Patents by Inventor Yoshitugu Hamada

Yoshitugu Hamada 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).

  • Sulphur and nitrogen treated iron based rotor for rotary piston engine
    Patent number: 4074956
    Abstract: A rotary piston engine has a pair of side housings made of high silicon aluminum alloy and a rotor made of iron-based material. The side surfaces of the rotor are subjected to a surface treatment called "Sulfinuz" to form surface layers rich in sulphur and nitrogen for minimizing scuffing between the side surfaces of the side housings and the side surfaces of the rotating rotor due to thermal expansion of the side housings and vibration of the rotor.
    Type: Grant
    Filed: June 9, 1976
    Date of Patent: February 21, 1978
    Assignee: Riken Piston Ring Kogyo Kabushiki Kaisha
    Inventors: Masayuki Maruyama, Yoshitugu Hamada, Ryoichi Yamauchi