Patents by Inventor Friedhelm Wirth

Friedhelm Wirth 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).

  • Refractory composition
    Patent number: 4174970
    Abstract: Improved refractory compositions for the production of blast furnace pouring ducts are realized by the inclusion of Cr.sub.2 O.sub.3 in said compositions.
    Type: Grant
    Filed: May 1, 1978
    Date of Patent: November 20, 1979
    Assignee: Didier-Werke A.G.
    Inventors: Gunter Gelsdorf, Friedhelm Wirth