JPH1128854A - Stencil printer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance operability by a method wherein double side concurrent printing, one side printing and multiple color printing in one process can be executed by one printer. SOLUTION: In this printer, a clamp mechanism 700C for nipping a printing paper S is provided to a transferring cylinder 700 disposed between a first plate cylinder 201 and a second plate cylinder 601. A first cam member 710 and a second cam member 720 for opening and closing the clamp mechanism 700C corresponding to a printing mode is provided in the vicinity of the transferring cylinder 700. The first cam member 710 takes selectively one of two positions for closing and opening the clamp mechanism 700C at the paper supplying timing.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stencil printing machine (hereinafter referred to as a "master") formed by perforation and stencil winding on an outer peripheral surface of a porous cylindrical plate cylinder, and ink is leached from a perforated portion of the master. The present invention relates to a stencil printing apparatus that transfers a printed image by transferring the ink to printing paper.

[0002]

2. Description of the Related Art Conventionally, digital thermosensitive stencil printing has been known as a simple printing method. This is because, after a master melt-punched by a thermal head or the like based on read information of a document image is wound around the outer peripheral surface of a porous cylindrical plate cylinder, ink is supplied by an ink supply mechanism arranged inside the plate cylinder. And transfers the printed image by exuding the ink from the perforated portion of the master and transferring it to printing paper. In recent years, in stencil printing, double-sided printing in which printing is performed on both sides of a printing paper has been increasing in order to save printing paper and prevent an increase in files. This double-sided printing is obtained by turning over the printed paper once and feeding it again,
There is a problem that the procedure for re-feeding the printing paper is troublesome. In addition, the printed matter after the printing is completed, the ink is not sufficiently dried, so if it is desired to immediately print on the back side, the transport rollers and press rollers in the paper feed path are pressed against the insufficiently dried image area, The printed image is dirty or unclear. For this reason, in most cases,
The printing on the back side has been performed several hours or more after the printing on the front side of the printing paper has been completed. In particular, when there is a so-called solid image portion having a large amount of ink, it is necessary to dry the ink for a long time, so that printing on the back surface has been performed the next day.

As described above, in duplex printing, it is necessary to wait for a long time until printing on the back side, and since the paper is fed twice, the net printing time requires twice as long as that in single-sided printing. And it takes too much time.

[0004] As a solution to the time problem of double-sided printing, for example, a stencil printing apparatus described in JP-A-6-71996 or JP-A-8-118774 is known. A stencil printing apparatus described in JP-A-6-71996 has an ink roller 1000 inside as shown in FIG.
And the like, and plate cylinders 1003 and 1004 each having a clamper 1001 for holding the master on the outer peripheral surface are arranged to face each other. The plate cylinder 1004 can be freely moved toward and away from the plate cylinder 1003, and the plate cylinder 1004 presses the plate cylinder 1003 with the plate-making masters corresponding to the front and back surfaces of the printing paper 1005 wound around each plate cylinder. Then, printing is performed simultaneously on both sides of the printing paper 1005. The printed printing paper 1005a is discharged to the paper discharge unit 1006. If an unprinted master is wound around one of the plate cylinders to perform the same operation as double-sided printing, single-sided printing can be performed.

[0005] As shown in FIG. 15, a stencil printing apparatus described in Japanese Patent Application Laid-Open No.
The transfer cylinder 1007 is provided between the transfer cylinders 04 and the plate cylinders 1003 and 1004 are provided so as to be able to freely contact and separate from the transfer cylinder 1007. The ink image of the plate cylinder 1003 is transferred to the transfer cylinder 1007, and thereafter, the plate cylinder 1004
And a transfer cylinder 1007 for simultaneous double-sided printing. In the stencil printing apparatus described in Japanese Patent Application Laid-Open No. 6-71996, when performing continuous printing, the back side image of the printing paper on which the ink has not yet dried sufficiently overlaps the uppermost surface of the discharged printing paper. Although there is a problem of causing image stains, according to the indirect transfer method using the transfer cylinder 1007, since the ink drying step can be secured, there is an advantage that the problem of image stains can be solved. Also, in the case of the stencil printing apparatus described in JP-A-8-118774, single-sided printing is possible by performing the same operation as above with the plate cylinder 1004 without transferring the ink image to the transfer cylinder 1007. Becomes

Conventionally, when printing not only a single color but also multicolor printing on one sheet of printing paper, such as when printing a flyer or the like, a plurality of color cylinders are prepared.
After printing the first color, the ink is sufficiently dried, and then the multi-color printing is performed by replacing the plate cylinder and refeeding the ink. For this reason, there is a problem that it takes too much time in the case of multi-color printing as in the case of double-sided printing.

As a solution to the time problem in multicolor printing, for example, a multicolor printing apparatus described in JP-A-4-329175 is known. This is, as shown in FIG. 16, around a printing cylinder 1009 provided with a clamper 1008 that clamps the leading end of the printing paper 1005 on the outer peripheral surface.
A plurality of plate cylinders 1010 and 1011 having different colors are arranged, and these plate cylinders 1010 and 1011 are attached to the printing cylinder 100.
9 is provided so as to be able to freely contact and separate. By making the plate cylinders 1010 and 1011 continuously contact and separate during one rotation of the print cylinder 1009 around which the printing paper 1005 is wound,
Multicolor printed matter can be obtained in one step.

[0008]

Incidentally, in the above three prior arts, the forms of printing that can be performed without re-feeding, that is, without time, are as shown in Table 1.

[0009]

[Table 1]

[0010] In recent years, there has been an increasing need by users for one-sided printing, two-sided simultaneous printing, and one-step multi-color printing with one device. There is no printer that enables all of these print modes, and it has not been possible to sufficiently meet user needs.

Accordingly, an object of the present invention is to provide a stencil printing apparatus which enables all printing modes of single-sided printing, double-sided simultaneous printing, and one-step multicolor printing with the same configuration.

[0012]

SUMMARY OF THE INVENTION The present invention provides a transfer cylinder having a function of clamping a printing paper to a transfer cylinder by fusing the concept of a print cylinder in multicolor printing with a transfer cylinder which has been conventionally provided separately. An object of the present invention is to open and close a clamp mechanism of a transfer cylinder, whose necessity changes according to a print mode, at a low cost by a simple mechanical configuration without complicated electric control. Specifically, according to the first aspect of the present invention, after the stencil printing paper is wound around the outer peripheral surface of the plate cylinder, the ink is exuded from the stencil printing paper, and the ink is supplied from the paper feeding unit. What is claimed is: 1. A stencil printing apparatus for transferring a print image by transferring to a printing paper and discharging the printing paper to a paper discharge unit, comprising: first and second plate cylinders; A transfer cylinder that is arranged between the plate cylinders at a position facing a surface of the printing paper opposite to the surface that is in contact with the plate cylinder, and that rotates at the same peripheral speed as the first and second plate cylinders; In a stencil printing apparatus in which the first plate cylinder and the second plate cylinder are provided so as to be able to freely contact and separate from the transfer cylinder, a clamp for holding the leading end of the printing paper in the supply direction is provided on the transfer cylinder. A mechanism is provided, and the clamp mechanism is opened near the transfer cylinder in accordance with a printing mode. Clamp driving member adopts a configuration that is provided for.

According to a second aspect of the present invention, in the configuration of the first aspect, the clamp mechanism includes a contact, and the clamp opening / closing member guides the contact and opens and closes the clamp mechanism. Is adopted.

