Patents by Inventor Norio Onuma

Norio Onuma 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).

  • Tournament oil path constituting apparatus
    Patent number: 6161586
    Abstract: A tournament oil path constituting apparatus in which while a laminated block is constituted by laminating a number of oil path plates, a number of shuttle valve holes and connection grooves made continuous to the shuttle valve holes are formed at overlap faces of the oil path plates, shuttle valves are integrated to the shuttle valve holes, introductory oil paths communicating with the shuttle valve holes are formed at both of the oil path plates formed with the shuttle valve holes and the oil path plates having match faces on sides of the shuttle valve holes and a high pressure oil is selected by the shuttle valves from pressure oils conducted both of the introductory oil paths and conducted to the connection grooves. The tournament oil path constituting apparatus also including a number of main paths penetrating the number of laminated oil path plates and branch grooves branched from the main paths.
    Type: Grant
    Filed: March 12, 1999
    Date of Patent: December 19, 2000
    Assignee: Hitachi Construction Machinery Co., Ltd.
    Inventors: Toichi Hirata, Genroku Sugiyama, Tsukasa Toyooka, Norio Onuma, Ikuo Inagaki, Masao Kashiwagi