Granted Patent
Utility
US 4,538,633 · App. 06/467,690
Optical-hydraulic control system
Inventor:
Curtis E. Stevens
Patented Case
View Patent ↗
Granted: Sep 3, 1985
Filed: Feb 18, 1983
Inventor
Curtis E. Stevens
Assignee (at issue)
Parker-Hannifin Corporation
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.