JPH11320835A - Gripper unit for printing plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gripper unit for giving a suitable tension to several types of printing plates having different tensile strengths. SOLUTION: A plurality of spring containing holes 46 are formed at a clamping base 31 of a trailing side clamping unit 30 for holding a winding end side of a printing plate A to be wound on an outer periphery of a plate cylinder 1, and the base 31 is pressed in a direction separating from a wall surface 3b of a clamp containing recess 2 by a spring 47 contained in a spring containing hole 46. A rod 48 having a flange 48a is inserted into springs 47 of half number of a plurality of springs 47. An end of the rod 48 is slidably passed to a closed end wall of the container 46, a nut 52 is engaged with male threads 48b formed on its end, an elastic force switching plate 54 is provided insertably or drawably between opposed surfaces of the nut 52 and the base 31, the plate 54 is inserted between the opposed surface of the nut 52 and the base 31, the spring 47 is held in a contracted state, thereby regulating the force for pressing the base 31 by the springs 47.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printing plate holding device which is wound around the outer periphery of a plate cylinder.

[0002]

2. Description of the Related Art Generally, a clamp accommodating recess extending in the axial direction of a plate cylinder is formed on the outer periphery of a plate cylinder in an offset printing press, and a pair of clamp devices are provided in the clamp accommodating recess. Thus, both ends of the printing plate wound around the outer periphery of the plate cylinder are clamped to apply an appropriate tension to the printing plate.

As means for applying tension to the printing plate, a clamping device for clamping the end of the printing plate at the winding end (the end on the rear side) is mounted on the rear wall of the clamping housing recess in the direction of rotation of the plate cylinder. The clamp device is movably supported, and a plurality of spring storage holes are formed on a surface of the clamp device facing the wall surface of the clamp table. The springs incorporated in the spring storage holes allow the clamp device to move away from the wall surface. Conventionally, a spring tension system in which pressure is applied is known.

[0004]

In a printing plate holding device of the spring tension type which has been conventionally known, the pressing force for pressing the clamping device by a plurality of springs is always constant. However, there is a problem that a tension suitable for various printing plates cannot be given due to a difference in thickness or thickness, and a stable mounting state cannot be obtained.

[0005] That is, the offset printing plate includes an aluminum plate based on aluminum, a paper plate based on paper, a plate based on film, and the like, and has a thickness of 0.1 mm.
There are various types up to about 0.3 mm. Since these various printing plates have different tensile strengths, if the pressing force of the multiple springs pressing the clamping device corresponds to a printing plate with a low tensile strength, the tension will be insufficient for a printing plate with a high tensile strength. As a result, it is not possible to obtain a good attachment state in which the entirety is in close contact with the outer periphery of the plate cylinder.

Further, when the above pressing force is applied to a printing plate having a high tensile strength, an excessive tensile force is applied to a printing plate having a low tensile strength to cause elongation, and printing with high precision cannot be performed.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a printing plate holding device capable of applying an appropriate tension to various types of printing plates.

[0008]

In order to solve the above-mentioned problems, according to the present invention, a clamp accommodating recess which is long in the axial direction of the plate cylinder is formed on the outer periphery of the plate cylinder. A leading clamp device for clamping the winding start end of the printing plate wound around the outer periphery of the plate cylinder and a trailing clamp device for clamping the winding end end are provided. The clamp storage recess is movably supported with respect to the trailing side wall surface in the plate cylinder rotation direction, and the clamp table is provided with a plurality of spring storage holes from the rear surface facing the trailing side wall surface toward the front surface, In a holding device for a printing plate, wherein a clamp table is pressed in a direction away from a wall surface by a spring incorporated in each spring accommodating hole, at least one of the plurality of springs Employs a resilient applied state in which the spring presses the clamping table, the configuration in which the resilient switching means for switching into a state of releasing the elastic granted.

