Granted Patent
Utility
US 5,118,078 · App. 07/701,200
Butterfly valve having improved sealing characteristics
Inventor:
Paul M. Younker
Patented Case
View Patent ↗
Granted: Jun 2, 1992
Filed: May 16, 1991
Inventor
Paul M. Younker
Assignee (at issue)
Tylan General, Inc.
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.