Granted Patent
Utility
US 6,220,290 · App. 09/581,126
Double block and bleed ball valves including retainer components
Inventor:
Stuart Lomax
Patented Case
View Patent ↗
Granted: Apr 24, 2001
Filed: Aug 25, 2000
Inventor
Stuart Lomax
Assignee (at issue)
Alco Hi-Tek Ltd.
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.