Patents by Inventor F. C. Witt

F. C. Witt 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).

  • Flexible lined tank with vacuum in the manway
    Patent number: 5505327
    Abstract: A vinyl lined tank has a manway opening formed of a vertical portion and a horizontal flange, with a vertical pathway, open at the bottom, inside the vertical portion that communicates with a conduit in the flange or in the vertical portion so that a vacuum can be maintained within the pathway that prevents the collapse of the liner when the tank is empty.
    Type: Grant
    Filed: March 13, 1995
    Date of Patent: April 9, 1996
    Inventor: F. C. Witt
  • Flexible tank liner with vacuum fitting
    Patent number: 5397020
    Abstract: In a vinyl lined metal tank, the manway or other opening includes a sealed vertical flanged collar that creates a space in the manway between the metal portion of the manway and the vinyl liner. A port extends from the periphery of the flange into communication with the created space. A vacuum maintained within the created space prevents the collapse of the vinyl liner while the tank is empty.
    Type: Grant
    Filed: January 18, 1994
    Date of Patent: March 14, 1995
    Inventor: F. C. Witt