Rotary Machines Patents (Class 101/116)
  • Patent number: 6305281
    Abstract: A stencil printer includes a document size sensing device for sensing the size of a document and a paper size sensing device for sensing the size of papers. A controller determines the orientation and size of the document and those of the paper on the basis of information output from the two sensing devices. If the document and paper are different in orientation, the controller controls a master making section on the basis of the orientation of the papers for forming a document image in a master in accordance with the orientation of the paper. At the same time, the controller controls a side fence moving device and an end fence moving device such that side fences and an end fence mounted on a paper discharge tray each are located at a particular position matching with the size of the papers. The side fences are movable in the widthwise direction of the paper while the end fence is movable forward and backward in the direction of paper discharge.
    Type: Grant
    Filed: September 22, 1999
    Date of Patent: October 23, 2001
    Assignee: Tohoku Ricoh Co., Ltd.
    Inventor: Hidetoshi Aizawa
  • Publication number: 20010029850
    Abstract: A printer of the present invention includes a timing belt passed over drive pulleys, each of which is mounted on a particular print drum, via phase adjusting means and deflection pulleys or rotary members. The deflection pulleys are rotatable in contact with the rear surface of the timing belt. The timing belt has its rear surface ground to have uniform thickness. The printer is free from the deviation of relative phase between the rotary members and offset ghosts ascribable to the irregular thickness of the timing belt, while preserving the low-cost configuration of timing belt connection.
    Type: Application
    Filed: February 28, 2001
    Publication date: October 18, 2001
    Applicant: Tohoku Ricoh Co., Ltd.
    Inventors: Keiichi Chiba, Hironobu Takasawa
  • 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: 6302016
    Abstract: The machine comprises a paper sheet-feed device (1), a device (2) for transferring toward a printing unit, a device for transferring printed sheets toward a unit (8) for checking the print quality and a storage unit (10, 11, 12). The printing unit can be altered to suit different types of security printing and consists of elements common to all these different types of printing. These common elements are: a screen-printing device (3, 4) comprising a screen stencil cylinder (3) cooperating with a press cylinder (4) and a drying/activation device (5) located downstream, followed by a transfer cylinder (6) for transferring toward a second press cylinder (7). The latter cooperates with at least one device (13) for printing a security element.
    Type: Grant
    Filed: August 30, 1999
    Date of Patent: October 16, 2001
    Assignee: De La Rue Giori S.A.
    Inventors: Giori Fausto, Johannes Georg Schaede
  • Patent number: 6298778
    Abstract: A sheet feeding device for a printer, e.g., a stencil printer including an ink drum with a master wrapped therearound and a press drum one of which is pressed against the other during printing is disclosed. The sheet feeding device is capable of feeding a sheet at a preselected speed without regard to a print speed varying every moment due to various factors particular to an ink drum driveline, i.e., whether a set print speed is higher than a standard print speed or lower than the same. This successfully obviates the short loop of a sheet which would result in a skew or a feed failure. In addition, the device reduces noise at print speeds lower than the standard print speed and used more often than the other print speeds.
    Type: Grant
    Filed: November 3, 1999
    Date of Patent: October 9, 2001
    Assignee: Tohoku Ricoh Co., Ltd.
    Inventors: Takayuki Onodera, Hideki Asai
  • Patent number: 6295924
    Abstract: A stencil printing apparatus includes a main body, a drum unit having a drum substantially in a cylindrical shape and attachable to and detachable from the main body, a drum detecting device for detecting a kind of the drum unit mounted to the main body and a control device for carrying out an auto idling operation prior to a successive perforating operation in a case when a non-operational time period of the main body exceeds a previously set time period or when the drum detecting device detects interchanging of the drum unit.
