Granted Patent
Utility
US 4,679,142 · App. 06/627,867
Radioactive material billing system and method
Inventor:
Denny L. Y. Lee
Patented Case
View Patent ↗
Granted: Jul 7, 1987
Filed: Jul 2, 1984
Inventor
Denny L. Y. Lee
Assignee (at issue)
E.I. DU PONT DE NEMOURS AND 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.