Patent Publication Number: US-2015059602-A1

Title: Printing press

Description:
TECHNICAL FIELD 
     The present invention relates to a printing press capable of performing collect printing on a sheet. 
     BACKGROUND ART  
     Collect printing has been conventionally provided as a special printing method in which multi-color printing can be performed at once by partially applying inks of different colors on one plate surface. The collect printing not only has a characteristic that the color of an image line can be changed in the middle of the line without misregistration but also has a characteristic that no misalignment occurs at all. Due to these characteristics, the collect printing is employed more often in cases where anti-counterfeit of a printed product is intended. 
     A printing press employing the collect printing described above is disclosed in, for example, Patent Literature 1. 
     CITATION LIST  
     Patent Literature 
     (Patent Literature 1) Japanese Patent Application Publication No. 2003-127321 
     SUMMARY OF INVENTION 
     Technical Problem 
     In the aforementioned conventional printing press, a collect printing part capable of performing collect printing is provided. The collect printing part performs collect printing on one surface of a conveyed sheet. Specifically, the conventional printing press performs collect printing only on one surface of the sheet in one pass from feeding to delivery of the sheet and cannot perform collect printing on both surfaces of the sheet. 
     The present invention has been made to solve the problem described above and an object thereof is to provide a printing press capable of performing collect printing on both surfaces of a sheet in one pass. 
     Solution to Problem  
     A printing press according to a first aspect of the present invention for solving the problem described above includes: a first collect printing unit configured to perform collect printing in which multi-color printing is performed by applying inks of multiple colors at once, on one surface of a conveyed sheet; and a second collect printing unit configured to perform collect printing in which multi-color printing is performed by applying inks of multiple colors at once, on another surface of the conveyed sheet. 
     A printing press according to a second aspect of the present invention for solving the problem described above further includes an offset printing unit configured to perform offset printing on the conveyed sheet. 
     In a printing press according to a third aspect or the present invention for solving the problem described above, the offset printing unit is provided downstream of the first collect printing unit end the second collect printing unit in a sheet conveying direction and performs offset printing on the sheet subjected to collect printing by the first collect printing unit and the second collect printing unit. 
     In a printing press according to a fourth aspect of the present invention for solving the problem described above, the first collect printing unit includes: a first impression cylinder configured to hold and convey the sheet; and a first collect printing device disposed above the first impression cylinder and facing the first impression cylinder, and the second collect printing unit includes: a second impression cylinder configured to hold and convey the sheet; and a second collect printing device disposed below the second impression cylinder and facing the second impression cylinder. 
     Advantageous Effects of Invention 
     As described above, the printing press of the present invention includes the first collect printing unit configured to perform collect printing on the one surface of the sheet and the second collect printing unit configured to perform collect printing on the other surface of the sheet and can thereby perform collect printing on both surfaces of the sheet in one pass. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a schematic configuration diagram of a printing press in one embodiment of the present invention. 
     
    
    
     DESCRIPTION OF EMBODIMENT 
     A printing press of the present invention is described below in detail by using the drawing. 
     Embodiment 
     As shown in  FIG. 1 , a printing press  1  can sequentially perform two types of printing of collect printing and offset printing on sheets S. Specifically, in the printing press  1 , a sheet feeding part  11 , a collect printing part  12 , an offset printing part  13 , and a sheet delivery part  14  are arranged in this order from an upstream side to a downstream side in a sheet conveying direction. 
     The sheet feeding part  11  includes a feeding tray  21  and a feeding board  22  provided downstream of the feeding tray  21  in the sheet conveying direction. 
     The feeding tray  21  is a tray on which the sheets S before printing are stacked and is supported to be capable of being lifted and lowered in an up-down direction. Moreover, the feeding board  22  is interposed between the sheet feeding part  11  and the collect printing part  12  and is inclined downward toward the downstream side in the sheet conveying direction. An upstream end portion of the feeding board  22  in the sheet conveying direction faces a forward edge portion of the top one of the sheets S stacked on the feeding tray  21  while a downstream end portion of the feeding board  22  in the sheet transfer direction is disposed inside the collect printing part  12 . 
