JPS6042030B2 - Master supply device in lithographic printing press - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The invention relates to a master feeding device in a lithographic printing press.

As a master supply device for a lithographic printing press, particularly an offset printing press, a master feeding device for a lithographic printing press, particularly an offset printing press, is disclosed in Japanese Patent Application Laid-Open No. 54-42202 (Japanese Patent Application No. 52-91451) proposed by the applicant of the present application.
There is one described in Japanese Patent Application No. 52-91451.

This is provided adjacent to the plate feeding device, and includes an etching device in which the distance between the master positioning stopper provided on the plate feeding device and the rearmost pair of etching rollers is shorter than the length of the master. . As shown in FIG. 7, an etching roller pair 28a at the forefront of the etching apparatus;
A guide plate 32a is provided between the conveyance path 30a that guides the master Ma to the plate feeding device and guides the master by bending the rear part of the master upward when the leading end of the master comes into contact with the stopper and stops. , and above the etching equipment,
A conveyor belt 29a is provided so as to be inclined in the conveyance direction of the master, and conveys the rear part of the master which bends upward along the lower surface of the guide plate 32a, and places and holds the master on the upper surface thereof. However, in the above method, when the rear part of the master Ma is placed and held by the conveyor belt 29a as shown by the dashed line in FIG. As shown in the guide plate 32
The master is bent upward along the lower surface of the master, but the bent part of the master is in a free state and is not supported by any member.

Therefore, the image area of the master ratio that is etched by passing through the etching roller pair 28a, and the non-image area is rendered fat-free and the image area is impressed, is not a character or line-shaped image.
For example, in the case of a peta part P as shown in Fig. 8, the peta part P
(image area) and the non-image area, and when the boundary between the image area and the non-image area forms the top of the curved part, the radius of curvature of the top becomes ``Because it is determined by the stiffness of the non-image area, the image area cannot form the top properly, and a crease often occurs at the boundary between the two areas.And once a crease occurs in the master, The master is then jammed when the pair of etching rollers 28a is carried out (see the solid line in Fig. 7).In addition, in the case of the above-mentioned one, the rear part of the master, which bends along the lower surface of the guide plate 32a, is sent out by the conveyor belt 29a, so that the rear surface of the master is There was a drawback that the image area formed on the image area was rubbed by the belt, causing stains on the image area, and that a master with stains on the image area could no longer function as a plate. When the rear part of the master is placed and held by the belt 29a, the leading end of the master is only stopped in contact with the stopper of the plate feeding device, and the conveyor belt 29a carries the rear part of the master in the opposite direction to the conveying direction of the master. Sometimes the master is fed in the direction of the deflection, and the tip of the master moves away from the stopper, making it impossible to hold the tip of the master in a fixed position in the standby state, resulting in feeding errors and failure to attach the master to the plate cylinder. This invention eliminates the drawbacks of the conventional methods described above, and the conveyor belt method does not prevent the miter from bending upward when holding the rear part of the master whose tip has come into contact with the stopper and has stopped. Lithographic printing is less prone to bending compared to other methods, and the tip of the master in contact with the stopper can always be held in a fixed position in the standby state, making it possible to reliably attach the master to the plate cylinder. The purpose is to provide a master feeding device for machines.

The present invention will be described below based on embodiments shown in the drawings.

FIG. 1 shows an offset printing machine 1 according to an embodiment of the present invention.
, a printing cylinder 5 having a master clamp device 4, a transfer cylinder 6, and an impression cylinder 7 are provided inside the printing press main body 2, and an inking device 8 is located adjacent to the printing cylinder 5.
and a plate supply/discharge device 9 are provided. Further, an etching device 3 is provided on one side of the main body 2.
A paper feed tray 10 is provided below. The plate feeding and discharging device 9 is shown in detail in FIG. 2, and the transport path 11 is provided with an actuating part 13 of a microswitch 12, and upper and lower plate feeding rollers 14 and 15 are provided in front of this master transport direction. It is being

The upper plate feed roller 14 is a cam mounted coaxially with the plate cylinder 5.
16, it is made to be able to swing up and down, and in the upper position, it is separated from the lower feed plate roller 15, and at this time, the conveyance path 1
A master positioning stopper 17 protrudes from the master positioning plate 1 and engages with the lower feeding plate roller 15 in the lower position, and at this time the stopper 17 is positioned below the conveyance path 11. In addition, it can swing between a position where it contacts the top surface of the conveyance path 11 and a position where it separates from the top surface of the conveyance path 11, and when the contact position is reached, the tip of the master is pressed against the conveyance path 11 and held. A sickle-shaped master tip holding member 31 and a solenoid 33 (FIG. 5) which is an operating member thereof are provided.

