Granted Patent
Utility
US 5,449,270 · App. 08/265,542
Tangential flow pumping channel for turbomolecular pumps
Inventors:
Giampaolo Levi, John C. Helmer
Patented Case
View Patent ↗
Granted: Sep 12, 1995
Filed: Jun 24, 1994
Inventors
Giampaolo Levi
John C. Helmer
Assignee (at issue)
Varian, 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.