     Accordingly, by lifting the feeding tray  21  on which the sheets S are stacked stepwise according to the thickness of each sheet S, the top one of the sheets S stacked on the feeding tray  21  is sent out to the downstream end portion of the feeding board  22  in the sheet conveying direction. 
     The collect printing part  12  performs collect printing in which multi-color printing is performed by applying inks of multiple colors at once, sequentially on top surface (one surface) and a bottom surface (another surface) of each of the sheets S. Specifically, in the collect printing part  12 , a swing arm shaft pregripper  31 ; transfer cylinders  32 ,  33 , and  34 , an upper collect printing unit (first collect printing unit)  40 , and a lower collect printing unit (second collect printing unit)  50  are arranged in this order from the upstream side to the downstream side in the sheet conveying direction. 
     The swing arm shaft pregripper  31  is supported to be swingable between the transfer cylinder  32  and the downstream end portion of the feeding board  22  in the sheet conveying direction, and the forward edge portion of each sheet S fed to the feeding board  22  can be passed to the transfer cylinder  32 . Moreover, the transfer cylinders  32 ,  33 ,  34  facing one another are rotatably supported and can grip the forward edge portion of the sheet S. An impression cylinder  46  of the upper collect printing unit  40  rotatably faces a portion of the transfer cylinder  34  which is downstream of a position facing the transfer cylinder  33  in a rotating direction (downstream in the sheet transfer direction). 
     Each sheet S sent out to the feeding board  22  is thus gripped by the swing arm shaft pregripper  31  upon reaching the downstream end portion of the feeding board  22  in the sheet conveying direction and then passed to the transfer cylinder  32 . 
     The upper collect printing unit  40  performs collect printing in which multi-color printing is performed by applying inks of multiple colors at once, on the top surface of the sheet S. 
     Here, the upper collect painting unit  40  includes: inking devices (first inking devices)  41   a,    41   b  which can supply inks of different colors respectively; partial plate cylinders (first partial plate cylinders)  42   a,    42   b  which are in contact with the inking devices  41   a ,  41   b  respectively; a collecting blanket cylinder (first collecting blanket cylinder)  43  which is in contact with both of the partial plate cylinders  42   a ,  42   b;  a collecting plate cylinder (first collecting plate cylinder)  44  which is in contact with the collecting blanket cylinder  43 ; a blanket cylinder (first blanket cylinder)  45  which is in contact with the collecting plate cylinder  44 ; and the impression cylinder (first impression cylinder)  46  which faces the blanket cylinder  45  in a portion downstream of a position facing the transfer cylinder  34  in a rotating direction and which holds and conveys the sheet S received from the transfer cylinder  34 . 
     Groups of rolls forming the inking devices  41   a,    41   b  and the cylinders  42   a ,  42   b,    43 ,  44 ,  45 ,  46  are rotatably supported. Moreover, the inking devices  41   a ,  41   b  are double-duct type inking devices capable of supplying inks of different colors in their respective roll axis directions and more ink colors can be thus used in the upper collect printing unit  40  including the inking devices  41   a,    41   b . Furthermore, the partial plate cylinder  42   a,    42   b,  the collecting blanket cylinder  43 , the collecting plate cylinder  44 , and the blanket cylinder  45  form an upper collect printing device (first collect printing device)  40   a.    
     Specifically, the collecting blanket cylinder  43  is rotatably in contact with portions of the partial plate cylinders  42   a,    42   b  which are downstream of contact positions with the inking devices  41   a,    41   b  in rotating directions (downstream in an ink supplying direction). Moreover, the collecting plate cylinder  44  is rotatably in contact with a portion of the collecting blanket cylinder  43  which is downstream of contact positions with the partial plate cylinders  42   a,    42   b  in a rotating direction (downstream in the ink supplying direction). Furthermore, the blanket cylinder  45  is rotatably in contact with a portion of the collecting plate cylinder  44  which is downstream of a contact position with the collecting blanket cylinder  43  in a rotating direction (downstream in the ink supplying direction). Moreover, the impression cylinder  46  rotatably faces a portion of the blanket cylinder  45  which is downstream of a contact position with the collecting plate cylinder  44  in a rotating direction (downstream in the ink supplying direction). Furthermore, an impression cylinder  56  of the lower collect printing unit  50  to be described later is rotatably in contact with a portion of the impression cylinder  46  which is downstream of a position facing the blanket cylinder  45  in the rotating direction (downstream in the ink supplying direction). 
