Patents by Inventor David K. Sandt

David K. Sandt 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).

  • Water supply winterizing system
    Patent number: 4531538
    Abstract: A system and apparatus operative in a winterizing mode for controllably filling hot and cold water supply lines with anti-freeze to prevent against burst pipes and, in a summerizing mode, for pump recovering the anti-freeze. In one embodiment, the system includes a closed loop, valve containing path having a separate pump, filter and anti-freeze tank. In other alternative embodiments, the water supply tank and a four-way valve are coupled to the closed loop path for switchably operating in the winterizing/summerizing modes, without resorting to a separate pump.
    Type: Grant
    Filed: January 6, 1984
    Date of Patent: July 30, 1985
    Inventors: David K. Sandt, Arthur V. Mitlyng, Jr., Harold W. Ilaug, Robert D. Quenemoen