    Type: Grant
    Filed: November 8, 1999
    Date of Patent: October 2, 2001
    Assignee: Riso Kagaku Corporation
    Inventors: Masahiro Nishihata, Yoshikazu Murayama, Yoshihiro Hayashi
  • Patent number: 6283021
    Abstract: According to the stencil making and attaching method of a printing device of the present invention, independent of variations in the detection of the stencil sheet set position detection sensor and variations in the clamped state due to curled stencil sheet, etc., it is possible to always set the image-formation start position of the stencil sheet at a regular position with respect to the drum rotation position, and consequently to improve the positional precision of the printing operation.
    Type: Grant
    Filed: September 11, 2000
    Date of Patent: September 4, 2001
    Assignee: Riso Kagaku Corporation
    Inventors: Hitoshi Watanabe, Kaoru Kimura, Masakazu Miyata
  • 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
  • Publication number: 20010015143
    Abstract: To pertinently control perforation and transfer (setting) of stencil sheet in correspondence with respectives of plural printing drums, perforated stencil sheet is set to plural printing drums by moving single stencil making unit, position of the stencil making unit is detected by position sensors and shield plate, printing drum information of ink color supplied to the respective printing drums is detected by printing drum information detecting means with regard to respective printing drums, the stencil making unit is made to be on standby as it is at a position of setting drum to which the stencil making unit has been transferred finally after finishing to transfer stencil sheet to the respective printing drums. At successive stencil making operation, stencil making instruction information expediting perforation to the operator, is displayed from the printing drum at standby position to displaying means.
    Type: Application
    Filed: February 12, 2001
    Publication date: August 23, 2001
    Inventor: Yasuhiro Takahashi
  • 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
  • Publication number: 20010013285
    Abstract: By making ON VSYNC signal, platen motor and feed motor are driven and thermosensitive perforation of stencil sheet is started. From the state, the platen motor is driven continuously for &ggr; second. When upstream side stencil sheet awaiting sensor is made ON and &agr; second has elapsed, feed of platen motor is controlled to reduce and actual perforation speed is made constant. Thereafter, when downstream side stencil sheet awaiting sensor is made ON and &agr; second has elapsed, feed motor is made OFF and stopped and lower side movable guide plate is moved to lower limit position by driving downstream side movable guide motor. Thereafter, when downstream side movable guide plate lower limit sensor is made ON, feed motor is made ON and driven again. When downstream side stencil sheet feed sensor is made ON and &dgr; second has elapsed, feed motor is made OFF and stopped.
    Type: Application
    Filed: February 12, 2001
    Publication date: August 16, 2001
    Inventor: Hideo Shoji
  • Patent number: 6263791
    Abstract: A stencil printer capable of printing an image on a paper or similar recording medium by causing ink to ooze out via the perforations of a master is disclosed. The printer includes an ink collecting device for collecting the ink from the circumference of an ink drum. The printer therefore maintains the circumference of the ink drum in a desirable condition and thereby reduces the number of waste papers as far as possible so as to reduced a printing cost.
    Type: Grant
    Filed: February 23, 1999
    Date of Patent: July 24, 2001
    Assignee: Tohoku Ricoh Co., Ltd.
    Inventor: Makoto Sato
  • Publication number: 20010007226
    Abstract: The disclosed stencil printing machine automatically judges the process to be executed by referring to the operation waiting state of the controller and its own operation waiting state. According to this disclosed structure, the user's operation of printing process is enhanced, and the efficiency of printing process is heightened.
    Type: Application
    Filed: January 4, 2001
    Publication date: July 12, 2001
    Inventor: Hideharu Yoneoka
  • Publication number: 20010007225
    Abstract: A printer including a plurality of print drums and capable of producing, e.g., color printings is disclosed. When a closed position sensor responsive to a door outputs a close signal and when a drum sensor assigned to a print drum to be mounted outputs an absence signal, a controller controls drum drive sections such that a mount/dismount drive section assigned to the print drum to be mounted takes the position corresponding to a mount position. Also, in response to a mount position signal output from a mount position sensor, the controller controls the drum driving device such that the mount/dismount drive section stops at the position corresponding to the mount position. The printer allows an operator thereof to mount the print drums without pressing, e.g., mount/dismount keys each time and thereby saves time.
