JP2856622B2 - Stencil printing machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stencil printing apparatus for printing by supplying printing paper between a stencil sheet wound around a plate cylinder and a press roller.

[0002]

2. Description of the Related Art In a conventional stencil printing apparatus, a support shaft of a plate cylinder is used to release a press roller from a clamper (a metal fitting for holding a printing base paper) mounted on the plate cylinder (print drum) so as not to interfere with the press roller. A mechanism of a press roller supporting part which is provided with a cam on a separate shaft and driven in synchronization with the rotation of the plate cylinder, that is, a mechanism using a so-called jigging mechanism, does not interfere with a separation claw (discharge claw) from the clamper part. In order to relieve such a problem, there is known a technique in which a cam dedicated to driving a separation claw is provided separately from a cam rotation shaft of a plate cylinder.

[0003] As an improvement of the technique using the above-mentioned yam-robber mechanism, for example, Japanese Utility Model Application Laid-Open No. 59-5936 has been proposed.
As described in Japanese Patent Publication No. 1 (1993), when a cam plate is mounted on a plate cylinder, the phase of the cam plate with respect to the plate cylinder is uniquely determined so as to simplify the assembly or repair of a rotary copying machine. Originally, a press roller cam having a large diameter portion was attached to both ends of the plate cylinder coaxially with the plate cylinder with a predetermined phase relationship, and rollers provided at both ends of the press roller were respectively applied to the press roller cams. By pressing it,
A technique using a plate cylinder-integrated cam mechanism that allows the press roller to escape from the clamper when the large diameter portion of the press roller cam and the roller come into pressure contact with each other has been proposed.

[0004]

However, in the former so-called flap mechanism, there is a problem that the bias of the pressing force of the press roller against the plate cylinder tends to occur.
In addition, in the case of a device equipped with a flap mechanism and a dedicated cam for driving the separation claw, a complicated mechanism for synchronizing the rotation of the plate cylinder with other camshafts makes the device larger and requires complicated adjustments. Met. In the latter cam mechanism integrated with the plate cylinder, there is a problem that the mechanism for pressing the press roller against the plate cylinder and the mechanism for supporting the same are not considered.

Accordingly, the present invention has been made to solve the above-mentioned problems, so that the bias of the pressing force of the press roller against the plate cylinder does not occur, the mechanism for moving the press roller toward and away from the plate roller and the mechanism for driving the separation claw are simplified. It is an object of the present invention to provide a stencil printing apparatus that can be reduced in size and weight, has high reliability, and can be manufactured at low cost.

[0006]

In order to achieve the above-mentioned object, according to the first aspect of the present invention, there is provided a plate cylinder on which a stencil sheet is wound, and a printing cylinder pressed against the plate cylinder via printing paper. A press roller selectively occupying a position and a non-printing position separated from the plate cylinder; a pair of swingable press roller arms rotatably supporting both ends of a shaft of the press roller; A separating claw that selectively occupies a separation position close to the outer peripheral surface of the printing cylinder and peels off the printing paper from the plate cylinder and a non-separation position separated from the separation position; and a swingable supporting shaft of the separation claw. In the stencil printing apparatus having the separation claw driving arm, the base end of each of the press roller arms is independently swingably supported on the stencil printing apparatus main body side, and the end of the stencil cylinder has the Center axis of rotation of plate cylinder Coaxially provided, a cam having a large diameter portion at a portion corresponding to the non-image printing area of the plate cylinder, having the same contour shape at both end sides of the plate cylinder, and provided in the same phase, respectively. A pair of cams, and a pair of press roller cam followers provided at both ends of the shaft of the press roller and respectively driven by the large-diameter portions of the cams, and a cam follower for each of the press rollers. A pair of press roller urging means for urging with the same load in the direction of pressing against the large diameter portion, respectively, and provided on the separation claw drive arm, and each of the above-described respective members as viewed in the rotation direction during printing of the plate cylinder. The cam follower for the separation claw, which is located on the downstream side of the cam follower for the press roller, and is driven by the large diameter portion of at least one of the cams, and the cam follower for the separation claw, A biasing means for biasing the at least one of the cams in a direction of pressing against the large-diameter portion of the at least one cam. On the peripheral surface excluding the diameter portion, the free ends of the press roller arms swing independently by the urging force of the pair of press roller urging means, and the press rollers occupy their printing positions, When the large-diameter portion of the cam is pressed against the cam follower for each press roller, the press roller is displaced from the printing position to the non-printing position, and then the large-diameter portion of at least one of the cams is displaced. The separation claw is displaced from the separation position to the non-separation position when pressed against the separation claw cam follower.

