JPH0351593B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION In the present invention, a plate-made base paper is attached to a plate cylinder, ink is supplied from inside the plate cylinder, and the ink is ejected through the plate-making part of the base paper, and the impression cylinder and plate cylinder are connected to each other. This invention relates to an ink dispenser in a so-called single-cylinder rotary copying machine, which prints by rotating a plate cylinder through which a sheet of paper to be printed is passed between.

As shown in FIG. 3, the ink dispenser in a conventional single-barrel rotary copying machine has an ink dispenser roller 8 installed inside the plate cylinder 1 parallel to the axis of the plate cylinder 1.
This is connected to the operating shaft 10 via arms 11a and 11b, the operating shaft 10 is passed through the inside of the drive shaft 9, and is brought out of the plate cylinder, and the operating shaft 10 is appropriately rotated from the outside. The plate cylinder 1 can be brought into contact with the inner wall of the plate cylinder 1 for driven rotation, or can be held suspended from the inner wall.

In the conventional system, when the ink bleed roller 8 is brought into contact with the ink bleed roller 8 and activated, the pressure is increased hydrodynamically between the inner wall of the plate cylinder 1 and the ink bleed roller 8, and the ink oozes out of the plate cylinder. However, this pressure increase tends to be more than necessary, and there is a tendency for too much ink to come out, which has the disadvantage that printing suddenly changes from a light state to an excessively dark state.

Also, at this stage, the amount of ink transferred to the paper naturally becomes excessive, and the paper that is ejected in duplicate causes a so-called set-off phenomenon in which the ink printed on the lower paper transfers to the back side of the upper paper, resulting in poor print quality. tends to decrease. In addition, since the ink dispenser roller 8 rolls on the inner wall of the plate cylinder 1, it rides on parts of the ink injection section that protrude from the inner wall, producing noise and also damaging the ink dispenser roller 8.

SUMMARY OF THE INVENTION An object of the present invention is to provide a novel ink fountain device for a single-barrel rotary copying machine that overcomes the above-mentioned drawbacks.

The configuration of the present invention will be described with reference to an embodiment shown in FIGS. 1 and 2.

Reference numeral 1 denotes a plate cylinder, which is formed by tightly fixing a net-like cylindrical body 12 in which a large number of small holes are formed in a metal net, a metal plate, or a synthetic resin film to flanges 13a and 13b. The plate cylinder 1 has frames 14a, 14
It is fixed to a shaft 4 supported by bearings 15a and 15b fitted in the shaft 4, and is rotationally driven by a sprocket 16 fixed to one end of the shaft 4. Sprocket 16 is a sprocket on the motor side (not shown)
It is connected and driven by a chain. Reference numeral 17 denotes an ink injection port, which is used to inject an appropriate amount of ink in advance. Alternatively, the ink inlet 17 may be omitted and ink may be injected from the outside through one end of the shaft 4. The outer periphery of the reticulated cylindrical body 12 is covered with a cloth or metal screen 18, and both ends of the screen 18 are fixed to the outer periphery by suitable means. In addition, there is a protrusion 1 for holding the base paper at its upper end.
A restraining plate 20 provided with 9 is fixed.

An air inlet joint 21 is loosely fitted to one end 4a of the shaft 4 from the air inlet pump 2 through a discharge passage 3 using a leak prevention means, and is opened into the inside of the plate cylinder through a conduction passage 5 bored in the shaft 4. are doing. A cover 22 prevents ink from adhering to the opening 5a of the conduction path 5.

Pump 2 connects pump motor 23 to coupling ring 2
4, and each time the pump is driven, air is sucked in from the suction hole 25 of the pump and pumped into the discharge path 3.

On the outer periphery of the plate cylinder 1, an impression cylinder 7 which is rotatable and driven in contact with the plate cylinder 1 is mounted so as to be pressed by a spring 33. Reference numeral 26 in FIG. 2 denotes a paper mounting table, and a paper feeding rubber roll 27 is provided at the front end of the upper part, and a paper sliding plate 28 and a paper sliding upper plate 29 are provided to the left of the paper feeding rubber roll 27. A synchronous roll 30 is provided below the paper sliding plate 28, and a synchronous upper roll 31 is provided above the paper sliding upper plate 29.

When the printing paper 32 is placed on the paper tray 26 and the printing state is started, the paper is fed one by one by the paper feeding rubber roll 27, and then the synchronous roll 30 and the synchronous upper roll 31 are fed.
The paper is fed so that printing is at a fixed position, and the printing and paper are ejected by pressing the plate cylinder 1 and the impression cylinder 7 together.

