Granted Patent
Utility
US 6,250,857 · App. 09/395,430
Drill
Inventor:
Heinrich Kersten
Patented Case
View Patent ↗
Granted: Jun 26, 2001
Filed: Sep 14, 1999
Inventor
Heinrich Kersten
Assignee (at issue)
Gebrueder Heller Dinklage 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.