Patents by Inventor Sinji Mitsuhashi

Sinji Mitsuhashi 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).

  • Vacuum evacuation system
    Patent number: 4797068
    Abstract: A vacuum evacuation system comprising a non-positive displacement type vacuum pump called molecular pump which obtains high pumping speed in a high vacuum range, and an oil-free, positive displacement type vacuum pump called screw vacuum pump. The non-positive displacement type vacuum pump and the positive displacement type vacuum pump are connected to each other such that the non-positive displacement type vacuum pump is located on a high vacuum side and the positive displacement type vacuum pump is located on a low pressure or atmospheric side, to thereby prevent oil from being penetrated into a system to be evacuated.
    Type: Grant
    Filed: June 5, 1987
    Date of Patent: January 10, 1989
    Assignee: Hitachi, Ltd.
    Inventors: Tadashi Hayakawa, Kazuaki Shiinoki, Sinji Mitsuhashi, Kotaro Naya