     In other words, as described above, one upper collect printing device  40   a  and the inking devices  41   a,    41   b  of the upper collect printing unit  40  are arranged above the sheet S conveyed by the impression cylinder  46 . 
     Accordingly, the inks or different colors supplied from the inking devices  41   a,    41   b  are supplied to the collecting blanket cylinder  43  via the partial place cylinders  42   a,    42   b  and are thereby integrated on an outer peripheral surface of the collecting blanket cylinder  43 . Next, the integrated inks of at least two colors are supplied to the blanket cylinder  45  via the collecting plate cylinder  44  and are then transferred to the sheet S conveyed by the impression cylinder  46 . 
     Meanwhile, the lower collect printing unit  50  performs collect printing in which multi-color printing is performed by applying inks of multiple colors at once, on the bottom surface of the sheet S. 
     Here, the lower collect printing unit  50  includes: inking devices (second inking devices)  51   a,    51   b  which can supply inks of different colors respectively; partial plate cylinders (second partial plate cylinders)  52   a,    52   b  which are in (second collecting blanket cylinder)  53  which is in contact with both of the partial plate cylinders  52   a,    52   b;  a collecting plate cylinder (second collecting plate cylinder)  54  which is in contact with the collecting blanket cylinder  53 ; a blanket cylinder (second blanket cylinder)  55  which is in contact with the collecting plate cylinder  54 ; and the impression cylinder (second impression cylinder)  56  which faces the blanket cylinder  55  in a portion downstream of a position facing the impression cylinder  46  in a rotating direction and which holds and conveys the sheet S received from the impression cylinder  46 . 
     Groups of rolls forming the inking devices  51   a,    51   b  and the cylinders  52   a ,  52   b,    53 ,  54 ,  55 ,  56  are rotatably supported. Moreover, the inking devices  51   a ,  51   b  are double-duct type inking devices capable of supplying inks of different colors in their respective roll axis directions and more ink colors can be thus used in the lower collect printing unit  50  including the inking devices  51   a,    51   b . Furthermore, the partial plate cylinders  52   a,    52   b,  the collecting blanket cylinder  53 , the collecting plate cylinder  54 , and the blanket cylinder  55  form a lower collect printing device (second collect printing device)  50   a.    
     Specifically, the collecting blanket cylinder  53  is rotatably in contact with portions of the partial plate cylinders  52   a,    52   b  which are downstream of contact positions with the inking devices  51   a,    51   b  in rotating directions (downstream in an ink supplying direction). Moreover, the collecting plate cylinder  54  is rotatably in contact with a portion of the collecting blanket cylinder  53  which is downstream of contact positions with the partial plate cylinders  52   a,    52   b  in a rotating direction (downstream in the ink supplying direction). Furthermore, the blanket cylinder  55  is rotatably in contact with a portion of the collecting plate cylinder  54  which is downstream of the contact position with the collecting blanket cylinder  53  in a rotating direction (downstream in the ink supplying direction). Moreover, the impression cylinder  56  rotatably faces a portion of the blanket cylinder  55  which is downstream of the contact position with the collecting plate cylinder  54  in the rotating direction (downstream in the ink supplying direction). 
     A transfer cylinder  81  rotatably faces a portion of the impression cylinder  56  which is downstream of a position facing the blanket cylinder  55  in the rotating direction (downstream in the sheet conveying direction) and an impression cylinder  73  of a lower first color (rower first stage) in the offset printing part  13  to be described later is rotatably in contact with a portion of the transfer cylinder  81  which is downstream of a position facing the impression cylinder  56  in a rotating direction (downstream in the sheet conveying direction). 
