Granted Patent
Utility
US 4,969,998 · App. 06/603,186
Composite semipermeable membrane
Inventor:
Robert Lyon Henn
Patented Case
View Patent ↗
Granted: Nov 13, 1990
Filed: Apr 23, 1984
Inventor
Robert Lyon Henn
Assignee (at issue)
W. L. Gore & Associates, Inc.
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.