Granted Patent
Utility
US 4,574,686 · App. 06/637,348
Digital proportional spool position control of compensated valves
Inventor:
Tadeusz Budzich
Patented Case
View Patent ↗
Granted: Mar 11, 1986
Filed: Aug 6, 1984
Inventor
Tadeusz Budzich
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.