Patents by Inventor Tomio Tanabe

Tomio Tanabe 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).

  • AC elevator speed control system
    Patent number: 4181197
    Abstract: A bidirectional triode thyristor is connected to an R phase of a three-phase induction motor through an up contact set and to its S phase through a down contact set. A full-wave rectifier bridge including four diodes is connected across the R and S phases to be enabled during deceleration of the motor. The thyristor is controlled by an R-to-S phase firing circuit responsive to a command acceleration signal during acceleration of the motor and a difference signal between a command deceleration signal and an actual speed signal for the motor during deceleration of the motor.
    Type: Grant
    Filed: April 11, 1978
    Date of Patent: January 1, 1980
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventors: Tomio Tanabe, Muneo Nishiwaki