Granted Patent
Utility
US 4,561,521 · App. 06/678,844
Variable assist power steering system
Inventor:
James J. Duffy
Patented Case
View Patent ↗
Granted: Dec 31, 1985
Filed: Dec 6, 1984
Inventor
James J. Duffy
Assignee (at issue)
Ford Motor 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.