Patent Publication Number: US-6655279-B2

Title: Roll support structure of printing device

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to a roll support structure of a printing device. More particularly, the invention relates to a roll support structure of a printing device, which allows a fountain roll and the like to be attached and removed with little effort, and which can respond to a change in printing conditions without difficulty. 
     2. Description of the Related Art 
     In a known flexographic press, a plurality of printing devices is disposed along the direction in which printing paper is fed. Each printing device transfers ink of a different color to printing paper, whereby polychromic printing is performed. Each printing device includes an ink pan, a fountain roll disposed such that an outer peripheral surface thereof faces the interior of the ink pan, an anilox roll contacting the outer peripheral surface of the fountain roll, a plate cylinder to which ink is transferred via the anilox roll, and a platen that faces the plate cylinder. Printing paper is supplied and fed between the plate cylinder and the platen, whereby predetermined printing is performed on the printing paper. 
     A gear is provided on one end side of each of support shafts of the above-mentioned fountain roll and the anilox roll. The gears on both the support shafts constitute an interlocking mechanism. One of the gears is engaged with a gear fixed to an output shaft of drive means including a motor and the like. Thus, when the motor rotates, the fountain roll and the anilox roll are interlocked with each other so that they can be rotated. 
     However, when the fountain roll is replaced by another fountain roll for changing the color of the ink filled in the ink pan, the above-mentioned gear needs to be removed from the support shaft. Thus, there is the inconvenience that an extensive operation is required. In addition, when the density of the plate for printing is changed, the anilox roll needs to be replaced by another anilox roll whose outer peripheral surface has a different finishing accuracy. In this case as well, there is the inconvenience that similar extensive operation is required. 
     These inconveniences result from use of the single motor constituting a drive source, and the mutual interlocking mechanism including the gear group transmitting the driving power of the motor. 
     SUMMARY OF THE INVENTION 
     In view of the above-mentioned inconveniences, it is an object of the present invention to provide a roll support structure of a printing device, which allows a fountain roll and the like to be replaced very easily and quickly, thereby facilitating roll replacement or maintenance and checking. 
     In order to achieve the above-mentioned object, the present invention provides a roll support structure of a printing device including a fountain roll disposed such that an outer peripheral surface thereof faces the interior of an ink pan, an anilox roll disposed so as to contact the outer peripheral surface of the fountain roll, a plate cylinder to which ink transferred to the anilox roll is transferred, and a platen disposed to face the plate cylinder. 
     The roll support structure of the printing device has a construction in which one end side of a support shaft of the above-mentioned fountain roll and/or the anilox roll is removably coupled to a rotating shaft for transmitting a predetermined rotating force, while the other end side thereof is supported via urging means that is movable in the axial direction. In this construction, the fountain roll and/or the anilox roll can be attached and removed very easily. Accordingly, when the color of the ink is changed, or when the roll is replaced by another roll for changing the printing accuracy, the efficiency of the operation can be significantly improved. 
     In the present invention, the construction may be such that one end side of the above-mentioned support shaft and the above-mentioned rotating shaft are coupled together via coupling means. In the construction, the coupling means includes a first coupling member fixed on the outer periphery of the above-mentioned support shaft, a second coupling member fixed on the outer periphery of the above-mentioned rotating shaft, a coupling hole formed in any one of the first and the second coupling members, and a shaft member which is fixed to the other of the first and the second coupling members, and which is fitted into the above-mentioned coupling hole. Accordingly, when the fountain roll and/or the anilox roll is removed, the coupling can be released by the operation of separating the above-mentioned support shaft and the rotating shaft such that the shaft member is pulled out of the coupling hole. 
     In addition, it is preferable to employ a construction in which the above-mentioned urging means includes a moving shaft that is movable in the axial direction, and in which the moving shaft and the above-mentioned rotating shaft each have a cone-shaped portion at the tip, which can be fitted in an end surface of the support shaft of the above-mentioned fountain roll and/or the anilox roll. Thus, centering of the fountain roll and the like can be performed with high accuracy. 
     Furthermore, it is possible to employ a construction in which one end side of the above-mentioned support shaft of the above-mentioned fountain roll and/or the anilox roll is supported by a chuck. In the construction, the fountain roll and the like can be supported at one end side by a scroll chuck which is used in a lathe turning machine and the like. Therefore, the installation cost of the roll support structure can be reduced by employing a construction which uses a versatile existing structure. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a schematic lateral view showing a roll support structure according to an embodiment of the invention; 
     FIG. 2 is a partial cross section view of the roll support structure taken along line A—A; 
     FIG. 3 is an enlarged cross section view of a left side region of FIG. 2; 
     FIG. 4 is an enlarged cross section view of a right side region of FIG. 2; and 
     FIG. 5 is an enlarged cross section view of a right side region, which shows a state in which support by a moving shaft is released. 
