Internal Inker Patents (Class 101/119)
  • Patent number: 6530318
    Abstract: An ink supply roll is disposed inside a printing drum of a stencil printer and supplies ink to the inner peripheral surface of the printing drum. At least the surface layer of the ink supply roll is formed of a nonmetal material which is not larger than 100° in contact angle and not larger than ±5% in swelling ratio to an ultraviolet-curing monomer.
    Type: Grant
    Filed: September 19, 2000
    Date of Patent: March 11, 2003
    Assignee: Riso Kagaku Corporation
    Inventors: Yasuo Yamamoto, Toshihiro Endo
  • Publication number: 20030000397
    Abstract: The amount of ink in an ink fountain in a printer is detected on the basis of change of oscillation. The oscillation frequency is changed on the basis of dielectric constant information on the dielectric constant of the ink.
    Type: Application
    Filed: July 1, 2002
    Publication date: January 2, 2003
    Applicant: Riso Kagaku Corporation
    Inventor: Hideaki Inoue
  • Patent number: 6484630
    Abstract: A stencil printing machine 1 is provided with a stencil drum 16 and a opposite 17 which are a pair of cylindrical parts located with their external peripheral surfaces being close to each other, a stencil sheet 15 being detachably wound on the external peripheral surface of the stencil drum 16, and serves to perform stencil printing process by rotating the stencil drum 16 and the opposite 17 in order that the external peripheral surfaces thereof are located close to each other and moved in the same direction while the stencil sheet 15 is pressed against the opposite 17, and by making the stencil sheet 15 in contact under pressure with a sheet of paper 22 passing between the stencil drum 16 and the opposite 17 by the pressing force of the stencil drum 16. The stencil drum 16 is detachably mounted on the stencil printing machine and provided with storage units 201 to 203 for storing information about the pressing force of the stencil drum 16 against the opposite 17.
    Type: Grant
    Filed: December 27, 2000
    Date of Patent: November 26, 2002
    Assignee: Riso Kagaku Corporation
    Inventors: Koji Nakayama, Hideharu Yoneoka
  • Patent number: 6477946
    Abstract: A stencil printing machine of the present invention has an inner press roller (47) arranged in the inside of a printing drum (16), an inner press mechanism (20) for shifting the inner press roller (47) between a pressure position (B) and a standby position and for adjusting a pressure power of the inner press roller (47) at the pressure position (B). At the pressure position (B), the inner press roller (47) presses the inner peripheral surface of a screen (19) forming a peripheral wall of the printing drum (16). At the standby position, the inner press roller (47) is separated from the inner peripheral surface. During printing, the inner press roller (47) is positioned at the pressure position (B) at which the inner press roller (47) presses the inner peripheral surface of the screen (19). The inner press mechanism (20) has an ink supply unit (38) arranged at the inside of the printing drum (16) in order to shift the inner press roller (47) between the pressure position (B) and the standby position.
    Type: Grant
    Filed: September 11, 2000
    Date of Patent: November 12, 2002
    Assignee: Riso Kagaku Corporation
    Inventor: Masaharu Ogata
  • Patent number: 6458211
    Abstract: The invention relates to a device and to a method for applying a medium in the form of liquid, powder or paste to a substrate, having a container for the medium and a transport device which takes the medium from the container and discretely distributes it. In a propelling device the medium is selectively transferred from the transport device to the substrate with a propellant which is separate from the medium, or in the propelling device the medium is selectively removed from the transport device, and the remaining medium is transferred from the transport device to the substrate.
    Type: Grant
    Filed: August 14, 2000
    Date of Patent: October 1, 2002
    Assignee: Stork Textile Printing Group B.V.
    Inventors: Lothar Wefers, Josef Juffinger
  • Patent number: 6446551
    Abstract: A regenerable stencil printing plate is provided, which can be repeatedly used in master making and printing. The stencil printing plate comprises a film made of a polymeric material that shrinks in response to a stimulus selected from heat and light, and numerous fine apertures are formed in the film in cross sectional direction thereof. Preferably, the polymeric material is mainly composed of a polymer selected from acrylamide based polymers, vinyl ether based polymers, and oxide based polymers. Stencil printing is performed by providing the film, giving the above stimulus to the film in such a manner that a desired image is traced on the film to expand said apertures selectively at sites to which said stimulus is given, and allowing an image forming material to pass through the thus expanded apertures to transfer the image forming material to a recording medium.
