Granted Patent
Utility
US 5,913,644 · App. 09/062,843
Helical mill having multiple flutes with differing rake angles
Inventors:
Kenneth G. DeRoche, Mark Alan Francis
Patented Case
View Patent ↗
Granted: Jun 22, 1999
Filed: Apr 20, 1998
Inventors
Kenneth G. DeRoche
Mark Alan Francis
Assignee (at issue)
KENNAMETAL INC.
This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.