Patents by Inventor Don D. Hughes

Don D. Hughes 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).

  • Two stage thermostatic valve device
    Patent number: 5690276
    Abstract: A thermostat having a main valve and a secondary valve is disclosed both of which are biased closed by a single coiled compression spring and opened by a single piston. The entrance to the channel of the secondary valve is maintained at a maximum dimension of approximately 0.015 inches in order to keep undesirable particulate matter out of the valve. The surfaces within the valve channel encourage laminar flow which increases the volume of flow which can be passed through the valve while keeping the total surface area of the valve small.
    Type: Grant
    Filed: October 31, 1996
    Date of Patent: November 25, 1997
    Assignee: Caltherm
    Inventors: Peter Thiel, Don D. Hughes, John F. Grote