Granted Patent
Utility
US 4,389,991 · App. 06/261,097
Rotation sensitive pressure regulator
Inventor:
Dennis H. Gibson
Patented Case
View Patent ↗
Granted: Jun 28, 1983
Filed: Sep 11, 1980
Inventor
Dennis H. Gibson
Assignee (at issue)
Caterpillar Tractor Co.
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.