Granted Patent
Utility
US 6,644,422 · App. 09/929,175
Pantograph underreamer
Inventors:
Monty H. Rial, Lawrence W. Diamond, Harold E. Payne
Patented Case
View Patent ↗
Granted: Nov 11, 2003
Filed: Aug 13, 2001
Inventors
Monty H. Rial
Lawrence W. Diamond
Harold E. Payne
Assignee (at issue)
CDX Gas, 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.