JPH02225078A - Rotary stencil printing device - Google Patents

Abstract

PURPOSE:To prevent a print image from becoming distorted by providing a constitution in which the peripheral wall with ink passage holes of a printing drum is composed substantially of only a network. CONSTITUTION:A printing drum 1 consists of annular members 3a, 3b on both ends and a steel wire-woven material 4 is arranged in a cylindrical form on the periphery of the annular members 3a, 3b. A bar 5 is provided on some section, along a bus, of the printing drum 1 and functions as a member which connects the annular members 3a, 3b firmly. Inside the printing drum 1, an intermediate push roller 2 is provided which is part, along the bus, of the peripheral section consisting of only the material 4 and pushes the opposite part to a backup roller 2 selectively to the roller 2 in a radial direction. The intermediate push roller 18 works to push the peripheral wall toward the backup roller 2, and at the same time, is a roller which supplies ink from inside.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to the technical field of stencil printing, and particularly to a rotary stencil printing apparatus.

One of the conventional stencil printing apparatuses is a printing drum which is rotatably supported around a central axis and is configured to have a cylindrical circumferential surface having ink passage holes and a perforated stencil paper wound around and loaded therein. , a sheet to be printed is sandwiched between a cylindrical circumferential surface of the printing drum and a circumferential surface of the printing drum, the sheet being rotatably supported around a central axis disposed parallel to the central axis of the printing drum; A rotary stencil printing apparatus is known that has a back-pressing roller that forms a nip area for feeding. The printing drum in such a rotary stencil printing device has conventionally been made of a metal cylinder element having a plain cylindrical wall with a large number of holes for ink passage perforated in the cylindrical wall. is constructed as a plate having a wall thickness necessary to maintain the strength and rigidity of the entire printing drum.

Problems to be Solved by the Invention In a rotary stencil printing device having a printing drum and a back-pressing roller as described above, ink is supplied to the inside of the printing drum, and from this the ink is applied to the peripheral wall of the printing drum. It reaches the outside of the peripheral wall through the drilled hole, is supplied to the inside of the stencil paper wrapped around it in a cylindrical shape, and further reaches the outside of the stencil paper through the perforated portion of the stencil paper.

In a conventional rotary stencil printing device having such a configuration, the printing drum has a cylindrical structure made of a plate material having a considerable thickness, and the ink passage hole is formed in the cylindrical body made of this plate material. The aperture density of the printing drum is naturally limited from the viewpoint of maintaining the strength and rigidity of the printing drum, and the ink sent through these mutually spaced holes is evenly distributed to the intermediate part between the holes. Therefore, a net material made of double or triple weaving or knitting of wire rods is usually wrapped around the cylindrical body, so the ink supplied to the inside of the printing drum is wound and loaded along the outer circumferential surface of the cylinder. A considerable amount of preliminary ink is required to be uniformly supplied to each part of the stencil paper, and this naturally takes a considerable amount of time, so that the printing drum is loaded with new stencil paper and a new When printing begins, it is unavoidable to carry out several initial trial printings before obtaining high-quality printed matter.

By the way, not only stencil printing devices but also rotary printing devices,
If the nip area between the printing drum and the backing roller is closed when no sheet to be printed is being fed, the surface of the backing roller will be contaminated with ink and the printing drum The pressing of the backing roller and the backing roller against each other must be allowed only when a printing sheet is being fed into the nipping area; therefore, in rotary printing machines, the nipping A structure is used in which the feeding of a printing sheet into a region is sensed and, in response to this, an extrusion roller is generally driven in each case towards a printing drum. This is because the extrusion roller can be constructed with a smaller diameter and lighter weight than the printing drum, so the extrusion roller, which has a smaller mass, is preferred as an object that must be rapidly driven in response to the supply of printing sheets. This is because it is suitable.