According to a third aspect of the present invention, in the configuration of the second aspect, the cam member opens the printing paper in a predetermined printing mode with the first cam member located on the printing paper supply side. A second cam member located on the side to perform the clamping, wherein the first cam member is provided so as to be able to selectively take a position for closing and opening the clamp mechanism with respect to a sheet feeding timing. The configuration is adopted.

According to a fourth aspect of the present invention, in the configuration of the third aspect, a driving member for moving the first cam member to a position for closing or opening the clamp mechanism is provided, and the driving member is provided. Is provided in accordance with the input of the print mode.

According to a fifth aspect of the present invention, in the configuration of the first or second aspect, a plurality of paper feed units are provided that share the paper discharge unit as a final position of the paper feed path, and the plurality of paper feed units are provided according to a print mode. The configuration is such that each paper feeding unit is used properly.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic diagram illustrating the overall configuration of a stencil printing apparatus according to the present embodiment. In FIG. 1, a stencil printing machine 1
Are roughly divided into a first plate making section 100, a first printing section 200,
A sheet feeding unit 300, a first sheet discharging unit 400, a second plate making unit 500,
Second printing unit 600, transfer cylinder 700, and second paper discharge unit 900
It is composed of

The first plate making section 100 is provided with a master 101. The master 101 has a laminate structure in which a thin paper of about 1 to 2 μm is attached with Japanese paper or synthetic fiber serving as a porous support, or a mixture of both materials. I have. The master 101 is wound around a core material 101A in a roll shape and can be sequentially fed out.
The master 101 pulled out from the roll state is pressed against the thermal head 102 by the platen roller 103, and is perforated in the main scanning direction and the sub-scanning direction by the selective heat generation of the heating element of the thermal head 102. In this case, the main scanning direction corresponds to the axial direction of the platen roller 103, and the sub-scanning direction corresponds to a direction perpendicular to the main scanning direction. For this reason, the platen roller 103 can rotate not only to simply press the master 101 toward the thermal head 102 but also to extend the master 101 in the sub-scanning direction. The master 101 that has completed the perforating process, that is, the plate making, is cut into a required length by the cutter 104 and is conveyed toward the first plate cylinder 201 via the guide member 105.

The first printing unit 200 includes a porous cylindrical first printing unit 200.
And an ink supply mechanism 202 disposed inside the first plate cylinder 201 as a main part thereof. The first plate cylinder 201 is rotatable around the rotation axis 201A in the direction of the arrow shown in the figure, and a large number of perforations are formed on its peripheral surface except for a part. Although not shown, a thin mesh screen made of synthetic fibers is attached to the surface. Metal can be used as a material for the mesh screen. First
A stage 203 made of a magnetic material on which the tip of the master 101 is mounted, and a stage 203 that is freely movable toward and away from the stage 203, is provided on a portion of the peripheral surface of the plate cylinder 201 where no perforation is made. Is provided. With this configuration, the master 101 is nipped and fixed by the clamper 204 in a state where the master 101 has its tip mounted on the stage 203.

The ink supply mechanism 202 includes an ink roller 2
05 and a doctor roller 206. The ink roller 205 is disposed below the rotation axis 201A of the first plate cylinder 201 and opposed to a transfer cylinder 700 described later, and serves as a metal roller that rotates in the direction of the arrow shown in the figure. The ink roller 205 contacts the inner peripheral surface of the first plate cylinder 201 while
The ink rotated at a peripheral speed slightly lower than the peripheral speed of
To the plate cylinder 201 and the perforated portion of the mesh screen. The ink whose amount is regulated by the doctor roller 206 is dropped from an ejection port formed on the rotating shaft 201A into the ink reservoir 207. In addition, since the ink roller 205 is disposed at a position facing the transfer cylinder 700, the ink roller 205 also functions as a backup roller that prevents deformation when the first plate cylinder 201 comes into contact with the transfer cylinder 700 during printing. It has become.

The first plate cylinder 201 is provided so as to be able to advance and retreat with respect to the transport path of the printing paper S by the advance and retreat mechanism shown in FIG.
The reciprocating mechanism includes a plate cylinder moving arm 206. The plate cylinder moving arm 206 can swing between a position at which the printing paper S advances into the conveyance path with the support shaft 206A supported by an immovable portion of the printing apparatus main body as a fulcrum and a position at which the printing paper S retreats from the conveyance path. When it is in the retracted position, it is locked by the arm stopper 207 located at the tip on the swinging side. The arm stopper 207 is a swingable arm. The arm stopper 207 can be disengaged from the swing-side tip of the plate cylinder moving arm 206 by a solenoid 208 having an actuator 208A connected near the swing end. Actuator 2 for solenoid 208
08A is always projected by a return spring 209, so that the arm stopper 207 can always be engaged with the tip of the plate cylinder moving arm 206 on the swing side. When the solenoid 208 is operated by a signal from a print paper detection sensor P disposed upstream of the first plate cylinder 201 in the transport direction of the print paper S fed from the paper supply unit 300, the arm stopper 207 and the plate cylinder movement The engagement of the arm 206 with the swing-side tip is released.

A rotating shaft 201A of the first plate cylinder 201 is supported at a part of the swinging end of the plate cylinder moving arm 206. Between the rotating shaft 201A and the tip of the swinging side,
A cam follower 210 rotatably supported by a shaft 210A supported by the plate cylinder moving arm 206 is provided. The cam follower 210 faces a plate cylinder moving cam 211 constituted by an eccentric cam rotatably provided at an immobile portion of the printing apparatus main body. Plate cylinder moving cam 2
11, the first plate cylinder 201 advances to the conveying path of the printing paper S when the small diameter portion faces the cam follower 210, and the first plate cylinder 2 when the large diameter portion faces the cam follower 210.
01 from the conveyance path of the printing paper S, and the leading end of the plate cylinder moving arm 206 on the swing side is
7 is formed in such a shape that it can be engaged. In FIG. 2, reference numeral 212 denotes a tension spring for applying a biasing force to swing the plate cylinder moving arm 206 in a direction in which the cam follower 210 of the plate cylinder moving arm 206 comes into contact with the plate cylinder moving cam 211. I have.

The following operation is performed by the above-mentioned advance / retreat mechanism. First, when the first plate cylinder 201 is set at a position retracted from the conveyance path of the printing paper S, the plate cylinder moving cam 2
When the large-diameter portion 11 faces the cam follower 210, the tip of the plate cylinder moving arm 206 on the swinging side engages with the arm stopper 207. Thus, the first plate cylinder 201 is held at a position retracted from the conveyance path of the printing paper S against the urging force of the tension spring 212 hung on the plate cylinder moving arm 206. Next, when the first plate cylinder 201 is advanced to the conveyance path of the printing paper S, the solenoid 208 causes the arm stopper 207 to move the arm stopper 207 against the biasing force of the return spring 209 to the leading end of the plate cylinder moving arm 206 on the swing side. And release the locked state. The plate cylinder moving arm 206 includes a tension spring 212.
Of the plate cylinder moving cam 21 by the urging force of
It swings in the direction to move toward 1. Plate cylinder moving cam 211
By contacting the cam follower 210 with the small diameter portion of
The plate cylinder moving arm 206 moves the first plate cylinder 201 to the printing paper S
To the transport path.

The paper feeding section 300 includes a registration roller 301 for setting the timing at which the printing paper S is fed. The registration roller 301 holds the leading end of the printing paper S conveyed from a paper cassette (not shown) and aligns the transfer position of the printing paper S with the leading end of the image of the master 101 on the first plate cylinder 201. It is provided for the purpose. The fed print sheet S is fed by a guide member 302 toward a position facing the ink roller 205.