    Type: Grant
    Filed: October 8, 1999
    Date of Patent: September 10, 2002
    Assignee: Riso Kagaku Corporation
    Inventor: Hideo Watanabe
  • Publication number: 20020050217
    Abstract: A printing-agent replenishing device including a replenisher which has a container for accommodating a printing agent and a delivery nozzle disposed at one end of the container and which is operable to delivery the printing agent from the delivery nozzle, for replenishing a printing-agent replenishment object in a screen printer, the device further including a cutting wire for cutting off a mass of the printing agent which extends from a free end of the delivery nozzle, and a cutting-wire holding device which holds the cutting wire such that the cutting wire is held in contact with or in close proximity to the free end face of the delivery nozzle, so as to traverse an opening in the free end face, and such that the cutting wire is rotatable about an axis substantially aligned with an axis of the delivery nozzle.
    Type: Application
    Filed: October 26, 2001
    Publication date: May 2, 2002
    Applicant: FUJI MACHINE MFG. CO., LTD
    Inventors: Toshinori Shimizu, Manabu Mizuno, Jun Adachi
  • Publication number: 20020043162
    Abstract: Improved air embossing systems, improved air lances, and improved methods of air embossing fabrics, which are able to produce an unprecedented level of fine detail, crisp transition between unembossed and embossed regions, lack of undesired embossing artifacts, and a high degree of uniformity across the width of an embossed fabric, when compared to the performance of typical, conventional air embossing systems are disclosed. The disclosed air embossing systems utilize generally cylindrical, rotating stencils with air lances positioned therein for directing a stream of air through apertures in the stencil and onto the embossable surface of a fabric.
    Type: Application
    Filed: August 3, 2001
    Publication date: April 18, 2002
    Inventors: William Laird, Kevin R. Crompton
  • Patent number: 6336401
    Abstract: A stencil printer of the type including a print drum around which a master is to be wrapped is disclosed. A press roller presses a paper sheet or similar recording medium against the master wrapped around the print drum. A press roller displacing device moves the press roller between an operative position where it presses the recording medium against the master and an inoperative position where it is spaced from the print drum. A press roller driving device causes the press roller held at the inoperative position to rotate, at a position where the roller faces the print drum, in the same direction as the direction in which the drum rotates during printing. The press roller driving device causes the press roller to rotate only when the roller is held at the inoperative position. The printer is capable of effecting preliminary rotation of the press roller at a stable, accurate speed with a relatively simple configuration while freeing the master, recording medium and print drum from loads.
    Type: Grant
    Filed: June 22, 2000
    Date of Patent: January 8, 2002
    Assignee: Tohoku Ricoh Co., Ltd.
    Inventor: Daisuke Hasebe
  • Publication number: 20010052298
    Abstract: A stencil printing machine is provided as including first and second printing drums 25 and 26 carrying thereon respective screens30, a press drum 27 located in close proximity to the printing drums and a stencil making unit 9. In a control method, the stencil making unit 9 supplies a perforated stencil sheet 11a onto a selected printing drum 25 and a non-perforated stencil sheet 11b onto a non-selected printing drum 26, wherein a print sheet 41 clamped to the press drum 27 is transferred along an outer periphery of the press drum 27 to allow the perforated stencil sheet of the first printing drum 25 to transfer printing ink with a first color to the print sheet 41 while the non-perforated stencil sheet mounted onto the second printing drum prevents printing ink to be transferred to the print sheet 41.
    Type: Application
    Filed: May 7, 2001
    Publication date: December 20, 2001
    Inventors: Hiroshi Watanabe, Yoshikazu Hara
  • Publication number: 20010042457
    Abstract: A stencil printing machine and a control method is provided wherein first and second printing drums 25 and 26 are rotatably supported in close proximity to an outer periphery of a press drum 27 at positions spaced by a given angle, wherein outer circumferential peripheral walls of the first and second printing drums 25 and 26 carry stencil clamping bases 28, respectively, and inner press rollers 33 are located inside the printing drums 25 and 26, respectively. During printing operation, the printing drums 25 and 26 are rotated with a rotational phase angle of 180 degrees relative to the press drum and, at termination of printing operation, the printing drums 25 and 26 are stopped at respective stationary rest positions which are out of ink stain zones of respective printing drums.
    Type: Application
    Filed: May 2, 2001
    Publication date: November 22, 2001
    Inventor: Hiroshi Watanabe
  • Patent number: 6314877
    Abstract: In a printer including a plurality of print drums sequentially arranged in a direction of sheet conveyance, a member causative of noticeable variation in load during printing is driven by a driveline assigned to one print drum that is connected to a main drive source. The printer reduces synchronization errors between the print drums ascribable to variation in load and therefore reduces offset ghosts while making the most of the advantages of a timing belt type drive system.
    Type: Grant
    Filed: June 27, 2000
    Date of Patent: November 13, 2001
    Assignee: Tohoku Ricoh Co., Ltd.
