Granted Patent
Utility
US 4,483,721 · App. 06/565,262
Method and apparatus for cutting patterns through pipe
Inventor:
David D. Hearn
Patented Case
View Patent ↗
Granted: Nov 20, 1984
Filed: Dec 27, 1983
Inventor
David D. Hearn
Assignee (at issue)
Atlantic Richfield 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.