Patent Publication Number: US-9427951-B2

Title: Printing press

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a printing press. 
     The Sammeldruck printing method is known as a special printing method capable of performing multicolor printing at once by applying inks of a plurality of colors to separate portions of one plate surface. A related Sammeldruck printing press that executes the Sammeldruck printing method is, e.g., one having an arrangement as shown in  FIG. 5 . 
     A Sammeldruck printing press  21  shown in  FIG. 5  is an apparatus that performs Sammeldruck printing on a sheet  22 , and includes a printing unit  23 . The sheet  22  is transported on a transport path  26  constituted by an impression cylinder  24  of the printing unit  23  and a transport cylinder  25  in contact with the impression cylinder  24 . 
     The printing unit  23  includes the impression cylinder  24 , a blanket cylinder  28  in contact with the impression cylinder  24 , a collecting plate cylinder  29  in contact with the blanket cylinder  28 , a collecting blanket cylinder  30  in contact with the collecting plate cylinder  29 , two partial plate cylinders  31  in contact with the collecting blanket cylinder  30 , and two inking devices  32  that supply ink to the partial plate cylinders  31 . A printing configuration having the cylinder array of the impression cylinder  24 , the blanket cylinder  28 , the collecting plate cylinder  29 , the collecting blanket cylinder  30 , and the plurality of partial plate cylinders  31  is called a Sammeldruck configuration. In the Sammeldruck printing press  21 , a dry offset plate  33  and dry offset plates  34  are mounted on the collecting plate cylinder  29  and the two partial plate cylinders  31  in the Sammeldruck configuration, respectively. 
     In Sammeldruck printing by the Sammeldruck printing press  21 , a plurality of colors are printed on the same drawing line without misregistration, and a drawing line whose color changes midway can be printed. Sammeldruck printing has a feature in which no misregistration occurs, and is often employed to prevent forgery of printing products. A printing press employing Sammeldruck printing is disclosed in, e.g., Japanese Patent Laid-Open No. 2013-86437. 
     Printing presses as described above are strongly requested to perform more advanced forgery prevention printing. 
     SUMMARY OF THE INVENTION 
     The present invention has been made to meet this demand, and has as its object to provide a printing press capable of performing more advanced forgery prevention printing. 
     To achieve the above object, according to the present invention, there is provided a printing press comprising an impression cylinder which holds and transports a sheet, a blanket cylinder which is in contact with the impression cylinder and on which a first blanket is mounted, a collecting plate cylinder which is in contact with the blanket cylinder and on which a first plate including a lithographic printing plate is mounted, a collecting blanket cylinder which is in contact with the collecting plate cylinder and on which a second blanket is mounted, a plurality of partial plate cylinders which are in contact with the collecting blanket cylinder and on which a plurality of second plates are mounted, respectively, a plurality of inking devices which correspond to the plurality of partial plate cylinders and supply ink to the plurality of partial plate cylinders, respectively, and a dampening unit which supplies dampening water to the collecting plate cylinder. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side view showing a printing press according to an embodiment of the present invention; 
         FIG. 2  is a side view showing a dampening unit; 
         FIG. 3  is a partial sectional view showing a state in which the dampening unit is exploded when viewed two-dimensionally; 
         FIG. 4  is a partial sectional view showing a state in which the dampening unit is exploded when viewed two-dimensionally; and 
         FIG. 5  is a side view showing a Sammeldruck printing press related to the present invention. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     A printing press according to an embodiment of the present invention will now be described in detail with reference to  FIG. 1 . A printing press  41  shown in  FIG. 1  is an apparatus that performs printing on the two surfaces of a sheet  42 , and includes a first printing unit  43  shown on the upper part of  FIG. 1 , and a second printing unit  44  shown on the lower part of  FIG. 1 . The first printing unit  43  and the second printing unit  44  are printing units each having a Sammeldruck configuration, and take the same configuration. Thus, in the following explanation of the first printing unit  43  and second printing unit  44 , the same reference numerals denote parts having the same functions, and a repetitive description for each printing unit will be omitted. The “Sammeldruck configuration” is a printing configuration having a cylinder array constituted by first and second impression cylinders  48  and  49 , a blanket cylinder  51  serving as the first blanket cylinder, a collecting plate cylinder  52 , a collecting blanket cylinder  53 , and a plurality of partial plate cylinders  55 , which will be described later. 
