Patent Publication Number: US-6712004-B2

Title: Plate inserting apparatus

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a plate inserting apparatus for inserting a new plate in the plate clamp device of a plate cylinder. 
     Japanese Patent Publication No. 7-75885 (reference 1) discloses a plate inserting apparatus of this type. The apparatus disclosed in reference 1 has a plate magazine supported to be movable between an inserting position for inserting a new plate into the plate clamp device of a plate cylinder and a wait position, a conveyor belt provided in the plate magazine to feed out the new plate into a plate fixing unit, and a driver for driving the conveyor belt. When the plate magazine is located at the inserting position, the conveyor belt is driven by the driver. As a driving belt travels, the new plate is fed out from the plate magazine into the plate clamp device of the plate cylinder, and is mounted on the plate cylinder. 
     In the conventional plate inserting apparatus described above, since the new plate is fed out into a plate fixing device by the travel of the conveyor belt, the driver for driving the conveyor belt to travel is required. As the driver is large and heavy, a rotational driving unit for rotating the plate magazine also becomes large, and the entire apparatus becomes large and complicated. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide a compact plate inserting apparatus. 
     It is another object of the present invention to provide a simplified plate inserting apparatus. 
     In order to achieve the above objects, according to the present invention, there is provided a plate inserting apparatus comprising plate holding means for holding a plate to which an elastic restoration force is applied, and releasing means for releasing the plate held by the plate holding means, wherein the plate released by the releasing means is inserted into a plate fixing unit provided in a plate cylinder by the elastic restoration force thereof. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a view showing the arrangement of a sheet-fed rotary printing press to which a plate inserting apparatus according to the present invention is applied; 
     FIG. 2A is a side view showing the structure of the plate cylinder shown in FIG. 1; 
     FIG. 2B is a perspective view of a plate to be mounted on the outer surface of the plate cylinder of FIG. 2A; 
     FIG. 3 is a side view of a plate inserting apparatus according to an embodiment of the present invention; 
     FIGS. 4A and 4B are enlarged views of a portion IV of FIG. 3; 
     FIG. 5 is a side view of the plate inserting apparatus which has prepared for supplying a new plate; 
     FIG. 6 is a side view of the plate inserting apparatus in a state wherein a plate feed unit is close to the plate cylinder; 
     FIG. 7 is a side view of the plate inserting apparatus in a state wherein a plate changing device releases a plate and a new plate is inserted into the leading edge plate clamp device of the plate cylinder; 
     FIG. 8 is a side view of the plate inserting apparatus in a state wherein the new plate is mounted on the plate cylinder; and 
     FIG. 9 is a side view of the plate inserting apparatus in a state wherein the plate feed unit is restored to the original position. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     A plate inserting apparatus according to an embodiment of the present invention will be described with reference to FIGS. 1 to  9 . As shown in FIG. 1, a sheet-fed rotary printing press  1  has a feeder  2  for feeding sheets, a plurality of printing units  3  corresponding to four different ink colors to print the sheets fed from the feeder  2  in the respective ink colors, and a delivery unit  4  where the sheets delivered from the last printing unit  3  are stacked. A plate cylinder  5  on which a plate is mounted and which is rotatably supported by frames is provided in each printing unit  3 , and a safety cover  6  is provided on the delivery side of each printing unit  3 . The safety cover  6  is moved up and down (in the vertical direction) by an air cylinder (not shown). When the safety cover  6  moves upward, it opens the front portion of the corresponding plate cylinder  5 . When the safety cover  6  moves downward, it covers the front portion of the corresponding plate cylinder  5 . 
     A suction pump  51  is connected to the lower ends of the safety covers  6  to supply suction air to a plurality of suction pads for chucking the front ends of the corresponding plates. Solenoid valves (releasing means)  52  are connected between the suction pump  51  and the suction pads, and open/disconnect air flow channels by their opening/closing operations. The opening/closing operations of the solenoid valves  52  are controlled by a controller  53 . 
