Patents by Inventor Frich Renfordt

Frich Renfordt 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).

  • Process for producing a gas purging plug with increased resistance to infiltration and oriented porosity
    Patent number: 5225247
    Abstract: A process for producing a plug with increased resistance to infiltration and oriented porosity for use in metallurgical melting crucibles, in which the matrix material of the plug is subjected to an impregnating treatment.
    Type: Grant
    Filed: July 17, 1991
    Date of Patent: July 6, 1993
    Assignee: Radex-Heraklith Industriebeteiligungs Aktiengesellschaft
    Inventors: Lorenz Dotsch, Helmut Preyer, Frich Renfordt, Jean-Louis Retrayt