Granted Patent
Utility
US 4,434,971 · App. 06/233,561
Drilling rig drawworks hook load overspeed preventing system
Inventor:
Richard N. Cordrey
Patented Case
View Patent ↗
Granted: Mar 6, 1984
Filed: Feb 11, 1981
Inventor
Richard N. Cordrey
Assignee (at issue)
Armco 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.