Riso Kagaku Corporation

Yoshiharu Ohinata

Yasuhiro Takahashi

Noboru Hayama

Yoshihiro Noguchi

Hideo Negishi

Nagon Takita

Kazuo Sakamoto

Matsuo Nakamura

To remarkably decrease the amount of material for the manufacture of ink containers and the volume of the ink containers after use, so as to contribute to the economy of natural resource consumption and solving the problem of destruction of global environment by the waste of products, without sacrificing the easiness of handling of the ink containers for printers, the ink container for directly storing ink is principally constructed by a thin walled vessel contractible according to discharge of ink therefrom, with a nozzle being connected to an end portion of the vessel, with a disk handle being mounted to the nozzle, so that the disk handle can be grasped by five fingers of a hand for carrying the ink container by hand and for removing a cap therefrom. For the ink container being housed in a printer, the ink container is charged into a reinforcing case with the nozzle and the disk handle engaged with an end wall portion of the case, so that the ink container is handled like the case.

Collapsible ink container having disk shaped handle and ink supply

To remarkably decrease the amount of material for the manufacture of ink containers and the volume of the ink containers after use, so as to contribute to the economy of natural resource consumption and solving the problem of destruction of global environment by the waste of products, without sacrificing the easiness of handling the ink containers for printers, the ink container for directly storing ink is principally constructed by a thin walled vessel contractible according to discharge of the ink therefrom, with a nozzle being connected to an end portion of the vessel, with a disk handle being mounted to the nozzle, so that the disk handle can be grasped by five fingers of a hand for carrying the ink container by hand and for removing a cap therefrom. For the ink container being mounted into a printer, the ink container is mounted into a reinforcing case with the nozzle and the disk handle, so that the ink container is handled like the case. The disk handle is equipped with press claws adapted to engage a portion of the case for easily guiding the ink container relative to the case and stabilizing the mounted state of the ink container in the case.

Ink supply source device for printers by collapsible ink container

Firming folds for increasing the firmness of the stencil itself are generated at a leading end of the stencil to be mounted to a cylindrical printing drum of a rotary stencil printer or a trailing end of the stencil mounted to the printing or both. To do so, a pair of rollers one of which has projections to form the folds at the stencil are provided to feed the stencil therebetween toward a stencil leading end mounting means of the printing drum positioned at a standby position.

Rotary stencil printer with a firming fold application means

The rotation of the inner press roller 16 is synchronized with the rotation of the printing drum 10 by the gear train including a gear wheel 22 coaxial with the printing drum, a gear wheel 24 meshing with the gear wheel 22 and rotatably supported by an arm 26 swingable about the central axis of the printing drum, and a gear wheel 28 meshing with the gear wheel 24 and coaxially connected with the inner press roller 16 to rotate therewith and rotatably supported by an arm 18 swingable about a pivot axis Ob parallel with and distant from the central axis Oa of the printing drum. A clutch 86 is provided to apply a torque from the printing drum when driven to the arm 26 to control the biasing out operation of the inner press roller 12 against the circumferential wall 12 of the printing drum. The clutch may be replaced by the linear actuator 96. The clutch or linear actuator may be temporarily actuated stronger during a starting up of the printing operation. The distance between the axes of the gear wheels 24 and 28 may desirably be restricted not to increase beyond a predetermined distance.

Rotary stencil printer having gear train for synchronizing inner press

The rotation of the inner press roller 16 is synchronized with the rotation of the printing drum 10 by the gear train including a gear wheel 22 coaxial with the printing drum, a gear wheel 24 meshing with the gear wheel 22 and rotatably supported by an arm 26 swingable about the central axis of the printing drum, and a gear wheel 28 meshing with the gear wheel 24 and coaxially connected with the inner press roller 16 to rotate therewith and rotatably supported by an arm 18 swingable about a pivot axis Ob parallel with and distant from the central axis Oa of the printing drum. In the gear train, a brake 86 or 90 is provided for braking the gear wheel 28 or 24 to control the biasing out operation of the inner press roller 12 against the circumferential wall 12 of the printing drum. The braking action may be temporarily increased during a starting up of the printing operation. The distance between the axes of the gear wheels 24 and 28 may desirably be restricted not to increase beyond a predetermined distance.