    Type: Application
    Filed: November 30, 2000
    Publication date: July 12, 2001
    Inventor: Mituru Takahashi
  • Publication number: 20010006024
    Abstract: A stencil printer includes a stencil making system which makes a stencil by imagewise perforating a stencil material in a controlled position on the basis of an image signal, a printing system which makes prints by the use of the stencil made by the stencil making system and a control system which controls the stencil making system and the printing system. The control system is provided with a first stencil making position controller adapted to control of the stencil making position when a stencil is to be made on the basis of an internal image signal optically read out from an original, a second stencil making position controller adapted to control of the stencil making position when a stencil is to be made on the basis of an external image signal input through a path different from the path along which the internal image signal is input, and a selector which selectively makes active one of the first and second stencil making position controllers.
    Type: Application
    Filed: December 22, 2000
    Publication date: July 5, 2001
    Inventor: Hidetoshi Watanabe
  • Publication number: 20010004866
    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: Application
    Filed: December 27, 2000
    Publication date: June 28, 2001
    Inventors: Koji Nakayama, Hideharu Yoneoka
  • 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: 6247401
    Abstract: A stencil printer includes an ink drum having a hollow cylindrical porous support and a pair of flanges supporting opposite ends of the support. Annular elastic members are respectively affixed between the inner periphery of the porous support and the outer circumferences of the flanges. When the ink drum is pressed against a press roller, the elastic members deform and cause an ink roller disposed in the ink drum to be displaced. As a result, the ink roller contacts the inner periphery of the porous support brought into contact with and positioned by the press roller. The ink roller and the inner periphery of the ink drum can therefore contact each other under uniform pressure without the rigidity of the drum being reduced and without any shaking.
    Type: Grant
    Filed: August 13, 1999
    Date of Patent: June 19, 2001
    Assignee: Tohoku Ricoh Co., Ltd.
    Inventors: Mitsuo Sato, Masayuki Shima, Tomoya Otomo
  • Patent number: 6230617
    Abstract: A printer of the present invention is capable of stably conveying a perforated part of a stencil, or master, coming out of master making means to master clamping means mounted on an ink drum and surely handing it over to the master clamping means, and preventing the master from creasing during conveyance. Master holding means for holding the master is positioned upstream of, in a direction of master transport, cutting means used to cut the stencil at a preselected length.
    Type: Grant
    Filed: February 11, 1999
    Date of Patent: May 15, 2001
    Assignee: Tohoku Ricoh Co., Ltd.
    Inventor: Tomiya Mori
  • Patent number: 6227107
    Abstract: A stencil printer has a rotary printing drum removably supported in a printer body. A lamp is provided inside the printer body, and a control circuit permits, in response to an action necessary for maintenance of the printer body, the lamp means to be turned on.
    Type: Grant
    Filed: October 2, 1998
    Date of Patent: May 8, 2001
    Assignee: Riso Kagaku Corporation
    Inventors: Tetsuya Hashimoto, Toshihiro Bansyo, Masakazu Miyata, Hitoshi Watanabe
  • Patent number: 6227108
    Abstract: A magnet bar for exerting an attracting force on a doctor, which is arranged above the magnet bar, of a screen-printing or coating device comprises an elongate top plate and an elongate magnet carrier which extends below and substantially parallel to the top plate and on which permanent magnets are arranged next to one another in the longitudinal direction. The distance between the magnet carrier and the top plate can be adjusted by means of a displaceable adjustment member, which is arranged below the magnet carrier, in order to adjust the magnitude of the attracting force. The magnet carrier is supported freely on the adjustment member and the weight of the magnet carrier with magnets or the sum of the weight of the magnet carrier with magnets and the force of at least one spring acting upon the magnet carrier in downward direction is greater than the maximum attracting force which can be exerted by the magnets on a doctor which is arranged above the magnet bar.
    Type: Grant
    Filed: May 6, 1999
    Date of Patent: May 8, 2001
    Assignee: Stork Brabank B.V.