    Inventor: Hironobu Takasawa
  • Patent number: 6311614
    Abstract: According to the stencil printing machine of the present invention, ink that has entered the gap between a circumferential wall and a stencil sheet is allowed to escape to the outsides of an inner pressing roll in the axis direction. When it reaches the outer circumferential face of an ink free passage section of a screen, the escape ink is allowed to pass through the ink free passage section by a pressing force from the pressure drum, and directed to the inner circumferential side; therefore, it is possible to prevent the escape ink from reaching the right and left ends of the stencil sheet, and consequently to eliminate the limitation to the number of prints in endurance printing processes that is imposed due to ink leakage from the stencil. Moreover, since it is not necessary to form a raised portion along the circumferential face, the printing drum can be easily manufactured at low costs.
    Type: Grant
    Filed: September 14, 2000
    Date of Patent: November 6, 2001
    Assignee: Riso Kagaku Corporation
    Inventors: Masaharu Ogata, Koji Nakayama
  • Publication number: 20010032555
    Abstract: A stencil printing apparatus prevented from being irregular in printing density between the central portion and the marginal portions of the printing area of a printing drum is provided. The stencil printing apparatus comprises a cylindrical printing drum having an ink-passable circumferential wall, an inner roller disposed inside the printing drum for supplying ink to an inner circumferential surface of the circumferential wall, and an outer roller disposed outside the printing drum in opposite to the inner roller. The inner roller is disposed at a gap of 0.9 mm or less, preferably 0.3 mm or less from the inner circumferential surface of the circumferential wall, and the outer roller is larger in diameter than the inner roller.
    Type: Application
    Filed: March 19, 2001
    Publication date: October 25, 2001
    Inventors: Takashi Isozaki, Hirohide Hashimoto
  • Patent number: 6304279
    Abstract: An additive is dispersed in a matrix having a larger thermal expansion coefficient, which forms a film that prevents the permeation of the ink at the room temperature while allowing the permeation of the ink at high temperature. An ink roller is formed by covering a roller-like sponge body containing ink (an ink holder) with the film. Along the outer circumference of the ink roller, a thermal head that heats the surface of the ink roller according to a print pattern and a platen roller that sandwiches recording sheet between itself and the ink roller are disposed. Then, by rotating the ink roller and heating the thermal head, the ink permeates through the heated part of the film and is transferred to the recording sheet to form an ink image on the recording sheet.
    Type: Grant
    Filed: March 21, 2000
    Date of Patent: October 16, 2001
    Assignee: Asahi Kogaku Kogyo Kabushiki Kaisha
    Inventor: Minoru Suzuki
  • Patent number: 6293190
    Abstract: A stencil printer operable with a master wrapped around a print drum includes a rotatable print drum. An ink roller is rotatable in the same direction as the print drum for feeding ink to the inner periphery of the drum. An ink replenishing roller is rotatable in the same direction as the print drum and ink roller and movable between a first position where it is spaced from the inner periphery of the drum and ink roller and a second position where it contacts the inner periphery of the drum and ink roller. An ink collecting member is located downstream of the ink replenishing roller in the direction of rotation of the print drum and movable in interlocked relation to the ink replenishing roller. The printer is capable of surely removing excess ink from the inner periphery of the print drum and desirably forming even the first image after a long time of suspension.
    Type: Grant
    Filed: January 31, 2000
    Date of Patent: September 25, 2001
    Assignee: Tohoku Ricoh Co., Ltd.
    Inventor: Michihiro Yashima
  • Patent number: 6289812
    Abstract: A printing process including applying a composition to a substrate using a digital or stencil duplicator, the composition including a dispersion of particles of a thermoplastic or thermosetting polymer dispersed in an involatile organic liquid, where the size of the particles in the composition is less than 35 &mgr;m.
    Type: Grant
    Filed: October 2, 1998
    Date of Patent: September 18, 2001
    Assignee: G. R. Advanced Materials Ltd.
    Inventors: John Christopher Adams, John Hamilton
  • Patent number: 6283020
    Abstract: The stencil printing apparatus of the present invention is provided with a stencil making section for perforating each stencil sheet with a desired image pattern, a porous structure printing drum incorporating an ink supply mechanism and coming to have a stencil sheet perforated in the stencil making section to be wound thereon, a sheet supply section for supplying print sheets, a roller for pinching the print sheet supplied from the sheet supply section between the printing drum and itself, and time counting means for counting the rest time of the stencil printing apparatus.
