JPS6227404Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to a printing pressure adjustment device for a lithographic printing press that prints by stacking papers on a horizontally placed flat plate and sliding a squeegee or upper roller under pressure. be.

In a lithographic printing press, a lower roller (drive roller or pressure roller) rotated by a manual handle or an electric motor is supported horizontally on a frame, and receiver rollers are placed in front and behind it, and a squeegee or upper roller whose vertical position is adjustable is supported horizontally on a frame. The flat plate is placed directly on the bed plate or via a surface plate, and then paper and a top plate are placed on top of the flat plate, which is placed on the receiving roller and the lower roller, and the squeegee or upper roller is placed on an appropriate Printing is performed by adjusting the pressure, pressing it onto the top plate, and rotating the lower roller to move it in one direction.

The squeegee or upper roller is attached to a holder that moves up and down along the frame. This holder is moved up and down by a cam directly connected to a pressure rod, and the printing pressure is adjusted by a push screw. At this time, the pressure rod is pushed down manually to rotate the cam and lower the holder. That is, the pressure rod and the cam constitute a crank mechanism, which is generally moved between the pressure position and the retracted position by turning about 90 degrees. Therefore, since the required distance is moved with a relatively small rotation angle, a large force is required when approaching the pressurizing position, and when printing is repeated many times, fatigue becomes severe and problems in printing work. It was becoming.

In this case, the pressure rod and the cam are connected via a connecting member, and the rotation angle of the pressure rod is made larger than before, but the rotation angle of the cam is kept at the same level as before, so it requires less force. A predetermined printing pressure is obtained,
This is designed to prevent significant fatigue even when printing is repeated many times.

An example of the present invention will be explained below with reference to the drawings.
A lower roller 3 rotated by a handle 2 is horizontally supported in the center of a frame 1 placed on the floor of the workshop, and an appropriate number of receiving rollers 4 are provided at the front and rear of the lower roller 3.
and support it horizontally on frame 1,
Both ends of the holder 8 of the squeegee 7 are fitted into the guide groove holes 6 of the side frames 5, 5 formed vertically on the left and right sides of the center portion of the frame 1. A box-shaped housing 9 with an open top is fixed to the upper surface of the central part of the holder 8, and a set screw 11 is installed above the housing 9, which threads through a connecting frame 10 installed on the upper ends of the side frames 5, 5. ing. The push screw 11 is moved up and down while being rotated by the adjustment handle 12.

The base end of the pressure rod 13 disposed on the outside of the side frame 5 is attached to a drive shaft 16 supported by bearings 14 and 15 provided on the holder 8, and protrudes into the inside of the housing 9 of the drive shaft 16. The tip is crank 17
has a first shaft 18 protruding to an eccentric position via
A base end portion of a connecting member 19 is rotatably fitted onto this first shaft 18 . A second shaft 20 rotatably passes through the distal end of the connecting member 19, and protrusions at both ends of the second shaft 20 are connected to two plate-shaped crank members 21, 2.
It is rotatably supported on the base of 1. Holder 8
Both ends of a main shaft 23 having a cam 22 in the center are rotatably supported on the crank member 2.
The tips of 1 and 21 are fitted and fixed to the main shaft 23 with the cam 22 in between.

The cam 22 has an arc-shaped outer peripheral surface 24 centered at a point N ₂ eccentric by a distance a with respect to the rotation center N ₁ of the main shaft 23, and has a receiving portion 25 recessed in the same arc shape on the outside. The bridge member 2 is fitted onto the peripheral surface 24.
6 is placed on the cam 22, and the cushion material 29 sandwiched between the plate pieces 27 and 28 is connected to the push screw 11 and the bridge member 26.
is established between.

In this embodiment configured as described above, a plate 31 consisting of a surface plate, a flat plate, paper, and a top plate is placed on the bed plate 30, inserted between the lower roller 3 and the squeegee 7, and adjusted by turning the adjustment handle 12. Printing is performed by rotating the pressure rod 13 to adjust the printing pressure and rotating the handle 2 to move the bed plate 30 and plate 31 together, and when these pass between the lower roller 3 and the squeegee 7. The pressure rod 13 is reversed to release the printing pressure, and the bed plate 30 and plate 31 are pulled back to take out the printed paper.

