Granted Patent
Utility
US 4,991,476 · App. 07/486,213
Automatic knife sharpening method for forage harvesters
Inventors:
Mark K. Chow, John R. McClure
Patented Case
View Patent ↗
Granted: Feb 12, 1991
Filed: Feb 8, 1990
Inventors
Mark K. Chow
John R. McClure
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.