Granted Patent
Utility
US 6,516,899 · App. 09/957,411
Method and apparatus for directional boring under mixed conditions
Inventors:
Steven W. Wentworth, Robert F. Crane, Randy R. Runquist, Mark Van Houwelingen
Patented Case
View Patent ↗
Granted: Feb 11, 2003
Filed: Sep 20, 2001
Inventors
Steven W. Wentworth
Robert F. Crane
Randy R. Runquist
Mark Van Houwelingen
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.