    
    
     DETAILED DESCRIPTION OF PREFERRED THE EMBODIMENT 
     Hereinafter, an embodiment of the invention will be described with reference to the drawings. 
     FIG. 1 is a schematic lateral view showing a printing device of a flexographic press to which the invention is applied. FIG. 2 is a partial cross section view showing the main portion thereof. In these figures, a printing device  10  includes an ink pan  11  disposed between a pair of right and left frames F, F, a fountain roll  13  which faces the inside of the ink pan  11 , and which is disposed such that an outer peripheral surface thereof contacts ink I filled in the ink pan  11 , an anilox roll  15  disposed so as to contact the outer peripheral surface of the fountain roll  13 , a plate cylinder  16  to which ink I transferred to the anilox roll  15  is transferred, and a platen  17  which faces the plate cylinder  16 , and which sandwiches printing paper P so that the printing paper P can be fed. 
     The upper portion of the ink pan  11  is open. A pair of lateral walls  11 A,  11 A of the ink pan  11  have notch concave portions  11 B,  11 B at their upper central portions. Both end sides of a support shaft  20 ,  21  of the fountain roll  13  are positioned in the notch concave portions  11 B,  11 B. 
     In the above-mentioned fountain roll  13 , a flange  24  (a first coupling member) having a ring plate shape, which constitutes a coupling means  29 , is fixed to the outer periphery of one end side of the support shaft  20 , i.e., the left side of the support shaft  20  in FIG.  2  and FIG.  3 . In the present embodiment, coupling holes  25 ,  25  are formed in the flange  24  at two locations 180 degrees apart in the circumferential direction, respectively. The coupling holes  25 ,  25  extend substantially parallel with the axis line of the above-mentioned support shaft  20 . Coupling shaft members  27 ,  27  are provided such that they can be fitted into the coupling holes  25 ,  25 . Each of the coupling shaft members  27 ,  27  is fixed to a shaft support body  28  (a second coupling member) constituting the coupling means  29 . The shaft support body  28  is fixed around a rotating shaft  32  which is coupled to an output shaft  31  of a motor  30  by a coupling  31 A. The above-mentioned flange  24 , the coupling holes  25 ,  25 , the coupling shaft members  27 ,  27 , and the shaft support body  28  constitute the coupling means  29  for coupling the support shaft  20  to the rotating shaft  32 . Note that a cone-shaped portion  34  is provided at the tip of the rotating shaft  32 . The cone-shaped portion  34  is fitted in a conical groove  20 A formed at the center of the end surface of the above-mentioned support shaft  20  (see FIG.  3 ). 
     The above-mentioned motor  30  is supported by a support plate  38  via a retaining shaft  33 . The support plate  38  is provided on the interior surface side of the frame F. On the other hand, the above-mentioned rotating shaft  32  is rotatably provided on a bearing case  35  via a bearing  36 . The bearing case  35  is positioned on the outer peripheral side of the rotating shaft  32 . The bearing case  35  is supported by the support plate  38 . A support arm  40  having a substantially L-shape is provided on the lower end side of the support plate  38  in FIG.  2 . The support arm  40  includes a horizontal portion  40 A and a standing portion  40 B which extends upward from the tip of the horizontal portion  40 A. A branching portion  40 C is formed at the upper end of the standing portion  40 B. The branching portion  40 C bifurcates, and is substantially U-shaped. The support shaft  20  of the fountain roll  13  is positioned in the branching portion  40 C. When a cylinder  59  serving as urging means urges the cone-shaped portion  34  to be closely fitted in the conical groove  20 A of the support shaft  20  and supports them, a small clearance is formed between the support shaft  20  and a bottom surface  40 D of the branching portion  40 C. On the other hand, when the support shaft  20  is removed from the cone-shaped portion  34 , the bottom surface  40 D of the branching portion  40 C receives the support shaft  20  so as to prevent the support shaft  20  from falling down 
     The other end side of the support shaft  21 , which is positioned on the right side of the above-mentioned fountain roll  13  in FIG.  2  and FIG. 4, is supported by a moving shaft  45  which is movably provided along the axis line of the support shaft  21 . A coneshaped portion  46  is integrally formed at the tip of the moving shaft  45 , i.e., at the left end of the moving shaft  45  in FIG.  2 . The tip of the cone-shaped portion  46  is fitted in a conical groove  21 A formed in the end surface of the support shaft  21 . 
