Granted Patent
Utility
US 4,867,113 · App. 07/290,115
Reduced friction engine tappet construction
Inventors:
John Matthew Pieprzak, Pierre A. Willermet
Patented Case
View Patent ↗
Granted: Sep 19, 1989
Filed: Dec 27, 1988
Inventors
John Matthew Pieprzak
Pierre A. Willermet
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.