on the same sheet-like material.  
       [0003] 2. Description of the Related Art  
       [0004] To perform both of offset printing and screen printing on the same sheet-like material, the sheet-like material is printed by a printing press using one of the printing methods, and then the sheet-like material is transferred to a printing press using the other printing method, and printed thereby. Execution of these two types of printing on the same sheet-like material requires much labor for transfer and registration of the sheet-like material, resulting in poor operation efficiency.  
       SUMMARY OF THE INVENTION  
       [0005] The present invention has been accomplished to solve the above-described problem. It is an object of the invention to provide a printing press which can efficiently perform both of offset printing and screen printing on the same sheet-like material.  
       [0006] According to the present invention, there is provided a printing press comprising an offset rotary printing unit for offset printing a sheet-like material, and a rotary screen printing unit for screen printing the sheet-like material, and wherein the offset rotary printing unit and the rotary screen printing unit are connected together so that offset printing and screen printing can be continuously performed on the same sheet-like material.  
       [0007] In the above printing press, the rotary screen printing unit may include a rotatable impression cylinder having a gripper for holding the sheet-like material, and a rotatable rotary screen contacting the impression cylinder for screen printing the sheet-like material held on the impression cylinder, and wherein a rotatable transfer cylinder may connect the impression cylinder of the rotary screen printing unit to the offset rotary printing unit, the diametrical dimension of the impression cylinder of the rotary screen printing unit may be set such that the gripper of the impression cylinder is buried inwardly of the outer peripheral surface of the impression cylinder when the gripper holds the sheet-like material, and the diametrical dimension of the transfer cylinder may be set such that the sheet-like material can be transferred between the impression cylinder of the rotary screen printing unit and the offset rotary printing unit.  
       [0008] In the above printing press, the rotary screen printing unit may include a rotatable impression cylinder having sheet-like material holding means for holding the sheet-like material, and a rotary screen contacting the impression cylinder for screen printing the sheet-like material held on the impression cylinder, and wherein the sheet-like material holding means of the impression cylinder of the rotary screen printing unit may comprise suction holding means for sucking and holding the sheet-like material.  
       [0009] In the printing press, the suction holding means may include a suction holding implement provided in a gap of the outer peripheral surface of the impression cylinder, and having a suction port on the surface of the suction holding implement, suction means connected to the suction holding implement, and switching means provided between the suction holding implement and the suction means and adapted to establish communication between the suction holding implement and the suction means when receiving the sheet-like material and block communication between the suction holding implement and the suction means when transferring the sheet-like material.  
       [0010] In the printing press, a plurality of the suction holding implements may be provided along the axial direction of the impression cylinder, and opening/closing means for opening and closing the suction port of the suction holding implement may be provided for each of the suction holding implements.  
       [0011] In the printing press according to the present invention, the offset rotary printing unit and the rotary screen printing unit are connected together so that offset printing and screen printing can be continuously performed on the same sheet-like material. Thus, transfer of the sheet-like material between offset printing and screen printing, and registration of the sheet-like material in each of these types of printing become unnecessary, so that the operation efficiency can be increased. 
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0012] The present invention will become more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not limitative of the present invention, and wherein:  
     [0013]FIG. 1 is an overall schematic configuration view of a first embodiment of a printing press according to the present invention;  
     [0014]FIG. 2 is an extracted enlarged view of a portion indicated by an arrow II in FIG. 1;  
     [0015]FIG. 3 is an extracted enlarged view of a portion indicated by an arrow III in FIG. 1;  
     [0016]FIG. 4 is an extracted enlarged view of a portion indicated by an arrow IV in FIG. 3;  
     [0017]FIG. 5 is an extracted enlarged view of a portion indicated by an arrow V in FIG. 3;  
     [0018]FIG. 6 is an overall schematic configuration view of another example of the first embodiment of the printing press according to the present invention;  
     [0019]FIG. 7 is an overall schematic configuration view of still another example of the first embodiment of the printing press according to the present invention;  
     [0020]FIG. 8 is an overall schematic configuration view of a further example of the first embodiment of the printing press according to the present invention;  
     [0021]FIG. 9 is an overall schematic configuration view of a still further example of the first embodiment of the printing press according to the present invention;  
     [0022]FIG. 10 is an overall schematic configuration view of an additional example of the first embodiment of the printing press according to the present invention;  
     [0023]FIG. 11 is an overall schematic configuration view of a second embodiment of a printing press according to the present invention;  
     [0024]FIG. 12 is an extracted enlarged view of a portion indicated by an arrow XII in FIG. 11;  
     [0025]FIG. 13 is an extracted enlarged view of an end portion of a shaft of an impression cylinder of a screen printing unit;  
     [0026]FIG. 14 is a sectional view of FIG. 13;  
     [0027]FIG. 15 is a view taken from the direction of an arrow XV in FIG. 14;  
     [0028]FIG. 16 is a sectional view taken on line XVI-XVI in FIG. 14;  
     [0029]FIG. 17 is a sectional view taken on line XVII-XVII in FIG. 14;  
     [0030]FIG. 18 is an extracted enlarged view of a portion indicated by an arrow XVIII in FIG. 12;  
     [0031]FIG. 19 is a view taken from the direction of an arrow XIX in FIG. 18;  
     [0032]FIG. 20 is an internal structure view of a portion indicated by an arrow XX in FIG. 19;  
     [0033]FIG. 21 is an overall schematic configuration view of another example of the second embodiment of the printing press according to the present invention; and  
     [0034]FIG. 22 is an overall schematic configuration view of still another example of the second embodiment of the printing press according to the present invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
     [0035] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, but they in no way limit the invention.  
