Patents by Inventor Donald Raymond Marshall

Donald Raymond Marshall 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).

  • Apparatus for solids blending
    Patent number: 4042220
    Abstract: Apparatus for the blending of a bed of particulate solids operating cyclically by selectively regulated downward gravity flow of a fraction of the solids, fluidized mixing outside of the bed, followed by recycle to the top of the bed.
    Type: Grant
    Filed: August 17, 1976
    Date of Patent: August 16, 1977
    Assignee: E. I. Du Pont de Nemours and Company
    Inventors: Robert Garnett Humkey, Donald Raymond Marshall, Donald James Ryan