Granted Patent
Utility
US 6,533,052 · App. 09/767,106
Drill bit for impact-assisted directional boring
Inventors:
Steven W. Wentworth, Robert F. Crane, Mark D. Randa, Randy R. Runquist, Richard K. Smith
Patented Case
View Patent ↗
Granted: Mar 18, 2003
Filed: Jan 22, 2001
Inventors
Steven W. Wentworth
Robert F. Crane
Mark D. Randa
Randy R. Runquist
Richard K. Smith
Assignees (at issue)
Earth Tool Company LLC
Vermeer Manufacturing Company
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.