Patents by Inventor Robert W. Griffiths

Robert W. Griffiths 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: 7127943
    Abstract: A fluid level sensor is disclosed having first and second vertically and horizontally nonoverlapping electrode plates for placing on a wall of a fluid container. Most preferably, the plates are also vertically spaced from each other. The capacitor plates are driven by a high frequency square wave. By forming nonoverlapping plates and driving them using a high frequency, the level of a fluid within the container, particularly viscous fluid, is more accurately detected. Control and detection circuitry is also disclosed to trigger an alarm if the fluid level drops below a critical level within the container.
    Type: Grant
    Filed: January 19, 2000
    Date of Patent: October 31, 2006
    Assignee: Rocky Mountain Research, Inc.
    Inventors: Robert W. Griffiths, R. Bruce Draper