     As shown in FIG. 2A, the plate cylinder  5  has a notch  7  in its outer surface to extend in the axial direction. A leading edge plate clamp device  8  and trailing edge plate clamp device  9  are provided in the notch  7 . As shown in FIG. 2B, a new plate  10  has a U-shaped positioning notch  11   a  and a positioning notch  11   b  with a semicircular bottom in its leading edge, and a bent portion  12  bent at a right angle in its trailing edge. As shown in FIG. 3, the safety cover  6  is comprised of three covers, i.e., upper, middle, and lower covers  6   a ,  6   b , and  6   c . The three covers  6   a ,  6   b , and  6   c  are sequentially connected to each other, and are integrally moved by the air cylinder (not shown) vertically. 
     The plate inserting apparatus will be described with reference to FIG.  3  and FIGS. 4A and 4B. As shown in FIG. 3, the upper cover  6   a  has a locking portion  15  with an inverted-L shape, when seen from the side surface, to lock the trailing edge of the new plate  10 . A pair of rod-like guide bars  16  and  17  extend parallel to each other at a predetermined distance from the outer surface of the middle cover  6   b , such that their axes extend in the widthwise direction of the middle cover  6   b . The two ends of the guide bar  16  and those of the guide bar  17  are supported at the upper and lower portions of the middle cover  6   b  by support members  16   a  and  17   b , respectively. 
     A rectangular window  20  extending in the horizontal direction (the widthwise direction of the cover) is formed in the upper portion of the lower cover  6   c . At positions corresponding to the lower end of the window  20 , a pair of positioning pins  21  are fixed to the lower cover  6   c  through a support plate  22 . Before mounting the new plate  10  onto the plate cylinder  5 , its positioning notches  11   a  and  11   b  are engaged with the positioning pins  21 , so that the lower end of the new plate  10  is supported by the positioning pins  21 . 
     Subsequently, after the upper and lower portions of the new plate  10  are supported by the pair of guide bars  16  and  17 , the upper end of the new plate  10  is engaged in the locking portion  15  and locked by it. Thus, the new plate  10  elastically deforms in the widthwise direction between the pair of guide bars  16  and  17 , and flexes largely. Then, the lower end of the new plate  10  is chucked by suction pads  27  of a plate feed unit  25 , and the plate feed unit  25  is swung to come close to the plate cylinder  5 . At this time, the new plate  10  keeps flexing between the pair of guide bars  16  and  17 , as indicated by an alternate long and two short dashed line in FIG.  3 . 
     When the suction pads  27  release the new plate  10 , the lower end (leading edge) of the new plate  10  is inserted in the leading edge plate clamp device  8  of the plate cylinder  5  by the elastic restoration force generated by the flex of the new plate  10 . At this time, the pair of guide bars  16  and  17  guide the leading edge of the new plate  10  to insert it into the leading edge plate clamp device  8  of the plate cylinder  5 . 
     As shown in FIG. 4A, the plate feed unit  25  as a swing member is comprised of a swing plate  26  for selectively covering the window  20 , the suction pads  27  for attracting the new plate  10 , a first guide roller (first rotary member)  28  serving as a guide member when inserting the new plate  10  in the plate cylinder  5 , and a pin  29  for swinging the swing plate  26 . The swing plate  26  has an elongated rectangular shape with a size slightly smaller than that of the window  20 , and a pair of opposing bars  30  (one bar  30  is not shown) are fixed to its two ends in the horizontal direction. The swing plate  26  has a plurality of holes  26   a  in its lower portion, through which the suction pads  27  are exposed. 
     As the upper portions of the bars  30  are rotatably supported by a pivot shaft  32  standing from the lower cover  6   c , the swing plate  26  is supported by the middle cover  6   b  to be swingable about the pivot shaft  32  as the pivot center. The suction pads  27  are fixed to the rear side of the swing plate  26  through a bracket (not shown), and suction air is supplied to it from the suction pump  51  through the corresponding solenoid valve  52 . The pin  29  is fixed to the bars  30  through support plates (not shown), and projects from the sides of the plate feed unit  25 . 
