JP2000043396A - Stencil printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent ink leakage at both edges of a sheet in a stencil printer for printing the sheet by a plate cylinder and a roller. SOLUTION: A plate cylinder 200 has a pair of coaxial discs 102, and a peripheral wall 104 wound on their peripheries. An opening 105 is formed at the wall. An inner push roller 112 in the cylinder (inner roller) is oscillatory by an arm 111 to a fixed frame 110 to vertically move synchronously with a rotation of the cylinder to push the wall 104 at the time of printing. Auxiliary rollers 201 of the same diameter are disposed at both ends of the push roller. A rear push roller 101 (outer roller) is disposed at an outside. An engraved stencil base sheet 107 is wound on the wall, and the cylinder is rotated. A sheet is supplied between the cylinder and the outer roller. The sheet is sandwiched between the wall and the outer roller, conveyed and stencil printed. The wall of the outside of the inner roller is retained by an auxiliary roller so as not to be floated from the outer roller. An ink is not leaked to an axial outside of the cylinder from a gap between the base sheet and the wall.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention comprises a plate cylinder having a deformable peripheral wall, an intermediate press roller provided inside the plate cylinder so as to be able to move up and down, and a back press roller provided outside the plate cylinder. The present invention relates to a stencil printing apparatus. This stencil printing machine presses and deforms the peripheral wall with an intermediate pressing roller, transports the printing paper between the deformed printing cylinder and the backing roller, and supplies ink from inside the printing cylinder to print on the printing paper. I do. In particular, the present invention relates to the stencil printing apparatus, wherein the ink is prevented from leaking from both edges of the printing paper sandwiched between the plate cylinder and the backing roller.

[0002]

2. Description of the Related Art A stencil printing machine having the above-described structure and its problems will be described with reference to FIGS. As shown in FIG. 11, this stencil printing apparatus has a hollow cylindrical plate cylinder 1.
00 and a back-press roller 10 provided outside the plate cylinder 100.
One. The plate cylinder 100 and the backing roller 101 are arranged at a predetermined interval, and their central axes are parallel to each other.

[0003] First, the plate cylinder 100 has two annular portions 102 which are arranged to face each other at a predetermined interval. The two annular portions are connected by a connecting plate. A flexible peripheral wall 104 is wound around the outer peripheral surface of the annular portion 102. One edge of the peripheral wall 104 is fixed to the connecting plate, and the other end is connected to the connecting plate by a spring. The peripheral wall 104 has a substantially rectangular ink-permeable opening 105 formed therein. The opening 105 corresponds to a print area.
Although not shown, ink supply means is provided inside the plate cylinder 100, and ink can be supplied to the inner peripheral surface thereof.

The two annular portions 102 are coaxially penetrated by one shaft 103. The shaft 103 is supported in the frame of the printing device. Therefore, the plate cylinder 100 is
3 is rotatable. The plate cylinder 100 is driven by a driving unit (not shown) in the printing apparatus, and rotates with respect to the shaft 103.

[0005] Inside the plate cylinder 100, the shaft 103
Has a frame 110 attached thereto. Frame 1
Reference numeral 10 does not change the position even when the plate cylinder 100 rotates. Each base end of a pair of main arms 111 is rotatably attached to the frame 110. Two main arms 111
The intermediate pressing roller 112 is rotatably supported between the respective tips. The central axis of the intermediate pressing roller 112 is the axis 103
Is parallel to When the main arm 111 swings, the intermediate pressing roller 112 moves up and down in the plate cylinder 100. Middle press roller 1
Reference numeral 12 moves between a printing position (see FIG. 12) where the peripheral wall 104 is pressed radially outward and deformed, and a non-printing position where the deformation is released (see FIG. 11).

The plate cylinder 1 is operated by an interlocking mechanism (not shown).
The main arm 111 swings in synchronization with the rotation of 00. Due to the swing of the main arm 111, the intermediate pressing roller 112 causes the peripheral wall 1 to move.
The print position moves between a lower printing position where the user presses the button 04 and an upper non-printing position away from the peripheral wall 104. Middle press roller 112
The peripheral wall 104 pushed outward is deformed outward.

[0007] A stencil sheet 107 that has been made is wound around the outer peripheral surface of the peripheral wall 104 of the plate cylinder 100. When the plate cylinder 100 is rotated, the intermediate press roller 112 moves up and down in synchronization with the rotation. The printing paper 108 is supplied between the plate cylinder 100 and the backing roller 101 at a predetermined timing. The printing paper 108 is conveyed by being sandwiched between the peripheral wall 104 deformed by being pushed by the middle pushing roller 112 and the back pushing roller 101. During,
The ink 120 is transferred from the opening 105 to the printing paper 108 through the perforated portion of the stencil sheet 107, and stencil printing is performed.

[0008]

As shown in FIG.
According to the above-described conventional stencil printing apparatus, the intermediate pressing roller 1
There is a problem that the ink 120 leaks from both edges of the printing paper 108 sandwiched between the plate cylinder 100 deformed in step 12 and the backing roller 101.

