JP2968098B2 - Paper discharge device in stencil printing machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a paper discharge device in a stencil printing machine that performs printing using perforated base paper.

[0002]

2. Description of the Related Art A conventional stencil printing machine of this type is shown in FIG. 2 and has a large number of small openings for ink bleeding on the surface and clamps the leading end of the perforated base paper 2 on the outer peripheral wall. 1 includes a cylindrical plate cylinder 1 provided with a clamper 3 for pressing, and a press roller 4 for pressing a sheet 5 against the plate cylinder 1. The plate cylinder 1 is rotated clockwise by a drive unit (not shown) as shown by an arrow, and the ink supplied by an ink supply unit (not shown) provided in the plate cylinder 1 during printing is used for printing. The sheet 5 oozes out of the perforated base paper 2 through a large number of holes, and is conveyed from a paper feeding unit (not shown).
Is pressed against the perforated base paper 2 by the press roller 4 to perform printing. The paper 5 printed in this manner is peeled off from the perforated base paper 2 by air jetted from a tip port 32 for air jetting provided on the stripping claw 30. Supply air supply means; this air supply means
31 is a cylinder 34 connected to a peeling claw 30 and an air supply pipe 33.
One end of a link 16 is pivotally connected to the piston 14 mounted in the cylinder 34, and the other end is pivotally connected to a crank pulley 17 which rotates synchronously with the plate cylinder 1.
Is provided with a valve plate 18 for opening and closing the ventilation hole 13. Then, the sheet 5 peeled as described above is discharged to the transport belt 38 moved by the transport belt roller 37, and transported while being sucked by the suction fan 39. The piston 14 is positioned such that when the leading end of the paper 5 approaches the peeling claw 30, the air ejection speed is maximized. Note that
Numeral 40 denotes a paper feed registration roller.

[0003]

By the way, in such a paper discharge device, the paper 5 peeled off by the peeling claw 30 is provided.
If the sheet comes into contact with the peeling claw 30 before being discharged to the conveyor belt 38 and sucked by the suction fan 39, the image will be soiled. For that purpose, it is necessary to increase the ejection speed of the air ejected from the front end port 32 to make the paper 5 face downward. However, at this time, if the ejection speed is set too high,
There is a problem that the base paper 2 is peeled off from the plate cylinder 1, a large jetting sound of air is generated, or the load is increased because the air supply means 31 must be large.

Accordingly, an object of the present invention is to solve the above-mentioned problems of the conventional paper discharge device, and to remove the base paper from the plate cylinder by the air jetted from the stripping claws or generate a large jetting sound of air. Another object of the present invention is to provide a paper discharge device that does not require a large air supply means and does not increase the load.

[0005]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a cylindrical plate cylinder having a large number of openings for ink bleeding on its surface and wound with a perforated base paper; A stencil provided with a press roller for pressing a sheet against a plate cylinder, a peeling claw provided on the paper discharge side and having an air ejection port, and an air supply means interlocked with the plate cylinder and supplying air to the peeling claw. In a printing press, an abdomen port is provided in addition to the tip port as an air port of the peeling claw, and the timing of blowing air from these air ports is switched in accordance with the opening position of the plate cylinder. The air outlet speed after switching of the air outlet is set to be larger at the abdominal mouth than at the tip end.

[0006]

In the above-mentioned invention, when printing on a sheet by the plate cylinder is started, the air supply means operates in synchronization with the plate cylinder to supply air to the peeling claw, and the air is supplied to the separation claw. By jetting from the end opening and abdomen opening, the paper is peeled from the perforated base paper,
When the portion corresponding to the opening of the plate cylinder of the sheet thus peeled, that is, the printing portion, reaches the lower surface of the peeling claw, the speed of the air from the tip opening is reduced, and the air from the abdominal opening is reduced. The jet speed is increased to maintain such a state, and the air jetted from the abdominal opening presses the sheet downward, thereby preventing the sheet from contacting the peeling claw.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the embodiment of the present invention shown in FIG. 1, since many parts are the same as those of the prior art, these parts are referred to by the same numerals, and description thereof is omitted. explain. In this embodiment, reference numeral 6 denotes a peeling nail, which has an upper end 7 which is substantially parallel to the tangential direction of the nip for printing, and a lower opening 8 which is bent downward. I have. Numeral 11 denotes an air supply means, and the cylinder 12 has large and small through holes 15 and 24 in the wall 23 opposite the link 16 with the piston 14 interposed therebetween.
20 is fitted with a pipe 19, a sleeve 21 is attached to the outside thereof, and a spring 22 is housed therein.
The pipe 19 is always biased inward of the cylinder 12 via the. The sleeve 21 and the small through-hole 24 communicate with the distal end port 7 and the abdominal port 8 by air supply pipes 26 and 27, respectively.