    Inventors: Henricus G. M. Kempen, Patrick G. L .H. Lagarde
  • Patent number: 6213014
    Abstract: A stencil printer has a printing drum which has an ink-permeable peripheral wall around which a stencil master is wound and to the inner surface of which ink is supplied. The printing drum is rotated about its longitudinal axis. An internal press roller is disposed inside the printing drum and is rotated in contact with the inner surface of the peripheral wall of the printing drum. A paper pinch drum is disposed outside the printing drum and is pressed against the peripheral wall of the printing drum with a printing paper pinched between the pinching means and the stencil master wound around the peripheral wall. A retainer roller is disposed in a predetermined position near the internal press roller and the inner surface of the peripheral wall downstream of the contact line between the internal press roller and the inner surface of the peripheral wall in the direction of rotation of the printing drum.
    Type: Grant
    Filed: September 29, 1999
    Date of Patent: April 10, 2001
    Assignee: Riso Kagaku Corporation
    Inventors: Katsuro Motoe, Koji Nakayama
  • Patent number: 6205918
    Abstract: A stencil printer includes a plurality of ink drums spaced from each other in the direction of paper conveyance and each having a respective master wrapped therearound. An upstream ink drum and pressing means movable into and out of contact with the upstream ink drum define an upstream print position. A downstream ink drum and pressing means movable into and out of contact with the downstream ink drum define a downstream print position. An intermediate conveyor is located between the upstream print position and the downstream print position for conveying a paper carrying an image printed at the upstream print position toward the downstream print position. A distance which the paper moves from the upstream print position to the downstream print position is longer than a distance between the upstream print position and the downstream print position. Defective printing is reduced even when the peripheral speed of the upstream ink drum and that of the downstream ink drum are different from each other.
    Type: Grant
    Filed: March 23, 1999
    Date of Patent: March 27, 2001
    Assignee: Tohoku Ricoh Co., Ltd.
    Inventors: Mituru Takahashi, Hideaki Matsuda
  • Patent number: 6199479
    Abstract: By preventing a deformation of printing drum of a rotary stencil printing apparatus caused at the time of printing, uniform printed images can be printed even under conditions such as low temperature and high-speed printing and even using an apparatus provided with a large-sized drum. That is, the invention provides a method for stencil printing which comprises winding a perforated stencil sheet around the peripheral wall of a cylindrical printing drum having an ink permeable peripheral wall and rotating around its central axis, supplying an ink to the peripheral wall from the inside of the drum at the time of rotation of the drum, and pressing a printing paper to the outer surface of the peripheral wall of the drum to transfer the ink to the printing paper through the stencil sheet, wherein the peripheral wall of the drum has such a strength that the peripheral wall shows a stress of 0.75 kgf/cm2 or more, preferably 1.4 kgf/cm2 or more when it is deformed by 0.
    Type: Grant
    Filed: October 15, 1999
    Date of Patent: March 13, 2001
    Assignee: Riso Kagaku Corporation
    Inventors: Takashi Isozaki, Hiroyasu Kato, Kenji Suzuki, Sadanao Okuda
  • Patent number: 6192793
    Abstract: A printing drum (12) is supported by a first frame (36) to be rotatable around its central axis (38). The first frame (36) is supported by a second frame (52) to be movable relative to the second frame (52) along the central axis (38) for at least a distance corresponding to a maximum value of an adjustment of a transverse position of a printed image. The second frame (52) is removably mounted to a machine frame (10), wherein the first frame (36) is moved relative to the second frame (52) only for a distance required for an adjustment of a transverse position of a printed image.
