JPH04129787A - Rotary type screen printing apparatus - Google Patents

Abstract

PURPOSE:To obtain good printed matter from the attachment time of a plate regardless of continuous printing and printing after long-time standing by a method wherein not only a sheet member is displaced to an operating position but also a press roller is brought into contact with a plate cylinder at the time of the mounting of raw paper on the plate cylinder and the plate cylinder is rotated a predetermined number of times to be subsequently displaced to a stand-by position and the raw paper is peeled from the plate cylinder to be disposed while new raw paper is mounted on the plate cylinder to carry out usual printing. CONSTITUTION:A sheet member 20 is set at the operating position between a plate cylinder 2 and a press roller 6 to be pressed to the plate cylinder 2 by the press roller 6 and the plate cylinder 2 is rotated the predetermined number of times set corresponding to a standing time to supply ink to the inner surface of the plate cylinder 2 from an ink supply apparatus to fill the perforations of the support cylinder and mesh screen of the plate cylinder 2 with ink. Thereafter, the press roller 6 is separated from the plate cylinder 2 to retract the sheet member 20 to a stand-by position and raw paper up to now is peeled from the plate cylinder to be disposed and new raw paper is mounted on the plate cylinder to carry out a normal printing process. Since the perforations of the plate cylinder are sufficiently filled with ink, good printed matter is obtained from the attachment time of a plate.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a rotary stencil printing apparatus.

In a conventional rotary stencil printing apparatus, generally, as illustrated in FIG. 3, a metal support cylinder 2a with numerous holes and a mesh screen layer made of, for example, mesh polyester fibers are attached to the outer circumference of the metal support cylinder 2a. A perforated stencil paper 1 is held in a cylindrical perforated rigid plate cylinder 2 consisting of a cylinder 2b, and its tip is gripped by a clamper 3 provided on the plate cylinder 2, and then the base is placed inside the plate cylinder 2. The ink is applied to the outer peripheral surface of the plate cylinder 2 by the viscosity of the ink supplied to the numerous holes of the support cylinder 2a by the ink supply device provided by the ink supply device, and seeped out onto the outer periphery of the screen layer 2b.

The cylindrical plate cylinder 2 with the stencil paper 1 mounted on its outer circumferential surface is supplied with ink to its inner circumferential surface by an ink supply device, and is rotated around the shaft 16 by an electric motor.
Press roller arm 11 and press roller support arm 13 are supported by stencil paper 1 and spring 12 attached to the circumferential surface of
The printing paper 15 is sequentially fed between the press roller 6 which is urged toward the outer periphery of the plate cylinder 2 through the cylindrical plate cylinder 2.
Cam 7 rotates integrally with plate J] M2 in synchronization with the rotation of
The printing paper 15 is controlled by the press roller 6.
Printing is performed by conveying the stencil paper 15 while being pressed against the stencil paper 1, and moving the ink onto the printing paper 15 through the holes in the stencil paper 1.

As shown in FIG. 3, the press roller arm 11 has its lower end secured to a stopper 10 except during printing, and is pivotally supported at the tip of a press roller support arm 13 fixed to the spindle of the press roller arm 11. The press roller 6 is held at a position separated from the plate cylinder 2. As shown in FIG. 3, the cam 7 has a range corresponding to the non-perforated area where the stencil paper 1 is not wound around the plate cylinder protruding from the reference circle, and a part corresponding to the perforation range coincides with the reference circle. ing. A pair of registration rollers 8 are provided to feed the printing paper 15 at a timing that coincides with the leading edge of the image area on the stencil paper 1 wound around the rotating plate cylinder 2 during printing.

A feeler 9 that senses the paper is fixed to the shaft of the stopper 10 at a position immediately after the pair of registration rollers 8 in the paper feed path, and when the printing paper 15 passes over it during paper feeding, the feeler 9 detects the paper. As shown in FIG. 4, the paper 15 pushes down the feeler 9, rotates the stopper 10 counterclockwise in the figure, releases the engagement with the press roller arm 11, and moves the cam follower 11 at the upper end of the press roller arm. While a faces the reference inner portion of the cam 7 with a slight gap, the press roller arm 11 is pulled by the spring 12 and rotates clockwise around its fulcrum, and the press roller 6
is brought into pressure contact with the base paper 1 on the plate cylinder 2, the cam follower lla engages with the protruding part of the cam 7 in the non-perforated part of the plate cylinder 2, and the press roller 6 is moved to a position away from the plate cylinder as shown in FIG. When the paper 15 has finished passing through the feeler 9, the feeler 9 rotates clockwise and the stopper 10 locks the press roller arm 11.

When printing is performed, ink is consumed in the perforated portions of the stencil paper 1, ink is supplied to the screen layer 2b from the holes in the support cylinder 2a, and ink is supplied to the holes in the support cylinder 2a by an ink supply device. .

