Granted Patent
Utility
US 6,216,797 · App. 09/228,154
Thrust system for a horizontal directional drill
Inventors:
Robert G. Draney, Willie J. Lessard
Patented Case
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Granted: Apr 17, 2001
Filed: Jan 11, 1999
Inventors
Robert G. Draney
Willie J. Lessard
Assignee (at issue)
Case 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.