Granted Patent
Utility
US 5,971,078 · App. 08/839,573
Method and apparatus for retrieving downhole tools
Inventors:
Leonardo Ritorto, Dave L. Heinley
Patented Case
View Patent ↗
Granted: Oct 26, 1999
Filed: Apr 15, 1997
Inventors
Leonardo Ritorto
Dave L. Heinley
Assignee (at issue)
Canadian Downhole Drill Systems
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.