    Type: Grant
    Filed: April 6, 2000
    Date of Patent: September 4, 2001
    Assignee: Riso Kagaku Corporation
    Inventor: Katsumi Ohno
  • Patent number: 6276268
    Abstract: In order to provide a drum type printer having a mechanism for adjusting a transverse position of a printed image improved such that when a plurality of drawout type drum units are used in the drum type printer, the transverse position of the printed image once adjusted with respect to each drum unit is preserved in each drum unit, wherein the adjustment of the position of the frame means 86 supporting the printing drum 10 relative to the machine frame 24 along the central axis of the printing drum is adjusted by an axial shifting of the shaft member 116 relative to the frame means 86, a shaft member 116 being latched at its one end to the machine frame 24.
    Type: Grant
    Filed: February 7, 2000
    Date of Patent: August 21, 2001
    Assignee: Riso Kagaku Corporation
    Inventors: Yasuhiro Takahashi, Katsuro Motoe, Hitoshi Watanabe
  • Patent number: 6263296
    Abstract: A method for predicting printing density for use in a stencil printing in which an ink is transferred from a rotated printing drum to a printing sheet through a perforated stencil, by pressing the printing sheet and the printing drum against each other, is provided. The method comprises (a) a first step of measuring printing densities (OD) on at least two copies of print at corresponding printed portions thereof, the copies of print being obtained under different conditions of F/f, in which F is a pressing force at which the printing sheet is pressed to the drum and f is a rotation speed of the drum, (b) a second step of statistically processing the printing densities measured in the first step to obtain a function of printing density and F/f value, and (c) a third step of calculating a printing density at a desired pressing force and a desired rotation speed based on the function obtained in the second step.
    Type: Grant
    Filed: January 22, 1999
    Date of Patent: July 17, 2001
    Assignee: Riso Kagaku Corporation
    Inventor: Yasuo Nakamura
  • Publication number: 20010003953
    Abstract: A variable volume container includes a cylindrical main body having an end wall at an end thereof; an outlet projecting from an outer surface of said end wall for allowing a content to be supplied; a piston member fitted into said main body sealingly and slidably in an axial direction of said main body for defining a variable volume storage chamber between itself and said end wall; a plug member detachably mounted to said outlet; and an impact resisting reinforcement disposed at said end wall. The reinforcement may be a part of said end wall having a thickness gradually increased toward said outlet, or may be a rib shaped projection. Such a variable volume container placed upside down in packaging or transport is reinforced at the end wall of the main body where the outlet is disposed. Thus, impact is not concentrated at the root portion of the outlet but distributed, so that the outlet is prevented from being damaged, and the container is placed more stably.
    Type: Application
    Filed: December 11, 2000
    Publication date: June 21, 2001
    Inventors: Takahiro Wakayama, Takeshi Hirohira
  • Patent number: 6202554
    Abstract: An intaglio printing press comprises a plate cylinder having an intaglio plate mounted on a circumferential surface of the plate cylinder; an impression cylinder contacted with the plate cylinder; an ink collecting cylinder contacted with the plate cylinder and having a blanket mounted on a circumferential surface of the ink collecting cylinder; a chablon roller, intermediate rollers, an ink fountain roller, and an ink fountain, as a first ink supply means for supplying ordinary ink to the blanket of the ink collecting cylinder; a rubber roller, and a rotary screen, as a second ink supply means, contacted with the plate cylinder, for supplying special ink to the intaglio plate; and a wiping roller contacted with the plate cylinder. This intaglio printing press can use special ink with high efficiency.
    Type: Grant
    Filed: August 18, 1999
    Date of Patent: March 20, 2001
    Assignee: Komori Corporation
    Inventor: Hiroyoshi Kamoda
  • Patent number: 6186062
    Abstract: The stencil printing apparatus of the present invention is provided with a stencil making section for perforating each stencil sheet with a desired image pattern, a porous structure printing drum incorporating an ink supply mechanism and coming to have a stencil sheet perforated in the stencil making section to be wound thereon, a sheet supply section for supplying print sheets, a roller for pinching the print sheet supplied from the sheet supply section between the printing drum and itself, and time counting means for counting the rest time of the stencil printing apparatus.
    Type: Grant
    Filed: April 6, 2000
    Date of Patent: February 13, 2001
    Assignee: Riso Kagaku Corporation
    Inventor: Katsumi Ohno
  • Patent number: 6155165
    Abstract: A rotary screen printing cylinder including a cylindrical screen, a squeegee disposed within the screen, and two end pieces each fastened as an extension of the cylindrical surface of the screen. The screen cylinder has at least two zones which are provided with color-permeable openings at least in partial areas and are separated by a color-impermeable dead zone of predetermined width. The dead zone is designed so as to give the screen cylinder stability.
