Granted Patent
Utility
US 5,000,723 · App. 07/341,486
Universal joint for downhole motors
Inventor:
Ray Livingstone
Patented Case
View Patent ↗
Granted: Mar 19, 1991
Filed: Apr 21, 1989
Inventor
Ray Livingstone
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.