Granted Patent
Utility
US 4,303,521 · App. 06/161,020
Column for the treatment of a liquid by means of a particulate material
Inventor:
Hans D. Lehmann
Patented Case
View Patent ↗
Granted: Dec 1, 1981
Filed: Jun 19, 1980
Inventor
Hans D. Lehmann
Assignee (at issue)
Gambro Dialysatoren GmbH
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.