Plate inserting apparatus

#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.

#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;

#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 11a and a positioning notch 11b 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 6a, 6b, and 6c. The three covers 6a, 6b, and 6c are sequentially connected to each other, and are integrally moved by the air cylinder (not shown) vertically.