     In other words, as described above, the lower collect printing device  50   a  and the inking devices  51   a ,  51   b  of the lower collect printing unit  50  are arranged below the sheet S conveyed by the impression cylinder  56 . 
     Accordingly, the inks of different colors supplied from the inking devices  51   a,    51   b  are supplied to the collecting blanket cylinder  53  via the partial plate cylinders  52   a,    52   b  and are thereby integrated on an outer peripheral surface of the collecting blanket cylinder  53 . Next, the integrated inks of at least two colors are supplied to the blanket cylinder  55  via the collecting plate cylinder  54  and are then transferred to the sheet S conveyed by the impression cylinder  56 . 
     The offset printing part  13  performs offset printing on the top and bottom surfaces of the sheet S subjected to collect printing. Specifically, in the offset printing part  13 , three upper offset printing units (first offset printing units;  60  and four lower offset printing units (second offset printing units)  70  are alternately arranged from the upstream side to the downstream side in the sheet conveying direction. 
     The upper offset printing units  60  perform offset printing on the top surface of the sheet S. Note that the three upper offset printing units  60  perform offset printing by using inks of different colors respectively and offset printing of three colors is performed on the top surface of the sheet S. 
     Here, each of the upper offset printing units  60  includes: a plate cylinder  61  to which the ink is supplied; a blanket cylinder  62  which is in contact with the plate cylinder  61 ; and an impression cylinder  63  which faces the blanket cylinder  62  and which holds and conveys the sheet S. Note that the plate cylinder  61 , the blanket cylinder  62 , and the impression cylinder  63  are rotatably supported. 
     Specifically, the impression cylinder  63  rotatably faces a portion of the blanket cylinder  62  which is downstream of a contact position with the plate cylinder  61  in a rotating direction (downstream in an ink supplying direction). In each of the upper offset printing units  60  of the upper first color (upper first stage) and the upper second color (upper second stage), an impression cylinder  73  of the corresponding lower offset printing unit  70  to be described later rotatably faces a portion of the impression cylinder  63  which is downstream of a position facing the blanket cylinder  62  in a rotating direction (downstream in the sheet conveying direction). Moreover, in the upper offset printing unit  60  of the upper third color (upper third stage), a delivery chain  92  of the sheet delivery part  14  to be described later faces the portion of the impression cylinder  63  which is downstream of the position facing the blanket cylinder  62  in the rotating direction (downstream in the sheet conveying direction), to be capable of travelling. 
     The ink supplied to the plate cylinder  61  is thus supplied to the blanket cylinder  62  in contact with the plate cylinder  61  and then transferred to the sheet S conveyed by the impression cylinder  63 . 
     Meanwhile, the lower offset printing emits  70  perform offset printing on the bottom surface of the sheet S. Note that the four lower offset printing units  70  perform offset printing by using inks of different colors respectively and offset printing of four colors is performed on the bottom surface of the sheet S. 
     Here, each of the lower offset printing units  70  includes: a plate cylinder  71  to which the ink is supplied; a blanket cylinder  72  which is in contact with the plate cylinder  71 ; and the impression cylinder  73  which faces the blanket cylinder  72  and which holds and conveys the sheet S. Note that the plate cylinder  71 , the blanket cylinder  72 , and the impression cylinder  73  are rotatably supported. 
     Specifically, the impression cylinder  73  rotatably faces a portion of the blanket cylinder  72  which is downstream of a contact position with the plate cylinder  71  in a rotating direction (downstream in an ink supplying direction). In the lower offset printing unit  70  of the lower first color (lower first stage), a transfer cylinder  82  rotatably faces a portion of the impression cylinder  73  which is downstream of a position facing the blanket cylinder  72  in a rotating direction (downstream in the sheet conveying direction). Moreover, in each of the lower offset printing units  70  of the lower second color (lower second stage) to the lower fourth color (lower fourth stage), the impression cylinder  63  of the corresponding upper offset printing unit  60  rotatably faces the portion of the impression cylinder  73  which is downstream of the position facing the blanket cylinder  72  in the rotating direction (downstream in the sheet transfer direction). 