The first sheet discharging section 400 includes a conveying means 400A.
And a paper discharge tray 400B. Conveying means 40
Reference numeral 0A denotes a peeling claw 401A that peels off the printing paper S on which an image corresponding to the master 101 has been transferred, and a suction conveyance device 402.
A is provided. The peeling claw 401A is attached to the first plate cylinder 201.
Is a oscillating member that is disposed at a position corresponding to after the image is printed on the printing paper S in the rotation direction of the printing paper S and forms a peeling portion of the printing paper S. Can be selectively swung to a position between the front end of the first plate cylinder and the first plate cylinder 201. Although not shown, it is also possible to provide a structure in which air is blown to the printing surface of the printing paper S whose tip is separated from the surface of the plate cylinder by the peeling claw 401A to assist the peeling of the printing paper S. The suction conveyance device 402A is provided with the first plate cylinder 201.
The suction box 404A connected to a suction fan (not shown) is provided to convey the printing paper S peeled from the paper tray while sucking and holding it toward the discharge tray 400B.
And a transport belt 405A. The suction box 404A is separated from the first plate cylinder 201 by the peeling claw 401A.
It is provided to suck the printing paper S peeled off from the conveyor belt 405A. The transport belt 405A is
A plurality of the pulleys 406A and 407A are extended along the axial direction, and one of the pulleys 406A and 407A can be moved in a direction indicated by an arrow in FIG.

Next, the second plate making section 500 and the second printing section 60
0 will be described. The second plate making section 500 and the second printing section 600 are connected to the first printing section 2 with a transfer cylinder 700 described later interposed therebetween.
00 is provided at a position facing the first plate cylinder 201. The second plate-making unit 500 has the same configuration as the first plate-making unit 100. For convenience, the first digit of the reference numerals used in the description of the first plate-making unit 100 is applied as it is, and its detailed description is given. Description is omitted. The second printing unit 600 includes the first
Similar to the printing unit 200, the second plate cylinder 601 and the ink supply mechanism 602 are main components. Second plate cylinder 601
Like the first plate cylinder 201, is rotatable in the direction of the arrow shown in the figure around the rotation axis 601A, and a large number of perforations are formed on its peripheral surface except for a part. Although not shown, a thin mesh screen made of synthetic fibers is attached to the surface. Metal can be used as a material for the mesh screen. A portion of the peripheral surface of the second plate cylinder 601 where no perforation has been made is provided with a stage 603 made of a magnetic material on which the tip of the master 501 is mounted, and is freely movable toward and away from the stage 603. , A clamper 604 having a magnet is provided. With this configuration, the master 501 holds the clamper 60 with its tip mounted on the stage 603.
4 to be fixed.

The ink supply mechanism 602 includes an ink roller 6
05, the doctor roller 606 and the ink supply pipe 6
07 mainly. The ink roller 605 is
A metal roller that is located above the rotation axis 601A of the second plate cylinder 601 and rotates in the direction of the arrow shown in the figure. The metal roller contacts the inner peripheral surface of the second plate cylinder 601 and contacts the second plate cylinder 601. The ink is rotated at a peripheral speed slightly lower than the peripheral speed, and the amount of ink specified by the doctor roller 606 is supplied to the second plate cylinder 601 and the perforated portion of the mesh screen. Further, the ink roller 605 is disposed at a position facing the transfer cylinder 700, and the second plate cylinder 6
01 also functions as a backup roller for preventing deformation when it comes into contact with the transfer cylinder 700 during printing. In the case of the present embodiment, the ink supply pipe 607 supplies ink from the inside of the hollow pipe which also serves as the rotation shaft 601A of the second plate cylinder 601 to the ink reservoir 608 located above the rotation shaft 601A. It is supposed to. The ink pool 608 corresponds to a wedge-shaped space formed by the ink roller 605 and the doctor roller 606. For this reason, the ink supply pipe 607 extends from the rotation shaft 601A of the second plate cylinder 601, and its end is open toward the ink reservoir 608.

The second plate cylinder 601 can be moved toward and away from the transfer cylinder 700 by an advancing and retreating mechanism similar to the structure shown in FIG. In regard to the advancing / retracting mechanism, the fulcrum position of the plate cylinder moving arm 206 is different from the configuration shown in FIG. However, since the functions are completely the same, the reference numerals shown in FIG. 2 are used as they are, and detailed description thereof is omitted.

The second sheet discharging section 900 includes a conveying means 900A,
910A, a paper discharge tray 900B, and a guide plate 920. The transport unit 900A includes a peeling claw 901 that peels the printing paper S on which the image corresponding to the master 501 has been transferred.
A and a suction conveyance device 902A. Peeling nail 90
Reference numeral 1A denotes a swinging member which is disposed at a position corresponding to a position after printing the image on the printing paper S in the rotation direction of the second printing drum 601 and forms a peeling portion of the printing paper S, and a surface of the second printing drum 601. From the printing paper S and a position between the leading end of the printing paper S and the second plate cylinder 601. Although not shown, it is also possible to provide a configuration in which air is blown to the printing surface of the printing paper S whose tip is separated from the surface of the plate cylinder by the peeling claw 901A to assist the peeling of the printing paper S.

The suction transfer device 902A is connected to the second plate cylinder 60
The suction box 904A is provided for transporting the printing paper S peeled from the sheet No. 1 while sucking and holding it toward the guide plate 920, and connected to a suction fan (not shown).
And a transport belt 905A. The suction box 904A is moved by the peeling claw 901A to the second plate cylinder 601A.
It is provided to suck the printing paper S peeled off from the conveyor belt 905A. The transport belt 905A is
A plurality of pulleys are stretched along the axial direction of the pair of pulleys 906A and 907A, and one of the pulleys 906A and 907A can be moved in the direction of the arrow in FIG.

The guide plate 920 is provided to guide the printing paper S transported by the transporting means 900A to the transporting means 910A while changing its transport direction. The transfer means 910A includes a suction transfer device 912A. The suction conveyance device 912A is provided to convey the printing paper S conveyed from the guide plate 920 in a state of being suction-held toward the discharge tray 900B, and includes a suction box 914A connected to a suction fan (not shown). , Conveyor belt 9
15A. A plurality of the conveyor belts 915A are wound around the pair of pulleys 916A and 917A in the axial direction, and one of the pulleys 916A and 917A can be moved in a direction indicated by an arrow in FIG.

As shown in FIG. 1, a transfer cylinder 700 is disposed between the first plate cylinder 201 and the second plate cylinder 601. The transfer cylinder 700 is provided between the first plate cylinder 201 and the second plate cylinder 201. Can be rotated at the same peripheral speed as the plate cylinder 601 in the direction of the arrow shown in the figure. As is clear from FIG. 5, the transfer cylinder 700 includes the clamper 204 and the second
Is a drum member formed on a part of the peripheral surface thereof with a concave portion 700D into which the clamper 604 of the plate cylinder 601 can enter, and has a clamp mechanism 700C for clamping the leading end of the printing paper S in the supply direction. An elastic member made of synthetic rubber is attached to the peripheral surface other than the concave portion 700D so that the ink can be transferred to the surface.