In addition to the need for movement of the backing roller in synchronization with the feeding of such printing sheets, especially in rotary stencil printing machines, the printing drum has a Since an extending stencil trailing device is provided as an essential component, and this stencil trailing device typically has a structure that protrudes considerably beyond the cylindrical circumferential surface of the printing drum, the backing roller In order to avoid a collision with this stencil leading edge attachment device as the drum rotates, it must be moved away from the printing drum by a fairly large distance, no less than the small distance necessary to avoid ink contamination by direct contact with the printing drum. . Therefore, in a rotary stencil printing machine, even though the backing roller is made to have a considerably smaller diameter than the printing drum in order to reduce its mass, it is still necessary to rotate the printing drum over a considerable distance. It must be reciprocated with high acceleration in synchronization with However, there is a problem in that considerable noise and vibration are generated when the printing apparatus is operated.

The present invention provides a rotary stencil printing device that has been improved so as to eliminate the need for axial deviation of the backing roller in the above-mentioned rotary stencil printing device, and to reduce the number of sheets required for initial trial printing to almost zero. Patent application filed by the same applicant as the applicant 1986-2
It was proposed in No. 8553.

The rotary stencil printing device proposed in the above-mentioned earlier application is
a printing drum that is rotatably supported around a central axis and configured to have ink passage holes and a stencil sheet having a cylindrical circumferential surface perforated and wound thereon; a rear side that is supported so as to be rotatable around an arranged central axis and forms a nipping area between the cylindrical circumferential surface of the cylindrical circumferential surface and the circumferential surface of the printing drum to sandwich and feed the sheet to be printed; In the rotary stencil printing apparatus having a push roller, the peripheral wall portion of the printing drum having the ink passage holes is substantially composed only of a net material made of woven or knitted wire material, and the printing drum is substantially A rotary stencil printing apparatus characterized in that an intermediate push roller is provided in the peripheral wall made of only the net material from the inside in the radial direction and presses it toward the push roller in the radial direction. be.

As mentioned above, when the peripheral wall portion of the printing drum having ink passage holes is substantially composed only of a net material made of woven or knitted wire material, the peripheral wall portion of the printing drum is substantially made of only the net material. If the mesh of the mesh material is appropriately small, the ink supplied to the inside of the drum can be wrapped around it and guided quickly and uniformly to the entire inner surface of the loaded stencil paper. Even when a new stencil sheet is loaded into the printing drum and a new printing starts, there is a large deviation in the shading of the printed image from the first printing, and the ink supply needs to be greatly uneven. However, it is possible to obtain normal printed matter from about the second printing.

The peripheral wall of the printing drum that should have ink passage holes, that is, the main part of the printing drum except for both ends, is made of only net material, and the intermediate push roller is incorporated therein so that it can be operated from the outside. One method is to configure both ends of the printing drum with a pair of annular members, and to firmly connect these annular members using crossbars necessary to provide the above-mentioned stencil paper starting edge attachment device, and to insert a mesh material between them. This is achieved by stretching the

Further, when the main peripheral wall portion of the printing drum having the ink passage holes is substantially made of only the mesh material, 5,
Since this peripheral wall section made essentially only of net material has great flexibility and local bulge, a part of the wall section facing the backing roller is radially outwardly moved from the inside by an intermediate pushing roller. If the printing drum is pressed, the part can easily bulge elastically outward in the radial direction, so by controlling the radial movement of the intermediate pressing roller, the distance between the axes between the printing drum and the backing roller can be reduced. Even if it remains constant without changing, the peripheral walls of the printing drum and backing roller are pressed against each other only when there is a printing sheet in the nipping area between the printing drum and the backing roller, and the nipping area Control can be easily achieved to avoid contact between the two when there is no printed sheet on the backing roller, eliminating both the need for a drive mechanism for axial deviation of the backing roller and the noise problem associated with its operation. be able to.

In order to avoid direct contact between the printing drum and the backing roller when there is no printing sheet in the sandwich area between them, it is sufficient that their circumferential surfaces are separated by a very small distance of a few millimeters. This degree of deviation is easily achieved by elastic deformation of the printing drum peripheral wall, which is made essentially only of net material, by the intermediate pressing roller.