A stencil printing machine comprises: a rotary cylindrical drum having an ink passage part; an ink supplying roller rotatable around an axis in parallel with the central axis of the rotary cylindrical drum, the ink supplying roller being brought into contact with the inner cylindrical surface of the rotary cylindrical drum; a pair of cylindrical protrusions on both ends of the ink supplying roller, the cylindrical protrusions being smaller in outside diameter than the ink supplying roller and coaxial with the ink supplying roller; an ink coating roller arranged in parallel with the ink supplying roller, the ink coating roller applying ink onto the surface of the ink supplying roller in accordance with the ink supplying roller turning, an ink pool forming between the ink coating roller and the ink supplying roller; and a pair of ink banks are provided at both ends of the ink pool, respectively, the ink banks having sloped surfaces in contact with the cylindrical surfaces of the cylindrical protrusions, the sloped surfaces for leading the ink into the ink pool when ink leaks onto the cylindrical protrusions.

Stencil printing drum having squeegee and doctor roller end ink banks

In order to make the bulging out deformation of the printing drum of a rotary stencil printer having a flexible cylindrical body by the internal press roller to be more easy and more uniform over the entire width of the printing, a flexible perforated sheet (20) forming the flexible cylindrical body of the printing drum is beforehand constructed to be a cylindrical body with its opposite annular edge portions being laid over a pair of annular portions (10a, 10b) connected with one another by a transverse bar portion (12), wherein the internal circumferential length of the cylindrical body made of the flexible perforated sheet is larger than the outer circumferential length of the annular portions by a determinate amount for allowing a part of the flexible cylindrical body to bulge radially outwardly, and the flexible cylindrical body is latched at a portion thereof laid one over the other with the transverse bar portion against relative circumferential movement while relatively movable in the radial direction within a determinate range against the transverse bar portion.

Printing drum of rotary stencil printer having flexible perforated

In a stencil printing including the steps of supplying ink in the form of a layer on one side of a perforated stencil sheet, contacting another side of the stencil sheet to a surface for printing, applying a pressure to the ink layer by a pressing means so as to transfer the ink of the ink layer through perforations of the stencil sheet from the one side to the other side of the stencil sheet and to attach the ink thus transferred onto the surface for printing, and detaching the surface for printing from the other side of the stencil sheet, the improvement is which the surface for printing is detached from the other side of the stencil sheet at a portion thereof where a movement of the ink layer relative to the stencil sheet is substantially impeded by the pressing means so that a drawing out of the ink from the ink layer onto the surface for printing due to the adhesiveness and viscosity of the ink does not occur when the surface for printing is detached from the stencil sheet, thus also allowing the extrusion of the ink through the stencil perforations to be expedited before the stencil sheet tightly contacts the printing surface, so as to avoid blank shadows of fibers of the stencil sheet, while avoiding the problem of back contamination.

Stencil printing with no back contamination

A mimeographic printing machine comprises a rotary cylindrical drum having an ink-penetrable tubular wall for supporting a stencil on an outer circumferential surface thereof, and a device disposed outside the cylindrical drum for holding a paper sheet between the stencil on the outer circumferential surface of the cylindrical drum to perform printing. The ink-penetrable tubular wall of the cylindrical drum has an opening communicating with a hollow interior of the cylindrical drum, and an ink-impenetrable portion ahead of the opening in the rotating direction of the cylindrical drum, with a trailing end of the ink-impenetrable portion being inserted into the opening.

