Granted Patent
Utility
US 5,172,521 · App. 07/652,782
Sharpening apparatus for forage harvester knives
Inventors:
John R. McClure, Larry D. Hall
Patented Case
View Patent ↗
Granted: Dec 22, 1992
Filed: Feb 8, 1991
Inventors
John R. McClure
Larry D. Hall
Assignee (at issue)
Ford New Holland, 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.