According to a second aspect of the present invention, in the stencil printing machine according to the first aspect, when the press roller occupies a non-printing position, the pair of press roller arms hold the press roller at that position. A pair of printing pressure releasing members for locking the free ends of the printing rollers, and driving means for releasing the locked state by the pair of printing pressure releasing members so that the press roller occupies its printing position during printing. Features.

[0008]

According to the first aspect of the present invention, with the above arrangement, at the time of printing, the cam followers for the press rollers are formed on the peripheral surfaces of the cams corresponding to the image printing range of the plate cylinder except for the large diameter portion. The free ends of the press roller arms swing independently by the urging force of a pair of press roller urging means for urging the large diameter portions with the same load in the direction in which they are pressed against each other, and the press roller is moved to its printing position. By occupying,
When the press roller is uniformly pressed against the plate cylinder and the large-diameter portion of each cam is pressed against each press roller cam follower, the press roller is displaced from the printing position to the non-printing position, and then at least one of the cams. When the large-diameter portion of one of the cams is pressed against the separation-finger cam follower, the separation claw is displaced from the separation position to the non-separation position, so that the printing paper is reliably peeled off by the tip of the separation claw at the separation position.

According to the second aspect of the present invention, when the press roller occupies its non-printing position, a pair of printing pressures for locking the free ends of the respective press roller arms to hold the press roller at that position. By providing a release member and driving means for releasing the locked state of the pair of printing pressure releasing members so that the press roller occupies its printing position during printing, the printing roller is released by each printing pressure releasing member during non-printing. By holding each press roller arm so as to occupy the non-printing position, the state where the press roller is securely separated from the outer peripheral surface of the plate cylinder and the clamper can be maintained. When the locked state by the member is released, the press roller can occupy the printing position. Pressure, and it is possible to reliably print.

[0010]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 6 is a configuration diagram of a main portion of a stencil printing apparatus to which an embodiment of the present invention is applied. First, the configuration of the main portion will be described.

In FIG. 6, a main part of the stencil printing apparatus is a cylindrical plate cylinder 1 which is disposed at the center of a body part (not shown) and on which a stencil sheet 3 for stencil printing is wound on the outer peripheral surface.
A sheet feeding device 20 which is disposed at the lower left of the plate cylinder 1 and sends out the printing paper P stacked on the sheet feeding table 11 to the plate cylinder 1; And a discharge device 3 that is disposed below a body portion (not shown) that faces the printer and discharges the printing paper P printed by the plate cylinder 1 to a discharge tray 16.
0.

Hereinafter, the printing device 10, the paper feeding device 20, and the paper discharging device 30 will be sequentially described. As shown in FIG. 1, the printing apparatus 10 includes a plate cylinder 1 that is driven to rotate around a rotation center axis 2 in a direction indicated by an arrow (counterclockwise) by a drive motor (not shown). The openable and closable clamper 4 which extends in the axial direction of the base paper 3 to hold the leading end of the base paper 3, an ink supply roller 5 for supplying ink to the inner peripheral surface of the plate cylinder 1, and a minute gap between the ink supply roller 5 And a doctor roller 6, which forms an ink reservoir (not shown) between the ink supply roller 5 and the ink supply roller 5, serves as a rotation center axis of the plate cylinder 1 and also supplies ink to an ink reservoir (not shown). And an ink supply pipe 7 for supplying the ink. Here, the ink supply pipe 7, the ink supply roller 5 and the doctor roller 6 constitute an ink supply device 8.