    Type: Grant
    Filed: December 23, 1999
    Date of Patent: February 27, 2001
    Assignee: Riso Kagaku Corporation
    Inventors: Katsuro Motoe, Hiroyasu Kato
  • 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: 6173646
    Abstract: A stencil printing machine has a printing drum having a cylindrical circumferential wall adapted to receive a perforated stencil sheet wrapped on an outer circumferential surface thereof and driven to rotate around a central axis thereof the circumferential wall having an opening portion with many through holes formed therein, a non-opening portion formed around the opening portion, and at least one recessed portion formed in at least one part of the opening portion adjacent to the non-opening portion in an axial direction of the circumferential wall; an ink supplying roller situated in the printing drum for supplying ink to an inner circumferential surface of the cylindrical circumferential wall of the printing drum; and a press roller situated adjacent to the printing drum and being urged against the outer circumferential surface of the cylindrical circumferential wall of the printing drum.
    Type: Grant
    Filed: June 8, 1999
    Date of Patent: January 16, 2001
    Assignee: Riso Kagaku Corporation
    Inventors: Yoshitaka Tanaka, Hideo Negishi
  • Patent number: 6158337
    Abstract: A stencil-making-type printing machine in which plural types of rotary cylindrical drums having printing regions of different sizes can be replaceable loaded, in which a stencil sheet provided in the form of a roll is cut according to the printing region of a rotary cylindrical drum loaded therein to form a printing stencil, and a printing operation is carried out with the printing stencil wound on the rotary cylindrical drum, and before a printing operation is carried out for a new original, a used stencil is separated from the rotary cylindrical drum and discarded into a used-stencil accommodating box by a conveying means. The printing machine comprises a control system which controls operating time of the conveying means depending on the loaded rotary cylindrical drum, thereby stopping the operation of the conveying means immediately after the stencil has been discarded in the accommodating box and surely accommodating the stencil in the accommodating box.
    Type: Grant
    Filed: June 30, 1998
    Date of Patent: December 12, 2000
    Assignee: Riso Kagaku Corporation
    Inventor: Yoshikazu Hara
  • 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: 6135023
    Abstract: A stencil printing machine includes a printing drum having a flexible ink-permeable circumferential wall adapted to receive a perforated stencil sheet around an outer circumferential surface thereof, the printing drum being rotated around a central axis thereof; a squeegee roller having an axis and situated inside the printing drum to be parallel to the central axis of the printing drum, the squeegee roller being rotated around the axis in synchronization with rotation of the printing drum with an outer circumferential surface thereof contacting an inner circumferential surface of the printing drum; a pair of bearing members attached to end portions of the axis of the squeegee roller for rotationally supporting the axis; a doctor roller having an axis and situated parallel to the squeegee roller at a predetermined distance away from the outer circumferential surface of the squeegee roller; a pair of adjusting screws situated perpendicular to the axis of the squeegee roller and fixed to the pair of bearing mem
    Type: Grant
    Filed: October 4, 1999
    Date of Patent: October 24, 2000
    Assignee: Riso Kagaku Corporation
    Inventor: Shiro Sato
  • Patent number: 6129013
    Abstract: A stencil printer of the present invention includes at least one ink drum for wrapping a master around its outer periphery. An ink feed device feeds ink to the master wrapped around the ink drum. A pressing member is movable into and out of contact with the ink drum at a position where it faces the ink feed device. An image is printed on a paper fed from a paper feed section at a print section where the ink drum and pressing member face each other. A belt conveyor includes a belt extending between the paper feed section located upstream of the print section in the direction of paper conveyance and a paper discharge section located downstream of the print section in the same direction through the print section. The belt conveys the paper fed from the paper feed section while causing it to electrostatically adhere thereto. The paper is sufficiently electrostatically adhered to the belt before it reaches the print section, so that air suction, an air knife, a separator or the like is not necessary.
    Type: Grant
    Filed: September 9, 1998
    Date of Patent: October 10, 2000
    Assignee: Tohoku Ricoh Co., Ltd.
    Inventors: Hironobu Takasawa, Mituru Takahashi, Naoki Okazaki
  • 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: 6109172
    Abstract: A machine including a printing cylinder (6) engaging two stencil cylinders (7, 18) for printing at least two non-overlapping areas in different colors using the one printing cylinder. One of the stencil cylinders (7) is conventional and enables silk-screen printing in a first area. The other cylinder (18) includes raised portions provided with a stencil for printing one or more further areas different from the first area while preventing the rest of the stencil cylinder (18) from contacting the printing cylinder and particularly the area(s) printed by the first cylinder (7).