According to the conventional stencil printing apparatus, the printing pressure on the peripheral wall 104 of the intermediate pressing roller 112 is high at both ends in the axial direction. Due to the high printing pressure, the peripheral wall 104 extruded by the intermediate pressing roller 112 is deformed such that both sides in the axial direction are bent as shown in FIG. That is,
The central portion of the peripheral wall 104 directly pressed by the intermediate pressing roller 112 is pressed against the back pressing roller 101, but both outer portions outside the width range of the intermediate pressing roller 112 rise from the surface of the back pressing roller 101. In spite of printing, a gap is created between the peripheral wall 104 of the plate cylinder 100 and the backing roller 101.

For this reason, at both ends in the axial direction of the peripheral wall 104, the ink 120 protrudes from between the stencil sheet 107 and the peripheral wall 104 during printing, and the plate cylinder 100 and the back-press roller 101 are contaminated with the ink 120. There was a problem that it would.

The present invention relates to a stencil printing machine having a plate cylinder having a deformable peripheral wall, an intermediate press roller provided inside the plate cylinder so as to be able to move up and down, and a back press roller provided outside the plate cylinder. It is another object of the present invention to prevent ink from leaking from both edges of printing paper sandwiched between a plate cylinder deformed by an intermediate pressing roller and a back pressing roller.

[0012]

The stencil printing machine according to the present invention has a cylindrical peripheral wall (9, 104) having ink permeability and flexibility, and is formed on the outer peripheral surface of the peripheral wall. A printing drum (1,200,300) wound around a stencil sheet (107) and rotated around its own central axis; and the printing drum is provided outside the printing drum at a predetermined distance from the printing drum. A back-press roller (63, 101) provided in parallel with the printing cylinder, and a printing position and a deformation provided inside the printing cylinder in parallel with the printing cylinder and pressing the peripheral wall radially outward to deform. An intermediate press roller (23, 112) movable between a non-printing position to be released and a press roller between the plate cylinder deformed by the intermediate press roller at the printing position and the back pressing roller. Stencil printing is performed by transporting the printing paper (108) In the stencil printing apparatus, peripheral wall pressing members (201, 301) for pressing the peripheral wall outward are provided on both axial sides of the intermediate pressing roller for pressing the peripheral wall at the printing position. And

A stencil printing apparatus according to a second aspect of the present invention is the stencil printing apparatus according to the first aspect, wherein the plate cylinders (1, 2) are provided.
(00, 300), and a main arm having a base end pivotally attached to the frame and a middle push roller pivotally attached to a distal end of the frame (17, 110). (21,111)
And a drive mechanism (cam mechanism A) for moving the intermediate pressing roller by swinging the main arm in synchronization with the rotation of the plate cylinder, wherein the back pressing roller is substantially the same as the plate cylinder. A paper cylinder (6) having a clamp mechanism (clamp member 67, cam mechanism C) for locking the leading end of printing paper with the same diameter.
3).

According to a third aspect of the present invention, in the stencil printing apparatus according to the first aspect, at the time of printing, both ends of the peripheral wall in the axial direction of the plate cylinder are the peripheral wall pressing members (201, 301). And is pressed against the backing roller (63, 101) side.

In a stencil printing apparatus according to a fourth aspect of the present invention, in the stencil printing apparatus according to the second aspect, the peripheral wall pressing member is coaxial with the middle pressing roller, has substantially the same diameter, and is elastically deformable. (201).

According to a stencil printing apparatus according to a fifth aspect of the present invention, in the stencil printing apparatus according to the second aspect, the peripheral wall pressing member has an axis parallel to the intermediate pressing roller and separated by a predetermined distance, and is provided with a shaft. Is an auxiliary roller (301) having a small outer diameter and made of a rigid body.

The stencil printing device according to claim 6 is the stencil printing device according to claim 5, wherein the main arm (2)
1,111), and an auxiliary arm (302) that is swingably attached to the distal end and has the auxiliary roller (301) rotatably mounted at the tip thereof, and the auxiliary arm (302) in a direction in which the auxiliary roller approaches the peripheral wall. A biasing means (tensile coil spring 301) for biasing, and a stopper (305) for locking the auxiliary arm at a predetermined position so that the bottom of the auxiliary roller substantially coincides with the bottom of the intermediate pressing roller at the non-printing position. ).

A stencil printing apparatus according to a seventh aspect of the present invention is characterized in that, in the stencil printing apparatus according to the second aspect, the configuration of the drive mechanism for moving the intermediate pressing roller and the clamp mechanism of the paper cylinder. That is, the driving mechanism includes a driving unit (an electromagnetic clutch 45), a cam (an outer plate cam 35) that is driven by the driving unit and selectively set at two positions, A cam follower (cam follower roller 39) connected to the arm, and the main arm (21) is moved via the cam follower by selectively setting the cam at an arbitrary position by the driving means. And a cam mechanism (A) for selectively setting the intermediate pressing roller (squeegee roller 21) to a printing position and a non-printing position. Further, the clamp mechanism of the paper cylinder (63) includes a clamp member (67) for fixing printing paper to the outer peripheral surface of the paper cylinder, and a cam mechanism (C) for driving the clamp member.