     The above-mentioned moving shaft  45  is rotatably supported on the inner periphery of a bearing case  49  via a bearing  48 . Meanwhile, the bearing case  49  is attached to a support plate  50  disposed on the interior surface side of an interior frame F 1 . A support arm  52 , which is substantially L-shaped, is provided on the lower end side of the support plate  50  in FIG.  2  and FIG.  4 . The support arm  52  and the above-mentioned support arm  40  are substantially symmetrical. The support arm  52  includes a horizontal portion  52 A and a standing portion  52 B which extends upward from the tip of the horizontal portion  52 A. A branching portion  52 C is formed at the upper end of the standing portion  52 B. The branching portion  52 C bifurcates, and is substantially U-shaped. The support shaft  21  of the fountain roll  13  is positioned in the branching portion  52 C. When the cone-shaped portion  46  of the moving shaft  45  is pressed and fitted in the conical groove  21 A by an urging force of the cylinder  59 , a small clearance is formed between the support shaft  21  and a bottom surface  52 D of the branching portion  52 C. On the other hand, when the urging force of the cylinder  59  is cancelled, and the support shaft  21  is removed from the cone-shaped portion  46 , the bottom surface  52 D of the branching portion  52 C receives the support shaft  21  so as to prevent the support shaft  21  from falling down. 
     A bearing case  56  for retaining bearings  53 ,  54 ,  55  are provided on the outer periphery of the right side of the above-mentioned moving shaft  45  in FIG.  2  and FIG. 4. A coupling plate  58  is provided at the right end of the bearing case  56 . The coupling plate  58  is coupled to the cylinder  59  such that the coupling plate  58  can be advanced and retracted in the axial direction. The cylinder  59  and the above-mentioned moving shaft  45  constitute urging means. A nut member  47  for enclosing the bearing  45  is provided around the moving shaft  45  on the inner peripheral side of the coupling plate  58 . Therefore, when the above-mentioned moving shaft  45  is moved to the right side in FIG. 2 by operation of the cylinder  59 , the support shaft  21  loses support by the cone-shaped portion  46 . This permits removal of the fountain roll  13 . At this time, the support shaft  21  is retained on the bottom surface  52 D of the branching portion  52 C of the support arm  52 , so that the support shaft  21  is prevented from falling down (see FIG.  5 ). 
     When another fountain roll is used after the fountain roll  13  is removed, the other fountain roll is disposed such that both end sides of the support shaft  20 ,  21  are received by the above-mentioned bottom surfaces  40 D,  52 D of the horizontal arms  40 A,  52 A. Accordingly, when the above-mentioned moving shaft  45  is advanced, the fountain roll  13  can be centered and supported. 
     In the illustrated embodiment, only the support structure for the fountain roll  13  is shown. The anilox roll  15  in the present embodiment is also rotatably supported by using the same support structure for a support shaft  60  thereof (see FIG.  1 ). The fountain roll  13  and the anilox roll  15  each can be rotated by an independent motor  30  without using an interlocking mechanism such as gears. 
     Although the plate cylinder  16  and the platen  17  are omitted in the figures of the embodiment, they are interlocked with each other via gears at one end of each of support shafts  16 A,  17 A. However, in the present invention, the same support structure as that for the fountain roll can be employed for the plate cylinder  16  and the platen  17 . 
     In addition, although both end sides of the support shaft  20 ,  21  are supported by the cone-shaped portions  34 ,  46  in the above-mentioned embodiment, one end side thereof may be removably retained by a scroll chuck or the like. Furthermore, according to the present invention, it is also possible to employ a construction in which at least one of the fountain roll  13  and the anilox roll can be attached and removed easily according to the above-mentioned support structure. 
     As described above, according to the present invention, the fountain roll and anilox roll each can be attached and removed easily and quickly. Therefore, efficiency of the operation required for changing ink color or printing accuracy can be significantly improved as compared with a conventional structure. 
     In addition, the coupling means for coupling one end side of the above-mentioned support shaft to the above-mentioned rotating shaft includes the first and the second coupling means, the coupling hole formed in any one of the first and the second coupling means, and the shaft member which is fixed to the other of the first and the second coupling members, and which is fitted into the above-mentioned coupling hole. Therefore, when the fountain roll and/or the anilox roll is removed, the coupling of the support shaft and the rotating shaft can be released simply by moving the first and the second coupling members such that they are separated from each other. Thus, the roll replacement can be performed easily and quickly as compared with a conventional structure. 
     Further, the above-mentioned urging means includes the moving shaft that is movable in the axial direction, and the moving shaft and the above-mentioned rotating shaft each have the cone-shaped portion at the tip. Therefore, centering of the fountain roll and the like can be performed with high accuracy. 
     Furthermore, when one end side of the above-mentioned fountain roll and/or the anilox roll is supported by a chuck, it is also possible to reduce the installation cost by using the existing structure.