Patents by Inventor Al Marcum

Al Marcum 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).

  • Heat recovery apparatus
    Patent number: 4469276
    Abstract: The present invention discloses a heat recovery apparatus, for example for use in a fireplace having a firebox with an upwardly directed flue of selected peripheral configuration communicating with the firebox and having an atmospheric outlet.
    Type: Grant
    Filed: September 30, 1982
    Date of Patent: September 4, 1984
    Inventor: Al Marcum