In the example shown in FIG. 3, the ink supply device includes an ink supply roller 4 that contacts the inner circumferential surface of the plate cylinder 2 at a position facing the press roller 6 and rotates around its own axis in the direction of the arrow; A doctor roller 5 is provided with a slight gap therebetween and rotates around its own axis in the direction shown by the arrow in the figure, and a doctor roller 5 (not shown) that transmits the rotation of the cylindrical plate cylinder to these rollers 4 and 5 to rotate them. A drum shaft 1 that is formed as a hollow shaft with a gear train and a plurality of holes on the lower surface and also serves as an ink supply pipe.
6.

The V-shaped groove formed by the ink supply roller 4 and the doctor roller 5 forms an ink reservoir 17, and the ink sucked up and discharged from the ink pack by the ink pump is supplied to the ink reservoir 17. .

The ink in the ink reservoir 17 is taken along with the rotation of the ink supply roller 4 and the doctor roller 5, and is metered as it passes through the gap (doctor gap) between these rollers.
, an ink film is formed on the outer circumferential surface of the ink supply roller 4 , and the ink film is carried by the ink supply roller 4 and supplied to the inner circumference of the cylindrical plate cylinder 2 .

Now, in the rotary stencil printing apparatus with the above configuration, when printing is carried out by loading another plate immediately after printing with the previous plate is completed, the supporting cylinder of the plate cylinder and the mesh screen are sufficiently inked. However, if you print on a new base paper after being left for a long time, the support cylinder of the plate cylinder and mesh screen will be damaged. The ink components in the holes are reduced by evaporation or absorption by the base paper, and several sheets of waste paper are required until enough ink is supplied to obtain a good image.

In order to solve this problem, we have provided a means to increase the contact pressure between the plate cylinder and the ink supply port roller. Japanese Patent Laid-Open No. 61-188180 discloses a stencil printing device that increases the amount of ink adhering to the paper by increasing the amount of ink attached to the paper and reduces the number of sheets of waste paper. Mesosh screen,
Since the stencil paper is soft to some extent, it is not possible to increase the contact pressure very much, and it takes time to supply enough ink to adhere the appropriate amount of ink, and uneven contact pressure causes ink unevenness. The disadvantage is that it is not possible to obtain better printed matter than with plate printing.

Problems to be Solved by the Invention The present invention has been made in view of the above-mentioned drawbacks of conventionally implemented and proposed rotary stencil printing apparatuses having the above-mentioned configuration, regardless of continuous printing or printing after being left for a long time. An object of the present invention is to provide a rotary stencil printing device that can produce good quality printed matter and reduce the amount of waste paper.

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention provides a rotary stencil printing apparatus having the above-mentioned configuration, with an operating position inserted between the press roller and the plate cylinder, and an operating position inserted between the press roller and the plate cylinder. A sheet member displaceable between a standby position retracted outside the printing paper conveyance path between the plate cylinder and a means for displacing the sheet member between the operating position and the standby position is provided. During printing, the sheet member is moved to the operating position, the press roller is brought into pressure contact with the plate cylinder, and after rotating the plate cylinder a predetermined number of times, it is moved to the standby position, and the original paper is peeled off from the plate cylinder and discarded. The present invention is characterized in that a control means is provided for controlling so that a new base paper is plated and a normal printing process is performed.

Function Since the structure is as described above, when printing is to be performed on a new stencil sheet after it has been left for a certain period of time, the sheet member is inserted into the operating position between the plate cylinder and the press roller, and the sheet member is pressed by the press roller. By pressing the member against the plate cylinder and rotating the plate cylinder a predetermined number of times set according to the standing time, ink is supplied to the inner surface of the plate cylinder by the ink supply device, and the support cylinder of the plate cylinder and mesh screen are opened. The holes are filled with ink. After that, the press roller is separated from the plate cylinder, the sheet member is retracted to the standby position, the old base paper is peeled off from the plate cylinder and discarded, the new base paper is applied, and the normal printing process is carried out to remove the ink. Since the apertures of the plate cylinder are sufficiently filled, good quality printed matter can be obtained from the time of printing, and waste paper will not be generated.

Embodiments Below, embodiments of the present invention will be explained in detail based on the drawings.

FIG. 1 is a diagram showing the configuration of the vicinity of the plate cylinder and press roller of an embodiment in which the present invention is applied to the rotary stencil printing apparatus previously described with reference to FIGS. 3 and 4. FIG. Therefore, members having the same functions are given the same reference numerals, and the explanation will focus on the differences.

In this embodiment, in addition to the press roller 6 being rotatably supported at the tip of the press roller support arm 13 as in the conventional case, there is also a press roller 6 supported over the entire length of the plate cylinder at the lower end of a downwardly projecting protrusion 13a. A plate member 20a that holds a flexible sheet member 20 extending from the front end thereof is pivotally supported. The shaft 21 of the plate member 20 a holding the flexible sheet member 20 is rotated by the first solenoid 22 fixed to the press roller support arm 13 via links 23 , 24 and a spring 25 . When turned on, the sheet member 20 is inserted between the plate cylinder 2 and the press roller 6 as shown in FIG. Also, when the first solenoid 22 is turned off, the spring 2
5 rotates the shaft 21 clockwise, and the sheet member 20 is retracted from the paper path between the plate cylinder 2 and the press roller 6.

