Granted Patent
Utility
US 5,601,692 · App. 08/565,851
Process for treating noncaking coal to form passivated char
Inventors:
Franklin G. Rinker, Deane A. Horne, Dennis W. Coolidge, Ernest P. Esztergar
Patented Case
View Patent ↗
Granted: Feb 11, 1997
Filed: Dec 1, 1995
Inventors
Franklin G. Rinker
Deane A. Horne
Dennis W. Coolidge
Ernest P. Esztergar
Assignee (at issue)
Tek-Kol
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.