Granted Patent
Utility
US 5,221,439 · App. 07/716,083
Orbital tube evaporator with improved heat transfer
Inventors:
Yao Li, Henry V. Huang, I-Chieng Ho, Albert P. Yundt, Jr.
Patented Case
View Patent ↗
Granted: Jun 22, 1993
Filed: Jun 17, 1991
Inventors
Yao Li
Henry V. Huang
I-Chieng Ho
Albert P. Yundt, Jr.
Assignee (at issue)
Y.T. Li Engineering, 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.