According to the stencil printing apparatus of the present invention, in particular, there are auxiliary rollers on both sides in the axial direction of the intermediate pressing roller. For this reason, the central portion of the peripheral wall is directly pressed by the intermediate pressing roller and pressed against the back pressing roller, and both outer portions out of the range of the width of the intermediate pressing roller are pressed by the auxiliary roller and closely contact the back pressing roller. Therefore, this portion does not rise from the surface of the backing roller. During printing, the peripheral wall of the plate cylinder and the back-press roller are in close contact with the stencil paper and the printing paper.

As described above, since the peripheral wall around the printing area is in close contact with the backing roller, the ink discharged from the printing area is sealed and does not leak outside. That is, the ink that has come out of the printing area does not leak outside in the axial direction of the plate cylinder through the gap between the stencil sheet and the peripheral wall.

According to the stencil printing apparatus of the present invention, particularly, the axis of the auxiliary roller does not coincide with the axis of the intermediate pressing roller, and the outer diameter of the auxiliary roller is smaller than the outer diameter of the intermediate pressing roller. For this reason, members such as an auxiliary arm are required, but they can be compactly arranged without taking up space in a limited space inside the plate cylinder. Further, the force by which the auxiliary roll presses the peripheral wall by the tension coil spring is always constant. Ink does not leak from both sides of the printing paper sandwiched between the plate cylinder and the back pressing roller.

[0022]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to FIGS. The present invention is applied to a stencil printing machine provided with a printing mechanism which the present inventors refer to as an inner press mechanism. Before a specific description, an outline of the inner press mechanism will be briefly described.

A stencil printing apparatus provided with an inner press mechanism includes a plate cylinder having an elastically deformable peripheral wall, an intermediate pressing roller provided inside the plate cylinder so as to be able to move up and down, and an ink supply provided inside the plate cylinder. Means and a backing roller provided outside the plate cylinder. The plate cylinder and the backing roller are arranged parallel to each other at a predetermined interval. The undeformed plate cylinder does not contact the backing roller. When the intermediate press roller presses the inner surface of the plate cylinder to deform outward, the deformed portion of the plate cylinder comes into contact with the back press roller. The stencil sheet made is wrapped around the plate cylinder. The printing paper is supplied between the rotating plate cylinder and the back-press roller, and the plate cylinder is deformed by the middle-press roller in time therewith. The paper is stencil-printed and sent while being conveyed while being sandwiched between the stencil sheet of the plate cylinder and the backing roller.

Next, a specific structure example of a stencil printing machine having an inner press mechanism to which the present invention can be applied will be described.
This will be described with reference to FIGS.

The plate cylinder 1 is provided with two disk-shaped side plates 3 arranged at both ends, a rigid clamp base plate 5 connecting the two side plates 3 parallel to the axial direction, and a wrapping around the outer periphery of the side plates. A peripheral wall 9 is provided.

The peripheral wall 9 is formed by weaving a wire material such as a stainless steel wire into a net shape. Therefore, it has flexibility and can pass the printing ink.

A clamp plate 11 is rotatably mounted on the clamp base plate 5. The clamp plate 11 can clamp one end (tip) of the stencil sheet. The stencil sheet is wound around the outer peripheral surface of the peripheral wall after its leading end is locked to the clamp base plate 5 by the clamp plate 11.

The plate cylinder 1 is rotatably supported on its own central axis by a central cylinder shaft 13. A plate cylinder driving gear 15 is formed on the outer peripheral portion of the two side plates 3. Further, the printing drum driving gear 15 meshes with a driving gear of a printing drum driving motor (not shown).

In the plate cylinder 1, an inner frame 17 supported by a center cylinder shaft 13 is fixedly arranged. The inner frame 17 supports one end of a roller support arm 21 by a pivot 19 so as to be swingable substantially vertically. Roller support arm 21
Supports the squeegee roller 23 rotatably at an intermediate portion thereof. The squeegee roller 23 extends parallel to the central axis of the plate cylinder 1, and its outer peripheral surface is in sliding contact with the inner peripheral surface of the flexible peripheral wall 7.

The roller support arm 21 is a squeegee roller 2
A doctor rod 25 extending parallel to the outer peripheral surface 3 at a small interval is fixedly supported. Squeegee roller 2
A wedge-shaped ink reservoir 27 is formed between the doctor rod 3 and the doctor rod 25. Further, an ink delivery pipe 29 for metering ink to the ink reservoir 27 extends in the plate cylinder 1 in parallel with the central axis of the squeegee roller 23 and the doctor rod 25. An ink supply hose 31 is connected to the ink delivery pipe 29. The ink supply hose 31 extends outside the plate cylinder 1 through the central cylinder shaft 13, and an ink supply source (not shown) installed outside the plate cylinder 1. It is connected to the.

