Patents by Inventor Tsunao Shima

Tsunao Shima 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).

  • Method of gas carburizing and hardening
    Patent number: 4836864
    Abstract: A method of gas carburizing and hardening a steel article and a continuous furnace therefor. The method includes the steps of carburizing the article in a carburizing atmosphere at atmospheric pressure, heating the article in a vacuum for a predetermined period of time, and hardening the article.
    Type: Grant
    Filed: September 26, 1986
    Date of Patent: June 6, 1989
    Assignee: Chugai Ro Co., Ltd.
    Inventors: Koji Murakami, Tsunao Shima, Yoshikazu Shimosato, Akira Yokoyama
  • Continuous furnace for gas carburizing and hardening
    Patent number: 4807853
    Abstract: A method of gas carburizing and hardening a steel article and a continuous furnace therefor. The method includes the steps of carburizing the article in a carburizing atmosphere at atmospheric pressure, heating the article in a vacuum for a predetermined period of time, and hardening the article.
    Type: Grant
    Filed: July 7, 1986
    Date of Patent: February 28, 1989
    Assignee: Chugai Ro Co., Ltd.
    Inventors: Koji Murakami, Tsunao Shima, Yoshikazu Shimosato, Akira Yokoyama