Granted Patent
Utility
US 6,171,026 · App. 09/121,418
Method and apparatus for replacement of pipelines
Inventors:
Robert F. Crane, Steven W. Wentworth
Patented Case
View Patent ↗
Granted: Jan 9, 2001
Filed: Jul 23, 1998
Inventors
Robert F. Crane
Steven W. Wentworth
Assignee (at issue)
Earth Tool Company LLC
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.