With the above-described structure, the spring can be switched between the elasticity applying state and the elasticity releasing state by the elasticity switching means, so that the pressing force with which the plurality of springs press the subsequent clamping device can be adjusted. It is possible to apply an appropriate tension to different types of printing plates.

Here, as the elasticity switching means, there is provided a rod which is inserted inside the spring and slidably penetrates the closed end wall of the spring accommodating hole. Can be used in which a nut is screw-engaged with a male screw on the outer periphery of one end located at the end, and a flange for receiving the end of the spring is provided at the other end of the rod. In this elasticity switching means, the spring is expanded and contracted by the axial movement of the rod due to the rotation of the nut to switch between the elasticity applying state and the application releasing state.

In the above elasticity switching means using a rod and a nut, an elasticity switching plate which can be inserted between the opposing surfaces of the clamp table and the nut is provided on the clamp table of the succeeding clamp apparatus so as to be swingable. In other words, by inserting the elasticity switching plate between the nut and the opposing surface of the clamp base, the rod is held in a state where the spring is contracted, so that the adjustment of the pressing force can be facilitated.

[0012]

Embodiments of the present invention will be described below with reference to the drawings.

As shown in FIGS. 1 to 3, a clamp receiving recess 2 is formed on the outer periphery of the plate cylinder 1 and extends in the axial direction of the plate cylinder 1.
A leading clamp device 10 for clamping the winding start end (holding end) of the printing plate A wound around the outer periphery of the printing plate A, and a clamping device for clamping the winding end end (tail end) of the printing plate A after clamping. A row-side clamp device 30 is provided.

The leading clamp device 10 includes a clamp table 1
1 and a plate-shaped gripper 12 for clamping the winding start side end of the printing plate A with the clamp base 11 and a camshaft 13 for opening and closing the gripper 12.

As shown in FIG. 1, the clamp table 11 is guided by guide pieces 14 attached to both ends in the axial direction of the clamp housing recess 2 and is located on the leading side wall surface 3a of the clamp housing recess 2 in the plate cylinder rotating direction. It is supposed to be movable,
By the spring 15 shown in FIG.
, And the tip of the torsion adjusting screw 16 screwed to the clamp table 11 is pressed against the wall surface 3a.

On the upper surface of the clamp table 11, a preceding side wall surface 3 is provided.
A protruding portion 17 for receiving the end of the printing plate A is provided at one end on the a side, and a positioning pin 18 for positioning the winding start side end of the printing plate A is provided on the protruding portion 17 as shown in FIG. Is provided.

A plurality of claw support shafts 19 are provided on the upper surface of the clamp table 11 at intervals in the axial direction of the plate cylinder 1.
A spherical projection 20 is formed at the tip of each claw support shaft 19.

The gripper 12 is provided above the clamp base 11. The holding claw 12 has a spherical concave portion 21 in spherical contact with the spherical protrusion 20 and a shaft insertion hole 22 into which the claw support shaft 19 is inserted with a margin.
It is supported so that it can be opened and closed around the center.

The camshaft 13 is rotatably supported by being inserted into a shaft insertion groove 23 formed at the other end of the upper surface of the clamp base 11, and is provided with a cylindrical surface 13a and a flat surface 13b on the outer periphery. ing.

At the center of the camshaft 13 in the longitudinal direction, a large-diameter rotary operation portion 24 is provided, and a tool is inserted into an engagement hole 25 formed in the rotary operation portion 24 to apply a rotational force. By doing so, the camshaft 13 can be rotated manually.

The end of the camshaft 13 is connected to a connecting shaft 27 via an Oldham type coupling 26. The connecting shaft 27 penetrates the side wall 4 of the clamp housing recess 2 and is rotatably supported at the penetrating position. The connection shaft 27 is rotated by a drive device whose rotation is omitted, and the rotation of the connection shaft 27 causes the camshaft 13 to rotate. The gripper 12 is opened and closed by the rotation of the camshaft 13.

