Patents by Inventor Norifumi Shiraga

Norifumi Shiraga 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).

  • Hydraulic circuit of construction machine
    Patent number: 8151688
    Abstract: A throttle path for returning a part of pilot oil to a tank is formed by a tank path provided in a valve block of a control valve and a notch provided in a spool thereof. The above path is opened within a section from a vicinity of a stroke where a hydraulic actuator starts moving to right before a stroke end among a spool stroke of the control valve. An opening area of the above path is slowly reduced in accordance with an increase in the stroke at a final phase of the section.
    Type: Grant
    Filed: December 19, 2008
    Date of Patent: April 10, 2012
    Assignee: Kobelco Construction Machinery Co., Ltd.
    Inventors: Yoshimi Saotome, Norifumi Shiraga
  • HYDRAULIC CIRCUIT OF CONSTRUCTION MACHINE
    Publication number: 20090205723
    Abstract: A throttle path for returning a part of pilot oil to a tank is formed by a tank path provided in a valve block of a control valve and a notch provided in a spool thereof. The above path is opened within a section from a vicinity of a stroke where a hydraulic actuator starts moving to right before a stroke end among a spool stroke of the control valve. An opening area of the above path is slowly reduced in accordance with an increase in the stroke at a final phase of the section.
    Type: Application
    Filed: December 19, 2008
    Publication date: August 20, 2009
    Applicant: KOBELCO CONSTRUCTION MACHINERY CO., LTD.
    Inventors: Yoshimi SAOTOME, Norifumi Shiraga