Patents by Inventor Tadanori Nakahiro

Tadanori Nakahiro 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 and apparatus for controlling the atmosphere in a heat treatment furnace
    Patent number: 6106636
    Abstract: In a method of and apparatus for controlling an atmosphere in a heat treatment furnace according to the present invention, a carburizing is carried out while supplying a hydrocarbon series gas and an oxidization gas into the furnace. The quantity of a residual CH.sub.4, a partial pressure of the oxidization gas and a partial pressure of CO are measured. The quantity of each gas to be supplied into the furnace is controlled according to either one of the values of the partial pressures.
    Type: Grant
    Filed: February 17, 1998
    Date of Patent: August 22, 2000
    Assignee: Dowa Mining Co., Ltd.
    Inventors: Takeshi Naito, Kouichi Ogihara, Akihiro Wakatsuki, Tadanori Nakahiro, Hideki Inoue, Yoshio Nakashima
  • Method and apparatus for controlling the atmosphere in heat treatment furnace
    Patent number: 6051078
    Abstract: In a method of and apparatus for controlling an atmosphere in a heat treatment furnace according to the present invention, a carburizing is carried out while supplying a hydrocarbon series gas and an oxidization gas into the furnace, and the supply of the hydrocarbon series gas is stopped either when the quantity of a residual CH.sub.4 in the furnace is changed to increasing from decreasing, or when a partial pressure of oxygen in the furnace reaches a predetermined value.
    Type: Grant
    Filed: February 16, 1998
    Date of Patent: April 18, 2000
    Assignee: Dowa Mining Co., Ltd.
    Inventors: Takeshi Naito, Kouichi Ogihara, Akihiro Wakatsuki, Tadanori Nakahiro, Hideki Inoue, Yoshio Nakashima