The trailing-side clamp device 30 includes the clamp table 3
1, a plate-shaped gripper 32 for clamping the end of the printing plate A on the winding end side with the clamp base 31, and a camshaft 33 for opening and closing the gripper 32.

As shown in FIG. 2, the clamp base 31 has guide grooves 34 at both ends in the longitudinal direction.
Guide pieces 35 fixed to both axial ends of the clamp housing recess 2 are inserted into the clamp housing 4, and are guided by the guide pieces 35 so as to be movable with respect to the wall surface 3 b on the trailing side of the clamp housing recess 2 in the plate cylinder rotation direction. It has been.

On the upper surface of the clamp table 31, a trailing side wall surface 3 is provided.
At one end on the b side, a protruding portion 36 for receiving the end of the printing plate A on the winding end side is provided. A plurality of claw support shafts 37 are provided on the upper surface of the clamp table 31 at intervals in the axial direction of the plate cylinder 1, and a spherical protrusion 38 is formed at the tip of each claw support shaft 37.

The holding claw 32 is disposed on the clamp table 31. The holding claw 32 has a spherical concave portion 39 which makes spherical contact with the spherical protrusion 38, and a shaft insertion hole 40 into which the claw support shaft 37 is inserted with a margin. The holding claw 32 is formed so as to be openable and closable about the spherical projection 38.

The camshaft 33 is rotatably supported by being inserted into a shaft insertion groove 41 formed at the other end of the upper surface of the clamp table 31, and is provided with a cylindrical surface 33a and a flat surface 33b on the outer periphery. ing.

The camshaft 33 is provided with a large-diameter rotary operating portion 42 at the center in the longitudinal direction. A tool is inserted into an engaging hole 43 formed in the rotary operating portion 42 to reduce the rotational force. By providing, the camshaft 33 can be manually rotated.

As shown in FIG. 1, the end of the camshaft 33 is connected to the connecting shaft 4 via an Oldham type coupling 44.
5. The connecting shaft 45 penetrates the side wall 4 of the plate cylinder 1 and is rotatably supported at the penetrating position. The connection shaft 45 is rotated by a drive device (not shown), and the rotation of the connection shaft 45 is transmitted to the camshaft 33. The gripper 32 is opened and closed by the rotation of the camshaft 33.

As shown in FIGS. 1, 3 and 5, a plurality of spring receiving holes 46 are formed in the clamp table 31 from the rear surface 31b facing the trailing side wall surface 3b of the clamp receiving recess 2 toward the front surface 31a. And each spring storage hole 46
A spring 47 and a rod 48 having a flange 48a receiving the elasticity of the spring 47 are incorporated therein.
Due to the elasticity of the spring 47, the clamp table 31 is pressed in a direction away from the trailing side wall surface 3b.

In the embodiment, the clamp base 31 is pressed by eight springs 47, and half of the springs 47 can be adjusted in elasticity by the elasticity switching mechanism 50.

As shown in FIGS. 3 and 4, the elasticity switching mechanism 50 has a rod insertion hole 51 formed at the closed end of the spring accommodating hole 46, and the distal end of the rod 48 is inserted into the rod insertion hole 51. Slide the rod 4
The nut 52 is screw-engaged with a male screw 48b formed on the outer periphery of the end of the rod 8, and the rotation of the nut 52 causes the rod 48 to move in the axial direction to expand and contract the spring 47. Is switched to

As shown in FIGS. 2 and 6, on the front surface 31a of the clamp table 31, the rod 48 of the elasticity switching mechanism 50 is provided.
A plurality of pins 53 are protruded at positions close to the
An elasticity switching plate 54 is swingably supported about the center 3. The elasticity switching plate 54 is provided with an operation piece 55 and a cutout 56 which can be fitted to the rod 48. The elasticity switching plate 54 is fitted in a direction in which the cutout 56 fits into the rod 48.
Is swung, and the tip end is moved to the front surface 31a of the clamp base 31.
The rod 48 is held in a state where the spring 47 is contracted by inserting the rod 48 between the rod 52 and the nut 52. In this holding state, the spring 47 is held in a state of releasing elasticity without pressing the clamp table 31.

