Patents by Inventor Seiju Nagakura

Seiju Nagakura has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 6722181
    Abstract: A method for bending a work of a plate shape by moving a die with the work being butted against a butting member, and an apparatus for executing the method are provided. The bending apparatus is provided with an input unit for inputting data on bending conditions including respective target values of a bending angle and a bending dimension, as well as respective measured values of a bending angle and a bending dimension of the work obtained in trial bending. A control device installed in the apparatus executes an initial computation for computing an operation amount of the die when the data on bending conditions are inputted. Further, the control device executes computation for a correction value for an operation amount of the die and computation for an estimated value of a bending dimension when the respective measured values of the bending angle and the bending dimension obtained in trial bending are inputted.
    Type: Grant
    Filed: July 16, 2002
    Date of Patent: April 20, 2004
    Assignee: Toyokoki Co., Ltd.
    Inventor: Seiju Nagakura
  • Publication number: 20030015012
    Abstract: A method for bending a work of a plate shape by moving a die with the work being butted against a butting member, and an apparatus for executing the method are provided. The bending apparatus is provided with an input unit for inputting data on bending conditions including respective target values of a bending angle and a bending dimension, as well as respective measured values of a bending angle and a bending dimension of the work obtained in trial bending. A control device installed in the apparatus executes an initial computation for computing an operation amount of the die when the data on bending conditions are inputted. Further, the control device executes computation for a correction value for an operation amount of the die and computation for an estimated value of a bending dimension when the respective measured values of the bending angle and the bending dimension obtained in trial bending are inputted.
    Type: Application
    Filed: July 16, 2002
    Publication date: January 23, 2003
    Inventor: Seiju Nagakura
  • Patent number: 6240758
    Abstract: A hydraulic machine for operation such as for pressurizing a workpiece and molding products from materials by using a reciprocation mechanism comprising a hydraulic cylinder unit. The cylinder unit comprises two types cylinder chambers having different cross-sectional areas, and a third or plural cylinder chambers. Hydraulic oil sent out from a hydraulic pump driven by a servo motor, is fed through a hydraulic circuit into the cylinder unit. The shifting position of the reciprocation movement is detected, and path switching in the hydraulic circuit and revolving operation of the servo motor are controlled on the basis of the detected shifting position. In case the reciprocation movement is used for pressurizing a workpiece by a die, the hydraulic oil is fed to the cylinder chamber for forward of small cross-sectional area until slightly before the die comes into contact against the workpiece, and the die shifts at high speed relative to a workpiece.
    Type: Grant
    Filed: June 21, 1999
    Date of Patent: June 5, 2001
    Assignee: Toyokoki Co., Ltd.
    Inventor: Seiju Nagakura
  • Patent number: 6032509
    Abstract: A press brake comprising a bed for supporting a lower mold on the upper surface thereof, a ram for supporting an upper mold in opposition to said lower mold a driver for causing either the ram or the bed to move for bending a workpiece between the upper and lower molds, and a distance adjusting device for adjusting the distance between the upper and lower molds via operation of a wedging unit and a pair of reciprocating units. The wedging unit is disposed either between the ram and the upper mold or between the bed and lower mold, and comprises a pair of movable wedges vertically disposed and a stationary wedge disposed between the movable wedges in contact with the movable wedges. Each of the contacting surfaces of the wedges is formed by a plurality of inclined planes having different angles of inclination. The reciprocating units are connected to the movable wedges to move the movable wedges along the length of the molds.
    Type: Grant
    Filed: February 17, 1999
    Date of Patent: March 7, 2000
    Assignee: Toyokoki Co., Ltd.
    Inventor: Seiju Nagakura
  • Patent number: 5865056
    Abstract: A method and an apparatus for executing a bending process on a workpiece plate is provided wherein a rear edge of the workpiece plate is place in contact with stop members of a back gauge unit. Simultaneous with input of target value of bending dimensions, a controller provides drive units of the stop members with operative amounts for achieving front/rear directional positioning of the stop members and a gradient angle of a horizontal surface a stop surface corresponding to the target value. In response to the effective value of the operative amount, the drive units are activated to cause stop members to be moved to predetermined positions. After executing a trial bending of a workpiece plate, bending dimensions at two arbitrary bent portions of the processed workpiece plate are measured.
    Type: Grant
    Filed: June 30, 1997
    Date of Patent: February 2, 1999
    Assignee: Toyokoki Co., Ltd.
    Inventor: Seiju Nagakura
  • Patent number: 5497647
    Abstract: A method and equipment for bending a work to the extent of a target bending angle, including a first process of bending to bend a work with a ram driven by a two-shaft system having a pair of right and left drive mechanisms to the extent of the quantity of motion for each shaft corresponding to the target bending angle, a measurement process to measure the bending angles at both ends of the work bent in the first process of bending, a correction process to correct the quantity of motion for each shaft according to each error between the target bending angle and the respective bending angles at both ends of the work measured in the measurement process, and a second process of bending to bend the work with the ram driven by the two-shaft system in which each shaft is actuated by each drive mechanism to the extent of the quantity of motion for each shaft corrected by the correction process, all of the above processes being performed in series.
    Type: Grant
    Filed: June 14, 1994
    Date of Patent: March 12, 1996
    Assignee: Toyokoki Co., Ltd.
    Inventor: Seiju Nagakura
  • Patent number: 4498328
    Abstract: A press includes a table for receiving a lower mold and a movable ram which moves up-and-down relative to the table, the ram being provided with a holder for supporting the upper mold utilizing an adapter mounted in alignment on the lower edge of the ram, the adapter being provided with an eccentric shaft member which is operable to adjust the vertical position of the holder relative to the ram by rotating the eccentric shaft member.
    Type: Grant
    Filed: April 21, 1983
    Date of Patent: February 12, 1985
    Assignee: Toyokoki Co., Ltd.
    Inventor: Seiju Nagakura