Granted Patent
Utility
US 5,639,957 · App. 08/542,064
Method and apparatus for performing modal mass analysis of exhaust gas from motor vehicle
Inventor:
Richard R. Zarchy
Patented Case
View Patent ↗
Granted: Jun 17, 1997
Filed: Oct 12, 1995
Inventor
Richard R. Zarchy
Assignee (at issue)
Snap-On Technologies, 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.