     As shown in FIG. 4B, an air cylinder  35  for swinging the plate feed unit  25  is rotatably supported by an apparatus fixing portion through a small shaft  36  provided to its lower end. An engaging member  38  is attached to the distal end of a rod  37  of the air cylinder  35 , and has a U-groove  38   a , in its upper end, to engage with the pin  29 . 
     In this arrangement, when the rod  37  of the air cylinder  35  moves backward, the plate feed unit  25 , in which the pin  29  engages with the U-groove  38   a  of the engaging member  38 , covers the window  20 , that is, the plate feed unit  25  is located at a wait position away from the plate cylinder  5 . When the rod  37  of the air cylinder  35  moves forward as indicated by an alternate long and two short dashed line in FIG. 4B, the plate feed unit  25  pivots counterclockwise about the pivot shaft  32  as the pivot center through the pin  29  engaging with the U-groove  38   a  of the engaging member  38 . Hence, the lower end of the plate feed unit  25  is positioned at the inserting position close to the plate cylinder  5 . 
     A second guide roller (second rotary member)  45  for guiding the leading edge of the new plate  10  to the plate cylinder  5 , and press rollers  43  for inserting the trailing edge of the new plate  10  into the plate cylinder  5  will be described with reference to FIG. 3. A driving shaft  40  rotatably supported between the pair of frames (not shown) is pivoted by a lever and actuator (not shown). One end of each of a pair of opposing support arms  41  (one support arm  41  is not shown) is fixed to the corresponding one of the two ends of the driving shaft  40 , and a shaft  42  extends horizontally between the other-end portions of the support arms  41 . The plurality of press rollers  43  are formed on the shaft  42  to line up in the axial direction. One end of a support plate  44  is fixed to the shaft  42 , and the other end of the support plate  44  rotatably, axially supports the second guide roller  45 . 
     In this arrangement, when the driving shaft  40  pivots clockwise in FIG. 3, the press rollers  43  come into contact opposite to the outer surface of the plate cylinder  5 . Simultaneously, the second guide roller  45  moves in a direction to come close to the first guide roller  28 , and clamps the distal end of the new plate  10  chucked by the suction pads  27  together with the first guide roller  28 . When the air flow channel is disconnected by the solenoid valves  52 , the new plate  10  chucked by the suction pads  27  is released. The released new plate  10  is clamped between the first and second first guide rollers  28  and  45  and guided to the leading edge plate clamp device  8  of the plate cylinder  5 . Therefore, the leading edge of the new plate  10  is inserted into the leading edge plate clamp device  8  of the plate cylinder  5 , and is gripped by it. 
     The plate inserting operation of the plate inserting apparatus with the above arrangement will be described with reference to FIG.  4 B and FIGS. 5 to  9 . 
     In the initial state, the upper, middle, and lower covers  6   a ,  6   b , and  6   c  are located in the lower portion. Accordingly, the front portion of the plate cylinder  5  is covered by the middle and lower covers  6   b  and  6   c . In this state, the notches  11   a  and  11   b  formed in the leading edge (lower portion in FIG. 5) of the new plate  10  engage with the positioning pins  21 , so that the lower end of the new plate  10  is supported by the positioning pins  21 . The new plate  10  is positioned temporarily by engagement of the notches  11   a  and  11   b  with the positioning pins  21 , so that the mounting precision of the new plate  10  with respect to the plate cylinder  5  improves. 
     Subsequently, the upper and lower portions of the new plate  10  are attached against the pair of guide bars  16  and  17 , and the upper end of the new plate  10  is locked by the locking portion  15 . Thus, the new plate  10  is supported by the safety cover  6 . At this time, the new plate  10  supported by the safety cover  6  largely flexes between the pair of guide bars  16  and  17 . Then, the solenoid valve  52  is opened by the control operation of the controller  53 , and the lower end of the new plate  10  is chucked by the suction pads  27  of the plate feed unit  25 . 