    Type: Grant
    Filed: September 14, 1998
    Date of Patent: August 29, 2000
    Assignee: De La Rue Giori S.A.
    Inventor: Hans Wyssmann
  • 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: 6098536
    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 sheet clamper is arranged on the press drum. A timing sensing device for allowing the leading edge of the sheet to be fed toward the sheet clamper at a preselecting timing is arranged on the press drum or a member associated therewith. With this configuration, the printer causes the sheet clamper to surely clamp the leading edge of the sheet and prevents the sheet from rolling up. In addition, the printer feeds the sheet at a preselected timing with stability and reliability and thereby enhances accurate registration.
    Type: Grant
    Filed: February 18, 1998
    Date of Patent: August 8, 2000
    Assignee: Tohoku Ricoh Co., Ltd.
    Inventor: Eiji Ohkawa
  • Patent number: 6098537
    Abstract: In a stencil printer, in order to definitely prevent an ink leakage even when the perforated portion 20c of the printing drum laps over the clamp 25 of the back press roller 14, the portions of a part of the outer circumferential surface of the back press roller positioned adjacent to the rear and opposite side edges of the clamp 25 is provided by a movable circumferential member 66 adapted to bias rearward relative to the clamp in synchronization with the opening operation of the clamp, so as thereby to cancel the clearance formed along the periphery of the clamp without obstructing the opening operation of the clamp.
    Type: Grant
    Filed: June 19, 1998
    Date of Patent: August 8, 2000
    Assignee: Riso Kagaku Corporation
    Inventors: Koji Nakayama, Yasuhiro Takahashi
  • Patent number: 6095040
    Abstract: A stencil printer or similar printer and an ink viscosity sensing device therefor are disclosed. The viscosity of ink which is the root cause of the degradation of image equality ascribable to, e.g., temperature and down time is directly sensed. The viscosity is combined with other information including a set print speed and the kind of the ink in order to effect delicate print pressure control matching the actual conditions of the printer. Stable image quality with a minimum of fluctuation is achievable against the varying environment and without resorting to complicated control pattern tables or a number of sensors.
    Type: Grant
    Filed: March 7, 1997
    Date of Patent: August 1, 2000
    Assignee: Tohoku Ricoh Co., ltd.
    Inventors: Atsushi Ashikagaya, Takayuki Onodera
  • Patent number: 6092462
    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 such a polymeric material as polypyrrole and polythiophene which shrinks when it adsorbs a specific compound, and numerous fine apertures are formed in the film in cross sectional direction thereof. Stencil printing is performed by providing the stencil printing plate as mentioned above, transferring the compound to the film in such a manner that a desired image is reproduced to expand the apertures selectively at sites to which the compound is transferred, and allowing an image forming material to pass through the thus expanded apertures and transfer to a recording medium. The stencil printing plate can constitute an outer circumferentical surface of an ink-permeable cylindrical printing drum used in a conventional stencil printing apparatus.
    Type: Grant
    Filed: October 14, 1999
    Date of Patent: July 25, 2000
    Assignee: Riso Kagaku Corporation
    Inventor: Hideo Watanabe
  • Patent number: 6089150
    Abstract: In a stencil printing machine, one surface of a stencil sheet with a perforated image is placed in contact with an upper surface of a printing material. Ink is provided on the other surface of the stencil sheet. Suction force is exerted on a bottom surface of the printing material, so that the ink is allowed to pass through the perforated image and then transfer to the upper surface of the printing material, thereby completing stencil printing.