    Type: Grant
    Filed: May 2, 1996
    Date of Patent: December 5, 2000
    Assignee: Giesecke & Devrient GmbH
    Inventor: Wittich Kaule
  • Patent number: 6123022
    Abstract: A stencil printing machine includes a printing drum rotationally driven around a central axis thereof and adapted to receive a perforated stencil sheet around an outer circumferential surface thereof, an ink container detachably attached to the printing drum, the ink container having ink therein, an ink supplying device situated inside the printing drum to be seen through an opening formed in the printing drum when the ink container is detached from the printing drum, the ink supplying device supplying the ink to an inner circumferential surface of the printing drum, and a lightening device for lightening the ink supplying device when the ink container is detached from the printing drum.
    Type: Grant
    Filed: October 22, 1999
    Date of Patent: September 26, 2000
    Assignee: Riso Kagaku Corporation
    Inventor: Atsushi Takata
  • Patent number: 6101936
    Abstract: A squeegee for a screen-printing machine, in particular a rotary screen-printing machine, comprises a supporting part, which can in principle be attached permanently to the frame of a screen-printing machine, as well as a removable part, which is detachably connected to the supporting part. The supporting part is designed as a rigid bar which extends in the longitudinal direction of the squeegee. The removable part is displaceable in the longitudinal direction with respect to the supporting part. The removable part forms the active squeegee part. The supporting part may be of rigid design, while the removable part may be of lightweight design. The removable part comprises in particular those components which regularly have to be removed from the screen-printing machine.
    Type: Grant
    Filed: February 12, 1998
    Date of Patent: August 15, 2000
    Assignee: Stork Brabant B.V.
    Inventor: Wilhelmus J.A.L.M. Claassen
  • Patent number: 6101935
    Abstract: A press roller for a stencil printer of the present invention is rotatable while pressing a recording medium against an ink drum which is rotatable with a master wrapped therearound. The press drum includes a hollow cylinder and an elastic layer formed on the outer periphery of the hollow cylinder. The elastic layer has a higher compressibility than a recording medium and performs, when compressed, elastic deformation in place of bulk movement. With this configuration, the press drum protects the master from damage ascribable to the localization of a pressing force. In addition, the press drum prevents a recording medium from creasing due to a difference in linear velocity otherwise occurring between the press drum and the recording medium at a pressing position.
    Type: Grant
    Filed: August 7, 1998
    Date of Patent: August 15, 2000
    Assignee: Tohoku Ricoh Co., Ltd.
    Inventor: Eiji Ohkawa
  • Patent number: 6098546
    Abstract: For security printing of documents, in particular banknotes, by printing a sheet or web using intaglio technology, an ink image is applied to transfer rollers (6) using rotary screen printing technology, said ink image is transferred from the transfer rollers to one or more intaglio plates which are provided with engravings and are fixed in or on the shell of a plate cylinder, and the ink present in the engravings of the intaglio plates is transferred to a sheet or web pressed against the plate cylinder (1) by a counter pressure cylinder (8).
    Type: Grant
    Filed: February 22, 1999
    Date of Patent: August 8, 2000
    Inventor: Karel Johan Schell
  • Patent number: 6076458
    Abstract: The stencil printing apparatus of the present invention is provided with a stencil making section for perforating each stencil sheet with a desired image pattern, a porous structure printing drum incorporating an ink supply mechanism and coming to have a stencil sheet perforated in the stencil making section to be wound thereon, a sheet supply section for supplying print sheets, a roller for pinching the print sheet supplied from the sheet supply section between the printing drum and itself, and time counting means for counting the rest time of the stencil printing, apparatus.
    Type: Grant
    Filed: March 18, 1999
    Date of Patent: June 20, 2000
    Assignee: Riso Kagaku Corporation
    Inventor: Katsumi Ohno
  • Patent number: 6032578
    Abstract: In a stencil printing in which a perforated stencil sheet is wound around a circumferential surface of a printing drum to which an ink is supplied, and the ink is transferred from the printing drum to a printing sheet through the perforated stencil sheet by pressing the printing sheet to the printing drum while the drum is rotated, a method for controlling a printing density is provided, which comprises controlling an amount of an ink transferred to a printing sheet by selecting a specific value of D from a range predetermined in accordance with the following equation:D=.sqroot. (F/f)in which F is a possible range of pressing force at which the printing sheet is pressed to the drum, and f is a possible range of rotation speed of the drum.