As shown in FIG. 3, the clamp mechanism 700C includes a magnet plate 705 as a stage on which the leading end of the printing paper S is placed, and the printing paper S between the magnet plate 705.
A clamper 706 made of a magnetic material sandwiching the tip of the transfer cylinder 700, a clamper shaft 707 for rotatably supporting the clamper 706 with respect to the transfer cylinder 700, and one end of a clamper shaft 707 protruding outward from the side surface of the transfer cylinder 700. A roller 708 as a contact rotatably provided and a clamper shaft 70 at one end.
7, and the other end thereof is locked at an appropriate position of the transfer cylinder 700, and the spring 709 urges the clamper 706 to be always closed.

In the vicinity of the transfer cylinder 700, a clamp mechanism 7
A first cam member 710 as a clamp opening / closing member for opening and closing 00C in accordance with the print mode and a second cam member 720 are provided. The first cam member 710 includes:
It is displaceably supported by two support shafts 730, 730 fixed to the housing 1B so as to be located on the supply side of the printing paper S and on the trajectory of the roller 708 accompanying the rotation of the transfer cylinder 700. ing. The second cam member 720 is positioned on the track of the roller 708 so that the first cam member 7
10 is fixed to the housing portion 1B at a fixed position (the opening position of the clamp mechanism 700C in the one-step multi-color printing mode described later) substantially in the radial direction. The first cam member 710 is formed with two long holes 710a penetrating in the axial direction of the transfer cylinder 700 at intervals in the circumferential direction of the transfer cylinder 700, and the support shaft 730 is inserted into the long hole 710a. It is inserted and supported. Also, the first cam member 710
A rack 710b is formed on the lower surface of the gear 733. A gear 733 fixed to a rotation shaft of a motor 732 as a driving member fixed to the housing 1B is formed on the rack 710b.
Are engaged. 3, the side plate of the transfer cylinder 700 is omitted.

As shown in FIG. 4 and the like, the first cam member 71
0, an initial guide surface 710c for smoothly moving the roller 708, a convex surface 710d for opening the clamp mechanism 700C, and a concave surface 710e for closing the clamp mechanism 700C are continuously formed from the right side in the drawing. And it is formed gently. From convex surface 710d to concave surface 710
When e is gently continued, abrupt closing operation of the clamper 706 can be avoided, and damage due to being pinched by the printing paper S can be prevented. The second cam member 720 also has a concave surface 720a and a convex surface 720b formed continuously. In the second cam member 720, the concave surface 720a side functions as an initial guide surface 710c of the first cam member 710, and a smooth opening operation of the clamper 706 is obtained. 4 to 7, the rack part 710b of the first cam member 710 is omitted.

The first cam member 710 is driven by a motor 732 in accordance with the print mode. In the drawing, the position where the support shaft 730 comes into contact with the right end of the elongated hole 710a, that is, the printing paper S is fed with respect to the feeding timing. Clampable position (Fig. 4,
The position shown in FIG. 5 = hereinafter referred to as a clamp position) and the position where the support shaft 730 contacts the left end of the elongated hole 710a, that is, the position where the clamp mechanism 700C is always closed with respect to the sheet feeding timing (FIGS. 6 and 7). (Hereinafter, referred to as a non-clamp position). The motor 732 as a driving member is driven by a main control unit of the stencil printing machine 1 (not shown) according to an input of a printing mode.

When the roller 708 rides on the convex surface 710d of the first cam member 710 or the convex surface 720b of the second cam member 720 with the rotation of the transfer cylinder 700, the clamper shaft 7
07 rotates and the clamper 706 is separated from the magnet plate 705, and the clamp mechanism 700C is opened. Therefore, when the first cam member 710 is at the clamp position shown in FIGS. 4 and 5, the timing at which the printing paper S is fed out by the registration rollers 301 and the timing at which the clamper 706 is opened are synchronized with each other. It is possible to hold the tip. However, when the first cam member 710 is at the non-clamp position shown in FIGS. 6 and 7, the timing at which the printing paper S is fed out and the timing at which the clamper 706 opens are not synchronized, that is, the rollers 708 have already been set.
Moves past the convex surface 710d and reaches the concave surface 710e,
06 is closed, the leading end of the printing paper S is
06 is not pinched.

As shown in FIG. 1, in the vicinity of the transfer cylinder 700, a cleaning roller 701 that can come into contact with and separate from the surface of the transfer cylinder 700 is disposed.
Reference numeral 01 denotes a cleaner supply roller 703 that is partially immersed in a cleaner 704 stored in a cleaner tank 702 and is rotatable. The cleaner is used to remove ink remaining on the peripheral surface of the transfer cylinder 700.

As will be described later in detail, in the embodiment according to the present invention, simultaneous printing on both sides and one-step multi-color printing are possible. In the case of printing, it is necessary to match the print start positions between the respective colors so as not to cause image shift so as not to deteriorate print quality. Therefore, in this example, a top-bottom moving mechanism for adjusting the phase of the printing start position for the printing paper S to the same position on both the upper and lower sides of the printing paper S is provided. As shown in FIG. 8, the vertical movement mechanism includes a first plate cylinder 201 and a transfer cylinder 7.
00 and a planetary gear mechanism having a gear group for driving the rotation of the second plate cylinder 601. The above-mentioned planetary gear group is provided between the first plate cylinder 201 and the transfer cylinder 700 and between the second plate cylinder 601 and the transfer cylinder 700, respectively. Therefore, in FIG. 8, the second plate cylinder 601 and the transfer cylinder 700
Only the group of gears between and will be described.

The second plate cylinder gear 601B and the transfer cylinder gear 700B are integrally provided on the rotation shafts 601A and 700A of the second plate cylinder 601 and the transfer cylinder 700, respectively. Of these gears, the transfer cylinder gear 700B meshes with a drive gear 800 fixed to the output shaft of the drive motor M1, and the second plate cylinder gear 601B and the transfer cylinder gear 700B have idle gears 801a, 801b are engaged with each other.

Since the transfer cylinder 700 does not have an advancing / retracting mechanism as provided in the second plate cylinder 601 and is merely rotatably supported by an immovable portion of the printing apparatus main body, the drive gear 800 is always rotated. It is designed to be able to mesh.

The idle gears 801a and 801b are
Of the plate cylinder 601 and transfer cylinder 700
00A, a connecting arm 802a whose one end is pivotally supported.
802b is supported by the other end. The shaft support portions of the idle gears 801a and 801b are connected by a connection link 803. As a result, the idle gears 801a and 801b can roll around the plate cylinder gear 601B and the transfer cylinder gear 700B while maintaining the engagement with the second plate cylinder gear 601B and the transfer cylinder gear 700B. One end of a moving rod 804 is connected to a connecting arm 802a located on the second plate cylinder 601 side. The moving rod 804 has arrows A and B shown in FIG.
It can be moved in the direction of.

When adjusting the phase of the printing position in the vertical moving mechanism, the moving rod 804 is moved, for example, in the direction of arrow A. Then, this displacement amount is converted into a clockwise rotational displacement of the connecting arm 802a, and the idle gear 801a meshed with the second plate cylinder gear 601B.
Rolls in a clockwise direction on the second plate cylinder gear 601B. Therefore, the idle gear 801b rotates counterclockwise, and the transfer plate cylinder gear 700B and the transfer cylinder 700 are rotated clockwise. Thus, the printing start position on the transfer cylinder 700 can be adjusted with respect to the printing start position on the second plate cylinder 601, so that the printing start position between the two can be matched.