     [0036] [First Embodiment] 
     [0037] A first embodiment of a printing press according to the present invention will be described using FIGS.  1  to  5 . FIG. 1 is an overall schematic configuration view of the printing press. FIG. 2 is an extracted enlarged view of a portion indicated by an arrow II in FIG. 1. FIG. 3 is an extracted enlarged view of a portion indicated by an arrow III in FIG. 1. FIG. 4 is an extracted enlarged view of a portion indicated by an arrow IV in FIG. 3. FIG. 5 is an extracted enlarged view of a portion indicated by an arrow V in FIG. 3.  
     [0038] As shown in FIG. 1, a feeder stand  11  is provided in a feeder unit  10 . The feeder unit  10  is provided with a feeder board  12  for feeding sheet-like materials, i.e., sheets  1 , on the feeder stand  11  one by one to a printing unit  20 . A swing arm shaft pregripper  13  for passing the sheet  1  on to an impression cylinder  21   a  of a first offset printing unit  20   a  of the printing unit  20  is provided at a front end of the feeder board  12 .  
     [0039] As shown in FIGS. 1 and 2, a blanket cylinder  22   a  contacts a portion of the impression cylinder  21   a  of the first offset printing unit  20   a  of the printing unit  20  downstream from the swing arm shaft pregripper  13  in the rotating direction of the impression cylinder  21   a . A plate cylinder  23   a  contacts a portion of the blanket cylinder  22   a  upstream from the impression cylinder  21   a  in the rotating direction of the blanket cylinder  22   a . An inking device  24   a  is provided upstream from the blanket cylinder  22   a  in the rotating direction of the plate cylinder  23   a . A dampening device  25   a  is provided upstream from the inking device  24   a  in the rotating direction of the plate cylinder  23   a.    
     [0040] As shown in FIG. 1, a portion of the impression cylinder  21   a  of the first offset printing unit  20   a  downstream from the blanket cylinder  22   a  in the rotating direction of the impression cylinder  21   a  contacts an impression cylinder  21   b  of a second offset printing unit  20   b  via a transfer cylinder  26   a . The second offset printing unit  20   b , like the first offset printing unit  20   a , includes a blanket cylinder  22   b , a plate cylinder  23   b , an inking device  24   b , and a dampening device  25   b.    
     [0041] A portion of the impression cylinder  21   b  of the second offset printing unit  20   b  downstream from the blanket cylinder  22   b  in the rotating direction of the impression cylinder  21   b  contacts an impression cylinder  21   c  of a third offset printing unit  20   c  via a transfer cylinder  26   b . The third offset printing unit  20   c , like the first and second offset printing units  20   a  and  20   b , includes a blanket cylinder  22   c , a plate cylinder  23   c , an inking device  24   c , and a dampening device  25   c.    
     [0042] A portion of the impression cylinder  21   c  of the third offset printing unit  20   c  downstream from the blanket cylinder  22   c  in the rotating direction of the impression cylinder  21   c  contacts an impression cylinder  21   d  of a fourth offset printing unit  20   d  via a transfer cylinder  26   c . The fourth offset printing unit  20   d , like the first to third offset printing units  20   a  to  20   c , includes a blanket cylinder  22   d , a plate cylinder  23   d , an inking device  24   d , and a dampening device  25   d . These first to fourth offset printing units  20   a  to  20   d  constitute an offset rotary printing unit in the present embodiment.  
     [0043] As shown in FIGS. 1 and 3, a transfer cylinder  26   d  contacts a portion of the impression cylinder  21   d  of the fourth offset printing unit  20   d  downstream from the blanket cylinder  22   d  in the rotating direction of the impression cylinder  21   d . Only the diametrical dimension of the transfer cylinder  26   d  is smaller than that of the other transfer cylinders  26   a  to  26   c  by a predetermined value. An impression cylinder  21   e  of a screen printing unit  20   e  as a rotary screen printing unit contacts a portion of the transfer cylinder  26   d  downstream from the impression cylinder  21   d  in the rotating direction of the transfer cylinder  26   d . Only the diametrical dimension of the impression cylinder  21   e  is larger than that of the other impression cylinders  21   a  to  21   d  by a predetermined value.  