     The sheet  42  is transported on a transport path  45  provided between the first printing unit  43  and the second printing unit  44 . The transport path  45  is constituted by the first impression cylinder  48  and second impression cylinder  49  that are positioned between a first transport cylinders  46  positioned upstream in the transport direction and a second transport cylinders  47  positioned downstream in the transport direction. The first transport cylinder  46  is in contact with the first impression cylinder  48 , the first impression cylinder  48  is in contact with the second impression cylinder  49 , and the second impression cylinder  49  is in contact with the second transport cylinder  47 . The sheet  42  is sequentially held by the first transport cylinder  46 , the first impression cylinder  48 , the second impression cylinder  49 , and the second transport cylinder  47 , and transported from right to left in  FIG. 1 . Although not shown, the first and second transport cylinders  46  and  47  and the first and second impression cylinders  48  and  49  that constitute the transport path  45  include gripper devices for transferring the sheet  42 . 
     The blanket cylinder  51  constituting part of the first printing unit  43  is in contact with the upper portion of the first impression cylinder  48  positioned upstream in the transport direction, out of the first impression cylinder  48  and the second impression cylinder  49 . The blanket cylinder  51  constituting part of the second printing unit  44  is in contact with the lower portion of the second impression cylinder  49 . A blanket  51   a  serving as the first blanket is mounted on the outer surface portion of the blanket cylinder  51 . Ink is transferred from the collecting plate cylinder  52  (to be described later) to the blanket  51   a.    
     The collecting plate cylinder  52  is in contact with the blanket cylinder  51 . A printing plate  52   a  serving as the first plate including a lithographic printing plate is mounted on the outer surface portion of the collecting plate cylinder  52 . As the printing plate  52   a , a so-called PS plate is used. The collecting plate cylinder  52  in the embodiment allows mounting a resin relief printing plate or a waterless lithographic printing plate instead of a lithographic printing plate. 
     A dampening unit  54  is connected to the collecting plate cylinder  52 . The dampening unit  54  supplies dampening water to the collecting plate cylinder  52  on which the lithographic printing plate is mounted. The dampening unit  54  in this embodiment has a structure in which dampening water is supplied to the collecting plate cylinder  52  via a plurality of rollers from a water pan  54   a  in which dampening water is stored. A water fountain roller  54   b  positioned in the water pan  54   a , a metering roller  54   c , an oscillating roller  54   d , and a form roller  54   e  are arranged and provided in the order named between the water pan  54   a  and the collecting plate cylinder  52 . A rider roller  54   f  is in contact with the form roller  54   e . The form roller  54   e  supplies dampening water to the collecting plate cylinder  52  by contact with the collecting plate cylinder  52 . When a resin relief printing plate or a waterless lithographic printing plate is mounted on the collecting plate cylinder  52 , the dampening unit  54  can be configured to separate the form roller  54   e  from the collecting plate cylinder  52  so as not to supply dampening water to the collecting plate cylinder  52 . 
     The collecting blanket cylinder  53  is in contact with the collecting plate cylinder  52 . A blanket  53   a  serving as the second blanket is mounted on the outer surface portion of the collecting blanket cylinder  53 . Ink is transferred from the two partial plate cylinders  55  (to be described later) to the blanket  53   a.    
     The two partial plate cylinders  55  are in contact with the collecting blanket cylinder  53 . Printing plates  55   a  each serving as the second plate including a resin relief printing plate or a waterless lithographic printing plate are mounted on the two partial plate cylinders  55 , respectively. 
     Inking devices  56  are connected to the partial plate cylinders  55 , respectively. That is, the inking device  56  is provided for each partial plate cylinder  55 . The two inking devices  56  supply inks of different colors to the two partial plate cylinders  55 . 