     Note that the transfer cylinder  82  is arranged between the impression cylinder  73  of the lower first color and the impression cylinder  73  of the lower second color. Specifically, the impression cylinder  73  of the lower second color is rotatably supported downstream of a position in the transfer cylinder  82  which faces the impression cylinder  73  of the lower first color in a rotating direction (downstream in the sheet conveying direction). 
     Accordingly, the ink supplied to the plate cylinder  71  is supplied to the blanket cylinder  72  facing the plate cylinder  71  and then transferred to the sheet S conveyed by the impression cylinder  73 . 
     The sheet delivery unit  14  includes a pair of front and rear sprockets  91   a ,  91   b  which are rotatably supported, the delivery chain  92  which is wound around between the sprockets  91   a ,  91   b , and three delivery trays  93  provided below the delivery chain  92 . 
     The delivery chain  92  can selectively deliver the printed sheets S received from the impression cylinder  63  of the upper third color to the three delivery trays  93 . Moreover, the delivery trays  93  are trays on which the printed sheets S delivered from the delivery chain  92  are stacked, and are supported to be capable of being lifted and lowered in the up-down direction. 
     The delivery chain  92  thus delivers each of the printed sheets S to a predetermined one of the delivery trays  93  and the delivery trays  93  are lowered stepwise according to the thickness of the delivered sheet S. A top surface of the top one of the sheets S stacked on each of the delivery trays  93  is thereby always maintained at a fixed height. 
     As shown in  FIG. 1 , due to the configuration described above, first the sheets S stacked on the feeding tray  21  of the sheet feeding part  11  are sent out one by one to the feeding board  22  and then passed to the impression cylinder  46  of the upper collect printing unit  40  via the swing arm shaft pregripper  31  and the transfer cylinders  32 ,  33 ,  34 . 
     Then, the integrated inks of at least two colors are transferred to the top surface of each of the sheets S conveyed by the impression cylinder  46  of the upper collect printing unit  40  when the sheet S passes through the position where the blanket cylinder  45  and the impression cylinder  46  face each other. Thereafter, the sheet S is passed to the impression cylinder  56  of the lower collect printing unit  50 . 
     Next, the integrated inks of at least two colors are transferred to the bottom surface of the sheet S conveyed by the impression cylinder  56  of one lower collect printing unit  50  when the sheet S passes through the position where the blanket cylinder  55  and the impression cylinder  56  face each other, and the sheet S is then passed to the transfer cylinder  81 . Thereafter, the sheet S conveyed by the transfer cylinder  81  and subjected to the collect printing on both surfaces are passed to the impression cylinder  73  of the lower offset printing unit  70  of the lower first color. 
     Subsequently, the ink of lower first color is transferred to the bottom surface of the sheet S conveyed by the impression cylinder  73  of the lower first color when the sheet S passes through the position where the blanket cylinder  72  and the impression cylinder  73  face each other, and the sheet S is then passed to the transfer cylinder  82 . Thereafter, the sheet S conveyed by the transfer cylinder  82  is passed to the impression cylinder  73  of the lower offset printing unit  70  of the lower second color. 
     Next, the ink of the lower second color is transferred to the bottom surface of the sheet S conveyed by the impression cylinder  73  of the lower second color when the sheet S passes through the position where the blanket cylinder  72  and the impression cylinder  73  face each other, and the sheet S is then passed to the impression cylinder  63  of the upper offset printing unit  60  of the upper first color. 
     Subsequently, the ink of the upper first color is transferred to the top surface of the sheet S conveyed by the impression cylinder  63  of the upper first color when the sheet S passes through the position where the blanket cylinder  62  and the impression cylinder  63  face each other, and the sheet S is then passed to the impression cylinder  73  of the lower offset printing unit  70  of the lower third color. 
