Patents by Inventor Lewis R. Shell

Lewis R. Shell 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).

  • Patent number: 4330740
    Abstract: Low voltage starting of a three-phase submersible pump motor in a shallow well is achieved by employing a high-impedance transformer for supplying the three-phase power to the motor. Upon starting, the normally heavy current drawn by the motor results in a voltage drop through the high-impedance transformer sufficient to substantially lower the voltage across the motor and hence the starting current. In the absence of limiting the starting current, abnormally high starting torques will be produced on the motor shaft resulting in mechanical fatigue and eventually shaft breakage.
    Type: Grant
    Filed: September 28, 1979
    Date of Patent: May 18, 1982
    Assignee: Centrilift-Hughes, Inc.
    Inventors: Lewis R. Shell, Joseph E. Vandevier