JP2000006371A - Delivery sheet brake for sheet-fed printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform double-side printing by sheet braking by an air jet at a suitable timing during a period from when a printing sheet is released from a chain gripper at a certain angle from forward vertical directions of the sheet to when the sheet is brought into contact with a sheet guide, thereby eliminating a vacuum wheel. SOLUTION: An inertial speed of a printing sheet P is braked by an air jet of an air jet nozzle 9 at an angle from vertical directions at a suitable timing during a period from when the sheet P is released from a chain gripper 1 to when the sheet P is brought into contact with a sheet guide 5. As a result, the sheets P are regularly stacked and aligned on a delivery sheet base 6. Air jet pressures in vertical, lateral and oblique directions of the air jet are regulated according to a speed change of the sheet P. Thus, since no vacuum wheel is used, the overall sheet can be printed without contaminating a rear surface of the sheet.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet-fed printing press for transporting printing paper from a discharge cylinder to a discharge tray by a chain gripper.

[0002]

2. Description of the Related Art A delivery sheet brake device of a conventionally known sheet-fed printing press sucks printing paper on an air vacuum wheel, drives the air vacuum wheel with a motor, and controls the speed of the air vacuum wheel with respect to the speed of the machine. There is a device that adjusts the speed with a motor and applies a seat brake to inertia due to the speed of printing paper.

[0003]

However, with the above-described apparatus, sheet-fed printing presses have also largely flowed from single-sided printing to double-sided printing. In the case of single-sided printing, there was no problem even when sucking on the vacuum wheel because it was not printed on the back side,
In the case of double-sided printing, printing is performed also on the back side, so that if it is sucked on the vacuum wheel, a problem of stain on the printed surface occurs. Therefore, all of the conventional double-sided printing presses cannot print the entire back surface.

[0004] Even if the width of the vacuum wheel is narrowed, it is impossible to print both sides unless some margin is provided on the printing surface of about 8 mm and the vacuum wheel is set in that portion. In view of the above problems, an object of the present invention is to provide a sheet brake device capable of applying a sheet brake to inertia due to the speed of printing paper without using a vacuum wheel in double-sided printing of a sheet-fed printing press and performing full-surface printing on the back side. And

[0005]

SUMMARY OF THE INVENTION In order to achieve the above object, a delivery sheet brake device of a sheet-fed printing press according to the present invention uses a conventional vacuum wheel suction device to stop inertia due to the speed of printing paper. Instead, the seat brake is applied with an air jet at a certain time from the time when the chain gripper releases the printing paper and hits the paper abutment at an angle from the upper and lower two directions from the front of the printing paper. Also, the pressure of the air jet blown from up, down, left, right and oblique directions of the air jet is adjusted by changing the speed of the printing paper.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described based on embodiments with reference to the drawings. FIG. 1 is a schematic drawing of a delivery seat brake device provided with an air jet nozzle. FIG. 2 is a schematic drawing of the delivery seat brake device of the present invention. In FIG. 1, a printing paper P is conveyed by a chain gripper 1 from a paper output cylinder 2 and is stacked on a paper output table 6 in a regular manner. It is a ruler for aligning.

In order to stop inertia due to the speed of the printing paper, the printing paper is sucked to the vacuum wheel 3 and the motor 4 is sucked.
By driving the vacuum wheel 3 and adjusting the motor driving speed according to the speed of the printing paper, the sheet brake can be applied and the printing papers can be stacked neatly.

If the vacuum wheel 3 is not used, the printing paper P cannot be aligned neatly due to the inertia of the speed of the printing paper P.

Therefore, a print portion 10 and a print margin portion 11 which require a place where the vacuum wheel can be set on the back surface of the printing paper are absolutely necessary. Therefore, the entire back surface cannot be printed. In addition, the printing paper in the margin is wasted.

In FIG. 2, a printing paper P is conveyed from a paper discharge cylinder 2 by a chain gripper 1 and is stacked on a paper discharge table 6 in an orderly manner. The paper blank 5, the horizontal paper blank 7, and the rear paper blank 8 are rulers for orderly stacking printing paper.

By stopping the inertia due to the speed of the printing paper and blowing the air jet nozzle 9 at an angle from the upper and lower directions at an appropriate timing, the sheet brake can be applied and the printing paper can be aligned in order.

Therefore, since the vacuum wheel is not used, the entire surface can be printed on the back surface.

[0013]

According to the present invention, the delivery sheet brake device of the sheet-fed printing machine is arranged so that the chain gripper 1 strikes the paper contact 5 from the time when the printing paper P is released.
The air jet nozzle 9 applies an angle from the direction to apply the sheet brake to the inertia due to the speed of the printing paper, and the conventional device that sucks the vacuum wheel 3 to apply the seat brake to the inertia according to the speed of the printing paper P has two sides. In the case of printing, the conventional seat brake device has a problem of smearing on the entire back surface printing, and is impossible.

In the present invention, since the seat brake is applied by the air jet ejected from the air jet nozzle without using the vacuum wheel 3 under the stain, there is no problem of the stain. Therefore, the entire surface can be printed on the back surface. Therefore, there is an effect that all double-sided printing can be performed.

[Brief description of the drawings]

FIG. 1 is a side view of a delivery seat brake device of the present invention.

FIG. 2 is a plan view of a vacuum wheel unit.

FIG. 3 is a side view of a vacuum wheel unit.

FIG. 4 is a side view showing a state where an air jet nozzle is installed.

FIG. 5 is an enlarged plan view of a part of FIG. 4;

FIG. 6 is an enlarged side view of a part of FIG. 4;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Chain gripper 2 Discharge cylinder 3 Vacuum wheel 4 Motor 5 Paper contact 6 Discharge stand 7 Cross paper contact 8 Back paper contact 9 Air jet nozzle 10 Printing part 11 Printing margin part P Printing paper

Claims (1)

[Claims] 1. An apparatus in which printing paper is conveyed from a paper discharge cylinder (2) of a printing machine to a paper discharge table (6) by a chain gripper (1), wherein the chain gripper (1) removes the printing paper (P). When the paper is released, the sheet is braked by the air jet of the air jet nozzle (9) and the inertia due to the speed of the printing paper is applied with an angle from the upper and lower directions at a certain timing while hitting the paper (5). ) Is stacked on the delivery tray (6) in an orderly manner.