JP2000079749A - Original plate clamping mechanism for stencil printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a strong holding force with a simpler constitution by a clamping mechanism for fixedly holding an original plate at a plate cylinder in a stencil printer. SOLUTION: The clamping mechanism 10 comprises a clamp base 14 and a clamp piece 16. A clamping groove 18 parallel to an axis of a plate cylinder 12 is provided at the base 1, and the piece 16 can be contained in the groove 18. In the case of adhering an original plate 26, a master end is positioned to cover the groove 18, the end is pressed by the piece 16, and contained in the groove 18. Further, a following part of the original plate is folded to cover the piece 16, and then the original plate 26 is wound on the cylinder 12. The piece 16 is slid by a tension of the plate 26 in the case of winding the plate 26 on the cylinder 12, and the plate 26 is sandwiched fixedly between a left side of the piece 16 and a left side face of the groove 18.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mechanism for gripping and fixing an original plate to a plate cylinder of a stencil printing machine.

[0002]

2. Description of the Related Art A perforated original plate is adhered to the surface of an ink-permeable plate cylinder, and ink supplied from the inside of the plate cylinder and exuded from the perforation to the surface is recorded on paper or the like. 2. Description of the Related Art A stencil printing machine for transferring to a medium is known. When attaching an original to a plate cylinder, one end of the original is gripped and fixed by a clamp mechanism provided on the plate cylinder, and then the subsequent original is wound and attached while rotating the plate cylinder. When changing the print content, the old original is peeled off from the plate cylinder, and the newly perforated original is attached to the plate cylinder. Therefore, simply
There is a need for a clamp mechanism capable of peeling the master from the plate cylinder and attaching the master to the plate cylinder. In addition, if the clamp mechanism cannot reliably hold the original plate, the position of the original plate may be shifted, which may affect print quality.

As the above-described clamp mechanism, there is known a clamp base for actually gripping the base paper, and a mechanism for holding one of the clamp pieces as a magnet and holding the base paper by the attraction force of the magnet. A mechanism is also known in which a spring is provided for urging the clamp base and the clamp piece in the closing direction, and the original is gripped by the urging force of the spring. In the case of these mechanisms, a magnet, a spring, and a structure for attaching the same are required. Further, a driving mechanism for separating the clamp base from the clamp piece by overcoming the attractive force of the magnet and the urging force of the spring is also required. For this reason, there has been a problem that the structure is complicated and the cost is high.

[0004] Patent Publication No. 2662647 (Japanese Patent Application Laid-Open
No. -306043) discloses a device for fixing a base paper without using a magnet or a spring. 10 and 11 show an apparatus according to this patent. Original feed roller 1
As a result, the leading end of the original 102 is
It is sent to the position of 04. The clamp mechanism 104 includes a clamp base 108 fixed to the plate cylinder 106 and a clamp piece 110. The clamp piece 110 is rotatable about a shaft 114 provided on a bracket 112 erected on the clamp base 108. The original plate 102 is held between the clamp base 108 and the clamp piece 110,
Further, the plate cylinder 106 is rotated in the direction of arrow B in the figure. Then, the original plate 102 is wound on the left side of the clamp mechanism 104 in the figure, passing over the clamp piece 110.

FIG. 11 shows a state where the plate cylinder 106 has made one revolution. As can be seen from FIG.
It is located lower than 14. Therefore, the tension applied to the original when the original 102 is wound generates a moment for rotating the clamp piece 110 clockwise about the shaft 114 in the figure. This moment acts to press the clamp piece 110 against the clamp base 108, whereby the original plate 102 is clamped by the clamp mechanism 104.

[0006]

In the apparatus disclosed in the above publication, a larger holding force for holding the base paper can be obtained by increasing the distance between the shaft 114 and the base paper. It is necessary to make it protrude more than the surface of. That is, when trying to obtain a large base paper holding force, there is a problem that the size of the apparatus cannot be avoided.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and has as its object to provide a base paper clamping mechanism capable of obtaining a large base paper holding force with a simple mechanism.