Mimeographic printing machine

A mimeographic printing machine comprises a cylindrical drum rotatable with a stencil supported thereon, a lower pusher roller located under the cylindrical drum coactive with the cylindrical drum to hold a paper sheet therebetween, an inside pusher roller movably received in the cylindrical drum for pushing the cylindrical drum toward the lower pusher roller, a drive gear drivable for rotation with the cylindrical drum, a support arm pivotally received in the cylindrical drum; an intermediate gear supported on the support arm and meshing with the drive gear, and an inside pusher gear mounted on the drive shaft of the inside pusher roller and meshing with the intermediate gear for pushing, with rotating, the inside pusher roller against the inner circumferential surface of the cylindrical drum.

In a rotary stencil printer having a printing drum made of two annular members connected by a transverse bar member and a net member of woven, non-woven or knitted fibers of a rectangular shape in development wound around the two annular members with opposite side edge belt portions thereof being slidably laid on outer circumferential surfaces of the annular members so as to form a porous cylindrical body for mounting a stencil sheet as wound therearound, a back press roller of a diameter common with the printing drum disposed to face an outside surface of the printing drum so as to define a print sheet nip region with the printing drum therebetween and having a groove in an outside surface portion thereof adapted to receive the transverse bar member therein in meeting therewith in synchronized rotations of the printing drum and the back press roller in opposite directions, and an inner press roller disposed in an inside space of the printing drum so as to contact with an inside surface of the porous cylindrical body along a generatrix thereof, the transverse bar member is spaced radially outwardly from a cylindrical outer configuration of the porous cylindrical body at a portion thereof facing the porous cylindrical body so that the inner press roller can traverse a portion facing the transverse bar member with no collision therewith.

Rotary stencil printer with printing drum of net cylindrical body

In a rotary stencil printer having a printing drum supported to be rotatable about a central axis thereof and having a cylindrical outer surface adapted to bear a perforated stencil sheet as attached therearound and formed with openings for supplying ink to an inside surface of the perforated stencil sheet, and a back press roller supported to be rotatable about a central axis thereof extending in parallel with the central axis of the printing drum and having a cylindrical outer surface which defines a nip area with the cylindrical outer surface of the printing drum therebetween for nipping and transferring a printing sheet therethrough. The printing drum has an outer peripheral wall portion substantially made of only a net material constructed by weaving or knitting filaments to provide the cylindrical outer surface thereof formed with the openings, and an internal press roller is provided so as to engage the outer peripheral wall portion at a radially inside surface thereof and to press the outer peripheral wall portion radially outwardly toward the back press roller, thereby locally elastically deforming the net material to traverse a nip area clearance when a printing sheet is supplied in the nip area.

Rotary stencil printer having printing drum having outer peripheral wall

A printing machine such as a stencil duplicator having an ink supply roller and a squeezer and adapted to hold a columnar ink deposit placed on the outer peripheral surface of the roller and substantially prevented by the squeezer from moving as a whole together with the outer peripheral surface of the roller, including a device for detecting the amount of ink in the ink deposit, having a pivotable lever whose one end contacts the ink deposit and which changes its pivotal position in accordance with the size of the ink deposit, and a means for detecting the pivotal position of the lever.

Ink amount detecting device

A sticky sheet which is to be disposed of is fed in a first direction parallel to its surface so that its leading edge abuts against a stopper construction. The sticky sheet is then further fed in the first direction and is folded up in a second direction substantially perpendicular to the first direction into several layers against the stopper construction, these layers resting upon a plane support construction which extends from the lower part of the stopper construction in the direction opposite to the first direction. Then the superposed layers of the folded sticky sheet are moved in a third direction substantially perpendicular to the first and second directions while being compressed together so as to stick them together so as to be disposed of in the form of a relatively thick and narrow strip including several superposed layers which are adhering together due to their stickiness. A machine is also disclosed for disposing of a sticky sheet in the above described way.

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Tokyo, Japan

Yoshiharu Ohinata