     Subsequently, the rod  37  of the air cylinder  35  is moved forward, and accordingly the pin  29  engaging with the U-groove  38   a  of the engaging member  38  also moves to the position indicated by an alternate long and two short dashed line in FIG.  4 B. As the pin  29  moves, the plate feed unit  25  pivots counterclockwise in FIG. 4B about the pivot shaft  32  as the pivot center. When the plate feed unit  25  pivots, the lower end of the plate feed unit  25  comes close to the plate cylinder  5 , and the plate feed unit  25  is accordingly positioned at the inserting position. 
     At this time, the notches  11   a  and  11   b  disengage from the positioning pins  21 , and the front end of the new plate  10  is held only by the suction pads  27 . With this arrangement, when the new plate  10  is to be moved to the inserting position, no actuator is needed for moving the positioning pins  21  (backward). 
     Then, the driving shaft  40  (FIG. 3) pivots clockwise in FIG. 3, and the press rollers  43  come into contact opposite to the outer surface of the plate cylinder  5 , as shown in FIG.  7 . Simultaneously, the second guide roller  45  comes into contact opposite to the first guide roller  28  through the new plate  10 . The solenoid valve  52  is then closed by the control operation of the controller  53 , and an air flow channel to the suction pads  27  is disconnected. Hence, the new plate  10  chucked by the suction pads  27  is released, and the lower end (leading edge) of the new plate  10  is inserted into the leading edge plate clamp device  8  of the plate cylinder  5  by the elastic restoration force generated by the flex of the new plate  10 . 
     According to this embodiment, as the new plate  10  is inserted into the leading edge plate clamp device  8  of the plate cylinder  5  by its elastic restoration force, no member is required for moving the new plate  10 , and the apparatus is made compact and simplified. As the new plate  10  can flex by its own weight, no driving source is required for inserting the leading edge of the new plate  10  into the leading edge plate clamp device  8  of the plate cylinder  5 , and the number of components can be reduced largely. As the new plate  10  can be held and released by supplying and disconnecting the suction air, the structure is simplified. 
     As the new plate  10  is guided to the leading edge plate clamp device  8  of the plate cylinder  5  by the first and second guide rollers  28  and  45 , the leading edge of the new plate  10  can be inserted into the leading edge plate clamp device  8  reliably. When the plate feed unit  25  is located at the position of inserting the new plate  10 , the pair of guide bars  16  and  17  guide the new plate  10  to the plate cylinder  5 . Thus, the new plate  10  can be inserted into the leading edge plate clamp device  8  of the plate cylinder  5  reliably. The guide bars  16  and  17  support the new plate  10  when the plate feed unit  25  is at a position retreated from the plate cylinder  5 . Hence, no exclusive support member is required, and the number of components and the manufacturing cost can be reduced. 
     Subsequently, as shown in FIG. 8, when the plate cylinder  5  pivots counterclockwise, the new plate  10  is pressed by the press rollers  43  to come into tight contact with the outer surface of the plate cylinder  5 . When the plate cylinder  5  rotates substantially by one turn, the bent portion  12  of the new plate  10  as the trailing edge is inserted into the trailing edge plate clamp device  9  of the plate cylinder  5  by the press rollers  43 . Hence, the trailing edge of the new plate  10  is gripped by the trailing edge plate clamp device  9  of the plate cylinder  5 , and the new plate  10  is mounted on the outer surface of the plate cylinder  5 . 
     Subsequently, as shown in FIG. 4B, the rod  37  of the air cylinder  35  is moved backward as indicated by a solid line, so that the pin  29  engaging in the U-groove  38   a  of the engaging member  38  also moves to the position indicated by a solid line. Thus, as shown in FIG. 9, the plate feed unit  25  pivots by its own weight clockwise in FIG. 9 about the pivot shaft  32  as the pivot center, and is positioned at a position retreated from the plate cylinder  5  to cover the window  20 . 
     As has been described above, according to the present invention, when inserting the plate into the leading edge plate clamp, a convey member for moving the plate and a driving means for driving the convey member become unnecessary. Thus, the apparatus is made compact and simplified.