     [0044] That is, as shown in FIG. 4, the distance between a gripper pad  21   ea  and the cylinder axis, the distance between a gripper holder  21   eb  and the cylinder axis, and the distance between a gripper  21   ec  and the cylinder axis in the impression cylinder  21   e  of the screen printing unit  20   e  are the same as those in the other impression cylinders  21   a  to  21   d  of an ordinary size. However, the distance between the outer peripheral surface (effective impression area) of the impression cylinder  21   e  and the axis of the cylinder (accordingly, the diametrical dimension) is set to be greater than that of the other impression cylinders  21   a  to  21   d  of an ordinary size (the size indicated by two-dot chain lines in FIGS. 4 and 5) so that when the gripper  21   ec  is closed (i.e., when the gripper  21   ec  holds the sheet  1 ), the gripper  21   ec  is buried inwardly of the outer peripheral surface of the impression cylinder  21   e . On the other hand, the distance between a gripper pad  26   da  and the axis, the distance between a gripper holder  26   db  and the axis, and the distance between a gripper  26   dc  and the axis in the transfer cylinder  26   d  are the same as those in the other transfer cylinders  26   a  to  26   c  of an ordinary size. However, the distance between the outer peripheral surface of the transfer cylinder  26   d  and the axis of the cylinder (accordingly, the diametrical dimension) is set to be smaller than the other transfer cylinders  26   a  to  26   c  of an ordinary size (the size indicated by two-dot chain lines in FIG. 4) so that the transfer cylinder  26   d  does not interfere with the outer peripheral surface of the impression cylinder  21   e , in other words, the transfer cylinder  26   d  can transfer the sheet  1  to the impression cylinder  21   e . Thus, the sheet  1  can be transferred, without problems, between the impression cylinder  21   d  of the fourth offset printing unit  20   d  and the transfer cylinder  26   d . Furthermore, the sheet  1  can be transferred, without problems and without interference, between the transfer cylinder  26   d  and the impression cylinder  21   e  of the screen printing unit  20   e.    
     [0045] As shown in FIGS. 1 and 5, a rotary screen  27  contacts a portion of the impression cylinder  21   e  of the screen printing unit  20   e  downstream from the transfer cylinder  26   d  in the rotating direction of the impression cylinder  21   e . The rotary screen  27  includes a hollow cylinder  27   a  comprising a rotatably supported cylindrical thin screen of stainless steel, nickel or the like having small holes corresponding to a pattern etched therein, and an ink fountain  27   b  and a squeegee  27   c  fixed to and supported by a frame inside the hollow cylinder  27   a . That is, in the rotary screen  27 , the hollow cylinder  27   a  is rotated in accordance with the rotation of the impression cylinder  21   e , and special ink or the like, a liquid in the ink fountain  27   b , is pushed out through the small holes of the hollow cylinder  27   a  by the squeegee  27   c . Thus, the rotary screen  27  can perform printing, corresponding to the small holes of the hollow cylinder  27   a , on the sheet  1  held on the impression cylinder  21   e.    
     [0046] As shown in FIG. 1, a transfer cylinder  26   e  contacts a portion of the impression cylinder  21   e  of the screen printing unit  20   e  downstream from the rotary screen  27  in the rotating direction of the impression cylinder  21   e . The transfer cylinder  26   e  has the same prescribed dimensions as the transfer cylinder  26   d . Thus, the sheet  1  can be transferred, without problems and without interference, between the impression cylinder  21   e  of the screen printing unit  20   e  and the transfer cylinder  26   e , as in the relation between the impression cylinder  21   e  and the transfer cylinder  26   d.    
     [0047] A transport cylinder  28  of a drying unit  20   f  contacts a portion of the transfer cylinder  26   e  downstream from the impression cylinder  21   e  in the rotating direction of the transfer cylinder  26   e . The transfer cylinder  26   e  and the transport cylinder  28  are designed such that the sheet  1  can be transferred therebetween without problems. A drying lamp  29  for applying ultraviolet radiation (UV) is disposed along a portion of the transport cylinder  28  downstream from the transfer cylinder  26   e  in the rotating direction of the transport cylinder  28 .  