    Type: Grant
    Filed: September 16, 1998
    Date of Patent: March 7, 2000
    Assignee: Riso Kagaku Corporation
    Inventor: Yasuo Nakamura
  • Patent number: 5937750
    Abstract: A stencil printer of the present invention includes a print drum and a pressing member. After a cut stencil or master has been wrapped around the print drum, the pressing member presses a paper or similar recording medium against the master. As a result, ink fed to the print drum oozes out to the paper and prints a desired image thereon. When the pressing member presses the paper against the master, an electric field is formed between the pressing member and the print drum in the direction in which the ink migrates from the drum to the paper. The printer is capable of adjusting image density without varying a mechanical pressure to act on the drum or varying the print speed.
    Type: Grant
    Filed: May 21, 1997
    Date of Patent: August 17, 1999
    Assignee: Tohoku Ricoh Co., Ltd.
    Inventor: Fuchio Takeda
  • Patent number: 5931090
    Abstract: A printer of the type wrapping a master around a print drum and pressing a sheet against the master with the print drum or a press drum is disclosed. A pulse encoder is mounted on the press drum for sensing changes in the rotation speed of the press drum, so that a timing for feeding the leading edge of the sheet toward a clamper can be controlled. The clamper is capable of surely clamping the leading edge of a sheet and preventing it from rolling up. The sheet can be fed stably and reliably and can therefore be brought into accurate registration.
    Type: Grant
    Filed: March 17, 1998
    Date of Patent: August 3, 1999
    Assignee: Tohoku Ricoh Co., Ltd.
    Inventor: Eiji Ohkawa
  • Patent number: 5806423
    Abstract: A roller squeegee apparatus for screen printing includes a resilient receptacle receiving a supply of printing material at one open side thereof. The resilient receptacle is connected at another open side thereof to a printing squeegee. One or more driven rollers are provided for squeezing the elastic receptacle for providing consistent and stable printing operations. Such arrangement of the roller squeegee apparatus provides relatively high printing precision even over long periods of continuous use.
    Type: Grant
    Filed: March 24, 1997
    Date of Patent: September 15, 1998
    Assignee: Tani Electronics Industry Co., Ltd.
    Inventor: Okie Tani
  • Patent number: 5782178
    Abstract: A stencil printer of the present invention is selectively operable in a simplex print mode or a duplex print mode and includes two drums. The drums each has a respective master support on its circumferential surface. The master supports of the two drums are movable into and out of contact with each other without the distance between the shafts of the drums being changed. In the duplex print mode, the master supports contact each other with the intermediary of a paper so as to print images on both sides of the paper at the same time. The printer obviates noise and insures high image quality.
    Type: Grant
    Filed: June 23, 1997
    Date of Patent: July 21, 1998
    Assignee: Tohoku Ricoh Co., Ltd.
    Inventor: Tomoya Otomo
  • Patent number: 5771800
    Abstract: In an ink supply control device for a stencil printing machine which controls the supply of printing ink to an ink reservoir formed in a printing drum according to a signal produced from an ink amount detecting device which produces a first signal when the amount of ink stored in the ink reservoir is detected to be greater than a prescribed level, and a second signal when the amount of ink stored in the ink reservoir is detected to be less than the prescribed level, time durations of the first and second signals over a certain time interval or a certain interval of the rotation of the angle of the printing drum are evaluated as a basis for determining true insufficiency of the level of the printing ink in the ink reservoir through an arithmetic computation to the end of preventing erroneous detection by the ink amount detecting device from adversely affecting the control of the supply of printing ink in the ink reservoir.
    Type: Grant
    Filed: May 2, 1994
    Date of Patent: June 30, 1998
    Assignee: Riso Kagaku Corporation
    Inventors: Noboru Inamine, Atsushi Harada
  • Patent number: 5730050
    Abstract: In an ink blocking member for a rotary stencil printing machine in which a printing drum has a printing region which is ink-permeable and a non-printing region which is not ink-permeable, for closing a part of the printing region, the ink blocking member is provided on the outer surface of the rear part of the printing region as viewed in the direction of rotation of the printing drum. The ink blocking member defines a space on the outer surface of the printing region of the printing drum which is opened in the direction of rotation of the printing drum, and which is communicated through the printing region with the inside of the printing drum. The ink blocking member is restorable in configuration to maintain the space constant in volume.
    Type: Grant
    Filed: November 28, 1995
    Date of Patent: March 24, 1998
    Assignee: Riso Kagaku Corporation
    Inventor: Hiroyasu Kato
  • Patent number: 5722322
    Abstract: The present invention provides a stencil printing process for printing an object to be printed by passing an ink through perforations made in a stencil sheet which has undergone plate-making which includes the following steps: supplying a solid ink capable of causing a phase change into a liquid state at a temperature of 30.degree.-150.degree. C. into a liquid ink having a viscosity of 10-1,000,000 cps with heat during printing; and passing the liquid ink through perforations made in a stencil sheet within a time of 0.001-10 seconds while pressing the stencil sheet against the object to be printed with a pressure of 0.01-10 kg/cm.sup.2 so as to transfer the ink onto the object. The invention also provides a water-in-oil (W/O) emulsion ink for stencil printing containing 10-90% by weight of an oil phase and 90-10% by weight of an aqueous phase, wherein the oil phase includes a compound capable of causing a phase change from a solid state to a liquid state by being heated to a temperature of 30.degree.-100.
