JPH06155884A - Cylinder for rotary stencil printer - Google Patents

Abstract

PURPOSE:To make a prescribed quantity of ink ooze out constantly from the surface of a plate cylinder even when a working environment and working conditions change, by a construction wherein an inking roller is fitted rotatably inside the plate cylinder and a gap of a specified dimension enabling passing of ink is formed by putting the outer peripheral surface of the inking roller and the inner peripheral surface of the cylinder in a state of noncontact. CONSTITUTION:An ink tank 18 is joined onto the suction side of an ink pump 17 and an ink pipe 19 onto the discharge side thereof, while the other end of the ink pipe 19 is connected to one end of a rotating shaft 2 by a joint 20 using a leak preventing means, and further made to communicate with an introducing passage 21 made by boring in the rotating shaft and opens in the central part of a cylindrical body l. An inking roller 6 is supported axially by an inking roller shaft 27 being in parallel with the rotating shaft 2 and it rotates while maintaining a prescribed roller gap 5 enabling passing of ink between the outer peripheral surface of the inking roller 6 and the inner peripheral surface of a mesh cylinder 1a. The gap 5 is made larger than 0mm and equal to or smaller than 1.5mm and is so made that the ink alone can be present therein.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention applies a plate-making base paper to a cylindrical plate cylinder, and allows ink leaching from the inside of the plate cylinder to be exposed on the surface through the plate-making part of the base paper. The present invention relates to a plate cylinder for a rotary roller copying machine, which feeds a printing paper while rotating in close contact with a cylinder and transfers the ink of a plate making portion onto the paper for printing.

[0002]

2. Description of the Related Art As a conventional plate cylinder for a tumbling photocopier, ink is injected into a hollow cylinder, and the surface of the cylinder is naturally moved by the capillary action of the screen and the centrifugal force generated by rotation during printing. A method of leaching ink is well known.

[0003] In the conventional well-known device, the ink is spontaneously leached onto the cylindrical surface only by the capillary action of the screen and the centrifugal force caused by the rotation during printing. However, even if the viscosity of the ink increases during cold weather and it becomes difficult to permeate to the outer circumference, this cannot be compensated for.

In order to overcome such a problem, there has been proposed a plate cylinder for a rotary copying machine in which an ink supply roller (inking roller) is provided in a cylindrical body (Japanese Patent Laid-Open No. Sho 5).
7-51483).

The plate cylinder for a rotary copying machine is provided with a rotary shaft and a stencil sheet supported on the rotary shaft and extending concentrically around the rotary shaft and on the outer peripheral surface thereof, and the rotary shaft itself is mounted by the rotary shaft. A porous cylindrical plate cylinder (cylindrical body) which is driven to rotate about a central axis, and a central axis of the cylindrical plate cylinder in a space between the rotary shaft and an inner peripheral surface of the cylindrical plate cylinder. An ink supply roller that is supported by rotating shafts that are arranged in parallel and that is arranged to contact the inner peripheral surface of the cylindrical plate cylinder at the outer peripheral surface and that rotates around its own central axis; and an outer peripheral surface of the ink supply roller. An ink applying device for applying an ink layer of a predetermined thickness to the press roller, a press roller having an outer peripheral surface arranged to face the outer peripheral surface of the cylindrical plate cylinder and rotating around its own central axis; On the rotary shaft of the plate cylinder and the rotary shaft of the ink supply roller A drive for rotating the ink supply roller according to the rotation of the cylindrical plate cylinder, which includes two pulleys each having the same diameter and attached to each other and an endless belt wound between the two pulleys. It has a force transmission means.

The ink in the cylindrical plate cylinder is pressed by the squeegee action (squeezing action) of the ink supply roller which is in contact with the inner peripheral surface of the cylindrical plate cylinder, and the cylindrical plate cylinder is pressed. Leach outside.