Furthermore, below the plate feeding section, there is provided a plate discharging section which includes a peeling claw 18 for separating the master from the copper plate 5 and a discharge belt 19 for discharging the separated master to the outside of the main body 2. . The etching device 3 is arranged so that the distance between the rearmost pair of etching rollers and the stopper 17 of the plate supply/discharge device 9 is shorter than the length of the manostar, and as shown in detail in FIG. A plate feeding table 20 is provided on which the plate is placed, and a steel ball 23 provided below the conveyance path 21 is engaged with the plate feeding table 20 .

A solenoid 2 is located in front of the plate feeding roller 22 in the conveying direction.
A stopper 26 is provided which is movable between a position protruding into the conveyance path 21 and a position below the conveyance path 21 by a swinging member 25 that is swung by the stopper 25 . Furthermore, an etching tank 27 filled with an etching solution is provided in the front, and a plurality of pairs of etching rollers 2 are installed in the upper part of this etching tank 27.
8 is provided with a lower roller immersed in the etching solution in the tank, and above the etching roller pair 28 are first and third rollers.
As shown in FIGS. 4 and 4, a mounting plate 34 at the rear of the master, which is inclined in the transport direction of the master, is provided so as to cover the pair of etching rollers 28. The base ends of a pair of push-up levers 36 are provided perpendicularly to the support shaft 35 of the mounting plate 34 and parallel to each other. A push-up roller shaft 38 having a plurality of lift rollers 37 in the axial direction is installed. The push-up lever 36 is always urged upward in FIGS. 1, 3, and 4 by a coil spring 39 provided between it and the support shaft 35, and further by a pin support plate provided on the support shaft 35. A pin 41 provided at the tip of the lever 40 engages with the push-up lever 36 to prevent it from rising. A cam follower 43 of a cam 42 provided in a drive source (not shown) is provided at one end of the support shaft 35. Further, a conveyance path 30 is provided on the main body 2 side to guide the master from the etching roller pair 28 to the main body 2, and a guide plate 32 is provided between the conveyance path 30 and the etching roller pair at the forefront. It is being A stopper pin 44 is provided above the side plate of the etching device 3 to prevent the rear end of the master carried out from the etching roller pair 28 from coming into contact with the side plate or the like in cooperation with the push-up rollers 37. Note that the etching device 3 is open above.

Next, the operation of the above will be explained.

When the printing press starts to drive, as shown in FIG. 3, the plate feeding roller 22 and the etching roller pair 28 begin to rotate, and the master is transported inside by the plate feeding roller 22, but the stopper 26 is at the position indicated by the solid line. Because of this, the tip of the master comes into contact with this and is stopped.

In this case, since only a light steel ball 23 is placed on the upper part of the plate feeding roller 22, no more than necessary force is applied to the master. After that, when the operation switch (not shown) is actuated, the solenoid 24 is activated and the swinging member 25 is swung as shown by the chain line, so that the stopper 26 is at the position shown by the chain line below the conveyance path 21, and the master is moved to the plate feeding roller 22. It is sent to the etching roller pair 28 by. The master passes through the etching roller pair 28 and is etched on the conveyance path 3.
0 to the plate feeding section of the plate supply/discharge device 9 shown in detail in FIG.

The master fed by the plate feeding section activates the multi-loss switch 12 provided in the conveyance path 11 to come into contact with the stopper 17 indicated by the chain line and stop. The master tip pressing member 31 is actuated to swing downward, and its tip presses and holds the tip of the master against the conveyance path 11. In this case, the tip of the master tip pressing member 31 is a rubber plate 45 as shown in FIG. 5, which prevents the surface of the master from being scratched.

When the tip of the master is pressed and held by the master tip pressing member 31, the rear end of the master is still located within the etching roller pair 28, and the rear end of the master M is moved to the third position by the conveyance of the etching roller pair 28. As shown in the figure, the guide plate 32 bends upward along the lower surface, and at the same time,
A drive source (not shown) is actuated by a setting device (not shown) that receives the signal from the microswitch 12, and the cam 4 is activated.
2 rotates to disengage the pin 41 from the push-up lever 36, the push-up lever 36 is pushed up by the coil spring 39, thereby causing the push-up roller 37 to move against the deflection of the master M. The upper part is supported under tension by a certain biasing force from the back side and lifted (see the solid line in Figure 3).
At this time, since the bent portion is lifted up while forming its top with the push-up rollers 37 having a predetermined radius of curvature, even if the image portion at the rear of the master is a flat portion, it is not the same as the conventional image portion. The occurrence of folds at the border with the non-image area is extremely reduced. When the rear end of the master is carried out from the frontmost pair of etching rollers 28, the stopper pin 44 pushes up the roller 3 to prevent the rear end of the master from contacting a side plate or the like.
7 (see the two-dot chain line in Figure 3). cam 4
2 further rotates, the pin 41 descends, and the push-up lever 36 engaged with this pin 41 also begins to descend, and when the pin 41 reaches the lowest position, the setting device (not shown) ), the drive source (not shown) is stopped, and the push-up lever 36 is held at the lowest position. At this time, the rear part of the master is placed and held on the upper surface of the placing plate 34 (see the dashed line in FIG. 3). Further, when the setting device (not shown) is activated by the operation of the microswitch 12 after a predetermined period of time has elapsed, that is, when the rear part of the master M is not held on the mounting plate 34, the plate feeding section of the plate feeding/discharging device 9 is activated. Activate.

