Granted Patent
Utility
US 6,802,673 · App. 10/049,367
Tunnel boring with foamed composition
Inventor:
Peter Ellenberger
Patented Case
View Patent ↗
Granted: Oct 12, 2004
Filed: May 3, 2002
Inventor
Peter Ellenberger
Assignee (at issue)
MBT Holding 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.