Patents by Inventor Yoshiei Niwa

Yoshiei Niwa 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).

  • Process and apparatus for high frequency discharge shaping of a workpiece by means of a rectangular bipolar pulsating voltage
    Patent number: 4447696
    Abstract: A method and apparatus for electrical discharge machining are disclosed. The method includes the use of a bipolar pulsating voltage to improve the quality of a discharge machining operation. The use of an intermittent AC voltage and an intermittent AC voltage with an intermittent DC voltage interposed during the quiescent periods thereof is also disclosed. A water bath for discharge machining is disclosed, as is a novel circuit for producing bipolar pulsating power and a novel apparatus for combining a plurality of such power supplies and insuring that all output power is maintained in the same phase. Electrode shielding and automatic drive methods and apparatus are disclosed as is a novel capacitive electrode coupling technique.
    Type: Grant
    Filed: September 3, 1981
    Date of Patent: May 8, 1984
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Yoshiei Niwa
  • Apparatus for high frequency discharge shaping of a workpiece by means of a rectangular bipolar pulsating voltage
    Patent number: 4211908
    Abstract: A method and apparatus for electrical discharge machining are disclosed. The method includes the use of a bipolar pulsating voltage to improve the quality of a discharge machining operation. The use of an intermittent AC voltage and an intermittent AC voltage with an intermittent DC voltage interposed during the quiescent periods thereof is also disclosed. A water bath for discharge machining is disclosed, as is a novel circuit for producing bipolar pulsating power and a novel apparatus for combining a plurality of such power supplies and insuring that all output power is maintained in the same phase. Electrode shielding and automatic drive methods and apparatus are disclosed as is a novel capacitive electrode coupling technique.
    Type: Grant
    Filed: February 7, 1977
    Date of Patent: July 8, 1980
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Yoshiei Niwa