Granted Patent
Utility
US 5,961,254 · App. 08/916,615
Hydraulic advancing support frame
Inventor:
Hans-Otto Friedrichs
Patented Case
View Patent ↗
Granted: Oct 5, 1999
Filed: Aug 22, 1997
Inventor
Hans-Otto Friedrichs
Assignee (at issue)
DBT Deutsche Bergbau-Technik 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.