    Type: Grant
    Filed: February 28, 1996
    Date of Patent: March 3, 1998
    Assignee: Riso Kagaku Corporation
    Inventor: Hideo Watanabe
  • Patent number: 5713275
    Abstract: A stencil printing machine includes a holding device for holding a stencil sheet perforated in accordance with an image; an ink supply device for supplying ink to one face side of the stencil sheet held by the holding means; a printing sheet conveying device for conveying a printing sheet in a predetermined direction near an opposite face side of the stencil sheet; and an air ejection means for ejecting air to the stencil sheet from the one face side of the stencil sheet and thereby causing the ink to pass through the image in the stencil sheet and transfer onto the printing sheet.
    Type: Grant
    Filed: June 10, 1996
    Date of Patent: February 3, 1998
    Assignee: Riso Kagaku Corporation
    Inventor: Ryoichi Imai
  • Patent number: 5699731
    Abstract: In a stencil printing machine, when quantity of ink supplied into an ink supplying section in a rotary cylindrical drum is smaller than a predetermine value, ink complementing means is driven to supply ink from an ink storing container into the ink supplying section, and when the quantity of ink in the ink supplying section does not reach the predetermined value within an ink-complementing-means operation time, a determination is made that no ink is left in the ink storing container, and a warning signal is produced.
    Type: Grant
    Filed: July 26, 1996
    Date of Patent: December 23, 1997
    Assignee: Riso Kagaku Corporation
    Inventor: Yoshikazu Hara
  • Patent number: 5690027
    Abstract: In a stencil printer having a printing drum 10 which has a circumferential wall portion for mounting a stencil sheet made of a flexible sheet member 20 and including a perforated portion 20c, an inking roller 12 provided inside of the printing drum for supplying ink to the printing drum from its inside, and a back press roller 14 for supporting a print sheet against the printing drum by holding a leading end of the print sheet by clamps 25, a strip of elastic sheet 52 is provided to prevent ink leakage from the perforated portion 20c of the printing drum due to insufficient support of the print sheet by the back press roller at the portion of the clamps 25.
    Type: Grant
    Filed: July 24, 1996
    Date of Patent: November 25, 1997
    Assignee: Riso Kagaku Corporation
    Inventors: Yasuhiro Takahashi, Koji Nakayama
  • Patent number: 5669298
    Abstract: In a stencil printer having a printing drum 10 which has a circumferential wall portion for mounting a stencil sheet made of a flexible sheet member 20 and including a perforated portion 20c, an inking roller 12 provided inside of the printing drum for supplying ink to the printing drum from its inside with radially shifting out the perforated portion, and a back press roller 14 for supporting a print sheet against the printing drum by holding a leading end of the print sheet by a clamp 25, a means is provided for restricting the radial shifting out of the inking roller 12 when the inking roller is opposed by the clamp 25 to prevent ink leakage from the perforated portion 20c of the printing drum due to insufficient support of the print sheet by the back press roller 14 at the portion of the clamp 25. As an embodiment, an annular cam follower 23 mounted on the inking roller 12 is engaged by a cam 48 mounted on the back press roller.
    Type: Grant
    Filed: July 25, 1996
    Date of Patent: September 23, 1997
    Assignee: Riso Kagaku Corporation
    Inventors: Hideo Negishi, Katsuro Motoe
  • Patent number: 5603260
    Abstract: 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.
    Type: Grant
    Filed: December 5, 1995
    Date of Patent: February 18, 1997
    Assignee: Riso Kagaku Corporation
    Inventors: Yoshiharu Ohinata, Yasuhiro Takahashi, Yoshihiro Noguchi
  • Patent number: 5601019
    Abstract: 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.
