Granted Patent
Utility
US 4,919,439 · App. 07/106,391
Balanced ring seal
Inventor:
Gregg Williams
Patented Case
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Granted: Apr 24, 1990
Filed: Oct 9, 1987
Inventor
Gregg Williams
Assignee (at issue)
WILLIAMS INTERNATIONAL CO., L.L.C.
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.