The body frame 17 rotatably supports the cam shaft 33. The inner frame 17 is provided with a cam mechanism A composed of a double heart-shaped outer plate cam 35 fixed to the cam shaft 33 and a cam follower roller 39 attached to the linking yoke member 37. I have. In the cam mechanism A, two stable states of a print execution rotation position and a non-print execution rotation position are obtained alternatively by the 90-degree division rotation of the outer plate cam 35. In addition,
The linking yoke member 37 is connected to the other end of the roller support arm 21 by a pivot 41.

The camshaft 33 is connected to a driven side of an electromagnetic clutch 43. The driving side of the electromagnetic clutch 43 is connected to a camshaft drive gear 45, and the camshaft drive gear 45 and the camshaft 33 are selectively connected. . The camshaft drive gear 45 meshes with a main body gear 47 fixed to the side plate 3 of the plate cylinder 1, and is driven to rotate as the plate cylinder 1 rotates.

A cam switch 49 constituted by a limit switch is attached to the inner frame 17.
The cam switch 49 is engaged with a switch operation piece 51 attached to the link yoke member 37.

The center cylinder shaft 13 rotatably supports an intermediate portion of the roller drive arm 53 inside the body. One end of the roller drive arm 53 rotatably supports the intermediate gear 55, and the other end is connected to a tension spring 57, and is urged in the counterclockwise direction in the figure by the spring force of the tension spring 57. With this bias, the intermediate gear 55 meshes with the main gear 47 inside the cylinder and the gear 58 provided concentrically at the end of the squeegee roller 23, and is rotated with the rotation of the plate cylinder 1 to rotate the squeegee roller 23.
Is rotated in the counterclockwise direction in the figure, that is, in the same direction as the plate cylinder 1.

The disc-shaped side plates 3 attached to both ends of the plate cylinder 1 are in sliding contact with a cam 60 having a crescent-shaped cam portion 61 formed on the inner peripheral surface of the plate cylinder 1. And a cam mechanism B constituted by a cam follower roller 59 which engages with the cam portion 61. The cam follower roller 59 is concentric with the squeegee roller 23, and is provided at an end of the squeegee roller 23 via a gear 58.

The back-press roller 63 has the same outer shape as the plate cylinder 1 and is provided in parallel with the plate cylinder 1 at a predetermined distance from the peripheral wall 7 by the central shaft 62. Back pushing roller 6
Reference numeral 3 denotes a concave portion 65 on the outer peripheral portion of the plate cylinder 1 at a rotation position corresponding to the base paper clamp portion for avoiding interference with the base paper clamp portion.
have.

The paper clamp member 6 is attached to the back pushing roller 63.
7 are provided. The paper clamp member 67 includes the pivot 6
9 swingably attached to the back pushing roller 63. A backing roller 63 is attached to one end of the paper clamp member 67.
Is provided with a clamping piece 71 for cooperating with the outer peripheral surface of the printing paper P to removably clamp the printing paper P.

The back pushing roller 63 is provided with a cam mechanism C for clamping or releasing the printing paper P. The cam mechanism C includes a substantially semicircular cam 75 fixed and arranged concentrically with the back pushing roller 63, and a cam follower roller 73 provided at the other end of the clamp piece 71 supported by the pivot 69. The outer periphery of the substantially half-moon-shaped cam 75 is formed by the left flat portion 70 and the right flat portion 7 in FIGS.
2 and a small-diameter portion 76, a cam portion 74 and a large-diameter portion 7.
8 are formed. The cam portion 74 forms a step with the left flat portion 70 and the small diameter portion 76, and the right flat portion 72 extends in a tangential direction of the small diameter portion 76. The cam follower roller 73 slidably contacts an outer peripheral surface of a substantially half-moon-shaped cam 75 and engages with the cam portion 74.

The paper supply unit 77 includes a paper supply table 81 on which the print papers P are stacked, a paper supply roller 83 and a paper separation roller 85 for taking out the print papers P one by one from the paper supply table 81, and a paper guide member 87. A pair of timing rollers 89 for feeding the printing paper P to the paper biting position by the clamp piece 71 of the back pressing roller 63 at a predetermined timing, and an optical paper feeding for detecting that the printing paper P has been fed to the paper biting position. It has a sensor 91. The paper biting position refers to a position at which the leading end of the printing paper P supplied from the left paper supply unit 77 in FIG. Means a rotational position a indicated by.

The paper discharge unit 79 is disposed at the paper release position and cooperates with the backing roller 63 to perform a pinch roller operation to discharge and convey the print paper P. Paper separation claw 95 to be separated from push roller 63
And a discharge pinch roller pair 99 for sending the printing paper P from the paper separating claw 95 to the printing flight table, and a printed printing paper P
And an optical paper discharge sensor 96 for detecting that the printing paper P has flown from the printing flight table to the paper discharge table 98. Note that the paper release position is a position where the clamp of the printing paper P is released, and a position b at which the clamp piece 71 is rotationally moved toward the right discharge unit 79 in FIG. Say.