     A case in which the printing press  41  performs Sammeldruck printing will be explained. Inks of different colors are supplied from the two inking devices  56  to the two partial plate cylinders  55 , and the inks are transferred from the partial plate cylinders  55  to the collecting blanket cylinders  53 . At this time, no dampening water is supplied to the partial plate cylinders  55 , and only the inks from the inking devices  56  are supplied. When the inks are transferred from the collecting blanket cylinders  53  to the PS plates of the collecting plate cylinders  52 , and dampening water is supplied from the dampening units  54  to the PS plates, drawing lines whose color changes midway are formed on the PS plates. The drawing lines formed on the collecting plate cylinders  52  are transferred to the blanket cylinders  51 . The PS plate used for the collecting plate cylinder  52  can decrease the width of a drawing line, in comparison with a relief printing plate used in a related Sammeldruck printing press. According to this embodiment, ink can be transferred from the collecting plate cylinder  52  to the blanket cylinder  51  so as to print a thinner drawing line than that by the related Sammeldruck printing press. 
     When the sheet  42  passes between the blanket cylinder  51  of the first printing unit  43  and the first impression cylinder  48  in a state in which the ink has been transferred to the blanket cylinder  51 , Sammeldruck printing is performed on one surface of the sheet  42 . After printing on one surface, the sheet  42  is transferred from the first impression cylinder  48  to the second impression cylinder  49 , and passes between the second impression cylinder  49  and the blanket cylinder  51  of the second printing unit  44 . When the sheet  42  passes between the second impression cylinder  49  and the blanket cylinder  51  of the second printing unit  44 , Sammeldruck printing is performed on the other surface of the sheet  42 . 
     The printing press  41  can perform even conventional Sammeldruck printing by mounting a dry offset plate such as a resin relief printing plate or a waterless lithographic printing plate on the collecting plate cylinder  52 , and separating the form roller  54   e  from the collecting plate cylinder  52  so as not to supply dampening water from the dampening unit  54  to the collecting plate cylinder  52 . In addition, the printing press  41  can print a plurality of drawing lines at separate positions different from those in Sammeldruck printing by mounting a lithographic printing plate or a dry offset plate on the collecting plate cylinder  52 . 
     Next, the structure of the dampening unit  54  will be further explained with reference to  FIGS. 2 to 4 . The water fountain roller  54   b  is dipped in dampening water stored in the water pan  54   a . The metering roller  54   c  contacts the water fountain roller  54   b . The metering roller  54   c  can change the contact pressure with respect to the water fountain roller  54   b.    
     The metering roller  54   c  contacts the oscillating roller  54   d . The oscillating roller  54   d  is supported by a frame. A lever support lever  112  is rotatably provided at the end portion of a shaft  111  of the oscillating roller  54   d . The lever support lever  112  extends to the upper side of the end portion of the shaft  111 . A pin shaft  113  is fixed in the middle of the lever support lever  112 . A form roller support lever  114  is pivotally attached to the pin shaft  113 . 
     The form roller  54   e  held by a holder  114   a  is supported at one end of the form roller support lever  114 .  FIG. 2  shows a state in which the form roller  54   e  is separated from the collecting plate cylinder  52 . A lever mechanism  100  is constituted by the form roller support lever  114  and the lever support lever  112 . The lever mechanism  100  supports the form roller  54   e  so that the form roller  54   e  can come into contact with the collecting plate cylinder  52  and separate from the collecting plate cylinder  52 . The lever mechanism  100  can be formed by one lever or more than two levers. 
     A pin shaft  115  is provided to extend through the other end portion of the form roller support lever  114 . A bracket  116  is provided on the bottom side of the lever support lever  112 . A rod  117  is interposed between an externally projecting portion of the pin shaft  115  and the bracket  116 . An end portion of the rod  117  on the side of the bracket  116  is connected to the bracket  116  by a pin  118 . The rod  117  extends upward through the pin shaft  115 . A collar  119  is fitted on the rod  117  on the upper side of the pin shaft  115 . Further, a fastening nut  120  and a locknut  121  are screwed at the screw portion of the upper end portion of the rod  117 . A spring seat  117   b  is formed at a portion of the rod  117  on the side of the bracket  116 . A spring  122  is provided between the spring seat  117   b  and the pin shaft  115 . By the spring force of the spring  122 , the form roller  54   e  is pressed against the oscillating roller  54   d  via the form roller support lever  114 . The nip pressure between the form roller  54   e  and the oscillating roller  54   d  is adjusted by changing the fastening position of the fastening nut  120  and locknut  121  and changing the biasing force of the spring  122 . 
