Granted Patent
Utility
US 4,480,813 · App. 06/400,431
Kelly cock rotary drive mechanism
Inventor:
Patrick C. Holley
Patented Case
View Patent ↗
Granted: Nov 6, 1984
Filed: Jul 26, 1982
Inventor
Patrick C. Holley
Assignee (at issue)
Hydril Company
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.