Granted Patent
Utility
US 4,627,431 · App. 06/710,670
Protective hood with CO.sub.2 absorbent
Inventor:
Bertil R. L. Werjefelt
Patented Case
View Patent ↗
Granted: Dec 9, 1986
Filed: Mar 12, 1985
Inventor
Bertil R. L. Werjefelt
Assignee (at issue)
E.I. DU PONT DE NEMOURS AND 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.