Due to the operation of the plate feeding section, a cam 16 provided coaxially with the copper plate 5 starts to rotate, so that the upper plate feeding roller 14 swings downward and engages with the lower plate feeding roller 15 . Due to this swinging of the upper plate feeding roller 14, the stopper 17 also moves to a position below the conveyance path 11, and furthermore, the solenoid 33 becomes inactive, and the master tip presser member 31 also moves its tip away from the upper surface of the conveyance path 11. As a result, the tip of the master is fed into the master clamp device 4 provided on the plate cylinder 5 by the upper and lower plate feeding rollers 14 and 15, and is mounted on the plate cylinder 5. After this, the printing operation is performed using the paper placed on the paper feed table 10 as in the conventional case. When a cleaner sheet for cleaning the inking device 8 provided near the plate cylinder 5 or a master that does not require etching processing is attached to the plate cylinder 5, the upper surface of the etching device 3 is open. To insert the plate from there, the microswitch 12 provided in the conveyance path 11 of the plate supply/discharge device 9 is operated, and the subsequent operations are the same as described above.

What is shown in FIG. 6 is another embodiment of the plate feeding table 20 provided in the etching apparatus 3. When a large number of masters are placed on the feeding table 20, the plate feeding roller 46 sequentially etches the masters. The paper is fed into the apparatus, and if the plate feeding roller 46 is driven in response to a print end signal, it is possible to automatically print a plurality of types. Since the present invention is constructed as described above, the leading end of the master that has stopped when it comes into contact with the stopper is pressed against the conveyance path by the presser member and held, and the rear end of the master is held between the pair of etching rollers. In order to support the bent part under tension with the push-up member and push it upward,
The occurrence of bends in the master is extremely reduced. Also,
Since the rear part of the master is not sent out using a conveyor belt as in conventional systems, there is no staining of the image area on the surface of the master, and as a result, the etched master is supplied without impairing its function as a plate. be able to.
In addition, since the tip of the master that has stopped due to contact with the stopper is pressed against the conveyance path by the holding member as shown in the figure, the tip of the master is To prevent the master from separating from the stopper, and to maintain the tip of the master always in a fixed position in contact with the stopper in a standby state, so that the master can be reliably attached to the plate cylinder without causing a feeding error. It has excellent effects such as -.

[Brief explanation of drawings]

FIG. 1 is a schematic layout diagram showing an offset printing press according to the present invention, FIG. 2 is a detailed diagram of the plate feeding device of the one shown in FIG. 1, and FIG.
The figure is a detailed view of the etching device shown in Figure 1, Figure 4 is a schematic layout diagram showing the relationship between the cam, push-up lever, and mounting plate, and Figure 5 is a diagram showing the relationship between the master tip pressing member and its operating member. FIG. 6 is a schematic layout diagram showing another embodiment of the one shown in FIG. 3, FIG. 7 is a detailed diagram of a conventional etching apparatus, and FIG. 8 is a perspective view showing an example of a master. . 1... offset printing machine, 3... etching device, 4... master clamp device, 5...
...? Limit 9: Plate feeding and discharging device, 10: Paper feed table, 11, 21, 30: Conveyance path, 12...
...Micro switch, 13... Actuation part, 14
...Upper feed roller, 15...Lower feed roller, 17.
...Stopper, 20...Plate feeding table, 22...
... Plate feeding roller, 27 ... Etching liquid tank,
28... Etching roller pair, 31...
Master tip holding member, 32...Guide plate, 34
...Place plate, 36...Push lever,
37...Master push-up roller, 39...Coil spring, 41...Pin, 42...Cam, 43...Cam follower, 44... Stopper Pin.

Claims (1)

[Claims] 1. The distance between a stopper that positions the master to be mounted on the plate cylinder, a presser member that presses and holds the tip of the master that is in contact with the stopper against the conveyance path, and the rearmost pair of etching rollers and the stopper is an etching device arranged to be shorter than the length of the master; a push-up member for pushing up a bent portion of the master; and a mounting plate at the rear of the master, which is provided above the etching device and inclined in the transport direction of the master. A master feeding device in a lithographic printing press having a.