Granted Patent
Utility
US 4,266,574 · App. 06/031,666
Vent valve
Inventor:
Basil B. Tilling
Patented Case
View Patent ↗
Granted: May 12, 1981
Filed: Apr 19, 1979
Inventor
Basil B. Tilling
Assignee (at issue)
Parker-Hannifin 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.