     A twist follow-up lever  123  is coaxially supported by the shaft  111  of the oscillating roller  54   d . The twist follow-up lever  123  is engaged with a twist follow-up cam  124  provided coaxially with the collecting plate cylinder  52 . The lever support lever  112  and the form roller support lever  114  are operated from the twist follow-up cam  124  via the twist follow-up lever  123  with respect to a twist of the collecting plate cylinder  52 , and the form roller  54   e  follows up the twist of the collecting plate cylinder  52 . 
     A bolt shank  126  is interposed via a spring  125  between the end portion of the twist follow-up lever  123  and the upper end portion of the form roller support lever  114 . A nut  127  is screwed in the screw portion of the bolt shank  126  extending through the upper end portion of the form roller support lever  114 . The twist follow-up lever  123  is pressed against the twist follow-up cam  124  by the biasing force of the spring  125 . The nip pressure of the form roller  54   e  with respect to the collecting plate cylinder  52  is adjusted by changing the projection amount of the bolt shank  126  from the lever support lever  112  by the nut  127 . 
     A connecting rod  132  connected to a rod  131  of a throw-on and throw-off form roller cylinder (air cylinder)  130  fixed on the frame side is connected by a pin  133  to a portion of the form roller support lever  114  that extends upward. By the operation of the throw-on and throw-off form roller cylinder  130 , the form roller support lever  114  and the lever support lever  112  pivot about the shaft center of the oscillating roller  54   d  to bring the form roller  54   e  into contact with the collecting plate cylinder  52  or separate the form roller  54   e  from the collecting plate cylinder  52 . Note that a stopper bracket  134  is provided on the outer surface of the bottom portion of the lever support lever  112 . The stopper bracket  134  hits against a stationary stopper  135  to limit the pivot amount of the lever support lever  112 . 
     The rear end portion of a doglegged rider roller support lever  136  is pivotally attached to the inner portion of the pin shaft  115  at the rear end of the form roller support lever  114 . The rider roller  54   f  is supported by a holder  137  at the distal end portion of the rider roller support lever  136 . The rider roller  54   f  contacts the form roller  54   e  and reciprocates in the shaft direction. Since the rider roller  54   f  reciprocates, an ink accumulation film generated on the form roller  54   e  is spread to suppress emulsification accumulation and prevent contamination of printing products. 
     A throw-on and throw-off rider roller cylinder (air cylinder)  139  is pivotally supported by a pin shaft  138  at the upper end portion of the form roller support lever  114 . A connecting rod  141  connected to a piston rod  140  of the throw-on and throw-off rider roller cylinder  139  is connected to the middle of the rider roller support lever  136  by a pin  142 . When the throw-on and throw-off rider roller cylinder  139  extends, the rider roller support lever  136  pivots toward the form roller  54   e  and the rider roller  54   f  contacts the form roller  54   e.    
     The throw-on and throw-off rider roller cylinder  139  is a double rod air cylinder. Nuts  143  and  144  are screwed in a portion of the piston rod  140  that projects from the rear portion of a cylinder main body  139   a . By changing the positions of the nuts  143  and  144  to adjust the stroke of the piston rod  140 , the nip pressure of the rider roller  54   f  with respect to the form roller  54   e  is adjusted. 
     Next, the operation of the dampening unit  54  will be explained. When performing printing in a state in which dampening water is supplied to the collecting plate cylinder  52 , the throw-on and throw-off form roller cylinder  130  extends, i.e., operates to the pressing side to bring the collecting plate cylinder  52  and the form roller  54   e  into contact with each other, and the form roller  54   e  and the oscillating roller  54   d  into contact with each other. The throw-on and throw-off rider roller cylinder  139  also extends to bring the rider roller  54   f  into contact with the form roller  54   e.    
