Patents by Inventor Grant E. Hagan

Grant E. Hagan 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).

  • Flue control device
    Patent number: 4953535
    Abstract: A device for adjustably restricting the flow of exhaust gases in a furnace flue to conserve fuel is disclosed. It comprises two interlocking pipe sections and a helical element having one end fixed to the inner surface of each pipe section. The helical element has a circular opening along its central axis. The degree of restriction provided by the device is adjusted by twisting or separating the two pipe sections.
    Type: Grant
    Filed: July 18, 1989
    Date of Patent: September 4, 1990
    Inventor: Grant E. Hagan
  • Flue control device
    Patent number: 4850336
    Abstract: A device for adjustably restricting the flow of exhaust gases in a furnace flue to conserve fuel is disclosed. It comprises two interlocking pipe sections and a helical element having one end fixed to the inner surface of each pipe section. The helical element has a circular opening along its central axis. The degree of restriction provided by the device is adjusted by twisting or separating the two pipe sections.
    Type: Grant
    Filed: December 5, 1988
    Date of Patent: July 25, 1989
    Assignee: Sankyo Manufacturing Company, Ltd.
    Inventor: Grant E. Hagan