Patents by Inventor Brian Mackinnon

Brian Mackinnon 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).

  • Pump-off control method of pump jack
    Patent number: 6599095
    Abstract: A pump off control method comprises detecting the speed of the induction motor and an instantaneous value of secondary current of the induction motor. Down stroke time in every cycle of the pump jack is detected. An average value of instantaneous values of the secondary current of the induction motor in the down stroke time in said every cycle is calculated. An average value reference of the secondary current of the induction motor to be compared with calculated average value of the instantaneous values of the secondary current of the induction motor is set. The calculated average value of the instantaneous values of the secondary current is compared with the average value reference after the down stroke end in each cycle. An occurence of pump off is detected if the calculated average value of the instantaneous values is greater than the average value reference.
    Type: Grant
    Filed: October 29, 2001
    Date of Patent: July 29, 2003
    Assignee: Kabushiki Kaisha Yaskawa Denki
    Inventors: Noriyuki Takada, Takayuki Yamakawa, Hidetoshi Ryu, Tetsuo Kawano, Koji Kawamoto, Toshio Miyano, Richard L. Pratt, Brian Mackinnon