A cylindrical cylinder for squirting ink is rotatably provided in the cylindrical plate cylinder, and the amount of ink is electrostatically charged between the cylindrical cylinder and the inner peripheral side surface of the cylindrical plate cylinder. A plate cylinder for a rotary copying machine in which an ink groove portion (space) in which an electrode for internal detection is formed is already proposed by the applicant of the present application (Japanese Patent Laid-Open No. 56-72987).

[0008]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
In the plate cylinder for a rotary copying machine disclosed in Japanese Patent No. 483, as described above, the ink supply roller comes into contact with the cylindrical plate cylinder,
The squeegee action of the contact pressure causes the ink to seep out of the cylindrical plate cylinder.

Therefore, the ink is always leached to the outside under a constant pressure, the physical properties of the ink change with temperature changes, and if the viscosity decreases, the ink leaches too much,
Further, if the viscosity is increased, there is a possibility that the ink may not be sufficiently leached out.

Further, since the leaching pressure of the ink is constant, only a certain amount of ink is leached out regardless of the size of the opening area of the master paper that has been plate-made, and the density of the document image formed on the master paper is high. If the density of the printed image is low, there is a risk that the ink will be excessive.

Further, in the plate cylinder for a rotary copying machine disclosed in Japanese Patent Laid-Open No. 56-72987, a twist cylinder is provided, but an ink supply roller is not provided,
On the inner peripheral side surfaces of the twist cylinder and the cylindrical plate cylinder, only a space in which electrodes are installed is formed.

Therefore, the ink in the cylindrical plate cylinder is not subjected to the leaching pressure by the twist cylinder, but the ink is leached by the differential of the inner and outer cylinders, which will be described when the conventional technique is described. Problems that have been solved cannot be solved.

[0013]

SUMMARY OF THE INVENTION According to the present invention, a cylindrical body having an ink supplying means to the inside thereof and at least a part of a peripheral side surface of which is porous is inserted in the cylindrical body and is parallel to a generatrix of the cylindrical body. An inking roller fixedly mounted on a rotating shaft extending in the direction of rotation and extending in a direction parallel to the extending direction of the rotating shaft is provided between the rotating shaft and the inner peripheral side surface of the cylindrical body so as to be rotatable. In the plate cylinder for a rotary copying machine, the inking
The roller is mechanically connected to the rotary shaft via a rotation transmitting means, and the outer peripheral side surface of the inking roller and the inner peripheral side surface of the cylindrical body are not in contact with each other, and ink passes between them. It is characterized in that a gap of not more than 0 mm and not more than 1.5 mm is formed, and only the ink can intervene in the gap.

[0014]

In the present invention, an inking roller (ink supply roller) is provided in the vicinity of the inner peripheral side surface of the cylindrical body (plate cylinder), and between the inking roller and the inner peripheral side surface of the cylindrical body. Since there is formed a gap through which the ink can pass, the ink leaches out from the cylinder by the pressure generated by the relative speed between the inking roller and the inner peripheral side surface of the cylinder.

It should be noted that the pressing force of the ink on the cylinder at the closest position between the inking roller and the cylinder on the upstream side in the direction of rotation of the inking roller is as follows:
Regardless of the direction of rotation of the inking roller and the cylindrical body, the higher the relative speed, the higher the pressure.

[0016]

1 is a longitudinal sectional view and FIG. 2 is a lateral sectional view.

In these figures, reference numeral 4 denotes an inner cylinder, which is rotatably fitted on a plate cylinder shaft (rotating shaft) 2. 9a, 9
Reference numeral b is a side body, which is provided on both sides of the inner cylinder 4 and is fixed to the plate cylinder shaft 2 so as to rotate integrally.

A metal net or a metal plate, a synthetic resin film, and a porous rope-like body 1a having a large number of small through holes are wound around and fixed to the outer circumferences of the side trunks 9a and 9b. A cloth screen 1b made of silk, cotton, synthetic resin or the like is wound around and covered, and a cylindrical body 1 is formed by both of them, and the joint portion of the screen is pressed by a pressing plate 11 provided with a base paper fixing pin 10.

