Granted Patent
Utility
US 5,139,674 · App. 07/571,608
Method of purifying dry-cleaning solvent
Inventor:
Masanobu Abo
Patented Case
View Patent ↗
Granted: Aug 18, 1992
Filed: Sep 5, 1990
Inventor
Masanobu Abo
Assignee (at issue)
Novo Nordisk A/S
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.