Patents by Inventor R. C. Zinkgraf

R. C. Zinkgraf 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).

  • Patent number: D253930
    Type: Grant
    Filed: November 10, 1977
    Date of Patent: January 15, 1980
    Assignee: Dart Industries Inc.
    Inventors: R. C. Zinkgraf, David L. Painter