JPH10296954A - Form plate clamp for printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To fix a print plate surely to a plate cylinder by an arrangement wherein a clamp plate supported by an arm having a plurality of centers of rotation receives the plate end in a retracted attitude and then performs pulling of plate while clamping the plate only through rotation of a cam shaft carrying three kinds of cam faces integrally. SOLUTION: The tail of a print plate 4 is received under a slack state where an arm 7 and a clamp plate 6 are open wide and a clamp base 5 abuts, at the end part thereof, against a groove wall 14. A cam shaft 8 is then turned by about 30 deg. and the arm 7 is turned with reference to a first center 8 of rotation by means of a cam face 20 for arm. The clamp plate 6 is thereby pushed up onto the cam face 21 for plate and begins to be tilted with reference to a second center 9 of rotation. When the cam shaft 18 is turned by about 180 deg., the clamp plate 6 is tilted and the tail of plate is clamped between the clamp plate 6 and a clank base 5. When the cam shaft 18 is further turned by about 40 deg., the clank base 5 is separated from the groove wall 14 by means of a cam face 19 for tension and the print plate 4 is stretched.

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 plate clamping device which does not need to bend a plate edge.

[0002]

BACKGROUND OF THE INVENTION In an offset printing press, a printing plate is wound and stretched around the plate cylinder, and an ink and dampening solution are supplied to the printing plate to form an image. Is transferred to a sheet via a blanket cylinder under pressure.

In order to mount a printing plate on a plate cylinder, a plate clamping device is provided in the cylinder groove as a pair of plate tip holding unit and plate edge holding unit.

[0004] In view of the ease and reliability of the plate mounting operation, it is desirable to bend the plate edge. However, in order to streamline such additional work, the plate must be bent without bending the plate edge. There is a demand for a plate clamping device that can securely attach the plate.

[0005]

2. Description of the Related Art Japanese Patent Application Laid-Open Nos. 6-23955 and 6-134972 also disclose plate clamping devices which do not require bending of plate edges. The structure for receiving the clamping device is extremely complicated, and various types of members are required for a drive system of various mechanisms for receiving, biting, and pulling the plate edge, and are complicated.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and has a simple structure and a simple operation, whereby a printing plate can be securely mounted on a plate cylinder without bending a plate end. It is intended to obtain a plate clamping device.

[0007]

For this purpose, a plate clamping device according to the present invention comprises a first rotation center (8) connected to a clamp base (5) and a second rotation center connected to a clamp plate (6). A camshaft integrally provided with an arm (7) having a center of rotation (9) and a cam surface for causing the pivotal movement of the arm (7), the undulation of the clamp plate (6) and the sliding of the clamp base (5). (1
8).

[0008]

The clamp plate (6) supported by the arm (7) having a plurality of rotation centers (8) and (9)
The plate edge is received without restriction in a greatly retracted position, and thereafter, a camshaft (1) integrally provided with three types of cam surfaces.
Only by the rotation of 8), the pivotal movement of the arm (7) → the plate holding by the clamp plate (6) and the clamp base (5) → the plate tension by the movement of the clamp base (5) is sequentially performed.

[0009]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a sectional explanatory view of a plate cylinder provided with a plate clamping device according to the present invention, FIG. 2 is a plan view thereof, and FIG.
6 to 6 are cross-sectional views illustrating the configuration and operation of the plate clamping device.

A cylinder groove (1) is formed by cutting out a cylinder groove (1) in the cylinder axis direction of the plate cylinder rotating in the direction of the arrow in FIG. 1 (a 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.

[0011] 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) holds the plate edge and pulls it to bring the printing plate (4) into close contact with the outer periphery of the plate cylinder. The present invention relates exclusively to the plate holding unit (4).

The clamp base (5) of the plate edge holding unit (3) is a long base extending in the body axis direction. For example, a ridge 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 a lateral direction in FIG. 3 or lower, in other words, a direction along the base of the trunk groove (1) and orthogonal to the trunk axis direction.

The main role of the clamp plate (6) is to undulate with respect to the clamp base (5) and to bite / release the end of the printing plate (4) with its tip. The support is by means of arms (7) connected on both sides. That is, the arm (7) has a first center of rotation (8) rotatably connected to the clamp base (5) at one end, and is rotatable with the side of the clamp plate (6) at the other end. And a second center of rotation (9) coupled to

Then, as shown in FIG. 3, the arm (7)
Is largely retracted by the first leaf spring (10), and the clamp plate (6) is also largely opened by the second leaf spring (11).

Assuming that the plate edge holding unit (3) is slid in the direction of the secant to pull / relax the plate (4), the clamp base (5) is attached by two kinds of spring members (12) and (13). It is being rushed. First, the spring member (12) urges the clamp base (5) in the direction of the groove wall (14), in other words, in the direction of relaxing the tension of the printing plate (4).