The elasticity switching plate 54 has a front end 31a of the front surface 31a of the clamp base 31 by a temporary fixing mechanism 60 shown in FIG.
Position between the nut and the nut 52 and the clamp table 31
Are temporarily stopped at the front surface 31a of the first nut and the disengagement position where it comes off between the nuts 52.

The temporary fixing mechanism 60 supports the central portion of the L-shaped leaf spring 61 with the pin 53, and protrudes from the front surface 31a of the clamp base 31 in an elongated hole 62 formed at one end of the leaf spring 61. The pin 63 is inserted to stop the leaf spring 61 from rotating, and the projection 64 provided at the other end of the leaf spring 61 is connected to the first recess 65 a or the second recess 65 b formed in the elasticity switching plate 54.
To be engaged.

As shown in FIGS. 1 and 5, a pressing mechanism 70 for pressing the clamp table 31 of the trailing-side clamp device 30 toward the trailing side wall surface 3b is provided in the clamp receiving recess 2. .

In the pressing mechanism 70, a bearing 71 is mounted on the bottom surface of the clamp receiving recess 2, and one end of a rotating shaft 72 rotatably supported by the bearing 71 is formed in a shaft insertion hole formed in the side wall 4 of the plate cylinder 1. The rotating shaft 72 is rotated in the direction of the arrow in FIG. 5 by a rotating device (not shown) provided outside the plate cylinder 1, and a roller at each end of a plurality of arms 74 attached to the rotating shaft 72. 75 presses the front surface of the clamp table 31.

The holding device shown in the embodiment has the above-described structure, and when the printing plate A is mounted, the printing plate A
The end of the winding start side of the front side of the clamp unit 10 of the leading side clamp device 10 and the protruding portion 17 of the holding claw 12 opened.
The printing plate A is positioned by fitting a notch (not shown) formed at the end on the winding start side with the positioning pin 18, and then the gripper 12 is closed by the rotation of the camshaft 13. , The tip of the holding claw 12 and the projection 17
And the end of the winding start of the printing plate A is clamped.

After holding the winding start end of the printing plate A, the plate cylinder 1 is rotated, and the printing plate A is moved along the outer periphery of the printing cylinder A. Then, the winding end side end is clamped to the trailing side clamping device. 30 is inserted between the protrusion 36 of the clamp base 31 and the tip of the gripper 32.

At this time, the clamp table 31 of the trailing-side clamp device 30 pushes the pushing mechanism 70 so that the trailing side wall surface 3 is pressed.
It is retracted to the b side. Projection 36 of clamp base 31
After the end of the winding end of the printing plate A is inserted between the distal ends of the grippers 32, the grippers 32 are closed by the rotation of the cam shaft 33, and the distal ends of the grippers 32 and the protrusions 36 are formed.
After that, the end of the printing plate A on the winding end side is clamped, and then the pressing mechanism 70 is operated to release the pressing of the clamp table 31.

When the pressing of the clamp table 31 is released, the clamp table 31 moves forward by the elastic force of the spring 47 and separates from the trailing side wall surface 3b, and tension is applied to the printing plate A by the advance movement of the clamp table 31.

Here, there are several types of printing plates A having different tensile strengths. In the case of a printing plate A having a low tensile strength such as a paper plate, all of the plurality of springs 47 press the clamp table 31. In the state, the tension applied to the printing plate A is large, and the printing plate A may be stretched or torn.

Therefore, the pressing force of the spring 47 pressing the clamp table 31 is adjusted in accordance with the type of the printing plate A attached to the plate cylinder 1.

When adjusting the pressing force, the clamp table 31 is pressed by the pressing mechanism 70 and retreated, and the tip of the elasticity switching plate 54 is inserted into the gap formed between the front surface 31a of the clamp table 31 and the nut 52. insert.

