Patents by Inventor Michael D. Kieffer

Michael D. Kieffer 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).

  • Marking instrument
    Patent number: D316361
    Type: Grant
    Filed: April 11, 1988
    Date of Patent: April 23, 1991
    Assignee: Mannington Mills, Inc.
    Inventor: Michael D. Kieffer