Patents by Inventor Norio Sagara

Norio Sagara 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).

  • Control apparatus and method for preventing seizure in a spindle apparatus of a machine tool
    Patent number: 4992964
    Abstract: A control device for a spindle apparatus including a spindle in a housing supported by bearings includes a sensor that senses the axial elongation of the spindle during rotation and outputs monitoring signals representing whether such an elongation exists. The monitored signals are compared and a variation value per unit time is calculated. A switching circuit receives the variation value and stops rotation of the spindle when the variation value is equal to or greater than a preset reference value by detecting abrupt elongation in the axial direction of the spindle immediately before seizure may happen and rapidly stopping rotation of the spindle to prevent seizure of the spindle.
    Type: Grant
    Filed: August 3, 1988
    Date of Patent: February 12, 1991
    Assignee: Nippon Seiko Kabushiki Kaisha
    Inventors: Norio Sagara, Shinya Nakamura