FIG. 3 shows a state in which the distal end portion of the elasticity switching plate 54 is inserted between the front surface 31a of the clamp base 31 and the nut 52, and the pressing of the pressing mechanism 70 is released. Is held in a contracted state, the spring 47 in the contracted state does not press the clamp table 31, the number of springs 47 pressing the clamp table 31 decreases, and the tension applied to the printing plate A decreases. Can be smaller.

Here, by inserting all of the plurality of elasticity switching plates 54 between the front surface 31a of the clamp table 31 and the nut 52, the pressing force applied to the clamp table 31 is minimized, and the number of insertions is reduced. , The pressing force can be gradually increased.

As described above, since the plurality of springs 47 can adjust the pressing force for pressing the clamp table 31, an appropriate tension can be applied to several types of printing plates A of different types. , A good attachment state can be obtained.

Further, the elasticity switching plate 54 is
The work of adjusting the pressing force can be performed simply and efficiently by making it possible to insert and remove the front surface 31a and the nut 52.

The elasticity switching plate 54 may be omitted, and the rod 48 may be moved in the axial direction by the rotation of the nut 52 to adjust the pressing force.

[0049]

As described above, according to the present invention, since the pressing force for pressing the clamp table can be adjusted by a plurality of springs, an appropriate tension can be applied to each of several types of printing plates having different tensile strengths. And various printing plates can be mounted very well.

Further, since the elasticity switching means for adjusting the pressing force has a simple structure with a small number of parts including a rod having an external thread and a nut, the assembly is easy.

Further, the pressing force can be adjusted by inserting and removing the elasticity switching plate swingably supported by the clamp table between the clamp table and the nut.
Adjustment of the pressing force is easy.

[Brief description of the drawings]

FIG. 1 is a plan view of a plate cylinder using a holding device according to the present invention.

FIG. 2 is a sectional view taken along the line II-II in FIG.

FIG. 3 is a sectional view taken along the line III-III in FIG. 1;

FIG. 4 is a cross-sectional view showing a state in which a printing plate of a trailing-side clamp device is fastened to a printing plate;

FIG. 5 is a sectional view taken along the line VV of FIG. 1;

FIG. 6 is a front view of a temporary fixing mechanism for temporarily fixing the elasticity switching plate.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 plate cylinder 2 clamp receiving recess 10 leading clamp device 30 trailing clamp device 31 clamp base 31 a front surface 31 b rear surface 46 spring receiving hole 47 spring 48 rod 48 a flange 50 elastic switching mechanism 52 nut 54 elastic switching plate

Claims (3)

[Claims] A clamp receiving recess which is long in the axial direction of the plate cylinder is formed on an outer periphery of the plate cylinder, and a winding start side end of a printing plate wound around the outer periphery of the plate cylinder is clamped in the clamp receiving recess. And a trailing-side clamping device that clamps the end of the winding end. The clamp base of the trailing-side clamping device is moved relative to the trailing side wall surface of the clamp receiving recess in the plate cylinder rotating direction. The clamp base is movably supported, and the clamp base is provided with a plurality of spring storage holes from the rear surface facing the trailing side wall surface toward the front surface, and the clamp base is separated from the wall surface by the spring incorporated in each spring storage hole. In the holding device of the printing plate that is pressed in the direction,
A printing plate, wherein at least one of the plurality of springs is provided with elasticity switching means for switching between an elasticity applying state in which the spring presses the clamp table and a state in which the elasticity application is released. Holding device. 2. A resilient switching means is provided inside a spring, and has a rod slidably penetrating a closed end wall of a spring accommodating hole. 2. The holding device for a printing plate according to claim 1, wherein a nut is screw-engaged with a male screw on the outer periphery of one end located at the end, and a flange is provided at the other end of the rod to receive the end of the spring. 3. The holding device for a printing plate according to claim 2, wherein an elasticity switching plate that can be inserted between the clamp base and the opposing surface of the nut is swingably mounted on the clamp base.