Granted Patent
Utility
US 4,251,671 · App. 06/082,078
Extraction of citric acid
Inventors:
John E. Alter, Ruth Blumberg
Patented Case
View Patent ↗
Granted: Feb 17, 1981
Filed: Oct 5, 1979
Inventors
John E. Alter
Ruth Blumberg
Assignee (at issue)
Miles Laboratories, 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.