Granted Patent
Utility
US 4,889,206 · App. 07/227,830
Viscous shear coupling
Inventors:
Helmut Wiese, Paul-Erich Schonenbrucher
Patented Case
View Patent ↗
Granted: Dec 26, 1989
Filed: Aug 3, 1988
Inventors
Helmut Wiese
Paul-Erich Schonenbrucher
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.