Granted Patent
Utility
US 4,415,438 · App. 06/324,450
Method for catalytically converting residual oils
Inventors:
Robert R. Dean, Warren S. Letzsch, Jean-Louis Mauleon
Patented Case
View Patent ↗
Granted: Nov 15, 1983
Filed: Nov 24, 1981
Inventors
Robert R. Dean
Warren S. Letzsch
Jean-Louis Mauleon
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.