Granted Patent
Utility
US 4,397,357 · App. 06/255,972
Disconnectable production riser assembly
Inventor:
Fredric L. Hettinger
Patented Case
View Patent ↗
Granted: Aug 9, 1983
Filed: Apr 20, 1981
Inventor
Fredric L. Hettinger
Assignee (at issue)
Vetco Offshore, 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.