As shown in FIG. 1, the plate cylinder 1 is made of a stainless steel porous cylinder extending in a direction parallel to the rotation center axis 2, and is attached to a frame (not shown) provided on the stencil printing apparatus main body side. It is a well-known one rotatably supported by the ink supply pipe 7 provided. A pair of cams 2 having the same contour are provided on both ends of the plate cylinder 1 coaxially with the rotation center axis 2.
2L and 22R are respectively substantially integrally attached. These cams 22L and 22R are made of a synthetic resin and are formed in a substantially disc shape, and the contour peripheral surfaces of the cams 22L and 22R have the same diameter contour peripheral surface portion 22c having the same diameter.
The same diameter contour peripheral surface portion 22c and a convex diameter portion 22a as a large diameter portion having a diameter larger than the outermost peripheral contour of the clamper 4 are formed respectively. Each of the cams 22L, 22R is attached to the end of the plate cylinder 1 such that the convex diameter portions 22a are in the same phase position on the left and right with the clamper 4 on the plate cylinder 1 interposed therebetween.

As shown in FIG. 2, each of the cams 22L, 22R
The outer peripheral surface of the convex diameter portion 22a in the non-image printing range a
In the cams 22L and 22R, the same-diameter contour peripheral surface portion 22 is provided.
c (excluding the convex diameter portion 22a) is set corresponding to the image printing range b. As shown in FIG. 3, in each of the cams 22 </ b> L and 22 </ b> R, four knurled concave portions for manually rotating the plate cylinder 1 are formed at four positions on the contour peripheral surface of the same diameter contour peripheral portion 22 c. Clues 22b are formed. In addition, each cam 22L, 22R
A flange 23A having substantially the same diameter as the outer peripheral surface of the plate cylinder 1 is provided on the side closer to the plate cylinder 1 with the same diameter contour peripheral surface 22c and the flange 23A.
Between the peripheral surface portion 22c of the same diameter and the flange portion 23A
The flange portion 23B having a slightly larger diameter than the cam 22L,
22R and each are integrally formed of a synthetic resin. A flat knurl 23a for clues is also provided on the flange portion 23B.
Are formed on the entire peripheral surface, and the cue 22b
The plate cylinder 1 can be easily rotated by manually operating the flat knurl 23a. This manual rotation operation has no problem due to a well-known mechanism in which a one-way clutch is attached to a drive shaft (not shown) of the ink supply roller 5 (shown in FIG. 6). A number of punches (the pullout of the flange 23A is not shown in the figure) are formed on the side surfaces of the cams 22L, 22R and the flange 23A, and the weight of the plate cylinder 1 is reduced by these punching structures. Contributes to a reduction in inertia during rotation of the motor.

A printing position (corresponding to an image printing range b shown in FIG. 2) in which the outer peripheral surface of the plate cylinder 1 is in pressure contact with the outer peripheral surface of the plate cylinder 1 via the printing paper P near the ink supply roller 5. The position of the clamper 4 corresponding to the non-image printing area a shown in FIG. 2 so as not to interfere with the clamper 4. A press roller 9 that selectively occupies a position separated from the outer peripheral surface in the centrifugal direction) is provided.

In FIG. 1, a press roller 9 is provided on the plate cylinder 1.
Is a well-known synthetic rubber extending in a direction parallel to the rotation center axis 2, and is attached substantially integrally to the axis 9s. In the vicinity of both ends of the shaft 9s, cams 22L, 2
2R, that is, a pair of press roller cam followers 9L, 9R (hereinafter simply referred to as “cam followers 9L, 9R”) having the same shape and mutually engaging only with the convex diameter portion 22a.
9R ") are attached substantially integrally with the press roller 9 therebetween. As shown in FIG. 2, the outer diameter of each of the cam followers 9L and 9R is formed to be slightly smaller than the outer diameter of the press roller 9, and between the outer peripheral surface of the plate cylinder 1 and the press roller 9 in the image printing range b. Thus, a gap c is provided such that the printing paper P is pressed and a print image can be transferred.

In FIG. 1, bearings 9j are provided at the outer ends of the cam followers 9L and 9R on the shaft 9s. These bearings 9j are held by a pair of press roller arms 25L, 25R having the same shape on the left and right. Each press roller arm 25L, 25R
The base ends of the fulcrum shafts 24 in the machine frames 29L and 29R which are arranged on the stencil printing apparatus main body side and are partially cut away.
L, 24R (fulcrum shaft 24R is not shown in the figure)
And are pivotally supported independently in the vertical direction. At the free end of each of the press roller arms 25L, 25R, a notch claw 25a that locks with a later-described printing pressure release member is formed.

