Granted Patent
Utility
US 4,828,221 · App. 07/118,188
Valve assembly
Inventors:
William B. Scobie, Paul A. Yohner
Patented Case
View Patent ↗
Granted: May 9, 1989
Filed: Nov 6, 1987
Inventors
William B. Scobie
Paul A. Yohner
Assignee (at issue)
Keystone International
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.