Granted Patent
Utility
US 5,902,460 · App. 08/717,560
Multi-stage fractional distillation process and apparatus
Inventor:
Bruce W. Gerhold
Patented Case
View Patent ↗
Granted: May 11, 1999
Filed: Sep 23, 1996
Inventor
Bruce W. Gerhold
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.