    Type: Grant
    Filed: September 24, 1998
    Date of Patent: July 18, 2000
    Assignee: Riso Kagaku Corporation
    Inventor: Koichi Uchiyama
  • Patent number: 6076460
    Abstract: A master making device of the present invention includes a support member supporting a stencil roll such that a stencil can be paid out from the roll. A thermal head perforates the stencil paid out from the roll while a platen roller rotates while pressing the stencil against the head. The support member, thermal head and platen are constructed into a master making unit. The master making unit is removably mounted to the body of a printer via rails. A broader space than is conventional is available for the stencil to be set or replaced or for a jam to be dealt with without a document reading section being displaced relative to the printer body.
    Type: Grant
    Filed: January 27, 1998
    Date of Patent: June 20, 2000
    Assignee: Tohoku Ricoh Co., Ltd.
    Inventor: Hideyuki Kagawa
  • Patent number: 6067901
    Abstract: A device for collecting waste or used masters and applicable to a stencil printer or similar printer is disclosed. The device includes a waste master box accommodating a compression plate therein. The compression plate is rotatable at least more than 90 degrees about a shaft on which it is mounted. Every time a waste master peeled off a print drum is introduced into the box, the compression plate rotates over the above angular range in order to compress the waste master. The box prevents consecutive waste masters sequentially compressed by the compression plate from being localized.
    Type: Grant
    Filed: September 9, 1997
    Date of Patent: May 30, 2000
    Assignee: Tohoku Ricoh Co., Ltd.
    Inventor: Takayuki Takahashi
  • Patent number: 6041705
    Abstract: A rotary silk screen printing machine or press with a modular design of the individual printing mechanisms and fully integrated control modules within a digital network system of the printing machine is set forth.As a result of the logical, modular design of the individual printing mechanisms, on a given printing machine base with a continuous conveyor belt fixed between two main rollers and which is driven by a main drive motor, it is possible to insert, replace and reprogram individual printing mechanisms. Both during the installation of a new printing system and when reequipping existing systems, considerable technical and economic advantages arise.
    Type: Grant
    Filed: December 17, 1998
    Date of Patent: March 28, 2000
    Inventor: Alexander Lintner
  • Patent number: 6038968
    Abstract: In a stencil printer, a printing drum is provided with a clamp plate for clamping an end portion of a stencil master, thereby holding the stencil master on the printing drum. A paper supply mechanism supplies printing sheets to the printing drum in synchronization with rotation of the printing drum. A first motor drives the paper supply mechanism by way of a first transmission mechanism, and a second transmission mechanism is operatively connected to the first transmission mechanism to be driven by the first motor by way of the first transmission mechanism, thereby rotating the printing drum. A phase adjustment mechanism driven by a second motor drives the second transmission mechanism with the first transmission mechanism held stopped, thereby changing the relative phases of rotation of the printing drum and sheet supply operation of the paper supply means. A drum position sensor generates a detecting signal upon detection that the printing drum comes to a reference position.
    Type: Grant
    Filed: August 17, 1998
    Date of Patent: March 21, 2000
    Assignee: Riso Kagaku Corporation
    Inventors: Yoshikazu Hara, Katsuro Motoe, Hisashi Sanagi
  • 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: 6026744
    Abstract: In stencil printing, a printing matrix is thermally made in a printing matrix area on a stencil material on the basis of image information representing an image on an original. The printing matrix area is determined according to the sheet size of printing paper sheet. The stencil thus obtained is wrapped around a printing drum and a printing paper sheet fed toward the printing drum is pressed against the printing drum by a pressure member. A memory which is provided on the printing drum side stores information on the area of the printing matrix. The sheet size is compared with the area of the printing matrix based on information extracted from the memory. When the former is smaller than the latter, printing is inhibited and an error signal which advises against printing is output.
    Type: Grant
    Filed: June 30, 1998
    Date of Patent: February 22, 2000
    Assignee: Riso Kagaku Corporation
    Inventor: Masakazu Miyata
  • Patent number: 6019036
    Abstract: A stencil printer of the present invention includes an ink drum and a press drum rotatable with a paper or similar recording means wrapped therearound while pressing the paper against the ink drum. A moving mechanism selectively moves the press drum into or out of contact with the ink drum in synchronism with the feed of the paper order to prevent the press drum from contacting the ink drum when the paper is absent therebetween. Even when the moving mechanism angularly moves the press drum, the press drum is free from a change in peripheral speed and can surely catch the leading edge of the paper. Drive transmission to the press drum is implemented by an Oldham coupling or a universal coupling.