Further, plate tension means by a combination of a push pin (15), a flange member (16), a spring member (13) and a ring member (17) is fitted into a plurality of places of the clamp base (5). , Are arranged. Push pin (15)
Is freely inserted into the clamp base (5),
Further, a spring member (13) is engaged with the flange member (16) in contact with the push pin (15). The left end of the flange member (16) is freely inserted into the center of the H-shaped cross-section member (17). The ring member (17) is fitted into the clamp base (5) while receiving the spring member (13) on one side thereof, and the other end thereof is in contact with the groove wall (14).

The pushing pin (15) of the plate tension means contacts the cam surface of a cam shaft (18) integrated with the clamp base (5), and this cam shaft (18) is manually or automatically rotated. The plate (4) is moved and tension / relaxation of the printing plate (4) is performed as described later. doing.

That is, the camshaft (18) has a tension cam surface (1) with which the tip of the push pin (15) abuts.
9) as well as an arm cam surface (20) with which an arm (7) pivoted based on the first rotation center (8) abuts.
And three types of cam profiles of a plate cam surface (21) on which the bottom surface of the clamp plate (6) which is raised and lowered based on the second center of rotation (2) of the arm (7) abuts. They are distributed and provided integrally. The phases of these cam profiles are shown in parallel in FIGS. 3 to 6, which are operation explanatory diagrams.
The camshaft (1) integrated with the clamp base (5)
The technique of turning 8) manually with an appropriate tool or automatically from the side frame side of the printing press with a motor or the like has already been established.

Next, the operation will be described. In the state shown in FIG. 3, the arm (7) and the clamp plate (6) are widely opened, and the ends of the clamp base (5) are also groove walls (14). It is in a relaxed state in contact with. That is, the arm (7) is largely retracted by the first leaf spring (10), and the clamp plate (6) is also largely opened by the second leaf spring (11). Also, the clamp base (5) is pressed against the groove wall (14) by the spring member (12) for relaxation since the spring member (13) of the plate tensioning means is practically ineffective.

In this state, the plate edge of the printing plate (4) whose plate edge is kept straight is received without restriction. An appropriate plate pressing tool (22) or a plate pressing roller is operated by an air cylinder or the like in order to press the plate bottom against the upper surface of the clamp base (5) and level it. Are also well known.

Next, when the camshaft (18) is rotated by about 30 degrees and the cam phase also changes as shown in FIG. 4, the arm (7) is moved by the arm cam surface (20). It is pivoted largely with respect to the first rotation center (8) while opposing the first leaf spring (10), and at the same time, the bottom surface of the clamp plate (6) is pushed up to the plate cam surface (21). The arm (7) starts falling down against the second leaf spring (11) with reference to the second rotation center (9) of the arm (7).

Then, the camshaft (18) is further
When rotated by 0 degrees, the clamp plate (6) is completely laid down, and the plate bottom is held between the clamp plate (6) and the clamp base (5) (FIG. 5).

When the camshaft (18) is further rotated about 40 degrees with the plate edge held, the clamp base (5) separates from the groove wall (14) as shown in FIG. (4) is pulled. That is, by the action of the tension cam surface (19), the pushing pin (15) of the plate tension means is pushed in the direction of the drawing, and the spring member (13) is compressed. Overcoming the relaxation spring member (12), the entire clamp base (5) is slid rightward, thereby pulling the printing plate (4).

[0024]

According to the plate clamping device of the present invention,
Since the clamp plate is supported by the second center of rotation of the arm which is largely pivoted with respect to the first center of rotation, a straight printing plate can be received without any restrictions. In addition, since all operations can be performed by the camshaft integrally having three types of cam surfaces, there is a significant effect that the structure can be extremely simplified.

[Brief description of the drawings]

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

FIG. 2 is a plan view of the right half of the plate cylinder shown in FIG.

FIG. 3 is a cross-sectional view for explaining the configuration and operation of the plate clamping device, showing a state where an arm and a clamp plate are opened and the printing plate is also relaxed.

FIG. 4 is a sectional view showing a state in which the arm is closed.

FIG. 5 is a cross-sectional view showing a state where a clamp plate is closed.

FIG. 6 is a sectional view showing a state where the printing plate is pulled.

[Description of Signs] 1 Body groove 2 Plate holding unit 3 Plate holding unit 4 Printing plate 5 Clamp base 6 Clamp plate 7 Arm 8 First rotation center 9 Second rotation center 18 Cam shaft 19 Tension cam surface 20 Cam surface for arm 21 Cam surface for plate

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, and the plate edge holding unit (3) is It has a clamp base (5) slidable in the direction of the secant of the plate cylinder and a clamp plate (6) movably connected to the clamp base (5), and the clamp plate (6) is raised and lowered. In the plate clamping device of a printing press of the type in which the plate end is gripped / released and the printing plate (4) is pulled / relaxed by sliding the clamping base (5). ) And the clamp plate (6)
Arm (7) having a second center of rotation (9) coupled to the arm (7)
And a camshaft (18) integrally provided with a cam surface for causing the arm (7) to pivot, to move up and down the clamp plate (6) and to slide the clamp base (5).
And a plate clamping device for a printing press.