Granted Patent
Utility
US 5,159,577 · App. 07/755,483
Technique for reducing whirling of a drill string
Inventor:
James R. Twist
Patented Case
View Patent ↗
Granted: Oct 27, 1992
Filed: Sep 5, 1991
Inventor
James R. Twist
Assignee (at issue)
Baroid Technology, Inc.
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.