Patents by Inventor Robert T. Spitz

Robert T. Spitz 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).

  • Gypsum calcination
    Patent number: 3956456
    Abstract: The calcination of gypsum by continuously feeding fine gypsum spirally downwardly through a cylindrical zone into which heated air is injected almost tangentially forming a spiral air conveyor. The calcined gypsum collected at the bottom is of unusual uniformity and can be readily and controllably varied by controlled variations in the characteristics of the heated air conveyor.
    Type: Grant
    Filed: December 17, 1971
    Date of Patent: May 11, 1976
    Assignee: National Gypsum Company
    Inventors: Joseph A. Keller, Robert T. Spitz