Granted Patent
Utility
US 5,030,672 · App. 07/593,390
Membranes
Inventors:
Richard A. Hann, David R. Holmes, III, John W. Smith
Patented Case
View Patent ↗
Granted: Jul 9, 1991
Filed: Oct 1, 1990
Inventors
Richard A. Hann
David R. Holmes, III
John W. Smith
Assignee (at issue)
IMPERIAL CHEMICAL INDUSTRIES LIMITED
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.