    Type: Grant
    Filed: December 30, 1997
    Date of Patent: February 1, 2000
    Assignee: Tohoku Ricoh Co., Ltd.
    Inventor: Eiji Ohkawa
  • Patent number: 6009806
    Abstract: In the ink supply construction of a stencil printer, having an ink holding space 14 defined by an outer circumferential surface of an ink supply roller 4 and an ink supply control member 8, there is provided an ink interrupting member 30 as opposed to the ink supply control member across the ink holding space for restricting a side of the ink holding space opposite to the ink supply control member, in order to stabilize and highly uniformalize the cross sectional size of a rotating lump of ink L formed in the ink holding space along the length of the lump of ink. The lump of ink may be rotationally driven by an ink driving rod member 15 provided in the ink holding space. When the lump of ink is not rotationally driven by the ink driving rod member, the ink interrupting member may be constructed to rotationally drive the lump of ink.
    Type: Grant
    Filed: August 19, 1998
    Date of Patent: January 4, 2000
    Assignee: Riso Kagaku Corporation
    Inventors: Katsuro Motoe, Koji Nakayama
  • Patent number: 5992313
    Abstract: A doctor arrangement is located inside a rotary cylindrical screen for applying a substance to a moving web that is adjacent the rotary screen. The doctor is supported on a carrier beam that is mounted within the rotary screen. The substance is applied through the rotary screen onto the moving application surface with the doctor, which may be a roll doctor or doctor blade. The carrier beam is slidable along a longitudinal axis of the rotary screen into and out of the rotary screen through a through hole in a bearing of the rotary screen at one end of the apparatus. The carrier beam has guide rails that slide along guide rolls mounted outside the width of the application surface on bearings that the rotary screen. The carrier beam and doctor arrangement can be inserted and withdrawn from the rotary screen with the carrier beam in an elevated position wherein the doctor does not interfere with the rotary screen member.
    Type: Grant
    Filed: April 16, 1998
    Date of Patent: November 30, 1999
    Inventor: Johannes Zimmer
  • Patent number: 5988061
    Abstract: In a stencil printer, when a print drum reaches a stand-by position where a new master produced by a master making operation should have its leading edge clamped on the drum, a master discharging operation under way for discharging a used master is interrupted. After the leading edge of the new master has been clamped on the print drum, the master discharging operation is resumed while a master feeding operation for wrapping the new master around the print drum is under way. A printing operation for printing a document image on a sheet is effected simultaneously with the resumption of the master discharging operation. Such a procedure is implemented as a high speed 1 control mode and executed by a main control unit.
    Type: Grant
    Filed: September 9, 1997
    Date of Patent: November 23, 1999
    Assignee: Tohoku Ricoh Co., Ltd.
    Inventor: Hideyuki Kagawa
  • Patent number: 5964148
    Abstract: In a stencil sheet discharge device having a pair of stencil sheet discharge rollers for transferring a stencil sheet removed from the outer circumferential surface of a printing drum of a rotary stencil printer toward a stencil sheet disposal spot, it is prevented that the trailing end of the stencil printer mounted around the printing drum is contaminated with ink by a contact with the stencil sheet discharge rollers, by a cover member being provided between at least one of the pair of stencil sheet discharge rollers and the printing drum. The cover member may be movable between an operating position interposed between the at least one of the pair of stencil sheet discharge rollers and the printing drum and a non-operating position for exposing the pair of stencil sheet discharge rollers to the printing drum.
    Type: Grant
    Filed: February 13, 1998
    Date of Patent: October 12, 1999
    Assignee: Riso Kagaku Corporation
    Inventor: Shigenori Ishii