The upper surface of the discharge paper pinch roller 93 and the upper roller of the discharge paper pinch roller pair 99, which are in sliding contact with the upper surface of the print paper P to be discharged, that is, the print image surface, are provided on both sides of the print paper P. Only the print margin). These rollers move in the axial direction according to the size of the printing paper P set on the paper feeding table 81 so as to slide only on both side margins of the printing paper P regardless of the width dimension of the printing paper P. Automatically adjusted. In this case, the paper feed table 81 is provided with a paper size sensor for detecting the size of the print paper P (not shown).

The operation of the stencil printing apparatus having the above configuration will be described. First, a stencil sheet that has been made is wound around the outer peripheral surface of the plate cylinder 1 and mounted. After the completion of the printing, the number of prints is input using the ten keys on the operation panel (not shown), and then the start key is pressed. Then, by the engagement of the plate cylinder drive gear portion 15 of the plate cylinder 1 with the drive gear of the plate cylinder drive motor,
The plate cylinder 1 is driven to rotate counterclockwise in the figure with the central cylinder shaft 13 as a fixed support shaft.

In the rotation phase in which the concave portion 65 of the back pushing roller 63 faces the plate cylinder 1, the cam follower roller 59
The rotation of the plate cylinder 1 engages with a cam portion 61 formed on the inner peripheral surface of the plate cylinder 1. The cam follower roller 59 is provided in the cam portion 6.
The squeegee roller 23 is lifted during the rotation phase corresponding to the stencil clamping area of the plate cylinder by the engagement with the squeegee 1, that is, is moved radially inward, and separates the squeegee roller 23 from the inner peripheral surface of the peripheral wall 7. Thereby, collision between the clamp base plate 5 and the corner of the concave portion 65 of the back pushing roller 63 can be avoided.
The generation of collision noise is prevented, and the peripheral wall 9 is protected.

When the start key on the operation panel is pressed, the backing roller 63, like the plate cylinder 1, is rotated at the same speed as the plate cylinder 1 by a synchronous rotation driving device (not shown) around its own central axis. In the figure, the motor is driven synchronously in a clockwise direction.

With the start of rotation of the plate cylinder 1 and the backing roller 63, the printing paper P is taken out one by one from the paper feeding table 81 by the paper feeding roller 83 and the paper separating roller 85, and guided to the paper guide member 87. While moving toward the timing roller pair 89.

When the plate cylinder 1 and the backing roller 63 rotate to a predetermined rotational phase position, the timing roller pair 89 moves the printing paper P against the backing roller 63 at a predetermined timing.
The sheet is fed to the sheet biting position a by the clamp piece 71 of FIG.

Next, if the cam switch 49 is not on, the electromagnetic clutch 43 is energized for a predetermined time. As a result, the cam rotates by 90 degrees and is located at the print execution rotation position. At this time, the cam switch 49
With the engagement of the switch operating piece 51 with the switch operating piece 51, it is detected that the outer plate cam 35 is located at the print execution rotational position.

The squeegee roller 23 descends and comes into contact with the inner peripheral surface of the peripheral wall 7 of the plate cylinder 1. With the rotation of the plate cylinder 1, the squeegee roller 23 presses the peripheral wall 7 outward in the radial direction, and deforms the peripheral wall 7 toward the back pushing roller 63.

At this time, the ink in the ink fountain portion 27 is measured when passing through the minute interval with the doctor rod 25 by the counterclockwise rotation of the squeegee roller 23 in the drawing, and the outer periphery of the squeegee roller 23 is measured. After the squeegee roller 23 rotates, the squeegee roller 23 conveys it to the inner peripheral surface of the peripheral wall 7 and squeezes the inner peripheral surface thereof.

When the printing paper P is supplied from the paper feeding unit 77 on the left side in FIG. 2 in synchronization with the rotation of the back pushing roller 63, the printing paper P is fed at the paper feeding position a by the engagement of the cam mechanism C. The tip of P is clamped. And
The printing paper P is wound around the outer peripheral surface of the back pressing roller 63 by the rotation of the back pressing roller 63, and heads toward a contact portion with the plate cylinder 1, in this case, a bulging deformation portion of the peripheral wall 7. As a result, the printing paper P is sandwiched between the swelled and deformed plate cylinder 1 and the back pressing roller 63 with a predetermined pressing force together with the stencil sheet wound around the plate cylinder outer peripheral surface. The printing paper P is subjected to stencil printing while being sent rightward with the rotation of the plate cylinder 1 and the back-press roller 63.

