Granted Patent
Utility
US 5,272,874 · App. 07/765,689
Exhaust treatment system
Inventor:
Norbert Paas
Patented Case
View Patent ↗
Granted: Dec 28, 1993
Filed: Sep 26, 1991
Inventor
Norbert Paas
Assignee (at issue)
Dry Systems Technologies
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.