Each press roller arm 25L, 25R is
A pair of left and right sides whose one end is locked at the approximate center and the other end is locked to a stationary member on the stencil printing apparatus main body side,
Tension coil spring 26 as biasing means for press roller
Is always urged in the upward direction of the arrow. That is, each of the cam followers 9L and 9R causes the corresponding press roller arm 25L, 2
5R, the convex diameter portion 22a of each of the cams 22L, 22R.
The press roller 9 is urged in such a direction as to press against it, and the press roller 9 is moved through the respective press roller arms 25L and 25R.
It is urged in a direction of pressing against the outer peripheral surface of the plate cylinder 1. As for the spring characteristics of the spring 26, its load, height, spring constant and the like are set stricter than usual quality standards.

The press roller 9 is rotatably supported in the same phase by the respective press roller arms 25L and 25R via the respective bearings 9j at the left and right ends of the press roller 9 in the above configuration. The swinging behavior of the direction of being pressed against the outer peripheral surface of the body 1 is given.
Accordingly, at the time of printing, on the peripheral surface of each of the cams 22L and 22R corresponding to the image printing range b of the plate cylinder 1 except for the convex diameter portion 22a, each of the cams 22L and 22R is biased by the pair of springs 26 biased with the same load. The free ends of the press roller arms 25L and 25R swing independently of each other, and the press roller 9 occupies the printing position. Therefore, the press roller 9
Is uniformly pressed against the outer peripheral surface of the plate cylinder 1 with an evenly distributed load over the entire region in the direction of the axis 9s.

As shown in FIG. 4, each bearing 9j is
The retaining members 27L and 27R that press the respective ends of the bearings 9j in the axial direction prevent the bearings 9j from coming off. In FIG. 5A, the holding member 27L has a convex portion serving as a swing fulcrum.
5L, and its long groove portion is supported by a stepped screw 27a with a gap in the axial direction that is swingable between a retaining click position and a retaining release click position. The rollers can be easily replaced. Further, as shown in FIG. 5B, the pressing member 27R on the press roller arm 25R side is a stepped screw, and the stepped screw 27R prevents the bearing 9j from coming off.

In the vicinity of each press roller arm 25L, 25R, when the press roller 9 occupies its non-printing position, the free end of each press roller arm 25L, 25R holds the press roller 9 at the non-printing position. Pressure releasing claw members 28 as a pair of printing pressure releasing members for respectively locking
L, 28R are provided. Each printing pressure release claw member 28
L and 28R are respectively fixed to both ends of a connection shaft 28s rotatably supported in each machine frame 29L and 29R. At the free ends of the printing pressure release claw members 28L and 28R,
Notch 25a of each press roller arm 25L, 25R
And locking pawls 28a for selectively locking are formed. On the right side in the drawing at the base end of each printing pressure release claw member 28L, 28R, the other end of the tension coil spring 31 whose one end is locked to a pair of left and right pins 32 implanted in the machine frames 29L, 29R. Each is locked. By the urging force of the spring 31, each of the printing pressure releasing claw members 28L, 28R
Has a habit of always swinging in the counterclockwise direction, that is, a swinging habit of the direction in which the notch claw 25a and the locking claw 28a are locked. On the left side of the drawing at the base end of the printing pressure releasing claw member 28L, each printing pressure releasing claw member 28L, 2 is arranged so that the press roller 9 occupies its printing position during printing.
A solenoid 33 is connected via a plunger 33p as drive means for releasing the locked state of each press roller arm 25L, 25R with the notch claw 25a by the 8R. The solenoid 33 is fixed to the machine frame 29L.

In the vicinity of the outer peripheral surface of the plate cylinder 1, a separation position where the tip is close to the outer peripheral surface of the plate cylinder 1 and the printing paper P (shown in FIG. 2) is peeled off from the plate cylinder 1, A separation claw 15 that selectively occupies a non-separation position separated from the outer peripheral surface of the plate cylinder 1 is provided. Here, the separation position means that the tip of the separation claw 15 does not interfere with the outer peripheral surface of the plate cylinder 1,
Further, it is a position displaced from the outer peripheral surface of the plate cylinder 1 to a position having a minimum gap in the centrifugal direction, which is optimal for peeling the leading end of the printing paper (not shown) from the outer peripheral surface of the plate cylinder 1.
The non-separation position refers to a position where the tip of the separation claw 15 is separated from the contour outer peripheral surface of the clamper 4 in the centrifugal direction so as not to interfere with the clamper 4. The rear end base of the separation claw 15 has one end in the machine casing 29L and the other end in the machine casing 29L.
At R, it is attached with a screw 15a to an angular separating claw shaft 34 that is rotatably supported. Separation claw 15
The separation claw shaft 34 is rotatably supported and driven by a swingable separation claw driving arm 36 as described later.