In the above-described sheet discharging device, when printing on the sheet 5 by the plate cylinder 1 is started, the crank pulley 17 of the air supply means 11 is rotated synchronously with the plate cylinder 1 and the link 16 is rotated.
Movement of the piston 14 starts moving, and this piston
The paper 14 is supplied from the cylinder 12 to the peeling claw 6 through the air supply pipes 26 and 27 by the movement of the paper 14, and the printed paper 5 is peeled from the perforated raw paper 2 by the air jetted from the air jet ports 7 and 8 thereof. When the portion corresponding to the opening of the plate cylinder 1 of the paper 5 thus peeled, that is, the printing portion, reaches the lower surface of the peeling claw 6, the piston 14 abuts on the pipe 19 to close the entrance, and thereafter, A small amount of air is supplied from the pipe 19 to the distal end port 7 through the fine holes 25, and the injection speed of the air from the abdominal port 8 increases. Against this, the pipe 19 is pushed and the air ejected from the abdominal opening 8 pushes the paper 5 downward, thereby preventing the paper 5 from coming into contact with the peeling claw 6. In this embodiment, the timing of air ejection from the air outlets 7 and 8 is determined by the cylinder of the air supply means 11.
It is switched by 12, piston 14, pipe 19, etc.
Alternatively, a switching valve may be provided in the peeling claw 6 or the air supply pipe 26, or the like.

[0009]

The present invention is as described above, and has a cylindrical plate cylinder for winding a perforated base paper having a large number of openings for ink bleeding on the surface, and a press for pressing a sheet against the plate cylinder. A roller, a peeling claw provided on the paper ejection side and having an air ejection port,
In a stencil printing machine equipped with an air supply means for supplying air to the peeling claw in cooperation with the plate cylinder, an abdomen port is provided in addition to a tip port as an air outlet of the peeling claw, and these air outlets are provided. The time at which air is blown from the plate is switched in accordance with the position of the hole in the plate cylinder. Then, high-speed air can be injected from the abdominal opening to the paper thus peeled in this manner, and the paper can be reliably prevented from contacting the peeling claw. In this manner, the base paper may be peeled off from the plate cylinder by the jet air from the peeling claw, a large jetting sound of air may be generated, or the load may be increased without the necessity of increasing the size of the air supply means. There is no effect.

[Brief description of the drawings]

FIG. 1 is a vertical sectional front view of a main part of an embodiment of the present invention.

FIG. 2 is a front view similar to FIG. 1 of the same type as the conventional invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Plate cylinder 2 Base paper 3 Clamper 4 Press roller 5 Paper 6 Peeling claw 7 Tip opening 8 Abdominal opening 11 Air supply means 12 Cylinder 14 Piston 15 Large through hole 16 Link 17 Clamp pulley 19 Pipe 21 Sleeve 22 Spring 23 Wall surface 24 Small through hole 26, 27 Air supply pipe

Claims (2)

(57) [Claims] 1. A cylindrical plate cylinder having a large number of apertures for ink bleeding on its surface and wound with a perforated base paper, a press roller for pressing a sheet against the plate cylinder, and provided on a paper discharge side. In a stencil printing machine provided with a peeling claw having an air ejection port, and an air supply means interlocking with the plate cylinder and supplying air to the peeling claw, an abdomen other than a tip port as an air ejection port of the peeling claw is provided. A sheet discharge device having an opening and switching the timing of blowing air from these air outlets in accordance with the position of the opening of the plate cylinder. 2. The paper discharge device in a stencil printing machine according to claim 1, wherein the air ejection speed after switching of the air ejection port is made larger at the abdomen port than at the tip port.