JPH10235835A - Shared plate clamping device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily and quickly perform a plate clamping work without extra labour even when a paper plate is installed by a method wherein a spherical body, which is made of elastic material and is projectably and retractably energized, is provided at the lower part on the gripping side of the clamping plate or the upper part on the gripping side of the clamping base of a plate tail gripping unit. SOLUTION: A printing plate 4 is pinchingly held by a plate head gripping unit and a plate tail gripping unit 3 provided in the notched groove of a plate cylinder and tightly contactingly mount under tension on the outer periphery of the plate cylinder. In addition, the clamping plate 6 of the plate tail gripping unit is upsettingly and downturningly attached onto the clamping base 5 by means of semi-spherical spot-faced holes and bolts so as to pinch or release the end parts of the printing plate by setting up or turning down the clamping plate through a bar-like ham 8. Further, mounting holes 9 are bored in the lower part on the gripping side of the clamping plate 6 so as to arrange spherical bodies 11 projectably and retractably energized with elastic members 10 such as coiled springs or the like therein. Furthermore, when a paper plate is employed, since its plate tail is fixed to the base 5 by being pressed with the spherical bodies 11, no paper plate is damaged even by moving the base 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plate clamping device for a printing press, and more particularly to a common plate clamping device which can be used not only for a PS plate but also for a paper plate.

[0002]

2. Description of the Related Art In an offset printing press, a printing plate is wound and stretched around the plate cylinder, and an image is formed by supplying ink and dampening solution to the printing plate. Is transferred to a sheet via a blanket cylinder under pressure.

As a printing plate, an aluminum-based PS plate is usually used. Since the PS plate is based on a thin metal plate, the PS plate has excellent tensile strength. Therefore, even if a tensile force is applied by a plate clamping device that stretches the printing plate onto the plate cylinder, the PS plate hardly deforms. Easy to mount on plate cylinder.

Recently, paper plates made of water-resistant paper have been increasingly used, supported by the advantages of low plate material costs and plate making costs. However, this paper plate has very low tensile strength,
It is easy to stretch and therefore requires special care when it is mounted on the plate cylinder by the plate clamping device.

[0005]

2. Description of the Related Art In Japanese Patent Laid-Open Publication No. Hei 3-61044, a paper plate is glued onto a dummy PS plate which is not used for actual printing, so to speak, and this combined body is mounted on a plate clamping device. Techniques are disclosed. Also, JP-A-8-150
Japanese Patent Publication No. 700 discloses a technique in which a paper plate is glued on a dummy PS plate, and a rear end of the paper plate is fixed by a positioning pin and a roller.

[0006]

However, all of the above-mentioned techniques require additional processing on the paper plate and require troublesome work such as gluing, and ultimately require high speed. A lot of man-hours were to be spent on plate clamp work.

[0007] The present invention has been made in view of the above problems,
It is an object of the present invention to provide a common type plate clamping device that can perform a plate clamping operation simply and quickly without requiring extra work when mounting a paper plate.

[0008]

In order to achieve the above object, the present invention relates to a common type plate clamping device, comprising: a lower portion of a clamp plate (6) of a plate edge holding unit (3); An elastic member (1
A plurality of spheres (11) biased so as to be able to appear and disappear by (0) are provided.

[0009]

When mounting the PS plate, the plate butt is inserted between the clamp base (5) and the clamp plate (6) and is temporarily held down by the sphere (11), but the clamp plate (6) falls down. Then, the sphere (11) sinks, is essentially firmly bitten by the clamp base (5) and the clamp plate (6), and a tensile force is applied by the movement of the clamp base (5).

[0010] On the other hand, when the paper plate is mounted, the plate edge is inserted between the clamp plate (6) and the clamp base (5) in the raised state, and the plate edge is connected to the elastic member (1).
0) is pressed against the clamp base (5) or the clamp plate (6) by a plurality of spheres (11) protruded by the sphere (11). Be fixed. After this, even if the clamp base (5) is moved, the sphere (11) rotates and the plate bottom slides freely,
No excessive tensile force is applied to the paper plate.

[0011]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a cross-sectional explanatory view of a plate cylinder provided with a shared plate clamping device according to the present invention, FIG. 2 is a plan view of the same, and FIG. 3 shows an embodiment of a shared plate clamping device according to the present invention. It is sectional explanatory drawing.

A drum groove (1) is cut out in the drum shaft direction of the plate drum rotating in the direction of the arrow in FIG. 1 (the direction perpendicular to the plane of FIG. 1 and the horizontal direction in FIG. 2). A pair of plate tip holding units (2) and a plate edge holding unit (3) are provided in the body groove (1). And
The printing plate (4) is bitten and pulled by these units (2) and (3), and is closely attached to the outer periphery of the plate cylinder.

