Granted Patent
Utility
US 4,431,539 · App. 06/009,444
Semipermeable membrane mass transfer apparatus and method for making same
Inventor:
Alexander S. Borsanyi
Patented Case
View Patent ↗
Granted: Feb 14, 1984
Filed: Feb 5, 1979
Inventor
Alexander S. Borsanyi
Assignee (at issue)
American Hospital Supply Corp.
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.