     Next, the ink of the lower third color is transferred to the bottom surface of the sheet S conveyed by the impression cylinder  73  of the lower third color when the sheet S passes through the position where the blanket cylinder  72  and the impression cylinder  73  face each other, and the sheet S is then passed to the impression cylinder  63  of the upper offset printing unit  60  of the upper second color. 
     Subsequently, the ink of the upper second color is transferred to the top surface of the sheet S conveyed by the impression cylinder  63  of the upper second color when the sheet S passes through the position where the blanket cylinder  62  and the impression cylinder  63  face each other, and the sheet S is then passed to the impression cylinder  73  of the lower offset printing unit  70  of the lower fourth color. 
     Next, the ink of the lower fourth color is transferred to the bottom surface of the sheet S conveyed by the impression cylinder  73  of the lower fourth color when the sheet S passes through the position where the blanket cylinder  72  and the impression cylinder  73  face each other, and the sheet S is then passed to the impression cylinder  63  of the upper offset printing unit  60  of the upper third color. 
     Subsequently, the ink of the upper third color is transferred to the top surface of the sheet S conveyed by the impression cylinder  63  of the upper third color when the sheet S passes through the position where the blanket cylinder  62  and the impression cylinder  63  face each other, and the sheet S is then passed to the delivery chain  92 . 
     The sheet S which has been subjected to collect printing and offset printing on both sides is made to travel by the delivery chain  92  and is then delivered to a predetermined one of the delivery trays  93 . 
     Note that, although the collect printing part  12  and the offset printing part  13  are arranged in this order from the upstream side to the downstream side in the sheet, conveying direction in the embodiment described above, the arrangement order of these parts may be reversed. 
     Moreover, in the case of providing the offset printing part  13 , it is only necessary for the offset printing part  13  to include at least one of a set of the upper offset printing units  60  and a set of the offset printing units  70 . 
     Furthermore, although the upper collect printing unit  40  and the lower collect printing unit  50  for performing collect printing are grouped as the collect printing part  12  while the upper offset printing units  60  and the lower offset printing units  70  for performing the offset printing are grouped as the offset printing part  13 , this grouping is unnecessary for the printing press as a whole. 
     In this case, the arrangement order are numbers of the upper collect printing unit  40 , the lower collect printing unit  50 , the upper offset printing units  60 , and the lower offset printing units  70  can be changed as needed depending on the number of colors (number of ink colors) and the like on each of the top and bottom surfaces of the sheets S which are printed final products. 
     As described above, the printing press  1  of the present invention includes the upper collect printing unit  40  configured to perform collect printing on the top surface of each of the sheets S and the lower collect printing unit  50  configured to perform collect printing on the bottom surface of the sheet S and can thereby perform collect printing on both surfaces of the sheet S in one pass. 
     Moreover, providing the upper offset printing units  60  and the lower offset printing units  70  downstream of the upper collect printing unit  40  and the lower collect printing unit  50  in the sheet conveying direction enables offset printing on both surfaces of the sheet S subjected to collect printing on both surfaces. The collect printing and the offset printing can be thus performed on both surfaces of the sheet S in one pass. 
     INDUSTRIAL APPLICABILITY 
     The present invention can be applied to a printing press intended to make a printing position of collect printing variable on a sheet conveying route. 
     REFERENCE SIGNS LIST  
     
         
           1  PRINTING PRESS 
           11  SHEET FEEDING PART 
           11  COLLECT PRINTING PART 
           13  OFFSET PRINTING PART 
           14  SHEET DELIVERY PART 
           40  UPPER COLLECT PRINTING UNIT 
           40   a  UPPER COLLECT PRINTING DEVICE 
           41   a ,  41   b  INKING DEVICE 
           46  IMPRESSION CYLINDER 
           50  LOWER COLLECT PRINTING UNIT 
           50   a  LOWER COLLECT PRINTING DEVICE 
           51   a,    51   b  INKING DEVICE 
           56  IMPRESSION CYLINDER 
           60  UPPER OFFSET PRINTING UNIT 
           70  LOWER OFFSET PRINTING UNIT 
         S SHEET