Granted Patent
Utility
US 4,919,341 · App. 07/289,059
Grinding method and grinding apparatus
Inventor:
Ludger Lohnherr
Patented Case
View Patent ↗
Granted: Apr 24, 1990
Filed: Dec 23, 1988
Inventor
Ludger Lohnherr
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.