Granted Patent
Utility
US 6,050,351 · App. 08/922,574
Drilling hole system for horizontal boreholes
Inventors:
Josef Eckenfels, Herbert Haas, Norbert Prinz, Christian Wartel, Dominique Pfeiffer
Patented Case
View Patent ↗
Granted: Apr 18, 2000
Filed: Sep 3, 1997
Inventors
Josef Eckenfels
Herbert Haas
Norbert Prinz
Christian Wartel
Dominique Pfeiffer
Assignee (at issue)
Gaz de France (G.D.F.) Service National Powerdrill GmbH Und Co KG
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.