JPH0620044U - Offset printing press front structure - Google Patents

Abstract

(57) [Summary] [Object] An object of the present invention is to provide a front contact structure of an offset printing machine that enables printing even on small printing paper. Immediately before the printing paper 16 is supplied to the blanket cylinder 20 and the impression cylinder 22, a position where the printing paper 16 is stopped by coming into contact with the leading edge of the printing paper 16 sandwiched by the feed roller 24 and the pressing roller 26, and the printing paper 16 In an offset printing machine having a front pad 32 that rotates to a position that allows forward movement, the axis of the feed roller 24 and the front pad 3
The two rotating axes are aligned.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an offset printing press front structure.

[0002]

[Prior art]

 In a conventional offset printing machine, just before supplying the printing paper to the blanket cylinder and the impression cylinder, the printing paper sent by the feeding mechanism is nipped by the feed roller and the pressing roller, and the leading edge of the printing paper is moved forward. It pauses at the pad and rotates the front pad in synchronism with the timing of the rotation of the blanket cylinder and impression cylinder to supply the printing paper. FIG. 5 is a schematic side view showing the structure of the front pad. The printing paper 4 sent by the feeding mechanism is nipped by the pressing roller 2 and the feed roller 3, and the leading end 6a of the front pad 6 is positioned at the leading end position of the printing paper 4 to temporarily stop the forward movement of the printing paper. . The front pad 6 is rotatable, and for example, a rotary shaft 6b is located behind the feed roller 3. When the printing paper 4 is supplied to the blanket cylinder 7 and the impression cylinder 8, the front pad 6 rotates about the rotation shaft 6b to release the printing paper 4 from the stopped state.

[0003]

[Problems to be solved by the device]

 However, when the front pad 6 rotates about the rotation shaft 6b to make the printing paper 4 forward, the front end 6a of the front pad 6 advances L and the front end 6a moves downward. Will be done. For this reason, it is necessary to secure a large gap between the feed roller 3 and the impression cylinder 8. That is, the pressure roller 8 is moved forward in order to secure a space of L or more in the front-rear direction between the feed roller 3 and the pressure roller 8 and to secure a space for the tip portion 6a of the front pad 6 to move downward. You have to move to the position. For this reason, at least the rear end of the supplied printing paper 4 is clamped by the pressing roller 2 and the feed roller 3, and at the same time, the leading end of the printing paper 4 is clamped by the clipper of the impression cylinder 8. I couldn't. For this reason, it was not possible to print small items such as business cards. Therefore, it is an object of the present invention to provide a front contact structure for an offset printing machine that enables printing even on small printing paper.

[0004]

[Means for Solving the Problems]

 In order to solve the above problems, the present invention has the following configuration. That is, immediately before the printing paper is supplied to the blanket cylinder and the impression cylinder, the position where it abuts against the leading edge of the printing paper nipped by the feed roller and the pressing roller to stop it, and the position where the printing paper can be moved forward. In an offset printing machine having a front pad that pivots to and, the axis of rotation of the feed roller and the pivot axis of the front pad are made to coincide.

[0005]

[Action]

 The operation will be described. The supply of printing paper is temporarily stopped by the front cover, and the front cover is rotated in accordance with the tamping of the blanket cylinder and the impression cylinder to release the stopped state and supply it. At this time, the front pad rotates about the same axis as the axis of rotation of the feed roller.

[0006]

【Example】

 Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. FIG. 1 is a schematic explanatory view showing the structure of an offset printing machine. In the offset printing machine 10, the printing paper 16 stocked for printing is supplied to the paper feeding conveyor 14 by the feeding mechanism 12, and the printing paper 16 is fed to just before the blanket cylinder 20 and the impression cylinder 22 by the paper feeding conveyor 14. 16 is supplied. Immediately before the blanket cylinder 20 and the impression cylinder 22, a feed roller 24 and a pressing roller 26 are arranged following the paper feed conveyor 14.

The structure of the feed roller 24 will be described with reference to FIGS. 2 to 4 together with FIG. 1. As shown in FIG. 4, shafts 24a and 24b having a reduced diameter extend from both ends of the feed roller 24. A cylindrical shaft 26a is provided on one shaft 24a so as to be rotatable separately from the shaft 24a via a bearing, and one end of the shaft 24a is a bearing fixed to the frame 11 of the offset printing machine 10. 28a is pivotally supported. A pulley 29 is provided at the tip of the shaft 24a. A cylindrical shaft 26b is provided on the other shaft 24b so as to be rotatable separately from the shaft 24b via a bearing. The tip of the shaft 24b is pivotally supported by a bearing 28a fixed to the frame 11.

Inner side surfaces of both ends of the side L-shaped front pad 32 are fixed to the cylinder shaft 26a and the cylinder shaft 26b. On the other hand, a pulley 30 is provided at the tip of the cylinder shaft 26b, and this pulley 30 can be rotated in the forward and reverse directions by a timing belt. The feed roller 24, the shaft bodies 24a and 24b, and the cylindrical shafts 26a and 26b have the same axis line 34. The cylinder shaft 26b is rotated by the forward and reverse rotations of the pulley 30, and the cylinder shaft 26a and the front pad 32 are rotated accordingly. The front end 32a of the front pad 32 is located at the stop position of the printing paper 16 (shown by the solid line in FIG. 3) and the paper feeding position where the stop of the printing paper 16 is released and advanced (shown by the broken line in FIG. 3). The front pad 32 rotates about the axis 34 so as to be positioned.

