Granted Patent
Utility
US 4,287,778 · App. 06/106,693
Hydraulic valve for two-speed power take-off drive
Inventor:
David C. Quick
Patented Case
View Patent ↗
Granted: Sep 8, 1981
Filed: Dec 26, 1979
Inventor
David C. Quick
Assignee (at issue)
Allis-Chalmers Corporation
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.