Patents by Inventor Douglas Canfield

Douglas Canfield 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).

  • Heating method and assembly utilizing electric heating elements in conjunction with combustion
    Patent number: 5235667
    Abstract: A heater for radiant heating of an object in a heating tunnel, furnace or the like has a layer of ceramic fibers through which a fuel/air mixture is fed for combustion at the surface and use of the heater as a gas burner. Partly embedded in the surface is an electrical-resistance heater which is heated up by the burner action and then can be energized to provide controlled heating of the object when the gas is shut off. A flow of cooling air through the heater can terminate the heating operation and rapidly quench the heater.
    Type: Grant
    Filed: May 24, 1991
    Date of Patent: August 10, 1993
    Assignee: Casso-Solar Corp.
    Inventors: Douglas Canfield, David Jacobson