In addition, as the printing drum rotates, it approaches the roller equipped with the above-mentioned stencil paper starting edge attachment device provided along one of the generatrices on its circumferential surface, and while passing through the nipping area, interference between the two is prevented. It is necessary to avoid this by making the outer diameter of the back-pressing roller the same as that of the printing drum, and by rotating both at the same rotational speed in synchronization with each other in opposite directions. is easily achieved by providing a groove along one of the generatrices of its cylindrical circumferential surface for receiving the crosspiece of the printing drum. In this case, the backing roller no longer prints like a conventional backing roller. Since there is no need to deviate the axis of the drum as it rotates, the size of its mass is not an issue, and there is no problem in making it the same diameter as the printing drum. No problem.

In the configuration of the rotary stencil printing apparatus proposed earlier as described above, the printing drum has a pair of annular members fixed to both ends of the crossbars necessary for supporting the stencil paper starting edge attachment device as described above, and The printing drum has a structure in which a net material made of woven or knitted wire rods is stretched between the annular members of the printing drum.As can be understood from the structure, the printing drum as a whole has In particular, the rigidity against torsion around the center axis of rotation is quite low. Therefore, the net material stretched between the pair of annular members is likely to be twisted around the rotation center axis of the printing drum, that is, torsion based on the relative deviation in the rotational direction between the pair of annular members. I have a good knowledge of it. The net material itself, which is made by woven or knitted wire rods, has sufficient flexibility to absorb such twisting, but if the net material is twisted due to such causes, the stencil paper wrapped around it will be damaged. There is a risk that wrinkles may occur in the printed image and distortion may occur in the printed image.

Means for Solving the Problems The present invention solves the problem of distortion of printed images caused by twisting of the printing drum in a rotary stencil printing device, which was previously proposed by the same applicant as the present applicant. The object of the present invention is to provide an improved rotary stencil printing device to solve this problem.

In order to achieve such an object, the present invention provides the printing drum with two annular members forming both ends in the axial direction thereof;
a stencil paper starting end attachment device that extends between the two annular members along one generatrix of the cylindrical peripheral wall surface and selectively attaches the starting end of the stencil paper; It is constructed of a net material having a developed shape of a rectangle (of course, including a square) having a front edge and a rear edge facing each other and both side edges facing each other, and the net material is a portion of the front edge thereof. The stencil sheet is fixed to the starting end fixing device at the side edges thereof, is freely seated on the circumferential surface of the annular member and wound into a cylindrical shape, and the rear edge portions thereof are fixed to the both side edges. It is proposed that the portion of the annular member be elastically pulled in a direction in which it is wrapped around the circumferential surface of the annular member.

Functions and Effects In the structure in which the rectangularly developed mesh material is attached along the periphery of a pair of annular members spaced apart from each other along the rotation center axis of the printing drum as described above, both side edges of the mesh material are attached. is not fixed to the annular member, but is seated freely on the circumferential surface of the annular member, and the front edge of the net material is fixed to the stencil paper starting edge attachment device extending between the pair of annular members. The rear edge of the net material is elastically pulled in the direction in which the side edge portions are wrapped around the circumferential surface of the annular member, so that some relative distance between the pair of annular members Even if a rotational deviation occurs, the relative rotational deviation between the two annular members can be absorbed without the net material being distorted due to slipping between the side edges of the mesh material and the circumferential surface of the annular member. Ru. With this configuration, according to the present invention, it is possible to reliably avoid wrinkles in the stencil paper pasted around the net material.

