Granted Patent
Utility
US 4,369,778 · App. 06/252,234
Method and apparatus for a portable respirator
Inventors:
Amos Norris, Edwin J. Dorius
Patented Case
View Patent ↗
Granted: Jan 25, 1983
Filed: Apr 8, 1981
Inventors
Amos Norris
Edwin J. Dorius
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.