Granted Patent
Utility
US 6,690,617 · App. 09/904,434
Application of sonic signals to detect buried, underground utilities
Inventor:
Robert W. Cribbs
Patented Case
View Patent ↗
Granted: Feb 10, 2004
Filed: Jul 12, 2001
Inventor
Robert W. Cribbs
Assignee (at issue)
Gas Research Institute
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.