Then, the plate cylinder 1 and the back-press roller 6 are moved until the leading end of the clamped printing paper P reaches the paper release position b.
When 3 rotates, the clamp of the printing paper P by the clamp piece 71 is released, and the conveyance of the printing paper P is taken over by the discharge pinch roller. Thereafter, the printing paper P is transferred to the paper separating claw 9.
5, the sheet is separated from the back pushing roller 63 by the paper ejection pinch roller pair 99, is sent out to the paper flying table 97, flies from the paper flying table 97 to the paper ejection table 98, and the print image surface is directed upward on the paper ejection table 98. Is placed.

The back-pressing roller 63 of the present embodiment moves the printing paper P between the paper biting position a and the paper opening position b.
As a paper cylinder having a printing paper transport mechanism for forcibly transporting the paper by winding it around the roller outer peripheral surface.

An example of an embodiment of the present invention will be described with reference to FIGS. 5 and 6 on the premise of a stencil printing apparatus having the above-described inner press mechanism. The basic structure of the plate cylinder and the back-press roller in this example is the same as that of the above-described conventional apparatus, and the corresponding portions are denoted by the same reference numerals as in FIGS.

The plate cylinder 200 of this embodiment has an auxiliary roller 201 as a peripheral wall pressing member for preventing both sides of the peripheral wall 104 in the axial direction from floating. The auxiliary roller 201 is attached to the outer end of the shaft 202 of the intermediate pressing roller. The auxiliary roller 201 may be fixed to the shaft 202 or may be rotatably attached. Both the auxiliary roller 201 and the middle pressing roller 112
The rollers may be fixed to the shaft 202 so that both rollers rotate synchronously. In addition, both rollers are connected to the shaft 202 respectively.
May be independently rotated.

The auxiliary roller is made of an elastically deformable material, for example, rubber. The outer diameter of the auxiliary roller is substantially the same as the outer diameter of the intermediate pressing roller.

The operation of the above configuration will be described. Stencil 10 made on the outer peripheral surface of the peripheral wall 104 of the plate cylinder 200
Wind 7 When the plate cylinder 200 is rotated, the intermediate pressing roller 112 moves up and down in synchronization with the rotation. The printing paper 108 is supplied between the plate cylinder 200 and the backing roller 112 at a predetermined timing. The printing paper 108 includes a peripheral wall 104 that is deformed outward by being pressed by the middle pressing roller 112 and the back pressing roller 1.
01 and transported. Meanwhile, ink 12
0 is transferred from the opening 205 to the printing paper 108 through the perforated portion of the stencil sheet 107, and stencil printing is performed.

According to the stencil printing apparatus, the intermediate pressing roller 1
There are auxiliary rollers 201 on both sides in the axial direction of twelve. For this reason, the central portion of the peripheral wall 104 is directly pressed by the intermediate pressing roller 112 and pressed against the back pressing roller 101, and both outer portions outside the width of the intermediate pressing roller 112 are pressed by the auxiliary roller and Adhere to 101. This portion does not rise from the surface of the backing roller. At the time of printing, the peripheral wall 104 of the plate cylinder 100
And the backing roller 101 are composed of the stencil sheet 107 and the printing paper 1.
08 in close contact.

As described above, the peripheral wall 10 around the opening 105
The ink 4 coming out of the opening 105 is sealed in the opening 105 and does not leak to the outside because the ink 4 comes into close contact with the backing roller 101. That is, the ink that has come out of the opening 105 is the stencil sheet 107.
Does not leak to the outside of the plate cylinder in the axial direction through the gap between the plate cylinder and the peripheral wall 104. Therefore, the plate cylinder 100 and the back-press roller 101 are not stained with the ink 120 as in the related art.

In this embodiment, since the auxiliary roller and the intermediate pressing roller are coaxial and have the same outer diameter, design and manufacture are easy. Also, once both rollers are mounted on a common shaft, the shafts of both rollers are unlikely to be displaced by use, and maintenance is easy.

In this embodiment, since the auxiliary roller and the intermediate pressing roller are coaxial and have the same outer diameter, when the intermediate pressing roller is lowered to the printing position, the auxiliary roller and the intermediate pressing roller contact the peripheral wall almost simultaneously. Therefore, the auxiliary roller is required to have a function of pressing both edges of the peripheral wall and not to hinder the action of the intermediate pressing roller pressing the center of the peripheral wall. Although the auxiliary roller in this example has the same diameter as the middle pressing roller and has the same outer diameter, it is formed of a deformable elastic material, so that the auxiliary roller can be deformed when pressing the peripheral edge of the peripheral wall. For this reason, despite the fact that the auxiliary roller is coaxial and has the same diameter as the intermediate pressing roller, the auxiliary roller of the present example does not hinder the pressing of the center of the peripheral wall by the intermediate pressing roller.

A second embodiment of the present invention will be described with reference to FIGS. In this example, as in the first example, FIG.
To the stencil printing apparatus of the inner press mechanism shown in FIG. In the basic structure of this example, parts corresponding to the first example are denoted by the same reference numerals as in FIGS. 5 and 6, and description thereof is omitted. The operation at the time of printing in this example is substantially the same as in the first example.