In the planetary gear mechanism constituted by such a gear group, the transfer cylinder gear 700B and the second plate cylinder gear 601B have the same number of teeth, and the idle gear 8
01a, the number of teeth of the idle gear 801b is set to be the same,
In addition, the number of teeth of the transfer cylinder gear 700B and the number of teeth of the second plate cylinder gear 601B are set to be an integral multiple of the number of teeth of the idle gear 801a and the idle gear 801b. By doing so, the idle gear 80 for adjusting the phase of the printing position can be used.
1a, 801b mesh with each other, idle gear 801a
And the second plate cylinder gear 601B, and the idle gear 801b and the transfer cylinder gear 700B are engaged in the same combination of teeth. If the ratio of the number of teeth is 1: 2 or 1: 3, the combination of teeth meshing every two or three rotations becomes the same, so that the meshing accuracy including the machining accuracy of the gears is somewhat poor. Also, the relative positional relationship between the second plate cylinder 601 and the transfer cylinder 700 can be kept unchanged. The top and bottom moving mechanism includes a first plate cylinder 201 and a second plate cylinder 601.
It is also possible to separately provide the print start position between the transfer cylinder 700 and the transfer cylinder 700.

The printing operation of the stencil printing apparatus 1 based on the above configuration will be described below. Prior to the printing operation,
The operator presses a print mode switching key on an operation panel (not shown) to select a print mode. First, the case where the duplex printing mode (simultaneous duplex printing) is selected will be described. Prior to printing, the first plate cylinder 201 and the second plate cylinder 6
Used masters 101 and 50 wound on 01
1 is separated from the plate cylinder surface by a plate discharging device (not shown) and is discarded. Next, a plate making process is performed in the first plate making section 100. In this processing step, the master 101, which has contacted the heating element of the thermal head 102, makes a perforation according to the image information by the heating element which is selectively heated according to an image reading signal from an image reading unit (not shown). It is formed. At this time, the master 101
Is fed toward the stage 203 of the first plate cylinder 201 by a transport mechanism using a stepping motor (not shown) as a drive source, and the amount of feeding is controlled based on the count of the number of pulses of the stepping motor. 204. In this state, the first plate cylinder 201 rotates at the same peripheral speed as the feeding speed of the master 101, and the master 101 is wound. When the feeding amount of the master 101 reaches a predetermined amount, this state is changed to the master 10.
The index is determined by the number of pulses of the stepping motor used for feeding one, and the trailing end of the master 101 in the feeding direction is cut by the cutter 104.

When the winding of the master 101 around the first plate cylinder 201 is completed, the master 501
And the winding of the master 501 around the second plate cylinder 601 is performed. Second plate making section 500
In the plate making process, the original used in the plate making process in the first plate making section 100 is exchanged, and based on this document, the master 501 that contacts the heating element of the thermal head 502 is replaced.
The hole is formed in accordance with image information by the heating element which selectively generates heat in response to an image reading signal from an image reading unit (not shown). At this time, the master 50
1 is perforated plate-making so as to be a real image when viewed from the surface side of the second plate cylinder 601. The master 501 that has been made is the first
In the same manner as when the sheet is wound around the plate cylinder 201, the second plate cylinder 601 is fed to the stage 603 and cut according to the pulse number of the stepping motor used for feeding, and is placed on the second plate cylinder 601. Wound.

When the winding of the master 101 on the first plate cylinder 201 and the winding of the master 501 on the second plate cylinder 601 are completed, a transfer process is performed between the second plate cylinder 601 and the transfer cylinder 700. Is done. In this transfer process, the first plate cylinder 201 does not come into contact with the transfer cylinder 700, and only the second plate cylinder 601 comes into contact with the surface of the transfer cylinder 700 by the above-described advance / retreat mechanism. That is, when the arm stopper 207 is separated from the swing-side tip of the plate cylinder moving arm 206 by the solenoid 208 provided in the advance / retreat mechanism, the plate cylinder moving arm 206 is rocked by the urging force of the tension spring 212 and the cam follower 210 is moved. Is brought into contact with the small diameter portion of the plate cylinder moving cam 211. Thus, the plate cylinder moving arm 206 can swing the second plate cylinder 601 in a direction in which the second plate cylinder 601 contacts the transfer cylinder 700.

Prior to this, first motor 732
Is moved to the unclamped position shown in FIGS. 6 and 7. Next, the second plate cylinder 601 and the transfer cylinder 700 contacting the surface of the transfer cylinder 700 rotate in the clockwise direction and the counterclockwise direction, respectively, so that the second plate cylinder to the transfer cylinder 700 is rotated. When the transfer of the print image from 601 is completed, the printing paper S is fed out from the paper feeding unit 300.
When the printing paper S is fed out from the paper feeding unit 300, the state is detected by the printing paper detection sensor P, and the first printing drum 201 is moved to the conveyance path of the printing paper S by the reciprocating mechanism on the first printing drum 201 side. Advances, and comes into contact with the transfer cylinder 700. At this time, the clamper 706 of the clamp mechanism 700C
08 reaches the concave surface 710e after passing through the convex surface 710d of the first cam member 710, and the opening / closing operation has already been completed.
The leading end of the printing paper S is not clamped by the clamper 706.

When the first plate cylinder 201 is in contact with the transfer cylinder 700, the transfer of ink to the transfer cylinder 700 via the perforated portion of the master 501 located on the second plate cylinder 601 is completed. Therefore, when the printing paper S is nipped and conveyed between the first plate cylinder 201 and the transfer cylinder 700, the image transfer is simultaneously performed on the front and back surfaces of the printing paper S. During the first double-sided printing, the image position after printing is observed, and if the image position is deviated, the printing start position on each of the front and back surfaces is adjusted by the above-described vertical movement mechanism.

Since the leading end of the printed printing paper S is not clamped by the clamper 706 of the transfer cylinder 700, the peeling claw 401 A of the first paper discharging unit 400 causes
The sheet is easily peeled off from the surface of the first plate cylinder 201 and is discharged by the suction / transport device 402A of the transport means 400A.
It is sucked and conveyed toward 00B and discharged.

After the adjustment of the top and bottom positions, when printing is performed for a predetermined number of prints, the second plate cylinder 601 and the transfer cylinder 700 that are in contact with the surface of the transfer cylinder 700 move clockwise. And continuously rotate in the counterclockwise direction.
Is transferred from the plate cylinder 601 to the transfer cylinder 700, and a predetermined number of print sheets S are fed out from the paper feed unit 300 between the first plate cylinder 201 and the transfer cylinder 700, so that each print sheet S The image transfer is simultaneously performed on both the front and back surfaces of. When printing is performed by the same master, the surface of the transfer cylinder 700 is cleaned by the cleaning roller 701 each time the image printing with the ink transferred from the second plate cylinder 601 is completed or every predetermined number of times of printing. In addition, when the printing process is performed by a new master, the cleaning is, of course, performed at a stage before that, that is, at the time when the final printing by the master in the previous stage is completed.