     [0048] A delivery cylinder  31  of a delivery unit  30  contacts a portion of the transport cylinder  28  of the drying unit  20   f  downstream from the drying lamp  29  in the rotating direction of the transport cylinder  28 . In the delivery cylinder  31 , a sprocket  32  is provided so as to be integrally rotatable coaxially with the delivery cylinder  31 . A delivery stand  35  is provided in the delivery unit  30 . A sprocket  33  is provided above the delivery stand  35 . A delivery chain  34  having a plurality of delivery grippers (not shown) attached thereto at predetermined intervals is looped between the sprockets  32  and  33 .  
     [0049] The actions of the printing press constituted as described above will be described. Sheets  1  are dispatched one by one from the feeder stand  11  of the feeder unit  10  onto the feeder board  12 . The sheet  1  is then transferred by the swing arm shaft pregripper  13  to the impression cylinder  21   a  of the first offset printing unit  20   a  of the printing unit  20 . Separately, ink and dampening water are supplied to the plate cylinder  23   a  from the inking device  24   a  and the dampening device  25   a  of the first offset printing unit  20   a , and supplied from the plate cylinder  23   a  to the blanket cylinder  22   a . The ink is transferred from the blanket cylinder  22   a  onto the sheet  1 , whereby the sheet  1  is printed in a first color. Then, the sheet  1  is passed on to the impression cylinder  21   b  of the second offset printing unit  20   b  via the transfer cylinder  26   a , whereupon the sheet  1  is printed in a second color in the second offset printing unit  20   b  in the same manner as in the first offset printing unit  20   a . Subsequently, the sheet  1  is printed in a third color and a fourth color in the third and fourth offset printing units  20   c  and  20   d  in the same manner as described above.  
     [0050] The sheet  1 , which has been printed in the fourth color in the fourth offset printing unit  20   d , is passed on to the transfer cylinder  26   d  from the impression cylinder  21   d . At this time, a larger gap than usual is formed between the outer peripheral surface of the impression cylinder  21   d  and the outer peripheral surface of the transfer cylinder  26   d . However, the distance between the gripper pad  26   da  and the cylinder axis, the distance between the gripper holder  26   db  and the cylinder axis, and the distance between the gripper  26   dc  and the cylinder axis in the transfer cylinder  26   d  are the same as those in the other transfer cylinders  26   a  to  26   c  of an ordinary size. Thus, the sheet can be passed on to the transfer cylinder  26   d  from the impression cylinder  21   d  without problems.  
     [0051] The sheet  1  passed on to the transfer cylinder  26   d  is transferred to the impression cylinder  21   e  of the screen printing unit  20   e . At this time, the diametrical dimension of the impression cylinder  21   e  is larger than the ordinary dimension indicated by the two-dot chain lines in FIG. 4. However, the diametrical dimension of the transfer cylinder  26   d  is smaller than the ordinary dimension, indicated by the two-dot chain lines in FIGS. 4 and 5, in response to the diametrical dimension of the impression cylinder  21   e . Also, the distance from the axis to the gripper device in each of the transfer cylinder  26   d  and the impression cylinder  21   e , which comprises the gripper pads  26   da ,  21   ea , gripper holders  26   db ,  21   eb , and grippers  26   dc ,  21   ec , is the same as that in the other cylinders  26   a  to  26   c  and  21   a  to  21   d . Thus, the sheet  1  can be transferred from the transfer cylinder  26   d  to the impression cylinder  21   e  without problems.  
     [0052] The sheet  1  transferred to the impression cylinder  21   e  of the screen printing unit  20   e  is printed with special ink or the like to a large thickness from the rotary screen  27  in the manner described earlier. At this time, the distance between the outer peripheral surface (effective impression area) of the impression cylinder  21   e  and the axis (accordingly, the diametrical dimension) is set such that when the gripper  21   ec  is closed (when the gripper  21   ec  holds the sheet  1 ), the gripper  21   ec  is buried inwardly of the outer peripheral surface of the impression cylinder  21   e . Thus, the gripper  21   ec  of the impression cylinder  21   e  does not interfere with the rotary screen  27 .  
     [0053] The sheet  1 , printed with special ink or the like to a large thickness, is passed on to the transfer cylinder  26   e  from the impression cylinder  21   e . At this time, the diametrical dimension of the impression cylinder  21   e  is greater, while the diametrical dimension of the transfer cylinder  26   e  is smaller like the transfer cylinder  26   d . Also, the distance from the axis to the gripper device in each of the transfer cylinder  26   e  and the impression cylinder  21   e  is the same as that in the other cylinders  26   a  to  26   d  and  21   a  to  21   d . Thus, the sheet  1  can be transferred from the impression cylinder  21   e  to the transfer cylinder  26   e  without problems.  
