Granted Patent
Utility
US 4,550,780 · App. 06/259,019
Pressure operated safety valve with lock means
Inventor:
James D. Mott
Patented Case
View Patent ↗
Granted: Nov 5, 1985
Filed: Apr 30, 1981
Inventor
James D. Mott
Assignee (at issue)
Hydril 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.