Patents by Inventor Katsuji Sunagawa

Katsuji Sunagawa 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).

  • Grindstone and method of manufacturing the same
    Patent number: 6273805
    Abstract: A sheet-shaped grindstone for grinding a workpiece includes a plurality of segments arranged in an appropriate pattern with sufficient spaces therebetween such that the grindstone becomes flexible. The segments are formed in a manner in which metal powder including diamond grinding grains is sintered to form granular chips, the chips are disposed in a die in such a density that the chips come into mutual contact, and gaps around the granular chips are filled with a resin through application of pressure. The grindstone is more flexible at contact points with a workpiece than are conventional vitrified grinding tools. The grindstone can evade collision of the segments with the workpiece and can grind a curved surface of the workpiece through smooth contact therewith.
    Type: Grant
    Filed: August 20, 1999
    Date of Patent: August 14, 2001
    Assignee: Showa Kenma Kogyo Co., Ltd.
    Inventor: Katsuji Sunagawa
  • Grindstone and method of manufacturing the same
    Patent number: 6071182
    Abstract: A sheet-shaped grindstone for grinding a workpiece includes a plurality of segments arranged in an appropriate pattern with sufficient spaces therebetween such that the grindstone becomes flexible. The segments are formed in a manner in which metal powder including diamond grinding grains is sintered to form granular chips, the chips are disposed in a die in such a density that the chips come into mutual contact, and gaps around the granular chips are filled with a resin through application of pressure. The grindstone is more flexible at contact points with a workpiece than are conventional vitrified grinding tools. The grindstone can evade collision of the segments with the workpiece and can grind a curved surface of the workpiece through smooth contact therewith.
    Type: Grant
    Filed: October 27, 1997
    Date of Patent: June 6, 2000
    Assignee: Sanwa Kenma Kogyo Co., Ltd.
    Inventor: Katsuji Sunagawa
  • Grinding disk
    Patent number: D444483
    Type: Grant
    Filed: August 2, 2000
    Date of Patent: July 3, 2001
    Assignee: Sanwa Kenma Kogyo Co., Ltd.
    Inventor: Katsuji Sunagawa
  • Grinding disc
    Patent number: D486839
    Type: Grant
    Filed: February 1, 2003
    Date of Patent: February 17, 2004
    Assignee: Sanwa Kenma, Ltd.
    Inventors: Katsuji Sunagawa, Hisayuki Murata
  • Grindstone
    Patent number: D609545
    Type: Grant
    Filed: February 3, 2009
    Date of Patent: February 9, 2010
    Assignee: Sanwa Kenma, Ltd.
    Inventors: Kazuhisa Ueno, Katsuji Sunagawa, Izumi Araki, Eiki Sakaguchi