    Type: Grant
    Filed: December 5, 1995
    Date of Patent: February 11, 1997
    Assignee: Riso Kagaku Corporation
    Inventors: Yoshiharu Ohinata, Yasuhiro Takahashi, Yoshihiro Noguchi
  • Patent number: 5595114
    Abstract: 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 slo
    Type: Grant
    Filed: March 20, 1995
    Date of Patent: January 21, 1997
    Assignee: Riso Kagaku Corporation
    Inventors: Hideo Negishi, Yoshiharu Ohinata
  • Patent number: 5579689
    Abstract: A printing drum for a rotary stencil printer having a sidewall in the form of a flexible perforated sheet. In order to allow for a bulging out deformation of the sidewall by an internal press roller to be easier and more uniform over the entire width of the printing, the flexible cylindrical body of the printing drum has its opposite side edge portions seated around the outer circumferential surfaces of a pair of annular portions (10a, 10b). The drum is constructed to have an inner circumferential length greater than the circumferential length of the outer circumferential surface of the annular portions by a predetermined amount which allows for a predetermined bulging out deformation of the flexible cylindrical body.
    Type: Grant
    Filed: November 1, 1994
    Date of Patent: December 3, 1996
    Assignee: Riso Kagaku Corporation
    Inventors: Yoshihara Ohinata, Nagon Takita, Hideo Negishi
  • Patent number: 5572928
    Abstract: A rotary stencil printing machine is formed of a cylindrical member, a clamping device formed on the cylindrical member for clamping a leading edge portion of a stencil sheet, and a back-up device provided outside the cylindrical member. The back-up device grips a printing sheet together with the cylindrical member to transfer the same. The cylindrical member includes a cylindrical peripheral surface for mounting thereon the stencil sheet; a first ink-pervious area formed on the peripheral surface on which an image forming area of the stencil sheet is disposed; at least one second ink-pervious area formed on the peripheral surface on which a trailing edge portion of the stencil sheet is disposed; and at least two first ink-impervious areas formed on the peripheral surface. The second ink-pervious area has an elongated shape continuously extending parallel to a center axis of the cylindrical member, and the ink-impervious areas sandwiches the second ink-pervious area.
    Type: Grant
    Filed: March 9, 1995
    Date of Patent: November 12, 1996
    Assignee: Riso Kagaku Corporation
    Inventor: Hideo Negishi
  • Patent number: 5566612
    Abstract: Disclosed is a mimeographic printing machine formed of a cylindrical printing drum which has an ink-previous area for passing ink from an inner peripheral surface to an outer peripheral surface, and is driven to rotate on the center axis of itself with a stencil paper wrapped around the outer peripheral surface; an ink supply device provided within the printing drum, for supplying the ink to the inner peripheral surface; a clamping device provided on the outer peripheral surface of the printing drum, for clamping on the printing drum a leading edge of the stencil paper wrapped around the outer peripheral surface; and a stencil paper holding device provided on the outer peripheral surface of the printing drum, for holding on the printing drum the leading edge of the stencil paper when the clamping device has released the stencil paper.
    Type: Grant
    Filed: July 27, 1995
    Date of Patent: October 22, 1996
    Assignee: Riso Kagaku Corporation
    Inventor: Yuji Satoh
  • Patent number: 5555802
    Abstract: 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
    Type: Grant
    Filed: November 1, 1994
    Date of Patent: September 17, 1996
    Assignee: Riso Kagaku Corporation
    Inventors: Yoshiharu Ohinata, Nagon Takita, Hideo Negishi
  • Patent number: 5537920
    Abstract: To allow data to be exchanged between a printing drum and a stencil printing device main body in a highly adaptable manner with regard to the increase in the kinds of data to be transmitted without requiring any change in mechanical structures, light emitting devices 43, 65 and light receiving devices 45, 63 are arranged in mutually opposing parts of the printing drum 7 and the main body frame 1 to allow optical communication between them. Other modes of wireless communication may be used in place of the optical communication. This invention is particularly useful when the printing drum 7 is detachably mounted on a main body frame 1 of the stencil printing device, and the main control unit is required to adapt itself to different printing drums.
    Type: Grant
    Filed: August 31, 1995
    Date of Patent: July 23, 1996
    Assignee: Riso Kagaku Corporation
    Inventors: Takanori Hasegawa, Junji Takahashi, Ryuji Higa
  • Patent number: 5517913
    Abstract: In a stencil printing device in which printing ink is supplied to the inner surface of a printing drum, and printing paper is pressed onto a stencil master plate sheet mounted on the outer circumferential surface of the printing drum by using a press roller for effecting a stencil printing on the printing paper, there are provided dip switches in the printing drum for identifying the type of the printing ink supplied to the inner surface of the printing drum, and the pressing force of the press roller against the printing drum is variably determined according to the detected type of the printing ink set on the dip switches so that a stencil printing is carried out with a prescribed printing density without regard to the type of ink, in particular the color of the printing ink used with the printing drum.
    Type: Grant
    Filed: December 20, 1993
    Date of Patent: May 21, 1996
    Assignee: Riso Kagaku Corporation
    Inventors: Susumu Oshio, Kenji Oshima