Granted Patent
Utility
US 4,777,981 · App. 07/050,788
Magnetic detent joy stick and stack remote control valves
Inventor:
John D. Petro
Patented Case
View Patent ↗
Granted: Oct 18, 1988
Filed: May 18, 1987
Inventor
John D. Petro
Assignee (at issue)
Commercial Shearing, Inc.
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.