Granted Patent
Utility
US 5,143,703 · App. 07/632,819
Fluid flow control and isolation
Inventor:
Keith W. Hovis
Patented Case
View Patent ↗
Granted: Sep 1, 1992
Filed: Dec 24, 1990
Inventor
Keith W. Hovis
Assignee (at issue)
Phillips Petroleum Company
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.