According to the configuration of the printing drum as described above, the front edge of the rectangular developed shape of the net material is fixed to the stencil paper starting edge attachment device, and the both side edges of the net material are freely seated on the circumferential surface of the annular member. In the state of being wound into a cylindrical shape, a pair of tension coil springs or the like are used at the rear edge, especially at the ends lined up on both side edges, in a direction in which the side edge portions are wound onto the circumferential surface of the annular member. When the net material is elastically stretched, the rigidity generated in the entire cylindrical body as a result of the mesh material being wound into a cylindrical shape allows its both side edges to be stably supported on the circumferential surface of the annular member. Even if these side edges are not fixed to the circumferential surface of the annular member with adhesive or other fixing means, the printing drum with such a structure is stable as a printing drum of a rotary stencil printing apparatus having the above-mentioned basic structure. operation can be performed.

In addition, according to this structure in which a rectangular net material is wound into a cylindrical shape and supported while freely sitting on a pair of annular members at both ends of the cylindrical body, the net material can be easily stretched by a simple light tension. Since it is placed below and is not subjected to irregular forces such as twisting, it is possible to use a nonwoven wire net material formed into a net shape without weaving wire rods as the net material.

Further, in this case, as will be understood from the description of the embodiments to be described later, the stencil paper starting edge attachment device extending between the pair of annular members need only function as a stencil paper starting edge attachment device; Since there is no need to function as a load-bearing member connecting the annular members to each other, the structure can be made lightweight and thin, and it is housed inside the stencil paper carrying cylindrical surface of the printing drum, and is used to control the printing sheet clamping area of the intermediate push roller. Since the structure can be constructed in such a way that interference with the intermediate push roller can be completely avoided by using a drive mechanism for this purpose, it is no longer necessary to have a recess in the roller to avoid interference with the stencil paper starting edge attachment device. Therefore, it is possible to construct a printing apparatus in which the diameter of the roller is smaller than the diameter of the printing drum.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in detail with reference to one embodiment with reference to the accompanying drawings.

FIG. 1 is a side view diagrammatically showing the configuration of the main parts of a rotary stencil printing apparatus according to the present invention, and FIG. This is a diagram seen from the right side.

In these figures, 1 is the printing drum and 2 is the actual roller. The printing drum 1 has both ends connected to an annular member 3.
As will be explained in detail later, on the circumferential surface of these annular members 3 as 3 b, wire rods are woven while sitting freely on both side edges. A net material 4 made of nonwoven or knitted material, for example, made of stainless wire woven vertically and horizontally, is installed in a cylindrical shape. A crosspiece 5 is provided along the generatrix of the printing drum 1.
is provided with a known stencil paper starting edge attachment device (not shown in the figure) in various forms for selectively attaching the starting edge of the stencil paper that is wound around the printing drum and loaded. ) are provided. In the embodiment shown in FIGS. 1 and 2, the crosspiece 5 also functions as a member that rigidly connects both the annular members 3a and 3b. The printing drum 1 has annular shaft portions 6a and 6b protruding from the annular members 3a and 3b at both ends, which are rotatably attached to the casing 8 via bearings 7a and 7b, respectively. It is rotatably supported around a central axis. In practice, the roller 2 is rotatably supported around its central axis by having shaft portions 9a and 9b protruding from both ends rotatably attached to the casing 8 via bearings 10a and 10b, respectively. There is.

The printing drum 1 and the actual roller 2 are synchronized in opposite directions as shown by the arrows in FIG. This rotation is actually performed by driving the shaft 9b of the roller 2 by a drive device 13 that includes an electric motor therein. In addition, in practice, the printing drum 1 is attached to the roller 2.
groove 14 corresponding to and capable of receiving the crosspiece 5 of the
is formed.

In FIGS. 1 and 2, the distance between the printing drum 1 and the actual cylindrical circumferential surface of the roller 2 is shown exaggerated compared to their diameter for illustrative purposes. However, this interval may be as small as 2 to 5 mm even in an actual apparatus in which the diameter of the printing drum is more than ten centimeters. This portion is a sandwiching area 15 that sandwiches the sheet S to be printed during printing. Note that 16 and 17 are feed rollers for feeding the sheet S toward the nipping area 15.

