Patents by Inventor Kazumitsu Minagawa

Kazumitsu Minagawa 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).

  • Cold forming tap having internal finish cutting edge and method of producing the same
    Patent number: 6217267
    Abstract: A cold forming tap with an internal finish cutting edge includes an external thread portion having radially outwardly protruding portions and relief portions which are alternately located in a helical direction in which an external thread extends. The protruding portions are forced into a surface of a prepared hole which has been previously formed through a workpiece, for thereby forming an internal thread on the surface. The improvement comprises: at least one of the protruding portions having a root diameter larger than that of the other of the protruding portions, the at least one of the protruding portions being removed down to a root of the external thread, and a flute being formed in a portion corresponding to the root of the at least one of the protruding portions, so as to provide the cutting edge in the portion corresponding to the root.
    Type: Grant
    Filed: February 17, 1999
    Date of Patent: April 17, 2001
    Assignee: OSG Corporation
    Inventors: Hiroto Sugano, Shigeru Hayashi, Kazumitsu Minagawa