Next, a multi-color printing mode (one-step multi-color printing)
The case where is selected will be described. In the case of multicolor printing, it is necessary to replace the printing drum with a plate cylinder filled with ink of a color intended by the user before printing. When the operator presses the multi-color printing mode key on the operation panel (not shown),
The used masters 101 and 501 wound on the first plate cylinder 201 and the second plate cylinder 601 are separated from the plate cylinder surface by a plate discharging device (not shown) and discarded. Next, a plate making process is performed in the first plate making section 100.
In this processing step, the master 101, which has contacted the heating element of the thermal head 102, makes a perforation according to the image information by the heating element which is selectively heated according to an image reading signal from an image reading unit (not shown). It is formed. At this time, the master 101 is fed toward the stage 203 of the first plate cylinder 201 by a transport mechanism using a stepping motor (not shown) as a driving source, and the feeding amount based on the count of the pulse number of the stepping motor is adjusted. By being controlled, it is clamped by the clamper 204. In this state, the first plate cylinder 201 is
1 rotates at the same peripheral speed as the feeding speed of
Is wound. When the feeding amount of the master 101 reaches a predetermined amount, this state is determined by the number of pulses of the stepping motor used for feeding the master 101, and the trailing end of the master 101 in the feeding direction is cut by the cutter 104.

When the winding of the master 101 around the first plate cylinder 201 is completed, the master 501 is moved to the second plate making section 500.
And the winding of the master 501 around the second plate cylinder 601 is performed. Second plate making section 500
In the plate making process, the original used in the plate making process in the first plate making section 100 is exchanged, and based on this document, the master 501 that contacts the heating element of the thermal head 502 is replaced.
The hole is formed in accordance with image information by the heating element which selectively generates heat in response to an image reading signal from an image reading unit (not shown). At this time, the master 50
1 is perforated plate making so as to be a mirror image when viewed from the surface side of the second plate cylinder 601. The master 501 that has been made is the first
In the same manner as when the sheet is wound around the plate cylinder 201, the second plate cylinder 601 is fed to the stage 603 and cut according to the pulse number of the stepping motor used for feeding, and is placed on the second plate cylinder 601. Wound.

When the winding of the master 101 around the first plate cylinder 201 and the winding of the master 501 around the second plate cylinder 601 are completed, the first cam member 7 is driven by the motor 732.
10 is moved to the clamping position shown in FIGS. Next, the printing paper S is fed from the paper feeding unit 300. When the printing paper S is fed out from the paper feeding unit 300, the state is detected by the printing paper detection sensor P, and the first state is detected.
The first plate cylinder 201 advances into the conveying path of the printing paper S by the advancing / retracting mechanism on the side of the plate cylinder 201, and comes into contact with the transfer cylinder 700.
At this time, since the first cam member 710 has moved to the clamp position, as shown in FIG. 5, the timing at which the printing paper S is fed out from the paper feeding unit 300 and the timing at which the clamper 706 opens are synchronized, and printing is performed. The leading end of the sheet S is held. Further, the image of the master 101 of the first plate cylinder 201 is transferred to the printing paper S by rotating the first plate cylinder 201 and the transfer cylinder 700 in the clockwise direction and the counterclockwise direction, respectively.

Since the leading end of the printed printing paper S is held by the clamper 706 of the transfer cylinder 700, the printing paper S is removed from the surface of the first plate cylinder 201 by the peeling claw 401 A of the first paper discharge unit 400. When the transfer cylinder 700 continues to rotate in the counterclockwise direction without being peeled, the second
To the plate cylinder 601. At this time, as in the case of double-sided printing, the second plate cylinder 601 is moved by the advance / retreat mechanism.
0 surface. That is, when the arm stopper 207 is separated from the swing-side tip of the plate cylinder moving arm 206 by the solenoid 208 provided in the advance / retreat mechanism, the plate cylinder moving arm 206 is rocked by the urging force of the tension spring 212 and the cam follower 210 is moved. Abuts on the small diameter portion of the plate cylinder moving cam 211. Accordingly, the plate cylinder moving arm 206 swings in a direction in which the second plate cylinder 601 contacts the transfer cylinder 700.

As described above, when the second plate cylinder 601 comes into contact with the transfer cylinder 700, the image of the master 501 of the second plate cylinder 601 is transferred to the printing paper S, and the printing paper S
The image formed by the master 101 of the first plate cylinder 201 and the image formed by the master 501 of the second plate cylinder 601 are transferred to the surface of. In advance, the first plate cylinder 201 and the second plate cylinder 60
Since 1 is filled with the ink of the color intended by the user, multicolor printing is performed. During the first multi-color printing, the image position after printing is observed, and if the image position is shifted, the printing start position between the transfer images is adjusted by the above-described vertical movement mechanism.

As shown in FIG. 9, as the image transfer from the second plate cylinder 601 proceeds, the roller 708 of the clamp mechanism 700C rides on the convex surface 720b of the second cam member 720, and the clamper shaft 707 rotates. The clamper 706 is separated from the magnet plate 705. As a result, the leading end of the printed printing paper S is opened. Therefore, the printing paper S is easily guided to the transporting means 900A by the peeling claw 901A of the second paper discharging unit 900, and is suction-transported toward the guide plate 920 by the suction transporting device 902A of the transporting means 900A. Further, the conveyance direction is changed by the guide plate 920, and the conveyance direction is also guided to the conveyance unit 910A, and the suction conveyance device 912A of the conveyance unit 910A suction-conveys and discharges the paper toward the paper discharge tray 900B.

After the adjustment of the top and bottom positions, when printing a predetermined number of prints, when the printing paper S is supplied from the paper feeding unit 300 to the predetermined space between the first plate cylinder 201 and the transfer cylinder 700, The sheet is fed out, and the image of the master 101 of the first plate cylinder 201 and the image of the master 501 of the second plate cylinder 601 are transferred to the surface of each printing sheet S.

Next, a case where the one-sided printing mode is selected will be described. When the operator presses a single-sided printing mode key on an operation panel (not shown), the used master 101 wound on the first plate cylinder 201 is peeled off the surface of the plate cylinder by a plate discharging device (not shown) and discarded. .
Next, a plate making process is performed in the first plate making section 100. This processing step is the same as in the case of the above-described two-sided printing mode, and thus the description is omitted. The used master 501 wound on the second plate cylinder 601 is left on the surface of the plate cylinder, and when the double-sided printing mode or the multi-color printing mode is selected later, as described above. Discarded.
Therefore, in the case of the single-sided printing mode, no waste of the master occurs.

Prior to this, the first cam member 710 is moved to the unclamped position shown in FIGS. 6 and 7 by the motor 732. When the winding of the master 101 around the first plate cylinder 201 is completed, the printing paper S is fed from the paper feeding unit 300. When the printing paper S is fed from the paper feeding unit 300,
The state is detected by the print paper detection sensor P, and the first plate cylinder 201 is moved by the reciprocating mechanism on the first plate cylinder 201 side.
Advances into the transport path of the printing paper S and contacts the transfer cylinder 700. At this time, the clamper 706 of the transfer cylinder 700
08 reaches the concave surface 710e after passing through the convex surface 710d of the first cam member 710, and the opening / closing operation has already been completed.
The leading end of the printing paper S is not clamped by the clamper 706. When the first plate cylinder 201 comes into contact with the transfer cylinder 700 and the printing paper S is nipped and transported between the first plate cylinder 201 and the transfer cylinder 700, image transfer is performed on the surface of the printing paper S. . As described above, in the single-sided printing mode, the transfer cylinder 700 functions only as a pressing unit that presses the printing paper S against the first plate cylinder 201.

Since the leading end of the printed printing paper S is not clamped by the clamper 706 of the transfer cylinder 700, the surface of the first plate cylinder 201 can be easily moved by the peeling claw 401A of the first paper discharge unit 400. From the transport means 4
00A suction discharge device 402A
It is sucked and conveyed toward 0B and discharged. At the time of the first printing, the image position after printing is observed, and if the image position is shifted, the printing start position is adjusted by the above-described vertical movement mechanism in the same manner as in each of the above-described printing modes.