[0008]

In order to solve the above-mentioned problems, a clamping mechanism according to the present invention comprises a groove provided on a surface of a plate cylinder substantially parallel to an axis of the plate cylinder; And a clamp piece that can be slidably held in the direction. Then, the leading end of the original plate is positioned so as to cover the groove, the leading end of the original plate is pushed in by the clamp piece and placed in the groove, and the original plate following the portion placed in the groove is covered with the clamp piece. And then wrap the original around the plate cylinder. Thereby, the clamp piece slides due to the tension when the original is wound around the plate cylinder, and the original is held and fixed between the clamp piece and the side surface of the groove.

Further, the outer peripheral surface of the plate cylinder is cylindrical, and the clamp piece can be held inside the outer peripheral surface of the plate cylinder.

[0010]

Embodiments of the present invention (hereinafter referred to as embodiments) will be described below with reference to the drawings. 1 to 3 show a schematic configuration of the present embodiment. FIG. 1 shows a state before the original is clamped, FIG. 2 shows the clamp after clamping, and FIG. 3 shows details of the clamp mechanism at that time. The clamp mechanism 10 has a clamp base 14 and a clamp piece 16 fixed to the surface of the plate cylinder 12. The clamp base 14 has a clamp groove 18 provided substantially parallel to the axis of the plate cylinder. The sectional shape of the clamp groove 18 is substantially rectangular as shown. The clamp piece 16 is shown in FIG.
Is a substantially rectangular plate having a slight warp as shown in FIG. 1, and has a through hole 20 at one end and a handle 22 at the other end. A shaft 24 provided at an end of the clamp groove 18 passes through the through hole 20, and the clamp piece 16 is supported on the clamp base 14 so as to be rotatable around the shaft 24. 1, the width of the clamp piece 16 is smaller than the width of the clamp groove 18, and the clamp piece 16 is slidable on the shaft 24 by the gap.

When attaching the original plate 26 to the plate cylinder, first, the clamp piece 16 is rotated, and as shown in FIG.
8 is in an open state where most of it comes out. Then, the original plate 26 is moved by the feed roller 28 so that
Send out to a position beyond 8. Therefore, the entire width of the clamp groove 18 is covered by the tip portion of the master 26.
Next, the clamp piece 16 is pushed down so as to fit in the clamp groove 18. Then, as shown in FIG. 5, the end of the clamp piece 16 on the side where the handle 22 is located is fixed by a hook 30 rotatably supported by the plate cylinder 12 or the clamp base 14. FIG. 5 shows a state in which the clamp piece 16 is accommodated in the clamp groove 18, and the warpage is extended and accommodated. Due to this warpage, a uniform holding force can be generated in the width direction of the original plate 26.

Next, while the plate cylinder 12 is being rotated in the direction of arrow A in FIG. As a result, the portion following the leading end of the original held by the clamp mechanism 10 is folded at the right end of the clamp piece 16 in the drawing, and covers the clamp piece 16. Further, at this time, the clamp piece 16 slides in the left direction in the drawing, that is, in the direction in which the tip of the original plate 26 exists, due to the tension applied to the original plate 26. Then, the original plate 26 is sandwiched between the left side of the clamp piece 16 and the left side surface of the clamp groove 18, and a strong holding force is generated. FIG. 2 shows a state in which the plate cylinder 12 has made one round.

FIG. 3 shows details of the clamp mechanism 10 with the original plate 26 adhered thereto. Clamp piece 16
The original 26 located between the clamp groove 18 and the bottom surface (in the range indicated by K in the drawing) is held by the reaction force that extends the warp. In addition, the clamp piece 16 is
Slides in the left direction in the figure, and the master 2 is also moved between the left side of the clamp piece 16 and the left side surface of the clamp groove 18 (the range indicated by M in the figure).
Hold 6. Since the holding force in the range M is generated by the tension pulling the master 26, the greater the tension, the greater the holding force, and the master 26 can be reliably held. Further, since the direction of the tension and the direction of the holding force substantially match, the tension works efficiently as the holding force.

Further, the tip of the original plate 26 is inserted into the clamp groove 1.
If it is arranged so that it goes out of 8, the clamp base 1
A force for holding the original plate 26 is also generated in the portion outside the clamp groove 4 (range indicated by N in the figure). That is, due to the tension acting on the original plate 26, the subsequent portion of the original plate 26 and the clamp base 14 that are placed on the distal end portion of the original plate 26 clamp the distal end portion of the original plate, and a holding force is generated. The holding force acting in this range N also increases as the tension of the master 26 increases, so that the master 26
Work to hold.

