Granted Patent
Utility
US 4,220,535 · App. 05/931,049
Multi-zoned hollow fiber permeator
Inventor:
Richard L. Leonard
Patented Case
View Patent ↗
Granted: Sep 2, 1980
Filed: Aug 4, 1978
Inventor
Richard L. Leonard
Assignee (at issue)
Monsanto 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.