Granted Patent
Utility
US 4,476,935 · App. 06/473,564
Safety valve apparatus and method
Inventors:
Joseph H. Hynes, Charles D. Morrill
Patented Case
View Patent ↗
Granted: Oct 16, 1984
Filed: Mar 9, 1983
Inventors
Joseph H. Hynes
Charles D. Morrill
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.