Granted Patent
Utility
US 5,143,385 · App. 07/830,509
Shaft seal
Inventors:
Stefan Sponagel, Waldemar Wachowitz
Patented Case
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Granted: Sep 1, 1992
Filed: Jan 31, 1992
Inventors
Stefan Sponagel
Waldemar Wachowitz
Assignee (at issue)
Firma Carl Freudenberg
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.