Granted Patent
Utility
US 6,749,172 · App. 10/423,105
Rotating blowout preventer with independent cooling circuits and thrust bearing
Inventor:
Joseph Kinder
Patented Case
View Patent ↗
Granted: Jun 15, 2004
Filed: Apr 25, 2003
Inventor
Joseph Kinder
Assignee (at issue)
Precision Drilling Technology Services Group, 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.