Next, an embodiment corresponding to claim 5 will be described with reference to FIG.
This will be described with reference to FIGS. The difference from the above embodiment is that the position of the second printing unit 600 and the advance / retreat mechanism with respect to the second printing unit 600, the position of the second plate making unit 500, the cleaning roller 70
1, the point that the second sheet feeding unit 350 is provided in addition to the sheet feeding unit 300, the point that the second sheet discharging unit 900 does not exist, and the shape of the cam member that opens and closes the clamp mechanism 700C.
The most significant feature of the stencil printing machine 2 in the present embodiment is that
Only a suitable one of the two paper feed units is automatically selected according to the print mode, and these paper feed units share one first paper output unit 400. The same parts as those in the above-described embodiment are denoted by the same reference numerals, and a duplicate description of functions will be omitted unless otherwise required.

The second paper supply section 350 includes a registration roller 351 for setting the timing for feeding out the printing paper S. The registration roller 351 holds the leading end of the printing paper S conveyed by a paper supply roller 352 from a paper supply cassette (not shown), and the master 501 on the second plate cylinder 601.
Is provided in order to align the leading edge of the image with the transfer position of the printing paper S. The fed printing paper S is fed by a guide member 353 toward a position facing the ink roller 605.

The paper feed unit 300 is selected by the main control unit (not shown) of the stencil printing apparatus 2 as the paper feed unit in the double-sided print mode or the single-sided print mode, and the second paper feed unit in the multi-color print mode. The section 350 is selected.

A cam member as a clamp opening / closing member for opening / closing the clamp mechanism 700C of the transfer cylinder 700 is a transfer cylinder 7
A first cam member 715 provided on the second paper feed unit 350 side near the position 00 and a second cam member 720 provided on the first paper discharge unit 400 side. As described above, since the second paper supply unit 350 is used only in the multi-color printing mode, the first cam member 715 has two cases, one in which the printing paper S is sandwiched as in the above-described embodiment and the other in which the printing paper S is not sandwiched. There is no need to support modes. Therefore, the first cam member 715 in the present embodiment is not movable, but is fixed to the housing 1B with the clamp position of the first cam member 710 in the above embodiment, similarly to the second cam member 720 in the above embodiment. Have been. As described above, since the first cam member 715 does not need to have a movable structure, the motor 732 as the driving member in the above embodiment is not required, and the elongated hole 710a and the rack 710b are not required. Therefore, it can be formed substantially by symmetrically arranging the second cam members 720. In addition, 715a, 715b, and 715c in the first cam member 715 correspond to the initial guide surface 710c, the convex surface 710d, and the concave surface 710e of the first cam member 710 in the above embodiment, respectively.

Based on the above configuration, only the main part of the printing operation of the stencil printing apparatus 2 will be described below. First, the case where the duplex printing mode (simultaneous duplex printing) is selected will be described. When the operator presses a double-sided printing mode key on an operation panel (not shown), the main control unit selects the sheet feeding unit 300 as a sheet feeding unit. First plate cylinder 2
01 and the second plate cylinder 601
Is completed, the transfer process is performed between the second plate cylinder 601 and the transfer cylinder 700.
In this transfer process, the first plate cylinder 201 does not come into contact with the transfer cylinder 700, and only the second plate cylinder 601 comes into contact with the surface of the transfer cylinder 700 by the above-described advance / retreat mechanism. Next, the second plate cylinder 601 and the transfer cylinder 70 that are in contact with the surface of the transfer cylinder 700
When the print image transfer from the second plate cylinder 601 to the transfer cylinder 700 is completed by the rotation of 0 in the clockwise direction and the counterclockwise direction, the printing paper S is fed out from the paper supply unit 300. . When the printing paper S is fed out from the paper feeding unit 300, the state is detected by the printing paper detection sensor P, and the first printing drum 201 is moved to the conveyance path of the printing paper S by the reciprocating mechanism on the first printing drum 201 side. Advances, and comes into contact with the transfer cylinder 700. At this time, since the clamper 706 of the clamp mechanism 700C is closed, the leading end of the printing paper S is not pinched.

In the state where the first plate cylinder 201 is in contact with the transfer cylinder 700, the transfer of ink to the transfer cylinder 700 via the perforated portion of the master 501 located on the second plate cylinder 601 is completed. Therefore, when the printing paper S is nipped and conveyed between the first plate cylinder 201 and the transfer cylinder 700, the image transfer is simultaneously performed on the front and back surfaces of the printing paper S.

Since the leading end of the printed printing paper S is not clamped by the clamper 706 of the transfer cylinder 700, the printing paper S is released by the peeling claw 401A of the first paper discharging unit 400.
The sheet is easily peeled off from the surface of the first plate cylinder 201 and is discharged by the suction / transport device 402A of the transport means 400A.
It is sucked and conveyed toward 00B and discharged.

Next, the case where the single-sided printing mode is selected will be described. When a single-sided printing mode key on an operation panel (not shown) is pressed by the operator, the main control unit selects the sheet feeding unit 300 as a sheet feeding unit. When the winding of the master 101 around the first plate cylinder 201 is completed, the printing paper S is fed from the paper feeding unit 300. When the printing paper S is fed from the paper feeding unit 300, the printing paper detection sensor P
Then, the state is detected, and the first plate cylinder 201 advances into the conveyance path of the printing paper S by the advance / retreat mechanism on the first plate cylinder 201 side, and abuts on the transfer cylinder 700. At this time, the transfer cylinder 7
Since the 00 clamper 706 is closed, the leading end of the printing paper S is not pinched. The used master 501 wound on the second plate cylinder 601 is left on the plate cylinder surface, and is discarded later when the double-sided printing mode or the multi-color printing mode is selected. Therefore, in the case of the single-sided printing mode, no waste of the master occurs. The first plate cylinder 201 contacts the transfer cylinder 700, and the printing paper S
Is transferred between the plate cylinder 201 and the transfer cylinder 700, image transfer is performed on the surface of the printing paper S.

Since the leading end of the printed printing paper S is not clamped by the clamper 706 of the transfer cylinder 700, the surface of the first plate cylinder 201 is easily moved by the peeling claw 401 A of the first paper discharge unit 400. From the transport means 4
00A suction discharge device 402A
It is sucked and conveyed toward 0B and discharged.

Next, a multi-color printing mode (one-step multi-color printing)
The case where is selected will be described. In the case of multicolor printing, it is necessary to replace the printing drum with a plate cylinder filled with ink of a color intended by the user before printing. When the operator presses the multi-color printing mode key on the operation panel (not shown),
The second paper supply unit 350 is used as paper supply means by the main control unit.
Is selected. Master 101 for first plate cylinder 201
When the winding of the master 501 and the winding of the master 501 on the second plate cylinder 601 are completed, the printing paper S is fed out from the second paper supply unit 350. When the printing paper S is fed out from the second paper supply unit 350, the state is detected by the printing paper detection sensor P, and the second printing drum 601 is transported by the second printing drum 601 by the reciprocating mechanism on the second printing drum 601 side. Advances to the road, transfer cylinder 700
Abut.

