Patents by Inventor Robert Jeffry Maddy

Robert Jeffry Maddy 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 manufacturing concrete masonry units
    Patent number: 6213754
    Abstract: A cementitious composition for the molding of ultra-lightweight, durable, large structural units comprising Portland cement, coal combustion byproducts, expanded or extruded polystyrene and water, and a modified block machine used in the manufacture of such structural units.
    Type: Grant
    Filed: September 30, 1997
    Date of Patent: April 10, 2001
    Inventors: Steven Everett Doty, Robert Jeffry Maddy
  • Cementitious compositions and lightweight structural units
    Patent number: 6030446
    Abstract: A cementitious composition for the molding of ultra-lightweight, durable, large structural units comprising Portland cement, coal combustion byproducts, expanded or extruded polystyrene and water, and a modified block machine used in the manufacture of such structural units.
    Type: Grant
    Filed: May 29, 1996
    Date of Patent: February 29, 2000
    Assignee: Peerless Block & Brick Co.
    Inventors: Steven Everett Doty, Robert Jeffry Maddy