Granted Patent
Utility
US 5,642,863 · App. 08/626,209
Method of extracting metals from ore material
Inventors:
Norbert Patzelt, Johann Knecht
Patented Case
View Patent ↗
Granted: Jul 1, 1997
Filed: Mar 29, 1996
Inventors
Norbert Patzelt
Johann Knecht
Assignee (at issue)
Krupp Polysius AG
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.