Granted Patent
Utility
US 4,345,593 · App. 06/231,994
Pressure-demand breathing apparatus with automatic air shut-off
Inventor:
John L. Sullivan
Patented Case
View Patent ↗
Granted: Aug 24, 1982
Filed: Feb 6, 1981
Inventor
John L. Sullivan
Assignee (at issue)
ATO BV
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.