On the separation claw shaft 34 near the machine frame 29L, a separation claw drive arm 36 provided with a roller 35 as a cam follower for separation claw provided at the free end thereof with the convex diameter portion 22a of the cam 22L is substantially provided. It is attached integrally. The roller 35 is provided on the downstream side of the cam follower 9L when viewed in the rotation direction of the plate cylinder 1 during printing. At the base end of the separation claw drive arm 36, the other end of a tension coil spring 38 serving as a separation claw urging means having one end locked to a pin 37 implanted in the machine frame 29L is locked. Have been. The roller 35 is formed by the tension coil spring 38.
Is biased via the separation claw driving arm 36 in a direction to always press against the convex diameter portion 22a of the cam 22L. Reference numeral 39 indicates an L-shaped angle-shaped stopper fixedly provided at a predetermined position of the machine casing 29L, and reference numeral 40 indicates a screw that comes into contact with the stopper 39. The adjustment mechanism including the stopper 39 and the screw 40 is for accurately adjusting the separation position of the separation claw 15.
By adjusting the separation claw, the degree of engagement between the convex diameter portion 22a of the cam 22L and the roller 35 is set to an appropriate range, and the circumferential surface of the same diameter contour peripheral surface portion 22c (shown in FIG. 3)
Also, a function of avoiding engagement between the clue 22b (shown in FIG. 3) and the roller 35, that is, selectively engaging only the convex diameter portion 22a of the cam 22L and the roller 35 is provided.

The paper feeding device 20 includes a paper feeding table 11 for stacking the printing paper P, a paper feeding roller 12 for feeding the printing paper P, and a pair of separation rollers 13a for separating the printing paper P one by one. , 13b, the outer peripheral surface of the plate cylinder 1 and the press roller 9
And a pair of feed roller pairs 14a and 14b for sending the printing paper P at a predetermined timing.

The paper discharge device 30 includes a paper discharge table 16 on which the printed printing paper Pa printed by the plate cylinder 1 is sequentially loaded, and a paper discharge table 16.
A separating claw 15 arranged near the outer peripheral surface of the printing paper Pa for separating the printing paper Pa from the plate cylinder 1, and suction unit rollers 17, 18 for transporting the printing paper Pa separated by the separating claw 15 onto a discharge tray 16. A forced paper discharging mechanism 21 including an endless transport belt 19 stretched between the suction unit rollers 17 and 18 is provided.

Next, the operation of the main part of the stencil printing apparatus will be described below. Hereinafter, in the description of the operation of the drawings to be referred to, the operation of the components existing on both the left and right sides will be described on only one side unless otherwise specified.

In FIG. 6, the printing paper P loaded on the paper feed table 11 is fed by a paper feed roller 12 and a separation roller pair 13.
a, 13b toward the pair of feed rollers 14a, 14b, and further, by the pair of feed rollers 14a, 14b at a predetermined timing synchronized with the rotation of the plate cylinder 1.
And between the press roller 9. At this time, as shown in FIG. 1 or FIG. 2, the base paper 3 wound on the outer peripheral surface of the plate cylinder 1 rotating in the direction of the arrow (counterclockwise) is rotated by a pair of left and right tension coil springs 26 to form a shaft. When the press roller 9 uniformly urged in the entire area in the 9s direction presses through the printing paper P, the ink is transferred from the perforated portion of the base paper 3 to the surface of the printing paper P, and the ink is transferred to the printing paper P as desired. Is printed. At this time, the ink supply roller 5 shown in FIG. 2 also rotates in the same direction as the rotation direction of the plate cylinder 1 to supply ink to the inner peripheral surface of the plate cylinder 1 (for simplicity of description, FIG. The spring 26 in FIG.
The illustrations of the printing pressure releasing claw members 28L and 28R and the solenoid 33 are omitted. The printed printing paper Pa is separated from the outer peripheral surface of the plate cylinder 1 by the separation claw 15, and in FIG.
The sheet is guided along the transport belt 19 that is wrapped around and moves around, falls onto the sheet discharge table 16, and the printing process for the first sheet of printing paper is completed.

