Granted Patent
Utility
US 4,460,042 · App. 06/316,397
Dual ring casing hanger
Inventor:
Edward M. Galle, Jr.
Patented Case
View Patent ↗
Granted: Jul 17, 1984
Filed: Oct 29, 1981
Inventor
Edward M. Galle, Jr.
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.