As described above, in the present embodiment, as the tension for shifting the original 26 is applied, the holding force generated in the range M is increased, and the original 26 is held at a predetermined position. Furthermore, if the holding force is generated even in the range N, the holding force also increases as the tension increases, and the original 26
Is more firmly held.

FIGS. 6 and 7 show another embodiment of the present invention. The clamp mechanism 40 has a clamp base 44 and a clamp piece 46 fixed to the surface of the plate cylinder 42. The clamp base 44 has a clamp groove 48 provided substantially parallel to the axis of the plate cylinder. The clamp base 44 is formed outside the cylinder formed by the plate cylinder 42 so as not to protrude. The cross-sectional shape of the clamp groove 48 is substantially rectangular as shown. Clamp piece 46
Includes arms 50 at both ends and a clamp piece main body 52 provided to bridge the arms. Arm 50
Are fixed to the plate cylinder frames 54 at both ends of the plate cylinder 50 to arm shafts 56 provided rotatably in parallel to the plate cylinder axis. The clamp piece main body 52 is engaged with guides 58 provided on the arm 50 at both ends thereof, and is slidable in the direction of the arm 50. FIG. 6 shows a state in which the clamp piece main body 52 is slid most toward the distal end side of the arm 50. At this time, the two arms 50 and the clamp piece 52 form a substantially U-shape. A knob 60 is provided on one of the arm shafts 56. By rotating the knob 60, the clamp piece 46 is moved to the open position, that is, the position outside the clamp groove 48 and the clamp groove 48.
It can be rotated to a position where it fits in. A cushion member 62 for preventing slippage is attached to a surface of the clamp piece main body 52 facing the clamp groove 48.

When the original plate 64 (see FIG. 7) is to be attached to the plate cylinder 42, the clamp piece 46 is first rotated to open the main part 64 from the clamp groove 48 as shown in FIG. I do. The original plate 64 is fed by the feed roller 66 from the crotch portion of the U-shaped clamp piece 46 to a position where the leading end of the original plate 64 exceeds the clamp groove 48. The entire width of the clamp groove 48 is covered by the tip of the original plate 64. Next, the clamp piece 46 is rotated so that the knob 60 is rotated to fit in the clamp groove 48.

Next, the original plate 64 is fed by the feed roller 66 while rotating the plate cylinder 42 in the direction of arrow B in FIG. As a result, the portion following the original plate tip held by the clamp mechanism 40 is folded back at the right end of the clamp piece main body 52 in the drawing, and covers the clamp piece main body 52. Further, at this time, due to the tension applied to the original plate 64,
The clamp piece main body 52 slides in the left direction in the figure, that is, in the direction where the leading end of the original plate 64 is located. And the clamp piece main body 5
2 and the left side of the clamp groove 48, the original 64
, And a strong holding force is generated. FIG. 7 shows a state in which the plate cylinder 42 has made one revolution. Further, if the tip of the original plate 64 is made to protrude from the clamp groove 48, the original plate 64 and the clamp base 44 covering the tip end portion allow
The tip portion is pinched and fixed, and a holding force is generated. As in the above-described embodiment, these holding forces increase as the force for shifting the original plate 64 increases, so that the original plate 64 can be more securely fixed and held.

In each of the above-described embodiments, at the time of plate discharge, the original plate 26, 64 is peeled off from the rear end and the clamp piece 1 is removed.
If the portion covering the portions 6 and 46 is peeled off, the holding force due to the tension of the original plate is lost, so that the plate can be easily discharged.