Inside the printing drum 1, a portion along the generatrix of the peripheral edge consisting essentially only of the net material 4 and facing the roller 2 is selectively formed, and a radius is formed toward the roller. An intermediate push roller 18 is provided for pushing outward.

This intermediate push roller is rotatably supported by a shaft 19 extending in alignment with its central axis, and the shaft 19 is supported at both ends by a shaft 20 via arms 21a and 21b. The shaft 20 extends through the annular shaft portions 6a and 6b at both ends of the printing drum 1, and is connected to the casing 8 through bearings 22a and 22b at both ends.
It is rotatably supported. One end of the shaft 20 is a lever 2
3 and a link 24, and is driven by the drive device 13 in synchronization with the rotation of the printing drum 1 and the backing roller 2 when a printing sheet is being supplied to the nipping area 15. It looks like this. That is, sheet S
When printing is to be performed while the paper is being supplied into the nipping area 15, the peripheral wall of the printing drum made of the net material 4 is directed toward the back-pressing roller only in areas other than the generatrix area where the crossbars 5 are present. In order to push elastically outward in the radial direction, the intermediate push roller 18 is moved to the position shown in FIG.

The printing ink is supplied to the inside of the printing drum 1 by an ink supply device (not shown) as in conventional rotary stencil printing machines, and from this, in particular in the nipping area 15.
It is supplied from the inside to the peripheral wall of the area. In a conventional rotary stencil printing device, the ink supplied to the inside of the printing drum is applied to the peripheral wall of the printing drum from the inside at a position corresponding to the sandwiching area 15, and the ink provided on the peripheral wall is coated. An ink feed roller, similar to the intermediate push roller 18 just shown, is provided for forcing it out through the passage hole. In the present invention, the intermediate push roller 18 may also serve as an ink supply roller for supplying such ink. Therefore, the intermediate push roller 18 in the illustrated embodiment selectively pushes the peripheral wall portion of the printing drum made of the net material 4 toward the back push roller 2 in the radial direction outward, and operates as a back roller. At the same time, it also functions as an ink supply roller that supplies ink to the peripheral wall of the printing drum from the inside. Such an intermediate push roller was used in early manual mimeograph machines that had a square frame covered with a mesh material.
It functions in the same way as a hand roller that presses the stencil paper against the printing surface and simultaneously supplies ink.

According to the configuration described above, the printing drum 1 whose ink passing portion is substantially made of only a mesh material passes the ink supplied into the inside of the drum 1 through the peripheral wall portion made of a thin layer of the mesh material. Since it is possible to easily and directly feed the entire area of the stencil sheet that has been wound and loaded along the outer surface, even when a new stencil sheet is wound and loaded around the printing drum and a new stencil printing is performed, the first stencil sheet can be easily and directly fed. Sufficient ink is supplied from the time of printing the first sheet, and stencil printing can be performed without repeating wasteful test printing.

Further, there is no need for a device that changes the distance between the axes between the printing drum 1 and the back-pressing roller 2 in synchronization with the rotation of the printing drum, and the intermediate pressing roller 18 is in the state shown in FIG. 1 and in the state shown in FIG. 3. Since the movement between the two rollers is achieved by slightly rotating the shaft 20 as in the illustrated embodiment, the drive structure for this purpose is extremely simple, and the intermediate push roller 18 is lightweight. Often, the distance it travels is so small that its operation occurs with little noise.

FIG. 4 is a perspective view showing in detail the structure of the printing drum 1, somewhat modified from the structure shown in FIG. That is, in the printing drum shown in FIG. 4, the annular gear 11 is provided as a pair of annular gears 11a and llb at both ends of the printing drum. A pair of binions 25a and 25b are provided which mesh with the llb, respectively, and these pair of binions are connected to each other by a shaft 26 so as to rotate at the same time. Although not shown in FIG. 4, both ends of the shaft 26 are rotatably received by a pair of bearings provided correspondingly to the casing 8, respectively. By providing the pair of annular gears 11a and 11b and the pair of pinions 25a and 25b connected to each other by the shaft 26, the annular member 3a is constructed as shown in FIG. Compared to the case where the annular member 3b is driven only through the crosspiece 5 as in the structure, the annular member 3 is driven in reliable synchronization with the annular member 3b.
The degree to which relative torsional rotation occurs between a and 3b is reduced.

