Granted Patent
Utility
US 4,417,633 · App. 06/245,092
Hydraulic system for preventing leak down of hydraulic implements
Inventor:
Donnell L. Dunn
Patented Case
View Patent ↗
Granted: Nov 29, 1983
Filed: Mar 18, 1981
Inventor
Donnell L. Dunn
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.