In FIG. 4, the plate cylinder 1 is further rotated in the direction of the arrow (counterclockwise) so that the convex portion 2 of the cam 22L is rotated.
When the roller 2a reaches the vicinity of the lower side, that is, the non-printing position, the convex diameter portion 22a and the cam follower 9L come into sliding contact with each other, and the press roller arm 25L swings downward about the fulcrum shaft 24L, thereby causing the press roller 9 to rotate. Is separated from the outer peripheral surface of the non-image printing area a of the plate cylinder 1 and the outer peripheral surface of the contour of the clamper 4 against the urging force of the spring 26. Thus, interference between the outer peripheral surface of the non-image printing area a on the plate cylinder 1 and the clamper 4 and the press roller 9 is avoided. When the plate cylinder 1 is further rotated in the direction of the arrow and the clamper 4 approaches the vicinity of the tip of the separation claw 15, the roller 3 (not shown) is attached to the convex diameter portion 22a.
5 (shown in FIG. 1) is contacted and rolled, and the separation claw shaft 34 is rotated counterclockwise through the separation claw drive arm 36, so that the tip of the separation claw 15 becomes the outer periphery of the contour of the clamper 4. It is separated from the surface and occupies a non-separable position. In this way, interference between the four parts of the clamper and the tip of the separation claw 15 is avoided. When the plate cylinder 1 is further rotated and the convex diameter portion 22a moves away from below, a printing process for the second sheet of printing paper is started, and the same operation as the above operation is repeated for a predetermined number of prints, thereby completing printing.

When printing is completed, in FIG. 1, while the press roller 9 is pressed against the plate cylinder 1 via the last printing paper, the solenoid 33, which has been kept in the excited state, is de-energized. And Then, in FIG. 4, the printing pressure releasing claw member 28L swings in the direction of the dashed line in the drawing, and the free end surface portion 28b of the printing pressure releasing claw member 28L contacts the free end protruding surface 25b of the press roller arm 25L.
Eventually, the last printing paper is discharged and the plate cylinder 1
With the rotation of the cam 22L, the convex diameter portion 22a of the cam 22L reaches the vicinity of the lower side and the convex diameter portion 22a and the cam follower 9L are slid in contact with each other, so that the free end protruding surface 25b of the press roller arm 25L releases the printing pressure. Free end surface 28b of claw member 28L
The press roller arm 25L is slidably contacted with the fulcrum shaft 24.
It swings downward about L. The notch 25a of the press roller arm 25L is located at the rotation position where the vicinity of the top of the convex diameter portion 22a of the cam 22L is located at the lowest position.
And the locking claw 28a of the printing pressure release claw member 28L mesh with each other as shown by the broken line in the figure. It should be noted that even if the plate cylinder 1 is rotated by one or more rotations in this state, the engagement does not come off. Therefore, in the above state, the state in which the press roller 9 is separated from the outer peripheral surface of the plate cylinder 1 and the outer peripheral surface of the contour of the clamper 4 is maintained.

At the time of printing, in FIG. 4, a printing pressure ON command is sent to the solenoid 33 while the plate cylinder 1 is rotated to be excited. At this time, the vicinity of the vertex of the convex diameter portion 22a of the cam 22L is located below, and when the vertex of the convex diameter portion 22a slides on the cam follower 9L, the press roller arm 25L resists the urging force of the spring 26. Pushed down slightly,
Thereby, the upper surface of the notch claw 25a and the lower surface of the locking claw 28a that have come into contact with each other are separated from each other. Then, the printing pressure ON command is sent to the solenoid 33, and the excited plunger 33p is suction-moved, the printing pressure release claw member 28L is displaced to the solid line position, and the engagement between the notch claw 25a and the locking claw 28a is established. It is released. Thereafter, again, the solenoid 33
Until the non-excitation state in which the image is in the non-excited state, the non-image printing range a and the image printing range b of the plate cylinder 1 are synchronized with the rotation of the plate cylinder 1.
Pressing of the press roller 9 to and from the press roller 9 (shown in FIG. 2) is repeated.