The netting material 4 having a rectangular developed shape is attached to the crosspiece 5 at its front edge, which is located on the back side of the crosspiece 5 and cannot be seen in FIG.
A free 1 is fixed on the peripheral surface of the annular members 3a and 3b at both side edges 4S.
' When the two are seated, it is wound in a cylindrical shape around the rear edge 4t, and in particular, in the portions lined up with both side edges 4S, a pair of tension coil springs 27a and 27b cause the both side edges 4s to form an annular member. It is elastically pulled toward the crosspiece 5 in a direction that wraps around the circumferential surfaces of 3a and 3b.

According to this configuration, even if a relative torsional rotational deviation occurs between the annular members 3a and 3b, the net material 4 will not slide in the rotational direction with respect to the annular members 3a and 3b at both side edges thereof. As a result, the netting material 4 is not twisted, the stencil printing paper pasted around it is not wrinkled, and a printed image without distortion can be obtained. This has been confirmed using a test machine.

By the way, as in the present invention, the peripheral wall portion of the printing drum having the ink passage holes is substantially constituted only by a rectangular net material made of woven, non-woven or knitted wire material, and furthermore, both side edges of this net material are When the part is mounted freely seated on the circumferential surfaces of a pair of annular members 3a and 3b, if these annular members are each provided with an annular gear lea and llb as in the embodiment of FIG. , a pair of binions 2
The inner annular member need not be rigidly connected by the crosspiece 5 if it is driven synchronously with each other via the shaft 26 carrying 5a and 25b. The crosspieces 5 are therefore connected to the annular members 3a and 3 as shown in the embodiments of FIGS.
Instead of being constructed as a thick and strong member that connects the annular members 3a and 3b relatively firmly, a relatively thin plate that is curved along the circumferential surface of the annular members 3a and 3b as shown in FIGS. 5 and 6 is used. It may be configured as a shaped member. When the crosspiece 5 is configured as a thin plate-like member along the circumferential surfaces of the annular members 3a and 3b, the intermediate push roller 18 is moved between the retracted position shown in FIG. 1 and the position shown in FIG. When the crosspiece 5 passes near the intermediate push roller, the intermediate push roller is slightly deflected toward the inside of the drum by using the intermediate push roller drive mechanism that moves the intermediate push roller between the intermediate push roller and the forward position. Interference between containers can be avoided. In this way, the crossbar 5 and the stencil paper starting edge attachment device provided thereon are structured so that they do not protrude outward in the radial direction from the outer peripheral surface of the printing drum due to the peripheral surfaces of the annular members 3a and 3b or the net material 4 wound around them. When the first
It is no longer necessary for the back-pressing roller 2 to be provided with a groove 14 for receiving it in synchronism with the crosspiece as shown in FIGS. The rollers can be configured as rollers of any diameter smaller than 1, thereby significantly reducing the weight and size of the printing device compared to the embodiments shown in FIGS. 1-3.

FIG. 6 shows an embodiment of a printing drum constructed using such a thin crosspiece 5 in a perspective view in the same manner as in FIG. As shown in the figure, the crosspiece 5 is an annular member 3
It extends between a and 3b and is configured as a band-shaped plate material that is curved to have a cylindrical outer surface along the circumferential surface of these annular members, and the front edge 5 of the net material 4 is The front edge 41 is attached by brazing, holding fittings, or other suitable attachment means. Tension coil springs 27g and 27b that pull both side edges of the rear edge 4t of the net material 4 in the direction in which the net material is wound around the annular members 3a and 3b are connected to the crosspiece 5.
It is housed in grooves 28a and 28b cut out along both ends of the trailing edge portion 5e, and protrudes outward from the outer circumferential surface of the printing drum provided by the net material 4 beyond the gap in the sandwiching region 15. There is no such thing.