     When performing printing in a state in which no dampening water is supplied to the collecting plate cylinder  52 , the throw-on and throw-off form roller cylinder  130  contracts, i.e., operates to the pulling side. By the contacting operation of the throw-on and throw-off form roller cylinder  130 , the form roller support lever  114  and the lever support lever  112  rotate about the shaft center of the oscillating roller  54   d , and the form roller  54   e  is separated from the collecting plate cylinder  52 . The stopper bracket  134  of the lever support lever  112  hits against the stopper  135 , and the lever support lever  112  stops. However, the form roller support lever  114  further rotates about the pin shaft  113  on the lever support lever  112 , and the form roller  54   e  is separated from the oscillating roller  54   d.    
     When, for example, cleaning the form roller  54   e , the throw-on and throw-off rider roller cylinder  139  further contracts, the rider roller support lever  136  pivots about the pin shaft  115  at the rear end portion of the form roller support lever  114 , and the rider roller  54   f  is separated from the form roller  54   e . As a result, a space for cleaning or the like is formed above the form roller  54   e , facilitating cleaning of the form roller  54   e , inspection, and the like. 
     In the dampening unit  54 , the rider roller support lever  136  is pivotally supported on the form roller support lever  114 . Thus, the form roller  54   e  follows up a twist of the collecting plate cylinder  52 , as described above, and the rider roller  54   f  also follows up the form roller  54   e . That is, the nip pressure between the form roller  54   e  and the rider roller  54   f  does not change in any state and the performance is not degraded. 
     With the dampening unit  54 , printing in a state in which dampening water is supplied to the collecting plate cylinder  52 , and printing in a state in which no dampening water is supplied to the collecting plate cylinder  52  can be switched by bringing the form roller  54   e  into contact with the collecting plate cylinder  52  and separating the form roller  54   e  from the collecting plate cylinder  52 . A switching mechanism  61  that implements this function is mainly constituted by the lever mechanism  110  and the throw-on and throw-off form roller cylinder  130  serving as an actuator connected to the lever mechanism  110 . 
     Next, the effects of this embodiment will be explained. The printing plate  52   a  of the collecting plate cylinder  52  is a lithographic printing plate, and the printing press  41  according to this embodiment includes the dampening unit  54  that supplies dampening water to the collecting plate cylinder  52 . The printing press  41  can perform, on the sheet  42 , printing of a very fine pattern or design exploiting the feature of lithographic printing using dampening water. For example, the printing press  41  can even print, on the sheet  42 , an extra fine line whose color changes midway. This embodiment can therefore provide a printing press capable of performing more advanced forgery prevention printing on the sheet  42 . 
     In this embodiment, a relief printing plate can be used as the printing plate  55   a  of the partial plate cylinder  55 . Since ink can be transferred to the collecting blanket cylinder  53  with high accuracy, a finer drawing line can be printed on the sheet  42 . Although this embodiment has explained an example in which the two partial plate cylinders  55  are provided, three or more partial plate cylinders  55  may also be provided. In this case, a plurality of printing plates  55   a  are mounted on the plurality of partial plate cylinders  55 , respectively. Also, a plurality of inking devices  56  are provided in correspondence with the respective partial plate cylinders  55 . 
     Although not shown, the printing press  41  according to this embodiment can be connected to another printing press and used. That is, the printing press  41  can be connected to the downstream end portion of another printing press or can be connected to the upstream end portion of another printing press. The printing press  41  can also be provided between a plurality of other printing presses. The other printing presses are, for example, an intaglio printing press and an alternate double-sided offset printing press. 
     Although this embodiment has described the printing press  41  that performs Sammeldruck printing on the two surfaces of the sheet  42 , the present invention is not limited to this. That is, the present invention is applicable to even a printing press that performs Sammeldruck printing on only one surface of the sheet  42 .