Granted Patent
Utility
US 4,608,911 · App. 06/697,021
Locking circuit for hydraulic systems
Inventor:
Stephen D. Johnson
Patented Case
View Patent ↗
Granted: Sep 2, 1986
Filed: Jan 31, 1985
Inventor
Stephen D. Johnson
Assignee (at issue)
J. I. Case 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.