Granted Patent
Utility
US 4,715,908 · App. 06/864,333
Duplex stainless steel product with improved mechanical properties
Inventor:
Robin K. Churchill
Patented Case
View Patent ↗
Granted: Dec 29, 1987
Filed: May 19, 1986
Inventor
Robin K. Churchill
Assignee (at issue)
ESCO GROUP LLC
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.