Patents by Inventor Robert Letterman

Robert Letterman 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).

  • Double walled tank
    Publication number: 20070056975
    Abstract: A double walled tank (12) is provided which includes an outer shell (14), a telescopically interfitted inner shell (16), and a cover (18) secured to outer shell (14). The tank (12) includes at least one spacer (48) located between the inner and outer shells (16, 14), as well as resilient seals (38, 72) serving to maintain an appropriate and safe spacing gap between the shells (14, 16). The inner shell (16) includes a top wall (38) equipped with a fill opening (52) defined by an upstanding central flange (50, 50a) surmounted by a detachably secured cover (54, 54a).
    Type: Application
    Filed: September 12, 2005
    Publication date: March 15, 2007
    Inventors: Dwayne Long, Scott Higgins, John Redmond, Dwayne Holden, Robert Letterman
  • Double-walled tank
    Patent number: D596265
    Type: Grant
    Filed: July 1, 2008
    Date of Patent: July 14, 2009
    Inventors: Dwayne Long, Scott Higgins, John R. Redmond, Dwayne Holden, Robert Letterman