Granted Patent
Utility
US 4,639,192 · App. 06/599,043
Propeller pitch controlling arrangement having a fuel economizing feature
Inventor:
David P. Harrell
Patented Case
View Patent ↗
Granted: Jan 27, 1987
Filed: Apr 11, 1984
Inventor
David P. Harrell
Assignee (at issue)
American Standard 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.