Patents by Inventor Mitishi Ishii

Mitishi Ishii 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 of and apparatus for automatically controlling pressing force of press machine
    Patent number: 5379688
    Abstract: Pressing force with which a die tool presses on a workpiece is controlled so as to be constant at all times. The magnitude of pressing force with which the die tool presses on the workpiece during press working is detected with a semiconductor strain gauge (84), and the pressing force detected and a preset pressing force are compared with each other by a controller. If there is a difference between the pressing force detected and the preset pressing force, a screw rod (35) is turned by an AC servomotor (24) so as to adjust the length of a lower ram (60), thereby controlling the pressing force.
    Type: Grant
    Filed: July 28, 1993
    Date of Patent: January 10, 1995
    Inventor: Mitishi Ishii