Also, a stopper 1 locks the lower end of the press roller arm 11 and holds the press roller 6 at a position separated from the plate cylinder 2.
A second solenoid 26 is provided to displace a release member 27 that releases the 0 without using the paper detection feeler 9.

The configuration other than the above is the same as the device shown in FIG.

Since this device is configured as described above, when a printing command is issued after being left unused for a certain period of time, the plate cylinder 2 is rotated clockwise by a motor (not shown), and after the amount of ink is detected by an ink detection member (not shown). , the first solenoid 22 is turned on, and the sheet member 20 is displaced to the operating position where it is inserted between the plate cylinder 2 and the press roller 6. Next, the second solenoid 26 is turned on, and when the cam follower lla at the upper end of the press roller arm 11 is engaged with the protrusion of the cam 8, the stopper 10 is released, and the cam follower lla moves inside the cam 70 as shown in FIG. When the arm 11 is pulled by the spring 12 and rotates around the fulcrum, the arm 11 rotates clockwise together with the press roller support arm 13, and the press roller 6 moves the sheet member 20 onto the plate cylinder. Press onto the rolled base paper. The number of rotations of the plate cylinder 2 in the pressed state is set in advance to the number of times that the apertures of the plate cylinder are sufficiently filled with ink depending on the standing time, and can be decreased if the standing time is short.

After the second solenoid 26 is turned off after the set number of rotations, the stopper 10 becomes free (when the cam follower lla of the arm 11 engages with the protrusion of the cam 7, the arm 11
rotates counterclockwise, its lower end is locked by the stopper 10, and the press roller 6 is held at a separated position. When the first solenoid 22 is turned off, the sheet member 20 is moved between the press roller 6 and the plate cylinder 2. As shown in FIG. 2, it is retracted from the gap and held at the standby position.

After that, the base paper is peeled off from the plate cylinder 2 by a plate discharge device (not shown) and discarded, and a new base paper perforated by a thermal head or the like is attached to the plate cylinder 2 with its leading end held by a clamper 3.

A sheet 15 is sent to a pair of registration rollers 8 by a sheet feeding device, and is fed between a plate cylinder 2 and a press roller 6 at a timing controlled by a sector gear, etc., and when the sheet passes over a feeler 9, a stopper is applied. 10 is removed, the press roller 6 rises and presses the paper, and printing (test printing) is performed. At this time, the holes in the plate cylinder are sufficiently filled with ink, so
By printing, it is possible to obtain good printed matter without ink marks or unevenness, and it is possible to prevent the occurrence of waste paper. The subsequent printing process is conventional.

As a result of the experiment, a printed matter equivalent to that obtained by printing the plate after being left for 30 days, rotating the plate cylinder at 4 rpm, and rotating the plate 10 times with the sheet member interposed (continuously used without any standing time) was obtained.

As described above, according to the present invention, with a simple configuration and control, even if the plate cylinder is left for a long time, the openings in the plate cylinder are sufficiently filled with ink, and then the base paper is replaced. It is possible to obtain good printed matter without unevenness, and it is possible to prevent the occurrence of waste paper.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing the configuration near the plate cylinder and press roller of an embodiment of the present invention, FIG. 2 is a cross-sectional view explaining its operation, and FIG. A cross-sectional view showing the structure near the press roller, and FIG. 4 is an explanatory diagram explaining its function. 8... Registration roller 9... Detection feeler 10... Stopper 11... Press roller arm 12... Spring 13... Press roller support arm 15... Printing paper 20... Sheet member 22... ...First solenoid 23,24...Link 26...Second solenoid 27...Release member diagram

Claims (1)

[Scope of Claims] Perforated stencil paper is wound around the outer periphery of a perforated rigid plate cylinder, and printing paper is pressed by a press roller that can come into contact with and separate from the stencil paper wrapped around the plate cylinder, In a rotary stencil printing device that performs printing by transferring ink supplied to the inner peripheral surface of the plate cylinder and seeped out through holes in the plate cylinder and stencil paper onto the printing paper, the press roller and the plate cylinder are connected to each other. a sheet member movable between an operating position inserted therebetween and a standby position retracted outside the printing paper conveyance path between the press roller and the plate cylinder;
Means for displacing the sheet member between the operating position and the standby position is provided, and at the time of printing, the sheet member is displaced to the operating position and the press roller is pressed against the plate cylinder, and the plate cylinder is moved a predetermined number of times. The printing press is characterized by being provided with a control means for controlling the printer to rotate and then move to a standby position, peel off the old base paper from the plate cylinder and discard it, apply a new base paper, and perform the normal printing process. A rotary stencil printing device.