Granted Patent
Utility
US 6,405,812 · App. 09/685,786
Drilling tool for the air-lifting process
Inventor:
Fritz Tibussek
Patented Case
View Patent ↗
Granted: Jun 18, 2002
Filed: Oct 10, 2000
Inventor
Fritz Tibussek
Assignee (at issue)
Wirth Maschinen-und Bohrgerate-Fabrik GmbH
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.