Granted Patent
Utility
US 4,766,893 · App. 07/040,936
Emergency oxygen supply unit with a respirator
Inventor:
Wolfgang Drews
Patented Case
View Patent ↗
Granted: Aug 30, 1988
Filed: Apr 21, 1987
Inventor
Wolfgang Drews
Assignee (at issue)
DRAGERWERK AKTIEGESELLSCHAFT
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.