The pressing roller 26 that sandwiches the printing paper 16 together with the feed roller 24 will be described. The press roller 26 sandwiches the printing paper 16 with the feed roller 24, and three press rollers 26 are provided on the rotary shaft 36 above the feed roller 24. Both ends of the rotary shaft 36 are fixed to the tips of the support arms 38a and 38b. A support shaft 40 penetrates the rear ends of the support arms 38a and 38b, and the support arms 38a and 38b are fixed onto the support shaft 40. The support shaft 40 is supported at a proper position by a bearing or the like. A pulley 42 is provided at one end of the support shaft 40, and a tamping belt (not shown) is stretched around the pulley 42. Then, by rotating the pulley 42 in the forward and reverse directions, the pressing roller 26 moves to a position where the feed roller 24 and the printing paper 16 are nipped and a position where the pressing roller 26 is in a free state.

As shown in FIG. 2, a concave opening 22a is formed on the peripheral surface of the impression cylinder 22, and a gripper 18 for holding the printing paper 16 is arranged in the opening 22a.

Here, the operation of supplying the printing paper of the offset printing machine configured as described above will be described. The printing paper 16 stocked for printing is supplied to the paper feed conveyor 14 by the supply mechanism 12. By the paper feed conveyor 14, the pressing rollers 26, ... Are not in contact with the feed rollers 24, and the front pad 32 is fed to a position where the printing paper 16 has moved to the stop position (shown by the solid line in FIG. 3). . In the state where the printing paper 16 is stopped by the front pad 32, the front pad 32 is moved forward through the pulley 30 by releasing the stop of the printing paper 16 after waiting for the supply timing to the blanket cylinder 20 and the impression cylinder 22. Simultaneously with the rotation to the paper feeding position (shown by the broken line in FIG. 3), the pulley 42 of the support shaft 40 is driven to hold the printing paper 16 between the pressing roller 26 and the feed roller 24. Then, the printing paper 16 advances by the rotation of the feed roller 24, and the leading end of the printing paper 16 is gripped and supplied to the gripper 18 located in the opening 22 a of the impression cylinder 22. Then, printing is carried out by the blanket cylinder 20 and the impression cylinder 22 and discharged. When the front end of the printing paper 16 is gripped by the gripper 18 of the impression cylinder 22, it is necessary that at least the rear end of the printing paper 16 is sandwiched between the pressing roller 26 ... And the feed roller 24. .

It should be noted that when the front pad 32 is rotated between the stop position of the printing paper 16 (shown by the solid line in FIG. 3) and the paper feeding position of the printing paper 16 (shown by the broken line in FIG. 3), The axis 34 of rotation of 32 and the axis 34 of the feed roller 24 are the same, and the front pad 32 rotates about the axis 34 along the peripheral surface of the feed roller 24. That is, unlike the conventional case, the front pad 32 does not rotate or move largely in front of the feed roller 24. Therefore, the position where the leading edge of the printing paper 16 is gripped by the gripper 18 of the impression cylinder 22 and the position where the printing paper 16 is sandwiched between the pressing roller 26 ... And the feed roller 24 can be shortened. It is also possible to print small prints such as. Although various explanations have been given with reference to the preferred embodiments of the present invention, the present invention is not limited to the above embodiments, and many modifications can be made without departing from the spirit of the invention. Is.

[0013]

[Effect of device]

 In the structure of the front pad of the offset printing machine according to the present invention, the axis of the feed roller and the rotation axis of the front pad are aligned, so that the position where the printing paper is gripped by the gripper of the impression cylinder, the press roller and the feed roller are aligned. The position where the printing paper is held can be shortened, and a small printed matter such as a business card can be printed.

[Brief description of drawings]

FIG. 1 is a schematic explanatory view showing the structure of an offset printing machine according to the present invention.

FIG. 2 is a perspective view showing a front contact structure of an offset printing machine according to the present invention.

FIG. 3 is a side view showing a front contact structure of an offset printing machine according to the present invention.

FIG. 4 is a sectional explanatory view showing a structure of a feed roller.

FIG. 5 is a side view showing a conventional front contact structure.

[Explanation of symbols]

 10 Offset Printing Machine 12 Supply Mechanism 14 Paper Feeding Conveyor 20 Blanket Cylinder 22 Impression Cylinder 24 Feed Roller 26 Pressing Roller

Claims (1)

[Scope of utility model registration request] 1. Immediately before the printing paper is supplied to the blanket cylinder and the impression cylinder, the position where the printing paper sandwiched by the feed roller and the pressing roller is brought into contact with the leading edge and stopped, and the printing paper can be moved forward. An offset printing press having a front cover that rotates to a position, wherein the axis of rotation of the feed roller and the rotating axis of the front cover are aligned with each other.