Patents by Inventor Mitsuhisa Yokoyama

Mitsuhisa Yokoyama 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).

  • Bit exchange method and bit exchange device for shield tunneling machine
    Patent number: 9222357
    Abstract: Sealing in the sliding gap of a rotating valve is improved to smoothly rotate the rotating valve during replacement of a roller bit. A valve housing portion is formed behind a bit housing portion having an opening at the front of a main cutter spoke. A rotating valve is rotationally disposed as a rotating body in the valve housing portion. A bit case containing the roller bit is moved into the bit housing portion so as to protrude from a removable passage of the rotating valve, and then the bit case is fixed by a cotter member to support a drilling reaction force. Thus, the sliding gap of the rotating valve is disposed in the bit housing portion and the valve housing portion and is covered with the bit case.
    Type: Grant
    Filed: May 25, 2012
    Date of Patent: December 29, 2015
    Assignee: HITACHI ZOSEN CORPORATION
    Inventor: Mitsuhisa Yokoyama
  • BIT EXCHANGE METHOD AND BIT EXCHANGE DEVICE FOR SHIELD TUNNELING MACHINE
    Publication number: 20140357461
    Abstract: Sealing in the sliding gap of a rotating valve is improved to smoothly rotate the rotating valve during replacement of a roller bit. A valve housing portion is formed behind a bit housing portion having an opening at the front of a main cutter spoke. A rotating valve is rotationally disposed as a rotating body in the valve housing portion. A bit case containing the roller bit is moved into the bit housing portion so as to protrude from a removable passage of the rotating valve, and then the bit case is fixed by a cotter member to support a drilling reaction force. Thus, the sliding gap of the rotating valve is disposed in the bit housing portion and the valve housing portion and is covered with the bit case.
    Type: Application
    Filed: May 25, 2012
    Publication date: December 4, 2014
    Applicant: HITACHI ZOSEN CORPORATION
    Inventor: Mitsuhisa Yokoyama