Granted Patent
Utility
US 4,874,058 · App. 07/222,276
Viscous shear coupling
Inventor:
Georg Kwoka
Patented Case
View Patent ↗
Granted: Oct 17, 1989
Filed: Jul 21, 1988
Inventor
Georg Kwoka
Assignee (at issue)
Viscodrive GmbH
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.