Granted Patent
Utility
US 4,425,994 · App. 06/257,787
Multiple disc friction clutch
Inventor:
Franz Schele
Patented Case
View Patent ↗
Granted: Jan 17, 1984
Filed: Apr 27, 1981
Inventor
Franz Schele
Assignee (at issue)
Zahnradfabrik Friedrichshafen AG
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.