Patents by Inventor Donald M. Herriott

Donald M. Herriott 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).

  • Spa-domestic hot water heat exchanger
    Patent number: 4381031
    Abstract: A first heat exchanger loop incorporates a thermostatically controlled circulating pump which draws hot water from the heater. Spa water is circulated by the spa pump through a second heat exchange loop surrounding the first. The thermostat sensor detects spa temperature when the spa pump is on and detects heater temperature, and therefore automatically shuts off the circulating pump, when the spa pump is off.
    Type: Grant
    Filed: October 27, 1980
    Date of Patent: April 26, 1983
    Inventors: Larry D. Whitaker, Donald M. Herriott