A strip-shaped metal plate 29 is held at the center of the crosspiece 5 in a magnetically attracted state. This metal plate 29 constitutes a stencil paper starting edge attaching device for attaching the starting edge of the stencil paper to the crossbar 5.

Such a band-shaped metal plate 29 may be very thin, and even if the metal plate is held magnetically attracted to the horizontal bar 5 with the starting end of the stencil paper sandwiched between them, the outer circumferential surface of the printing drum Since the pinching area 15 is kept to a size of only a few millimeters, there is no risk of it interfering with the backing roller 2.

Thus, according to the present invention, a rotary stencil printing device having the basic configuration of the above-mentioned proposal in which the peripheral wall portion of the printing drum having ink passage holes is substantially constructed only of a mesh material can be used to print images. It can be carried out without causing distortion. Further, as is clear from the structure illustrated in detail in FIGS. 4 and 6, the structure of the printing drum according to the present invention can be manufactured and assembled very easily and inexpensively, and can be easily manufactured and assembled as needed. Maintenance work such as replacing the netting material is also extremely easy to perform.

Although the present invention has been described in detail with respect to one embodiment above, the present invention is not limited to this embodiment, and various other embodiments are possible within the scope of the present invention. This will be clear to those skilled in the art.

[Brief explanation of the drawing]

FIG. 1 is a side view diagrammatically showing the main parts of the structure of a rotary stencil printing apparatus according to the present invention, and FIG. FIG. 3 is a view similar to FIG. 1 showing the structure shown in FIG. 1 in another operating state; FIG. A perspective view showing the two structures in more detail, No. 5
1 and 6 are views similar to FIGS. 1 and 4, respectively, showing another embodiment of the printing drum. 1...Printing drum, 2...Back pressing roller +3as3
b... Annular member, 4... Net material, 5... Crosspiece, 6a
, 6b... annular shaft portion + 7a, 7b... bearing, 8...
··casing. 9a, 9b---Shaft part, 10a, 10b
・= Bearing, 11.11a111b, 12... Annular gear, 13... Drive device, 14... Groove, 15... Snipping area, 16.17... Roller, 18... Intermediate push roller , 19.20...axis, 21a, 21b=・arm+
22a, 22b--bearings. 23...Lever, 24...Link, 25a, 25b.
...Pinion, 26...Shaft, 27 a s 27 b
...Tension coil spring, 28a, 28b...Groove, 2
9...Metal plate patent applicant Riso Kagaku Kogyo Co., Ltd. Representative Patent attorney Roki Akashi Figure 3 Figure 4 Figure 2

Claims (1)

[Claims] a printing drum that is rotatably supported around a central axis and configured to have a cylindrical circumferential surface having ink passage holes wound around and loaded with perforated stencil paper; and a printing drum arranged parallel to the central axis of the printing drum. a back support that is supported so as to be rotatable around a central axis line formed between the cylindrical circumferential surface and the printing drum or the circumferential surface, and forms a sandwiching area for sandwiching and feeding the sheet to be printed; a rotary stencil printing device, wherein the printing drum has a circumferential wall portion having the ink passage holes substantially consisting of only a net material made of woven, non-woven or knitted wire material. The printing drum has two annular members forming both ends in the axial direction thereof;
a stencil paper starting end attachment device extending between the two annular members along one generatrix of the cylindrical peripheral wall surface and selectively attaching the starting end of the stencil paper; A netting material having a rectangular developed shape having a front edge and a trailing edge facing each other and both side edges facing each other,
The front edge portion of the net material is fixed to the stencil paper starting edge attachment device, and the side edge portions of the net material sit freely on the circumferential surface of the annular member and are wound into a cylindrical shape. A rotary stencil printing device characterized in that the trailing edge portion is elastically pulled in a direction in which the both side edge portions are wrapped around the circumferential surface of the annular member.