The plate cylinder 300 of this embodiment has an auxiliary roller 301 therein as a peripheral wall pressing member for preventing both sides of the peripheral wall 104 in the axial direction from floating. The auxiliary roller 301 has an axis parallel to the intermediate pressing roller 112 and separated by a predetermined distance, has an outer diameter smaller than that of the intermediate pressing roller 112, and is made of a rigid body. Further, the auxiliary roller 301 of the present example is different from the auxiliary roller 201 of the first example,
It is not coaxial with the intermediate pressing roller 112. This example has a support mechanism dedicated to the auxiliary roller.

A central portion of an auxiliary arm 302 is attached to the main arm 111 so as to be swingable about a shaft 303.
The auxiliary roller 301 is rotatably attached to one end of the auxiliary arm 302 (on the side close to the middle pressing roller 112). The other end of the auxiliary arm 302 (on the side far from the intermediate pressing roller 112) is connected to the main arm 111 via a tension coil spring 304 as an urging means. A stopper 305 is attached to the main arm 111 as a member that regulates a range in which the auxiliary arm 302 can rotate. The stopper 305 is connected to the auxiliary arm 30
It faces the upper edge on the side where the two tension coil springs 304 are provided.

FIGS. 7 and 8 show a non-printing state in which the intermediate pressing roller 112 does not apply pressure to the inner surface of the peripheral wall 104. FIG.
The plate cylinder 300 is not deformed, and there is a gap between the plate cylinder 300 and the back roller 101. The auxiliary roller 301 is in contact with the peripheral wall 104, but does not apply a load thereto. In this state, the tension coil spring 304 pulls the other end of the auxiliary arm 302 to abut the stopper 305.
In this state, the lower end of the auxiliary roller 301 and the lower end of the intermediate pressing roller 112 substantially match.

FIGS. 9 and 10 show a printing state in which the intermediate pressing roller 112 pushes the inner surface of the peripheral wall downward. At this time,
The auxiliary roller 301 also pushes the peripheral wall downward. The auxiliary arm 302 rotates clockwise about the axis 303 in FIG. 10 and extends the tension coil spring 304. For this reason, the auxiliary roller 301 applies a downward load to the peripheral wall 104 by the elastic force of the tension coil spring 304.

According to the stencil printing apparatus, the intermediate pressing roller 1
There are auxiliary rollers 301 on both sides in the axial direction of twelve. The auxiliary roller can move independently of the intermediate pressing roller 112, and can press both edges of the peripheral wall 104 with an appropriate force by the tension coil spring 304 at the time of contact with the peripheral wall 104. For this reason, the central portion of the peripheral wall 104 is directly pressed by the intermediate pressing roller 112 and pressed against the back pressing roller 101, and both outer portions deviating from the width range of the intermediate pressing roller 112 are pressed by the auxiliary roller 301 and back pressed. It is in close contact with the roller 101. This part is the backing roller 1
01 does not rise from the surface. During printing, the peripheral wall 104 of the plate cylinder 300 and the backing roller 101
Are in close contact with the stencil sheet 107 and the printing sheet 108 therebetween.

Therefore, according to this embodiment, similar to the first embodiment,
Printing paper 1 sandwiched between plate cylinder 300 and backing roller 101
08 does not leak from both sides. Also, the second
In the case of the example, the axis of the auxiliary roller 301 does not coincide with the axis of the intermediate pressing roller 112, and the outer diameter of the auxiliary roller 301 is smaller than the outer diameter of the intermediate pressing roller 112. For this reason, members such as the auxiliary arm 302 are required, but they can be arranged compactly without taking up space in a limited space inside the plate cylinder. Further, the force by which the auxiliary roll 301 pushes the peripheral wall 104 by the tension coil spring 304 is always constant.

[0068]

According to the present invention, there is provided a stencil printing apparatus of a type in which a peripheral wall is extruded and deformed by an intermediate pressing roller, and a sheet is printed between the deformed peripheral wall and a back pressing roller outside the plate cylinder. On the outside, a peripheral wall pressing member that comes into contact with the inner surface of the peripheral wall together with the intermediate pressing roller was provided. For this reason, the peripheral wall outside the middle pressing roller does not rise from the surface of the back pressing roller. Therefore, it is possible to reliably prevent the ink from leaking at both edges of the printing paper sandwiched between the plate cylinder and the back pressing roller.

[Brief description of the drawings]

FIG. 1 is a schematic side view illustrating an example of the structure of a stencil printing apparatus to which the present invention can be applied, and is a diagram illustrating a printing state.

FIG. 2 is a schematic side view showing one structural example of a stencil printing apparatus to which the present invention can be applied, and is a view showing a non-printing state.

FIG. 3 is a perspective view showing a structural example of a stencil printing apparatus to which the present invention can be applied, and is a view showing a non-printing state.

