Granted Patent
Utility
US 4,290,787 · App. 06/148,846
Bottom-powered electrostatic precipitator
Inventor:
Melvin R. Kahl
Patented Case
View Patent ↗
Granted: Sep 22, 1981
Filed: May 12, 1980
Inventor
Melvin R. Kahl
Assignee (at issue)
Envirotech, 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.