Patents by Inventor Robert Lee Boyd

Robert Lee Boyd 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).

  • Hazardous leakage current preventing for refractory-encased heater elements
    Patent number: 3970817
    Abstract: Low-level "trickle" electric heater means in diverse forms prevents hygroscopic moisture accumulation adjacent relatively open or exposed ends of refractory-encased conventional electrical heating elements, thereby to prevent excessive leakage current through refractory otherwise potentially conductive with moisture buildup which may present a hazard at such time as the element is initially turned on.
    Type: Grant
    Filed: May 14, 1975
    Date of Patent: July 20, 1976
    Inventor: Robert Lee Boyd