Since the first cam member 715 is fixed at the clamp position, as shown in FIGS. 11 and 12, the timing at which the printing paper S is fed from the second paper feed unit 350 and the timing at which the clamper 706 opens are determined. Are synchronized, and the leading end of the printing paper S is nipped. Further, the master 50 of the second plate cylinder 601 is rotated by rotating the second plate cylinder 601 and the transfer cylinder 700 in the clockwise direction and the counterclockwise direction, respectively.
One image is transferred to the printing paper S. The printing paper S that has been subjected to the printing process has the leading end thereof at the clamper 70 of the transfer cylinder 700.
6, the transfer cylinder 700 continues.
Is rotated counterclockwise, so that the first plate cylinder 2
The contact point with 01 is reached. At this time, as in double-sided printing,
The first plate cylinder 201 comes into contact with the surface of the transfer cylinder 700 by the advance / retreat mechanism. When the first plate cylinder 201 comes into contact with the transfer cylinder 700, the image of the master 101 of the first plate cylinder 201 is transferred to the printing paper S, and the second surface is printed on the surface of the printing paper S.
The image by the master 501 of the plate cylinder 601 and the image by the master 101 of the first plate cylinder 201 are transferred. In advance,
Since the second plate cylinder 601 and the first plate cylinder 201 are filled with ink of a color intended by the user, multicolor printing is performed.

As shown in FIG. 13, as the image transfer from the first plate cylinder 201 proceeds, the roller 708 of the clamp mechanism 700C rides on the convex surface 720b of the second cam member 720, and the clamper shaft 707 rotates. The clamper 706 is separated from the magnet plate 705. As a result, the leading end of the printed printing paper S is opened. Accordingly, the printing paper S is easily guided to the transporting means 400A by the peeling claw 401A of the first paper discharging unit 400, and is suctioned and transported toward the paper discharge tray 400B by the suction transporting device 402A of the transporting means 400A to be discharged. . The top-bottom adjustment in each print mode is the same as in the above embodiment, and a description thereof will be omitted.

In each of the above embodiments, the transfer cylinder 70
Although the first plate cylinder 201 and the second plate cylinder 601 are configured to be brought into contact with each other with respect to 0 by their respective advance / retreat mechanisms, such a contact / separation configuration of the plate cylinder is not limited to this. For example, the member on the plate cylinder side that supports the master has flexibility, and the ink roller 205 of the first plate cylinder 201 is flexible.
And the ink roller 605 of the second plate cylinder 601 is transferred to the transfer cylinder 7.
It is also possible to adopt a configuration in which the master is swung toward the 00 side, that is, a partial area of the master is expanded.

[0075]

According to the first to fourth aspects of the present invention, the transfer cylinder between the first plate cylinder and the second plate cylinder is provided with a clamp mechanism for clamping the printing paper, and the clamp mechanism is provided near the transfer cylinder. Since the clamp mechanism is provided with a clamp opening / closing member that opens and closes the clamp mechanism according to the print mode, a single device wastes time by re-feeding all of double-sided printing, single-sided printing, and multicolor printing. And without causing image stains or the like. Further, since the opening and closing of the clamp mechanism can be performed without complicated electric control, it is possible to reduce the cost in supporting all printing modes.

According to the fifth aspect of the present invention, since the paper feed unit is changed according to the print mode, and each paper feed unit shares one paper discharge unit, a complicated paper discharge unit configuration is provided. Can be simplified, and the configuration in all print modes can be reduced in size.

[Brief description of the drawings]

FIG. 1 is an overall schematic diagram showing an embodiment of a stencil printing apparatus according to the present invention.

FIG. 2 is a side view showing an advance / retreat mechanism of a first plate cylinder in the stencil printing apparatus shown in FIG.

FIG. 3 is a perspective view showing a clamp mechanism and an opening / closing member thereof in the stencil printing machine shown in FIG.

FIG. 4 is a side view showing the stencil printing apparatus shown in FIG. 1 in a state in which a first cam member is at a clamp position and a clamper is closed.

FIG. 5 is a side view showing a state where the first cam member is at the clamp position and the clamper is opened in the stencil printing apparatus shown in FIG. 1;

FIG. 6 is a side view showing the stencil printing apparatus shown in FIG. 1 in a state where the first cam member is at the unclamped position and the clamper is closed.

FIG. 7 is a side view showing the stencil printing apparatus shown in FIG. 1 in a state where the first cam member is at the unclamped position and the clamper is closed at a timing different from the sheet feeding timing.

FIG. 8 is a side view showing a vertical moving mechanism in the stencil printing apparatus shown in FIG. 1;

9 is a side view of a main part of the stencil printing machine shown in FIG. 1 in a state where a roller rides on a second cam member and a clamper is opened in a multicolor printing mode.

FIG. 10 is an overall schematic diagram showing another embodiment of the stencil printing apparatus according to the present invention.

11 is a side view showing a state where the clamper is opened in the multicolor printing mode in the stencil printing apparatus shown in FIG.

FIG. 12 is a side view showing a state in which the clamper is closed and the printing paper is sandwiched in the multicolor printing mode in the stencil printing apparatus shown in FIG. 10;

13 is a side view of a main part of the stencil printing machine shown in FIG. 10 in a state where a roller rides on a second cam member and a clamper is opened in a multicolor printing mode.

FIG. 14 is a schematic diagram showing a conventional stencil printing apparatus that supports double-sided simultaneous printing.

FIG. 15 is a schematic view showing a conventional stencil printing apparatus that supports double-sided simultaneous printing using a transfer cylinder.

FIG. 16 is a schematic view showing a conventional stencil printing apparatus for one-step multi-color printing.

[Explanation of symbols]

101, 501 Master as stencil printing base paper 201 First plate cylinder 300 Paper supply unit 350 Second paper supply unit 400 First paper discharge unit 601 as paper discharge unit 601 Second plate cylinder 700 Transfer cylinder 700C Clamp mechanism 710 , A first cam member 720 as a clamp opening / closing member 720 a second cam member 732 as a clamp opening / closing member

Claims (5)

[Claims] 1. After printing a stencil sheet on the outer peripheral surface of a plate cylinder, ink is leached from the stencil sheet, and the ink is transferred to a printing sheet supplied from a paper feeding section. What is claimed is: 1. A stencil printing apparatus for transferring an image and discharging the printing paper to a paper discharge unit, comprising: a first and a second printing drum; and a printing paper between the first and the second printing drum. A transfer cylinder that is arranged at a position facing a surface opposite to a surface in contact with the plate cylinder, and rotates at the same peripheral speed as the first and second plate cylinders. 2. A stencil printing machine in which the second printing cylinder is provided so as to be able to freely contact and separate from the transfer cylinder. A clamp opening / closing member that opens and closes the clamp mechanism according to the printing mode in the vicinity of A stencil printing apparatus, comprising: 2. The clamp mechanism is provided with a contact,
The stencil printing apparatus according to claim 1, wherein the clamp opening / closing member is a cam member that guides the contact and opens and closes the clamp mechanism. 3. The cam member comprises a first cam member located on a side for supplying the printing paper, and a second cam member located on a side for releasing the printing paper in a predetermined printing mode. 3. The stencil printing apparatus according to claim 2, wherein the first cam member is provided so as to be able to selectively take a position for closing and opening the clamp mechanism with respect to a sheet feeding timing. 4. A drive member for moving the first cam member to a position for closing or opening the clamp mechanism, and control means for controlling the drive member in accordance with an input of a print mode. The stencil printing apparatus according to claim 3, wherein the stencil printing apparatus is provided. 5. A plurality of paper feed units which share the paper discharge unit as a final position of a paper feed path are provided, and each of the paper feed units is selectively used according to a print mode.
A stencil printing apparatus as described in the above.