According to the present embodiment, at the time of printing, on the peripheral surface of each of the cams 22L, 22R corresponding to the image printing range b of the plate cylinder 1 except for the convex diameter portion 22a, the respective press roller arms 25L, 25L, 25R, each of the press roller arms 2
Since the free ends of 5L and 25R swing independently of each other and the press roller 9 occupies the printing position, the press roller 9 uniformly presses the outer peripheral surface of the image printing range b on the plate cylinder 1. In addition, the bias of the pressing force of the press roller 9 with respect to the plate cylinder 1 does not occur.

Further, according to the present embodiment, at the time of non-printing,
Since each press roller arm 25L, 25R is locked and held by the printing pressure release claw members 28L, 28R so that the press roller 9 occupies the non-printing position, the press roller 9 is moved to the outer peripheral surface of the plate cylinder 1 and the clamper. 4 can be reliably maintained. When printing, the solenoid 3
By releasing the locking / holding state of the printing pressure release claw members 28L, 28R with the respective press roller arms 25L, 25R by 3, the press roller 9 can occupy its printing position. The roller 9 is pressed against the outer peripheral surface of the plate cylinder 1 via the printing paper P, so that printing can be reliably performed.

According to the present embodiment, the clue 22b
Alternatively, the plate cylinder 1 can be easily rotated by manually operating the flat knurl 23a for clues.
When the base paper 3 or the printing paper P is jammed around,
The jam can be corrected by manually rotating the plate cylinder 1. Further, these clues 22b and flat knurls 23a for clues are, for example, a fixed type in which the plate cylinder 1 cannot be detached, and a document reading device is mounted on the upper part of the printing press. Can be applied to a stencil printing machine of a type capable of exposing.

Further, according to the present embodiment, the cam followers 9L, 9R and the roller 35 are selectively slidably brought into contact only with the contour peripheral surface of the convex diameter portion 22a of each of the cams 22L, 22R. , Roller 35 and each cam 22L,
The durability performance (reliability) of the 22R is improved.

According to the present embodiment, the press roller 9
Coil spring 26 for urging the outer peripheral surface of the plate cylinder 1 into pressure contact
Are used in common on the left and right, and the press roller 9 is used.
5 as a stopper for the bearing 9j in the direction of the shaft 9s.
As shown in FIG. 5B, the press roller arm 25R has a stepped screw 27R, and as shown in FIG. 5A, the press roller arm 25L has a swing fulcrum convex portion.
By providing a holding member 27L having a long groove that is swingably supported about the swing supporting point convex portion between the retaining click position and the retaining releasing click position at the portion a, as a consumable product. The replacement of the press roller 9 and the tension coil spring 26 and the cleaning thereof can be easily performed.

[0036]

As described above, according to the first aspect of the present invention, with the above-described configuration, at the time of printing, on the peripheral surface except for the large-diameter portion of each cam corresponding to the image printing range of the plate cylinder, The free ends of each press roller arm swing independently by the urging force of a pair of press roller urging means that urges each press roller cam follower against the large diameter portion of each cam with the same load. Since the press roller occupies the printing position, the press roller uniformly presses the plate cylinder, so that the pressing force of the press roller with respect to the plate cylinder is not biased. When the large-diameter portion of each cam is pressed against the cam follower for each press roller, the press roller is displaced from the printing position to the non-printing position, and then the large-diameter portion of at least one of the cams is used for the separation claw. When the separation claw is displaced from the separation position to the non-separation position when pressed against the cam follower, the printing paper is reliably peeled off by the tip of the separation claw at the separation position. Therefore,
Since the large-diameter portion of the single cam and the cam follower for the press roller and the cam follower for the separation claw are sequentially engaged with each other, the press roller contact operation and the separation claw discharge operation are performed in common. The size and weight of the apparatus can be reduced by greatly simplifying the mechanism, and a stencil printing apparatus that is highly reliable and can be produced at low cost can be provided.