When the printing pressure is released, each part from the crank 17 to the bridge member 26 is in the state shown in FIGS. 3 and 4. When the pressure rod 13 is turned in the pressure direction, the crank 17 rotates counterclockwise in FIG. 4, and the connecting member 19 attached to the first shaft 18 at the tip thereof
The second shaft 20 at the tip of the main shaft 23 is moved along an arc R ₂ centered on the center N ₁ of the main shaft 23 .

If the drive shaft 16 and main shaft 23 are supported by the housing 9 at a fixed position, the first shaft 18 moves 180 degrees along an arc R ₁ centered on the rotation center of the drive shaft 16, and the second shaft 20 moves. Along said arc _R2
When moved by 90 degrees, the crank members 21, 21 fixed to the main shaft 23 rotate the main shaft 23 by 90 degrees, thereby rotating the cam 22 and moving the bridge member 26 sliding along its outer peripheral surface 24 by an eccentric amount a. The robot is raised by a distance corresponding to the distance shown in FIG. 5, and reaches the position shown in FIG. 6. If the cam 22 is initially eccentric in the horizontal direction with respect to the main shaft 23, when the cam 22 rotates 90 degrees, the bridge member 26 will rise by an amount a from the initial position indicated by the two-dot chain line 26a in FIGS.

In reality, the housing 9 is provided on the holder 8 which is movable up and down, and the bridge member 26 is held down by the push screw 11, so the holder 8 is pushed down by an amount a, and this becomes a printing pressure. Pressure rod 13
When the housing 9 or the holder 8 is reversed, the force of a return spring (not shown) acting on the housing 9 or the holder 8 causes the holder 8 to
is raised.

The holder 8 may rotatably support the upper roller instead of the squeegee 7, and the crank member 21 for rotating the cam 22 may be provided only on one side of the cam 22.

As described above, the present invention utilizes a dual crank mechanism that uses the eccentric relationship between the drive shaft and the first shaft to rotate the drive shaft through the operation of the pressure rod, and the other crank mechanism that uses the eccentric relationship between the crank member and the cam. This is because the printing pressure is generated by transmitting the pressure to the cam by pushing up the bridge member slidably fitted to the outer peripheral surface of the cam and relatively pushing down the holder. By designing the eccentricity, the dimensions of the connecting member, and the crank member so that the pressure rod is rotated greatly and the holder is lowered the same distance as before, it is possible to generate a predetermined printing pressure with a small force. Even if printing is repeated many times, it does not cause significant fatigue.

Furthermore, if the first shaft of the connecting member is positioned below the drive shaft and the pressure rod is rotated approximately 180 degrees in the retracted position where the printing pressure is released, as in the illustrated embodiment, the unit rotation of the drive shaft is The amount of vertical movement of the second axis per angle becomes smaller at the beginning and end of the stroke, so at the end when the printing pressure increases, the second axis becomes vertical compared to the large amount of lateral movement of the first axis. The holder is moved a minute distance in the direction and is lowered little by little, and an expanded force is applied to the holder without increasing the force applied to the pressure rod, making it easy to obtain the predetermined printing pressure. It is something.

[Brief explanation of the drawing]

Figure 1 is a side view showing an example of a lithographic printing machine;
The figure is a partial front view, Figure 3 is an enlarged longitudinal sectional view of the main part,
Figure 4 is a sectional view taken along line XX in Figure 3, Figure 5,
FIG. 6 is a sectional view showing the operating situation. 1... Frame, 8... Holder, 9... Housing, 11... Push screw, 13... Pressure rod, 16
... Drive shaft, 17 ... Crank, 18 ... First shaft, 19 ... Connection member, 20 ... Second shaft, 21 ...
...Crank member, 22...Cam, 23...Main shaft,
24...Outer peripheral surface, 26...Bridge member, 29...Cushion material.

Claims (1)

[Scope of utility model registration request] It has a housing 9 fixed to a holder 8 of a squeegee or upper roller provided on the frame 1 so as to be movable up and down, and a drive shaft 16 and a cam 22 to which a pressure rod 13 is rotatably supported on the housing 9. A main shaft 23, a crank member 21 fixed to the main shaft 23, a first shaft 18 provided eccentrically to the drive shaft 16, and a second shaft 20 supported by the crank member 21, both ends of which are rotatably supported. and a connecting member 19 that is connected to the cam 22.
has an arc-shaped outer circumferential surface 24 centered at a point eccentric from the rotation center of the main shaft 23, and a bridge member 26 opposed to the set screw 11 is slidably fitted onto this outer circumferential surface. Pressure adjustment device for lithographic printing presses.