FIGS. 8 and 9 show another structure of the clamp mechanism. This clamp mechanism 70 can be replaced with any of the clamp mechanisms of the above-described two embodiments. The clamp mechanism 70 includes a clamp base 72 and a clamp piece 74. Clamp base 72
Has a clamp groove 76 having a rectangular cross section slightly shorter than the clamp piece 74. The width of the clamp groove 76 is slightly larger than the width of the clamp piece 74, and the clamp piece 74 is slidable in the clamp groove 76 in the width direction, that is, in the circumferential direction of the plate cylinder. At both ends of the clamp groove 76, hook portions 78 for hooking the ends of the clamp pieces 74 are provided. As shown in FIG.
6, the upper surface of the end of the clamp piece 74 is pressed by the hook portion 78, and the lower surface of the clamp piece 74 is pressed by the bottom surface of the clamp groove 76. Thus, the clamp piece 74 is held in the clamp groove 76. Clamp piece 7
When a warp similar to that of the clamp piece 16 shown in FIG. 4 is provided on the plate 4, the original plate can be held stronger and uniformly in the width direction by the reaction force when the warp is extended. When the original is held, the original is sandwiched and fixed by one of the clamp pieces 74 and the side surface of the clamp groove 76 facing the same as in the above-described embodiments. Also, if the tip of the original is put out of the groove 76, this portion is clamped and fixed by the crank base 72 with the subsequent portion of the original. Therefore, as in the above-described embodiments, a greater holding force is generated by the application of the tension of the original plate, and secure fixing can be achieved.

In the embodiment shown in FIG. 6 and the like, the clamp base 44 has no portion protruding from the cylinder of the plate cylinder.
Alternatively, a laterally open clamp piece 16 shown in FIG. 1 or the like may be provided. If there is no portion protruding from the cylindrical surface of the plate cylinder, components around the plate cylinder can be arranged more advantageously, and the space can be used effectively. Therefore, the entire device can be reduced in size. Conversely, it is also possible to adopt the clamp piece shown in the embodiment in FIG. 6 or the like for the clamp base 14 in the embodiment shown in FIG. 1 or the like.

[Brief description of the drawings]

FIG. 1 is a diagram showing a schematic configuration of the present embodiment, and particularly shows a state before an original is attached.

FIG. 2 is a view showing a state after the original plate of the embodiment shown in FIG. 1 is attached.

FIG. 3 is a diagram showing details of a clamp mechanism of the embodiment shown in FIGS. 1 and 2;

FIG. 4 is a view showing details of a clamp piece of the embodiment shown in FIG. 1;

FIG. 5 is a view showing a state in which a clamp piece is accommodated in a clamp groove in the embodiment shown in FIG. 1;

FIG. 6 is a diagram showing a schematic configuration of another embodiment, and particularly shows a state before an original is attached.

FIG. 7 is a view showing a state after the original plate of the embodiment shown in FIG. 6 is attached.

FIG. 8 is a diagram showing another configuration of the clamp mechanism.

FIG. 9 is a view showing a state in which a clamp piece of the clamp mechanism of FIG. 8 is accommodated in a clamp groove.

FIG. 10 is a view showing a conventional clamp mechanism.

FIG. 11 is a view showing another conventional clamp mechanism.

[Explanation of symbols]

10, 40, 70 clamping mechanism, 12, 42 plate cylinder,
14, 44, 72 Clamp base, 16, 46, 74
Clamp piece, 18, 48, 76 Clamp groove, 26,
64 original.

Claims (2)

[Claims] 1. A stencil printing machine for causing ink to permeate out of the inside of a plate cylinder on a surface of a perforated plate having predetermined perforations attached to the surface of the plate cylinder and transferring the ink to a recording medium, wherein the plate is fixed to the plate cylinder. An original plate clamping mechanism, comprising: a groove provided on the surface of the plate cylinder substantially parallel to the axis of the plate cylinder; and a clamp piece that can be slidably held in the groove in the circumferential direction of the plate cylinder in the groove. Positioning the leading end of the original so as to cover the groove, pushing the leading end of the original by the clamp piece and placing it in the groove, and further covering the clamp following the original placed in the groove. Folding, thereafter, the original plate is wound around the plate cylinder, the clamp piece slides by the tension at the time of winding the original plate around the plate cylinder, and the original plate is clamped and fixed by the clamp piece and the side surface of the groove. mechanism. 2. The stencil clamping mechanism for a stencil printing machine according to claim 1, wherein the outer peripheral surface of the plate cylinder is cylindrical, and the clamp pieces can be held inside the outer peripheral surface of the plate cylinder. Original clamping mechanism of the machine.