Granted Patent
Utility
US 4,256,433 · App. 06/028,352
Hydraulic circuit for earthworking implement
Inventor:
Donald R. King
Patented Case
View Patent ↗
Granted: Mar 17, 1981
Filed: Apr 9, 1979
Inventor
Donald R. King
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.