     [0054] The sheet  1  passed on to the transfer cylinder  26   e  is transferred to the transport cylinder  28  of the drying unit  20   f . At this time, a greater gap than usual occurs between the outer peripheral surface of the transfer cylinder  26   e  and the outer peripheral surface of the transport cylinder  28 . However, the distance between the gripper device of the transfer cylinder  26   e  and the cylinder axis is the same as that in the other transfer cylinders  26   a  to  26   c  of an ordinary size. Thus, the sheet  1  can be transferred from the transfer cylinder  26   e  to the transport cylinder  28  without being pinched between the transfer cylinder  26   e  and the transport cylinder  28 .  
     [0055] The sheet  1 , held on the transport cylinder  28  of the drying unit  20   f , has the printed special ink or the like dried with ultraviolet radiation from the drying lamp  29 . Then, the sheet  1  is passed on to the delivery cylinder  31  of the delivery unit  30 , carried via the delivery grippers during traveling movement of the delivery chain  34 , and discharged onto the delivery stand  35 .  
     [0056] In the foregoing printing press, the distance between the outer peripheral surface (effective impression area) of the impression cylinder  21   e  of the screen printing unit  20   e  and the cylinder axis (accordingly, the diametrical dimension) is set such that when the gripper  21   ec  of the impression cylinder  21   e  is closed (when the gripper  21   ec  holds the sheet  1 ), the gripper  21   ec  is buried inwardly of the outer peripheral surface of the impression cylinder  21   e . Thus, the gripper  21   ec  of the impression cylinder  21   e  does not interfere with the rotary screen  27 . Consequently, the sheet  1  can be satisfactorily printed with the special ink or the like to a large thickness by the rotary screen  27 .  
     [0057] Furthermore, the diametrical dimensions of the transfer cylinders  26   d ,  26   e  for transfer of the sheet  1  to and from the impression cylinder  21   e  of the screen printing unit  20   e  are set to be small in response to the diametrical dimension of the impression cylinder  21   e  being set at a large value. Also, the distance between the axis and the gripper device in each of the transfer cylinders  26   d  and  26   e  is rendered the same as that in the other transfer cylinders  26   a  to  26   c . Thus, transfer of the sheet  1  between the transfer cylinders  26   d ,  26   e  and the impression cylinder  21   e  can be carried out without problems. Besides, transfer of the sheet  1  can also be performed, without problems, between the transfer cylinders  26   d ,  26   e  and the impression cylinder  21   d  and transport cylinder  28  serving for transfer to and from these cylinders  26   d ,  26   e.    
     [0058] That is, the first to fourth offset printing units  20   a  to  20   d , the screen printing unit  20   e , and the delivery unit  30  are connected together uninterruptedly by constituting the impression cylinder  21   e  of the screen printing unit  20   e  in the above-described manner, and the transfer cylinders  26   d ,  26   e  contacting the impression cylinder  21   e  in the above-described manner. According to the so constituted printing press, offset printing and screen printing can be performed continuously on the same sheet  1 . Thus, transfer of the sheet  1  between offset printing and screen printing, and registration of the sheet  1  in each of these types of printing become unnecessary, so that the operation efficiency can be increased.  
     [0059] In the present embodiment, the screen printing unit  20   e  and the drying unit  20   f  are disposed downstream from the first to fourth offset printing units  20   a  to  20   d . However, the screen printing unit  20   e  and the drying unit  20   f  may be disposed upstream from the first to fourth offset printing units  20   a  to  20   d , as shown in FIG. 6. Alternatively, the screen printing unit  20   e  and the drying unit  20   f  may be disposed between the first to second offset printing units  20   a  to  20   b  and the third to fourth offset printing units  20   c  to  20   d , as shown in FIG. 7. According to the present embodiment, moreover, the rotary screen  27  and the impression cylinder  21   e  directly contact each other. However, a blanket cylinder  22   e  maybe interposed between the rotary screen  27  and the impression cylinder  21   e , as shown in FIGS.  8  to  10 .  
     [0060] [Second Embodiment] 
     [0061] A second embodiment of a printing press according to the present invention will be described using FIGS.  11  to  20 . FIG. 11 is an overall schematic configuration view of the printing press. FIG. 12 is an extracted enlarged view of a portion indicated by an arrow XII in FIG. 11. FIG. 13 is an extracted enlarged view of an end portion of a shaft of an impression cylinder of a screen printing unit. FIG. 14 is a sectional view of FIG. 13. FIG. 15 is a view taken from the direction of an arrow XV in FIG. 14. FIG. 16 is a sectional view taken on line XVI-XVI in FIG. 14. FIG. 17 is a sectional view taken on line XVII-XVII in FIG. 14. FIG. 18 is an extracted enlarged view of a portion indicated by an arrow XVIII in FIG. 12. FIG. 19 is a view taken from the direction of an arrow XIX in FIG. 18. FIG. 20 is an internal structure view of a portion indicated by an arrow XX in FIG. 19. In these drawings, the same portions as in the aforementioned First Embodiment will be assigned the same numerals as used in the descriptions of the First Embodiment, and their explanations will be omitted.  
