Granted Patent
Utility
US 4,577,692 · App. 06/707,914
Pressure operated test valve
Inventor:
Daniel Reardon
Patented Case
View Patent ↗
Granted: Mar 25, 1986
Filed: Mar 4, 1985
Inventor
Daniel Reardon
Assignee (at issue)
Hughes Tool Company LLC
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.