Granted Patent
Utility
US 4,270,731 · App. 06/034,322
Valve with non-binding spool
Inventor:
George J. Jackson
Patented Case
View Patent ↗
Granted: Jun 2, 1981
Filed: Apr 30, 1979
Inventor
George J. Jackson
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.