     [0062] As shown in FIGS. 11 and 12, a transfer cylinder  126   d  having the same prescribed dimensions as the aforementioned transfer cylinders  26   a  to  26   c  contacts a portion of an impression cylinder  21   d  of a fourth offset printing unit  20   d  downstream from a blanket cylinder  22   d  in the rotating direction of the impression cylinder  21   d . An impression cylinder  100  of a screen printing unit  20   e  contacts the transfer cylinder  126   d . The impression cylinder  100  has a structure as described below.  
     [0063] As shown in FIGS. 13 and 14, an end portion of a rotary shaft  103  is rotatably supported by a frame  20   ea  of the screen printing unit  20   e  via a locking ring  101  and a bearing  102 . Inside the rotary shaft  103 , a communication hole  103   a  is formed along an axial direction. To a shaft end of the rotary shaft  103 , a connecting shaft  104  is attached coaxially. Inside the connecting shaft  104 , a plurality of (two in the present embodiment) communication holes  104   c  are formed along the axial direction. The communication hole  104   c  is connected at one end to the interior of the communication hole  103   a  of the rotary shaft  103  via a pipe  105 , and is closed at the other end.  
     [0064] Near the other end of an outer peripheral surface of the connecting shaft  104 , a coupling hole  104   a  connected to the communication hole  104   c  is formed at a prescribed position in a circumferential direction of the connecting shaft  104 . Near one end of the outer peripheral surface of the connecting shaft  104 , a coupling hole  104   b  connected to the communication hole  104   c  is formed at a prescribed position in the circumferential direction of the connecting shaft  104  (see FIGS. 16 and 17).  
     [0065] To an end portion of the locking ring  101  beside the connecting shaft  104 , one end portion of an outer tube  107  surrounding the connecting shaft  104  is connected and fixed via a connecting implement  106  coaxially with the connecting shaft  104 . In a peripheral surface of the outer tube  107 , coupling holes  107   a ,  107   b  for ensuring communication between the inside and the outside of the outer tube  107  are formed at prescribed positions in a circumferential direction of the outer tube  107  (see FIGS. 14 and 15).  
     [0066] Between the outer tube  107  and the connecting shaft  104 , a sleeve  108  is inserted coaxially with the connecting shaft  104  and the outer tube  107 . The sleeve  108  is fixed to and supported by the outer tube  107 , and supports the connecting shaft  104  rotatably. In a peripheral surface of the sleeve  108 , a coupling groove  108   a  and a coupling groove  108   b  are formed with predetermined lengths at prescribed positions in a circumferential direction of the sleeve  108  (see FIGS.  14 ,  16  and  17 ). The coupling groove  108   a  couples the coupling hole  104   a  of the connecting shaft  104  to the coupling hole  107   a  of the outer tube  107  with a prescribed cycle in accordance with the rotation of the connecting shaft  104 . Similarly, the coupling groove  108   b  couples the coupling hole  104   b  of the connecting shaft  104  to the coupling hole  107   b  of the outer tube  107  with a prescribed cycle in accordance with the rotation of the connecting shaft  104 .  
     [0067] To the coupling hole  107   a  of the outer tube  107 , a suction pump (not shown) is coupled via a hose  109 . To the coupling hole  107   b  of the outer tube  107 , an air muffler  110  is coupled. That is, when the rotary shaft  103  is rotated to rotate the connecting shaft  104  and the suction pump is actuated, the communication holes  104   c  of the connecting shaft  104  communicate with the coupling grooves  108   a  of the sleeve  108  via the coupling hole  104   a  with the prescribed cycle, and communicate with the suction pump via the coupling hole  107   a  of the outer tube  107 , whereby air inside them is sucked. On the other hand, the communication holes  104   c  communicate with the coupling groove  108   b  of the sleeve  108  via the coupling hole  104   b  with the prescribed cycle, and communicate with the air muffler  110  via the coupling hole  107   b  of the outer tube  107 , whereby the pressure inside them is returned to the outside air pressure.  
     [0068] As shown in FIGS. 12 and 18, a cylinder body  111  is integrally connected to and supported by the rotary shaft  103  via spokes  112  coaxially with the rotary shaft  103 . In an outer peripheral surface of the cylinder body  111 , a plurality of (two in the present embodiment) gaps  111   a  extending along an axial direction of the cylinder body  111  are formed at equal intervals along a circumferential direction of the cylinder body  111 .  
