Granted Patent
Utility
US 4,998,862 · App. 07/416,278
Air compressor pressure regulating valve system
Inventor:
William R. Hutchinson
Patented Case
View Patent ↗
Granted: Mar 12, 1991
Filed: Oct 2, 1989
Inventor
William R. Hutchinson
Assignee (at issue)
Ingersoll-Rand Company
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.