Since this invention is configured as described above,
When using this, first put a predetermined amount of ink into the plate cylinder 1 from the ink inlet 17 and feed the paper by rotation.
The liquid permeates through the perforations of the base paper 6 attached to the outer periphery and is printed on the paper. In this case, if the amount of ink transferred to the paper is greater than the amount of ink that leaches out, the print will gradually fade. At this time, pump motor 2
3, the air supply pump 2 will operate,
Air is introduced into the plate cylinder 1. During printing, viscous ink adheres to the inner wall of the reticulated cylindrical body 12 as a result of rotation, and the inner wall of the cylinder 12 is in a kind of sealing state, so that when air is introduced, the inner pressure of the plate cylinder 1 increases.
However, compared to the internal volume of the plate cylinder 1, which is mostly occupied by air, the amount of air fed per stroke of the air feeding pump 2 is quite small (about one hundredth in the example shown). ), this increase in internal pressure occurs extremely slowly. Also, as is obvious, the discharge hole of the air supply pump 2 is provided with a valve, so that during the intake stroke, the air supplied into the plate cylinder 1 may flow backwards or may temporarily close the plate cylinder 1. Since there is no communication between the inside and outside, the increased internal pressure does not drop. Since this internal pressure is applied evenly to the ink layer attached to the inner wall of the reticulated cylinder 12, the ink oozes out evenly and slowly into the reticulated cylinder 12 and the screen 18, and a small amount of ink leaks out from the perforated portions of the base paper 6 where the plate is made. The print density gradually reaches the optimum print density.

If the operation of the air supply pump 2 is stopped at this stage, the air supply will stop and the internal pressure inside the plate cylinder 1 will gradually become equal to the external pressure. (Actually, about 500 pages of fine print originals) can be printed continuously at a suitable density.

Furthermore, it goes without saying that the same effect can be achieved even if the air supply pump 2 is operated manually, not by the pump motor 23.

Although an example is shown in which an independent pump is used as the air supply pump, it is obvious that a switching valve may be provided so that the pump can also be used as an ink pressure supply pump.

As described above, according to the present invention, when air is fed by the air feeding pump 2, the ink oozes out into the reticulated cylindrical body 12 and the screen 18 very slowly and uniformly, and the base paper 6 is Since the optimum printing density can be gradually reached through the transparent printing process, printing will not suddenly become too dark or set-off will occur, and if air supply is stopped at this stage, it will be possible to achieve the optimum printing density from now on. Printing can be continued at the optimum density for the number of sheets. Further, since an ink-feeding roller is not necessarily required inside the plate cylinder 1, no noise is generated, and the roller is not damaged and needs to be repaired. Note that even if an ink spitting roller is used, the effects of the present invention will not change. In addition, ink can be dispensed efficiently by simple operation of a push button switch or manual lever at appropriate times during operation, and printing density can be easily controlled by changing the number of operations of the air supply pump 2. At the same time, the pressure inside the plate cylinder can be detected by a detection means and the air supply pump can be operated. Furthermore, a conduction path 5 is formed in the shaft 4 located at the center of rotation of the plate cylinder 1, and air is introduced into the plate cylinder 1 through the opening 5a of the conduction path 5. Air can also be introduced during rotation.

[Brief explanation of drawings]

Fig. 1 is a vertical sectional view showing an embodiment of the present invention, Fig. 2
The figure is a central sectional view of FIG. 1, and FIG. 3 is a central sectional view showing an assembled state of a conventional ink fountain device and plate cylinder. 1: Plate cylinder, 2: Air supply pump, 3: Discharge path, 4: Shaft, 5: Conduction path, 5a: Opening, 6: Base paper, 7: Impression cylinder, 12: Reticulated cylindrical body, 13a, 13
b: flange, 14a, 14b: frame, 1
8: Screen, 21: Air supply joint, 23: Pump motor, 25: Suction hole.

Claims (1)

[Claims] 1 Plate cylinder 1 provided with an independent ink injection port 17 and a screen 18 on the outer periphery for attaching base paper 6
An air feeding pump 2 is provided outside of the plate cylinder 1, and a discharge passage 3 of the air feeding pump 2 is connected to a shaft 4 passing through the center of rotation of the plate cylinder 1 through an air feeding joint 21 and leak prevention means. The air fed from the air supply pump 2 communicates with the provided conduction path 5 and the opening 5a provided in the conduction path 5, and the air sent out from the air supply pump 2 is connected to the discharge path 3, the air supply joint 21, the conduction path 5, and the opening. A single cylinder characterized in that the ink inside the plate cylinder 1 is leached out to the outside of the screen 18 by being fed into the plate cylinder 1 through the plate cylinder 5a and increasing the pressure inside the plate cylinder 1. Ink dispenser for rotary copying machines.