[0013] Of these units (2) and (3),
The plate holding unit (2) mainly serves to fixedly hold the plate edge and is not directly related to the present invention. On the other hand, the plate edge holding unit (3) grips the plate edge and, when the printing plate (4) is a PS plate, pulls it to bring the printing plate (4) into close contact with the outer periphery of the plate cylinder. The present invention
Exclusively related to this plate-butt holding unit (3).

The clamp base (5) of the plate edge holding unit (3) is a long base extending in the body axis direction. For example, a projection on the lower surface thereof and a concave groove at the base of the body groove (1) (not shown). ) Can be slid in the direction of the dividing line. Here, the dividing line direction refers to the left-right direction in FIG. 3, in other words, the direction along the base of the trunk groove (1) and orthogonal to the trunk groove direction.

The clamp plate (6) is formed by a known combination such as a hemispherical counterbore in itself and a bolt (7) having a hemispherical head corresponding to the counterbore. When the bar-shaped cam (8) is rotated by a tool (not shown), the bar-shaped cam (8) is raised and lowered with respect to the clamp base (5), and the end of the printing plate (4) is gripped / released. I do.

In the apparatus of the present invention, as shown in FIG. 3, a mounting hole (9) is formed in a lower portion on the grip side of the clamp plate (6), and an elastic member (1) such as a coil spring is provided.
A plurality of spheres (11) urged so as to be able to protrude and retract in the direction of the holding surface of the clamp base (5) by 0) are provided at appropriate positions in the longitudinal direction of the clamp plate (6).
As the sphere (11), a steel ball or a hard plastic sphere is appropriate, and it is a matter of design to provide a means for preventing the sphere (11) from falling off. In addition, contrary to the illustrated embodiment, the sphere (1) is
1) may be provided.

A wide variety of means are known for tensioning / relaxing the printing plate (4) by sliding the plate edge holding unit (3) in the direction of the secant line. Because it is not a simple matter,
In FIG. 3, the spring (12) urges the clamp base (5) in the left-right direction to relax the printing plate (4), while the other spring (13) pushes the clamp base (5) to the left. The printing plate (4) is urged to pull the plate. It should be understood that the clamp base (5) is slid in the direction of the secant by adjusting the spring force of the spring (13) by the rod-shaped cam (14) and the push pin (15) abutting on the cam.

Next, the operation will be described. In the case where the printing plate (4) to be mounted is a PS plate, the plate bottom inserted between the clamp base (5) and the clamp plate (6) has a spherical shape ( If the clamp plate (6) is laid down by the rod-shaped cam (8), the sphere (11) will sink into the mounting hole (9).
Essentially, it is firmly held by the clamp base (5) and the clamp plate (6), after which the movement of the clamp base (5) also exerts a tensile force.

On the other hand, when the printing plate (4) is a paper plate,
As shown in FIG. 3, the plate butt inserted between the clamp base (5) and the clamp plate (6) is an elastic member (1).
The state is pressed against the clamp base (5) by the plurality of spheres (11) biased by (0). Then, in the case of a paper plate, the plate bottom is fixed only by pressing the plurality of spheres (11) in a protruding state without closing the clamp plate (6). Therefore,
Thereafter, even if the clamp base (5) is moved solely to remove the slack of the paper plate, the sphere (11) rotates, and
Since the plate bottom slides freely, no excessive pulling force is applied to the paper plate, and the paper plate is mounted in a state of being in close contact with the plate cylinder.

[0020]

According to the present invention, when a paper plate is mounted, the printing plate can be simply and quickly mounted without the need for gluing or positioning holes. Also noteworthy are fine-tuning the mounting of the plate to the plate cylinder,
So-called plate cocking (for example, see Japanese Patent Laid-Open No. 5-7739)
See No. 8 publication. In this case, since the plate bottom can be moved without resistance, there is a significant effect that the cocking operation can be easily performed.

[Brief description of the drawings]

FIG. 1 is an explanatory sectional view of a plate cylinder provided with a common plate clamp device according to the present invention.

FIG. 2 is a plan view of the same.

FIG. 3 is an explanatory sectional view showing one embodiment of a common type plate clamping device according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Body groove 2 Plate holding unit 3 Plate holding unit 4 Printing plate 5 Clamp base 6 Clamp plate 9 Mounting hole 10 Elastic member 11 Sphere

Claims (1)

[Claims] 1. A pair of plate edge holding units (2) and a plate edge holding unit (3) are arranged in a cylinder groove (1) of a plate cylinder, at least a plate edge holding unit (3) of these.
Are slidable in the direction of the dividing line of the body groove (1), the plate base holding unit (3) is basically slid with respect to the body groove (1), and a clamp base (5). And a clamp plate (6), which is raised and lowered with respect to the plate bottom, to form a lower part of the clamp plate (6) or an upper part of the clamp base (5). A common type plate clamping device, comprising a plurality of spheres (11) urged by a resilient member (10) so as to be able to come and go.