Both ends of the rotary shaft 2 have frames 12a and 12b.
A sprocket 13 for rotatably driving the plate cylinder is fixed to one end and is connected to a sprocket (not shown) on the side of the electric motor by a chain or the like.

A fixed spur gear 14 is provided on the inner surface of the shaft support portion of the frame 12a so that the planetary gears 15a and 15b pivotally supported by the side movement 9a rotate integrally with each other. Float around the perimeter. The planetary gear 15b meshes with and drives a spur gear 16 fixed to the side surface of the inner cylinder 4.

The ink pump 17 has an ink tank 18 joined to the suction side and an ink pipe 19 joined to the discharge side. The other end of the ink pipe 19 is connected to one end of the rotary shaft 2 by a joint 20 using a leak preventer, communicates with an introduction path 21 bored in the rotary shaft, and opens at the center of the cylindrical body 1. .

As means for supplying ink to the inside of the cylindrical body 1, in addition to the means such as the ink pump 17 as described above, an ink supply hole with a screw lid for supplying ink to the non-printing area is provided. Of course, well known means for supplying ink from the ink supply hole when the apparatus is stopped may be used.

Bearings 22a, 22b and oil seals 23a, 23b are provided at the fitting portion of the inner cylinder 4 with the rotary shaft 2.
Is inserted to prevent leakage of ink sent under pressure.

Further, the inking roller 6 is composed of the rotating shaft 2
Is supported by an inking roller shaft 27 parallel to the inner side surface of the rope 1a with a predetermined roller gap 5 through which ink can pass. Rotate.

A drive gear 28 is fixed to the rotary shaft 2, and the end portion (right side in FIG. 1) of the dispersion roller 25 parallel to the rotary shaft 2 is meshed with the drive gear 28 to form the dispersion roller gear 2.
9 is provided.

Further, an idle gear 30 is provided, and this idle gear 30 meshes with the dispersion roller gear 29 and also meshes with an inking roller gear 31 provided at the end of the inking roller 6. ing. The inking roller 6 has a width substantially equal to the printing width.

Further, the inking roller 6 may be mechanically connected to the rotary shaft 2 via a rotation transmitting means such as a pulley or a belt. On the outer circumference of the cylindrical body 1,
A pressure drum 32, which is rotatable and is pressed and driven by the rotation of the cylindrical body 1, is pressed by a spring 33 and attached freely.

In FIG. 2, reference numeral 34 denotes a paper tray, a paper feeding rubber roll 35 is provided on the upper front end, and a paper sliding plate 36 and a paper sliding upper plate 37 are opposed to the front thereof. A synchronous roll 38 is provided below the paper slide plate 36, and the paper slide upper plate 3 is provided.
Synchronous upper rolls 39 are axially supported so as to be opposed to each other above 7. Reference numeral 40 denotes a printing paper placed on the paper tray 34.

When the printing paper 40 is placed on the paper tray 34 and the printing is started, the printing papers 40 are fed one by one by the rubber feed roll 35, and the synchronization roll 38,
From the perforated portion of the plate-making base paper stuck to the outer periphery of the cylinder 1 when the printing is synchronized by the synchronous upper roll 39 so that the printing becomes a fixed position, and when the printing is clamped between the cylinder 1 and the impression cylinder 32 of the plate cylinder. The exposed ink is transferred and discharged in a printed state, and the printing process is completed. The plate cylinder portion which is the object of the present invention will be described below.

Fixed spur gear 1 fixed to frame 12a
4, the planetary gears 15a and 15b pivotally supported by the side body 9a, and the spur gear 16 fixed to the side surface of the arm 4 form a so-called planetary gear train, and form the cylindrical body 1 and the inner cylinder 4
(That is, the inking roller 6) can be differentially rotated.

When an ink amount appropriately set to obtain an appropriate print density is pressure fed from the ink pump 17, the ink is ejected into the cylindrical body 1 through the ink pipe 19, the joint 20 and the introduction passage 21. Further, the ink spreads to the left and right along the extending direction of the dispersion roller 25, moves from the dispersion roller 25 to the inking roller 6, rotates, and is transferred and applied to the inner circumference of the rope 1a.

