Patents Assigned to Ryoko Co., Ltd.
  • Patent number: 5073257
    Abstract: A method and apparatus for treating contaminated water without addition of chemical agents. A treatment zone is provided, having water-impermeable bottom and side walls, the bottom sloping stepwise from an input end to an output end. Soil is disposed within the treatment zone, and plants are grown therein. Contaminated water is applied to the input end of the treatment zone and flows through the soil to the output end, thereby being treated by the soil and providing nutrients to the plants. Treated water is collected in a collection area at the bottom of the output end, from where it is removed for use.
    Type: Grant
    Filed: November 23, 1990
    Date of Patent: December 17, 1991
    Assignees: AKWN Xo., Ltd., Ryoko Co., Ltd.
    Inventor: Teruo Higa
  • Patent number: 4920694
    Abstract: Improved method and apparatus for plant culture, particularly in arid regions. A culture bed is defined by moisture-proof walls and is charged with soil. Pipes disposed at the bottom of the culture bed supply moisture to plants growing therein, the amount of moisture being controlled to maintain the upper boundary of the capillary penetration zone a distance below the soil surface.
    Type: Grant
    Filed: June 23, 1988
    Date of Patent: May 1, 1990
    Assignees: Saken Co., Ltd., Ryoko Co., Ltd.
    Inventor: Teruo Higa
  • Patent number: 4839051
    Abstract: A method and apparatus for treating contaminated water without addition of chemical agents. A treatment zone is provided, having water-impermeable bottom and side walls, the bottom sloping stepwise from an input and to an output end. Soil is disposed within the treatment zone, and plants are grown therein. Contaminated water is applied to the input end of the treatment zone and flows through the soil to the output end, thereby being treated by the soil and providing nutrients to the plants. Treated water is collected in a collection area at the bottom of the output end, from where it is removed for use.
    Type: Grant
    Filed: June 11, 1987
    Date of Patent: June 13, 1989
    Assignees: Saken Co., Ltd., Ryoko Co., Ltd.
    Inventor: Teruo Higa
  • Patent number: 4771572
    Abstract: Improved method and apparatus for plant culture, particularly in arid regions. A culture bed is defined by moisture-proof walls and is charged with soil. Pipes disposed at the bottom of the culture bed supply moisture to plants growing therein, the amount of moisture being controlled to maintain the upper boundary of the capillary penetration zone a distance below the soil surface.
    Type: Grant
    Filed: May 15, 1986
    Date of Patent: September 20, 1988
    Assignees: Saken, Co., Ltd., Ryoko Co., Ltd.
    Inventor: Teruo Higa