FIG. 4 is a perspective view showing one structural example of a stencil printing apparatus to which the present invention can be applied, and is a perspective view showing a printing state.

FIG. 5 is a front view of a first example of the embodiment of the present invention, in which a plate cylinder and a back-press roller are partially cut away, showing a non-printing state.

FIG. 6 is a front view, partially cut away, of a plate cylinder and a back-press roller in the first example of the embodiment of the present invention, showing a printing state.

FIG. 7 is a front view of the second example of the embodiment of the present invention, in which a plate cylinder and a part of a backing roller are partially cut away, showing a non-printing state.

FIG. 8 is a sectional view of a plate cylinder and a back-press roller in a second example of the embodiment of the present invention, showing a non-printing state.

FIG. 9 is a front view of a second example of the embodiment of the present invention, in which a plate cylinder and a backing roller are partially cut away, showing a printing state.

FIG. 10 is a sectional view of a plate cylinder and a backing roller in a second example of the embodiment of the present invention, showing a printing state.

FIG. 11 is a front view of a plate cylinder and a partly cut back roller in a conventional stencil printing apparatus.

FIG. 12 is a front view of a plate cylinder and a partly cut back roller in a conventional stencil printing apparatus, showing a state of ink leakage.

[Explanation of symbols]

 1,200,300 Plate cylinder 7 Flexible peripheral wall 9,104 Peripheral wall 17,110 Frame 21 Roller support arm 23,112 Middle push roller 35 Cam as outer plate cam 39 Cam follower roller as cam follower 45 Drive means Electromagnetic clutch 63 Paper cylinder as backing roller 67 Clamping member 107 Stencil sheet 108 Printing paper 111 Main arm 101 Backing roller 201, 301 Auxiliary roller as peripheral wall pressing member 302 Auxiliary arm 304 Tension coil spring as urging means 305 Stopper A Cam mechanism C Cam mechanism P Printing paper

Claims (7)

[Claims] 1. A plate cylinder having a cylindrical peripheral wall having ink permeability and flexibility, and a stencil sheet made of stencil wound on an outer peripheral surface of the peripheral wall, and rotated around its own central axis, A back-pressing roller provided outside the plate cylinder in parallel with the plate cylinder at a predetermined interval from the plate cylinder, and provided inside the plate cylinder in parallel with the plate cylinder, and radially extending the peripheral wall. The printing drum having an intermediate pressing roller movable between a printing position to be deformed by pressing outward and a non-printing position at which the deformation is released, the plate cylinder deformed by the intermediate pressing roller at the printing position A stencil printing apparatus that performs stencil printing by sandwiching and transporting a print sheet between the backing roller and the backing roller. Press outward Stencil printing apparatus characterized in that a peripheral wall pressing member. 2. A frame provided at a predetermined position inside the plate cylinder, and a main arm having a base end pivotally attached to the frame and the intermediate pressing roller pivotally attached to a tip end thereof. A drive mechanism for moving the intermediate press roller by swinging the main arm in synchronization with the rotation of the plate cylinder, wherein the back press roller has a printing cylinder of substantially the same diameter as the plate cylinder. 2. A paper cylinder having a clamp mechanism for locking a leading end.
A stencil printing apparatus as described in the above. 3. The stencil printing apparatus according to claim 1, wherein, at the time of printing, both ends of the peripheral wall in the axial direction of the plate cylinder are pressed by the peripheral wall pressing member and pressed against the back pressing roller. 4. The stencil printing machine according to claim 2, wherein the peripheral wall pressing member is an auxiliary roller having substantially the same diameter and the same diameter as the intermediate pressing roller and made of an elastically deformable material. apparatus. 5. The peripheral wall pressing member is an auxiliary roller having an axis parallel to the intermediate pressing roller and separated by a predetermined distance, having an outer diameter smaller than that of the intermediate pressing roller, and formed of a rigid body. The stencil printing apparatus according to claim 2, wherein 6. An auxiliary arm attached to the main arm so as to be swingable and rotatably attached to a distal end of the auxiliary arm, and biases the auxiliary arm in a direction in which the auxiliary roller approaches the peripheral wall. 6. A stencil printing machine according to claim 5, further comprising a biasing means for engaging the auxiliary arm and a stopper for locking the auxiliary arm at a predetermined position such that the bottom of the auxiliary roller substantially coincides with the bottom of the intermediate pressing roller at the non-printing position. apparatus. 7. The driving mechanism for moving the intermediate pressing roller includes a driving unit, a cam that is driven by the driving unit and is selectively set at two positions, and is interlocked with the cam and connected to the main arm. And a cam follower connected thereto. The main arm is moved via the cam follower by selectively setting the cam to an arbitrary position by the driving means, and the intermediate press roller is moved to a printing position and a non-printing position. Wherein the clamp mechanism of the press drum includes a clamp member for fixing printing paper to an outer peripheral surface of the press drum, and a cam mechanism for driving the clamp member. Item 3. A stencil printer according to item 2.