     [0069] As shown in FIGS.  18  to  20 , a piping  113  having a plurality of communication holes  113   a  (holes for communication between the inside and the outside) formed with predetermined spacing along an axial direction in a peripheral surface of the piping  113  is mounted in the gap  111   a  of the cylinder body  111  so as to have its axial direction heading along the axial direction of the cylinder body  111 . A holder  114  is mounted to the site of the communication hole  113   a  of the piping  113 . A circular mounting groove  114   b  is formed on the upper surface of the holder  114 . A communication hole  114   a  communicating with the communication hole  113   a  of the piping  113  is formed in the mounting groove  114   b  of the holder  114 . An opening/closing plate  116  for opening and closing the communication hole  114   a  upon rotation of a screw  115  is provided in the mounting groove  114   b  of the holder  114 . A head  117 , which is a suction holding implement of a plate shape having a hole for allowing the head of the screw  115  to protrude therethrough, is mounted on an upper portion of the holder  114 . A suction port  117   a  communicating with the communication hole  114   a  of the holder  114  is formed on the upper surface of the head  117 .  
     [0070] As shown in FIGS. 18 and 19, one end portion of a pipe  118  is coupled to a peripheral surface of the piping  113 . One end portion of a hose  119  is coupled to the other end portion of the pipe  118 . The other end portion of the hose  119  is inserted into the communication hole  103   a  of the rotary shaft  103 , and connected to the pipe  105  (see FIGS.  12  to  14 ).  
     [0071] In detail, when the rotary shaft  103  is rotated to rotate the connecting shaft  104  and the suction pump is actuated, the interior of the piping  113  coupled via the pipe  105 , hose  119  and pipe  118  is sucked from the communication hole  104   c  which communicates with the coupling hole  104   a  of the connecting shaft  104 , when the coupling hole  104   a  communicates with the coupling groove  108   a  of the sleeve  108 . Then, air is sucked from the suction port  117   a  of the head  117  through the communication hole  113   a  of the piping  113  and the communication hole  114   a  of the holder  114 . Furthermore, when the coupling hole  104   b  of the connecting shaft  104  communicates with the coupling groove  108   b  of the sleeve  108 , the communication hole  104   c  communicating with the coupling hole  104   b  communicates with the interior of the piping  113  connected via the pipe  105 , hose  119  and pipe  118 . As a result, the suction port  117   a  of the head  117  and the air muffler  110  enter into communication via the communication hole  113   a  of the piping  113  and the communication hole  114   a  of the holder  114 . Consequently, the portion between the suction port  117   a  and the air muffler  110  is returned to the atmospheric pressure. Further, when the screw  115  is rotated to open and close the communication hole  114   a  of the holder  114  with the opening/closing plate  116 , the suction port  117   a  of the head  117  can be opened and closed individually. Thus, regardless of whether the coupling hole  104   a  of the connecting shaft  104  and the coupling groove  108   a  of the sleeve  108  are coupled together or not, suction of air from the suction port  117   a  of the head  117  can be set for each head  117 .  
     [0072] In the present embodiment, the connecting shaft  104 , outer tube  107 , and sleeve  108  constitute switching means; the pipes  105 ,  118 , hoses  109 ,  119 , piping  113  and suction pump constitute suction means; the holder  114 , screw  115  and opening/closing plate  116  constitute opening/closing means; and the switching means, suction means, opening/closing means, and head  117  (suction holding implement) constitute suction holding means as sheet-like material holding means.  
     [0073] As shown in FIGS. 11 and 12, a rotary screen  27  contacts a portion of the impression cylinder  100  of the screen printing unit  20   e  downstream from the transfer cylinder  126   d  in the rotating direction of the impression cylinder  100 . A transfer cylinder  126   e  of the same prescribed size as the transfer cylinders  26   a  to  26   c  contacts a portion of the impression cylinder  100  of the screen printing unit  20   e  downstream from the rotary screen  27  in the rotating direction of the impression cylinder  100 .  
     [0074] In the so constituted printing press, when a gripper device  126   d   1  of the transfer cylinder  126   d  having received the sheet  1  approaches the head  117  of the impression cylinder  100  of the screen printing unit  20   e , the coupling hole  104   b  of the connecting shaft  104  communicating with the suction port  117   a  of the head  117  leaves the coupling groove  108   b  of the sleeve  108 . Thus, the communication between the air muffler  110  and the communication hole  104   c  of the connecting shaft  104  is cut off. Also, the coupling hole  104   a  of the connecting shaft  104  communicating with the suction port  117   a  of the head  117  enters into communication with the coupling groove  108   a  of the sleeve  108 . By the action of the suction pump, air is sucked from the suction port  117   a  of the head  117 . At the same time, the gripper device  126   d   1  of the transfer cylinder  126   d  releases a grip on the sheet  1 . Hence, the sheet  1  is sucked to and held by the head  117  of the impression cylinder  100 , and passed from the transfer cylinder  126   d  on to the impression cylinder  100 .  