In FIG. 2, the outer periphery of the inking roller 6 is drawn so as to approach in the direction opposite to the moving direction of the rope 1a and transfer the ink. Depending on the relationship, it may be better to rotate them in the same direction.

In any case, a predetermined roller gap 5 is provided between the inking roller 6 and the rope 1a so as not to cause an excessive increase in the pressure in the outer peripheral direction, and the ink consumption varies depending on the state of the printed document. The amount of leaching proportional to the amount is naturally obtained.

The roller gap 5 is about 0.5 mm in the experiment.
Good results were obtained between 1.5 mm. The ink gap 3 and the roller gap 5 are 1.5 m depending on the characteristics of the ink.
If it exceeds m, it becomes difficult to transfer and circulate.

When an ink having a low viscosity is used, the roller gap 5 may be about 0.1 mm, so long as the inking roller 6 and the rope 1a do not come into contact with each other, that is, the roller gap 5 is formed. Is larger than 0 mm, it can be put to practical use.

Due to the weak pressure in the roller gap 5 and the capillary phenomenon of the screen 1b, the ink is transferred to the screen 1
It appears on the surface layer of b and is printed on the printing paper 40 through the perforated portion of the plate-making base paper attached to this.

The inking roller 6 and the cylindrical body 1
Regardless of the direction of rotation with the (tether 1a), the higher the relative speed between the two, the higher the pressure on the ink,
It is easy to seep out from the screen 1b.

[0038]

According to the present invention, an inking roller is provided near the inner peripheral side of the cylindrical body, and a gap is formed between the inking roller and the cylindrical body to the extent that ink can pass through. Therefore, even if the components of the ink are separated, the ink is subjected to a forced wetting action by the inking roller, and the ink is easily mixed and restored by the wetting action.

Further, even if the physical properties of the ink change due to the temperature change, they are proportional to the above-mentioned changes in various places inside the plate cylinder (if the viscosity rises and the leaching degree decreases, the internal pressure rises to supplement the characteristics. There is a mechanical forcing force, which eliminates problems such as excess and deficiency of printing density and unevenness.

Furthermore, since the inking roller is not in contact with the inner peripheral side surface of the cylindrical body, there is a possibility that the ink will ooze out too much from the plate cylinder, and an appropriate amount of ink will always ooze out. Furthermore, when the relative speed between the inking roller and the cylinder is changed, the leaching pressure to the ink is changed, so that it can be easily brought to the optimum value.

Further, even when printing is in progress due to the small ink filling amount and the mechanical forcing force, when the ink pump 17 is actuated, the reaction immediately occurs and the printing becomes dark, so that the operation of ink replenishment is very easy to understand. .

In addition, since the ink appropriately leaches in response to the size of the opening area corresponding to the written image formed on the base paper, an appropriate amount of ink is always produced even if the density of the written image changes. It can be dipped to obtain a print of constant quality.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a plate cylinder according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram showing the relationship between the central cross section of the plate cylinder and the sheet feeding device according to the embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 cylindrical body 1a rope-like body 1b screen 2 rotating shaft 5 roller gap 6 inking roller 28 drive gear 29 dispersion roller gear 30 idle gear 31 inking roller gear.

Claims (1)

[Claims] 1. A cylinder having internal ink supply means, at least a part of the peripheral side surface of which is porous, is fixed to a rotary shaft which is inserted into the cylinder and extends in a direction parallel to its generatrix. An inking, which is provided between the rotary shaft and the inner peripheral side surface of the cylindrical body and extends in a direction parallel to the extending direction of the rotary shaft.
In a plate cylinder for a rotary copying machine in which a roller is rotatably mounted, the inking roller is mechanically connected to the rotating shaft via a rotation transmitting means, and the outer peripheral surface of the inking roller and the cylinder are There is no contact with the inner side of the body,
A plate cylinder for a rotary copying machine characterized in that a gap larger than 0 mm and not more than 1.5 mm is formed between them, and only the ink can intervene in the gap.