Patents by Inventor Shigenobu Igawa

Shigenobu Igawa 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 for manufacturing electroseamed metal tube
    Patent number: 11504797
    Abstract: A method for manufacturing an electric resistance welded metal pipe by butting side ends of a metal strip against each other and then welding the side ends by high frequency heating to manufacture an electric resistance welded metal pipe, each side end being provided with an inner surface side corner portion located on an inner surface side of the electric resistance welded metal pipe, the method includes a step of forming an inclined surface at the inner surface side corner portion before butting the side ends of the metal strip, and wherein the side ends are butted and welded to each other such that the inclined surface remains on an excess metal of the metal pipe after electric resistance welding and a discharged metal is not welded to the excess metal.
    Type: Grant
    Filed: April 15, 2020
    Date of Patent: November 22, 2022
    Assignees: Nippon Steel Nisshin Co., Ltd., Nippon Steel Nisshin Pipe Co., Ltd.
    Inventors: Kouji Omosako, Makoto Akiduki, Shigenobu Igawa, Yasumasa Makihara, Ryota Tanaka
  • Method for manufacturing electroseamed metal tube, and electroseamed metal tube
    Patent number: 10906125
    Abstract: Provided is a method for manufacturing an electric resistance welded metal pipe by butting side ends of a metal strip against each other and then welding the side ends by high frequency heating to manufacture an electric resistance welded metal pipe, each side end being provided with an inner surface side corner portion located on an inner surface side of the electric resistance welded metal pipe, wherein the method comprises a step of forming an inclined surface at the inner surface side corner portion before butting the side ends of the metal strip; and wherein the side ends are butted and welded to each other such that the inclined surface remains on an excess metal of the metal pipe after electric resistance welding and a discharged metal is not welded to the excess metal.
    Type: Grant
    Filed: February 8, 2018
    Date of Patent: February 2, 2021
    Assignees: Nippon Steel Nisshin Co., Ltd., Nippon Steel Nisshin Pipe Co., Ltd
    Inventors: Kouji Omosako, Makoto Akiduki, Shigenobu Igawa, Yasumasa Makihara, Ryota Tanaka
  • METHOD FOR MANUFACTURING ELECTROSEAMED METAL TUBE
    Publication number: 20200238431
    Abstract: A method for manufacturing an electric resistance welded metal pipe by butting side ends of a metal strip against each other and then welding the side ends by high frequency heating to manufacture an electric resistance welded metal pipe, each side end being provided with an inner surface side corner portion located on an inner surface side of the electric resistance welded metal pipe, the method includes a step of forming an inclined surface at the inner surface side corner portion before butting the side ends of the metal strip, and wherein the side ends are butted and welded to each other such that the inclined surface remains on an excess metal of the metal pipe after electric resistance welding and a discharged metal is not welded to the excess metal.
    Type: Application
    Filed: April 15, 2020
    Publication date: July 30, 2020
    Inventors: Kouji Omosako, Makoto Akiduki, Shigenobu Igawa, Yasumasa Makihara, Ryota Tanaka
  • METHOD FOR MANUFACTURING ELECTROSEAMED METAL TUBE, AND ELECTROSEAMED METAL TUBE
    Publication number: 20200009680
    Abstract: Provided is a method for manufacturing an electric resistance welded metal pipe by butting side ends of a metal strip against each other and then welding the side ends by high frequency heating to manufacture an electric resistance welded metal pipe, each side end being provided with an inner surface side corner portion located on an inner surface side of the electric resistance welded metal pipe, wherein the method comprises a step of forming an inclined surface at the inner surface side corner portion before butting the side ends of the metal strip; and wherein the side ends are butted and welded to each other such that the inclined surface remains on an excess metal of the metal pipe after electric resistance welding and a discharged metal is not welded to the excess metal.
    Type: Application
    Filed: February 8, 2018
    Publication date: January 9, 2020
    Inventors: Kouji Omosako, Makoto Akiduki, Shigenobu Igawa, Yasumasa Makihara, Ryota Tanaka