     [0075] The sheet  1  transferred to the impression cylinder  100  of the screen printing unit  20   e  is printed with special ink or the like to a large thickness from the rotary screen  27  in the same manner as in the aforementioned embodiment. On this occasion, the impression cylinder  100  holds the sheet  1  by the suction force of the head  117 , and lacks a member (such as a gripper) protruding from the surface of the cylinder body  111 . Thus, the impression cylinder  100  does not interfere with the rotary screen  27 .  
     [0076] After thick printing on the sheet  1  by the rotary screen  27 , the head  117  of the impression cylinder  100  approaches a gripper device  126   e   1  of the transfer cylinder  126   e . At this time, the gripper device  126   e   1  of the transfer cylinder  126   e  grips the sheet  1 , and the coupling hole  104   a  of the connecting shaft  104  in communication with the suction port  117   a  of the head  117  leaves the coupling groove  108   a  of the sleeve  108 . Thus, the communication with the suction pump is cut off, and suction of air from the suction port  117   a  of the head  117  is stopped. Also, the coupling hole  104   b  of the connecting shaft  104  in communication with the suction port  117   a  of the head  117  communicates with the coupling groove  108   b  of the sleeve  108 . As a result, the portion between the air muffler  110  and the suction port  117   a  of the head  117  is returned to the atmospheric pressure. Thus, the sheet  1  is released from suction holding by the head  117  of the impression cylinder  100 , and is passed from the impression cylinder  100  on to the transfer cylinder  126   e.    
     [0077] That is, according to the present embodiment, the first to fourth offset printing units  20   a  to  20   d , the screen printing unit  20   e , and the delivery unit  30  can be connected together uninterruptedly by constituting the impression cylinder  100  of the screen printing unit  20   e  in the above-described manner. In the above-described printing press, the impression cylinder  100  of the screen printing unit  20   e  does not interfere with the rotary screen  27  or the transfer cylinders  126   d ,  126   e . Hence, thick printing with special ink or the like by the rotary screen  27 , and transfer of the sheet  1  from and to the transfer cylinders  126   d  and  126   e  can be performed without problems. According to the so constituted printing press, therefore, offset printing and screen printing can be performed continuously on the same sheet  1  in the same manner as in the aforementioned First Embodiment. Thus, transfer of the sheet  1  between offset printing and screen printing, and registration of the sheet  1  in each of these types of printing become unnecessary, so that the operation efficiency can be increased. Furthermore, if any one of all heads  117  takes no part in the attraction and holding of the sheet  1  depending on the size in the width direction of the sheet  1 , the screw  115  of the head  117  that plays no role in the attraction and holding of the sheet  1  is rotated to close the suction port  117   a  of the head  117  with the opening/closing plate  116 . By so doing, the suction force can be increased without waste of suction by the suction pump.  
     [0078] In the present embodiment, each of the opening/closing plates  116  in the mounting grooves  114   a  of the holders  114  provided in the gap  111   a  of the cylinder body  111  of the impression cylinder  100  is turned by the screw  115 , whereby the suction range corresponding to the size of the sheet  1  is set. Instead of the opening/closing plate  116 , screw  115 , etc., the other end portion of the hose  119  may be bifurcated and directly connected to the holder  114 , and opening/closing valves may be provided at the branches of the bifurcated end portion of the hose  119 . By so doing, the presence or absence of suction through the head  117  can be set. If it is designed that the presence or absence of suction through the heads  117 , which are located at an equal distance from the center in the width direction of the sheet  1 , can be set by the same opening/closing valve, time and effort taken for setting can be halved.  
     [0079] In the present embodiment, moreover, the screen printing unit  20   e  and the drying unit  20   f  are disposed downstream from the first to fourth offset printing units  20   a  to  20   d . However, the screen printing unit  20   e  and the drying unit  20   f  may be disposed upstream from the first to fourth offset printing units  20   a  to  20   d , as shown in FIG. 21. Alternatively, the screen printing unit  20   e  and the drying unit  20   f  may be disposed between the first to second offset printing units  20   a  to  20   b  and the third to fourth offset printing units  20   c  to  20   d , as shown in FIG. 22.  
     [0080] In the aforementioned first and second embodiments, the printing press, having only the offset printing units  20   a  to  20   d  and screen printing unit  20   e  connected together uninterruptedly, is described. In this printing press, a gravure printing unit and a flexographic printing unit may be further connected to these printing units.  
     [0081] While the present invention has been described in the foregoing fashion, it is to be understood that the invention is not limited thereby, but may be varied in many other ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the appended claims.