Granted Patent
Utility
US 4,334,581 · App. 06/186,587
Balanced area safety valve
Inventor:
Henry P. Arendt
Patented Case
View Patent ↗
Granted: Jun 15, 1982
Filed: Sep 12, 1980
Inventor
Henry P. Arendt
Assignee (at issue)
Otis Engineering Corporation
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.