According to the second aspect of the present invention, when the press roller occupies its non-printing position, a pair of printing pressures for locking the free ends of the respective press roller arms to hold the press roller at that position. By providing a release member and driving means for releasing the locked state of the pair of printing pressure releasing members so that the press roller occupies its printing position during printing, the printing roller is released by each printing pressure releasing member during non-printing. Since each press roller arm is held so as to occupy the non-printing position, the state in which the press roller is securely separated from the outer peripheral surface of the plate cylinder and the clamper can be maintained. By releasing the lock state with each press roller arm by the above, the press roller can occupy its printing position, Pressed against the outer circumferential surface of the plate cylinder through the printing paper, it is possible to reliably print.

[Brief description of the drawings]

FIG. 1 is a perspective view of a stencil printing apparatus according to an embodiment of the present invention, around a press roller contact / separation mechanism and a separation claw swing mechanism.

FIG. 2 is a cross-sectional view of a main part showing an operation at the time of printing in FIG.

FIG. 3 is a perspective view showing a shape of a cam portion in FIG. 1;

FIG. 4 is a side view of a main part that supplements the configuration of FIG. 1 and shows the operation during non-printing.

5 (a) and 5 (b) are side views of a main part which supplement the configuration and operation of FIG. 4. FIG.

FIG. 6 is a configuration diagram of a main part of the stencil printing apparatus of FIG. 1;

[Explanation of symbols]

Reference Signs List 1 plate cylinder 2 rotation center shaft 9 press roller 9s press roller shaft 9L, 9R cam follower for press roller 15 separation claw 22a convex portion as large diameter portion 22L, 22R cam 25L, 25R press roller arm 26 for press roller Tension coil springs as biasing means 28L, 28R Printing pressure releasing claw member as printing pressure releasing member 33 Solenoid as driving means 34 Separating claw shaft 35 Roller as cam follower for separating claw 36 Separating claw driving arm 38 Urging for separating claw Tension coil spring as means a Non-image printing area b Image printing area P Printing paper

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) B41L 13/04 B41L 13/14

Claims (2)

(57) [Claims] 1. A plate cylinder on which a stencil sheet is wound, a press roller selectively occupying a printing position for pressing against the plate cylinder via printing paper and a non-printing position for separating from the plate cylinder. A pair of swingable press roller arms rotatably supporting both ends of a shaft of the press roller, a separation position where the tip is close to the outer peripheral surface of the plate cylinder, and the printing paper is peeled from the plate cylinder; A stencil printing machine having a separation claw that selectively occupies a non-separation position separated from the position and a swingable separation claw drive arm that supports a shaft of the separation claw; Are independently swingably supported on the stencil printing apparatus main body side, and are provided coaxially with the rotation center axis of the plate cylinder at an end of the plate cylinder, and a non-image printing area of the plate cylinder is provided. Large-diameter part on the part corresponding to A pair of cams having the same contour shape at both ends of the plate cylinder and provided at the same phase, respectively, and provided at both ends of a shaft of the press roller; A pair of press roller cam followers respectively driven by the large diameter portion, and a pair of press roller biases for urging the respective press roller cam followers with the same load in a direction to press the respective cams against the large diameter portions of the respective cams. Means, provided on the separation claw drive arm, and located downstream of each of the press roller cam followers as viewed in the direction of rotation of the plate cylinder during printing, and the large size of at least one of the cams. A cam follower for the separation claw that is driven by the diameter portion, and a cam follower for the separation claw that is urged in a direction of pressing against the large diameter portion of at least one of the cams. And a biasing force of the pair of press roller biasing means on a peripheral surface of each of the cams corresponding to the image printing range of the plate cylinder except for the large diameter portion during printing. When the free end of each of the press roller arms swings independently, the press roller occupies its printing position, and when the large-diameter portion of each of the cams comes into press contact with each of the press roller cam followers, When the roller is displaced from the printing position to the non-printing position, and then the large-diameter portion of at least one of the cams is pressed against the separation-follower cam follower, the separation claw is disengaged from the separation position. A stencil printing machine characterized by being displaced to a position. 2. The stencil printing machine according to claim 1, wherein when the press roller occupies its non-printing position, the free ends of the pair of press roller arms are engaged to hold the press roller at that position. Stencil printing, comprising: a pair of printing pressure releasing members to be stopped; and driving means for releasing the locked state by the pair of printing pressure releasing members so that the press roller occupies its printing position during printing. apparatus.