Patents by Inventor Isao Yamato

Isao Yamato 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).

  • Pumping system for oil production
    Patent number: 4537564
    Abstract: A pumping system for oil production comprises a hydraulic unit set on the ground and adapted to send out a pressure oil, and a pump unit set in an oil well and adapted to draw up crude oil therefrom. The pump unit comprises a pump cylinder, and a plunger reciprocatingly moved in the pump cylinder. The plunger is provided with a clearance formed between the outer circumferential surface of a lower end portion thereof and the inner circumferential surface of the pump cylinder. The pressure oil supplied from the hydraulic unit is ejected from the clearance along the inner surface of the pump cylinder into a cylinder chamber.
    Type: Grant
    Filed: March 8, 1984
    Date of Patent: August 27, 1985
    Assignee: Mitsui Engineering & Shipbuilding Co., Ltd.
    Inventors: Isao Yamato, Tominori Yamada
  • Pumping system for oil production
    Patent number: 4451212
    Abstract: A pumping system for oil production comprises a hydraulic unit set on the ground and adapted to send out a pressure oil, and a pump unit set in an oil well and adapted to draw up crude oil therefrom. The pump unit comprises a pump cylinder, and a plunger reciprocatingly moved in the pump cylinder. The plunger is provided with a clearance formed between the outer circumferential surface of a lower end portion thereof and the inner circumferential surface of the pump cylinder. The pressure oil supplied from the hydraulic unit is ejected from the clearance along the inner surface of the pump cylinder into a cylinder chamber.
    Type: Grant
    Filed: November 6, 1981
    Date of Patent: May 29, 1984
    Assignee: Mitsui Engineering & Shipbuilding Co. Ltd.
    Inventors: Isao Yamato, Tominori Yamada