Granted Patent
Utility
US 4,402,172 · App. 06/218,947
Flexible packaging structure and process for making it
Inventor:
Duane A. Krueger
Patented Case
View Patent ↗
Granted: Sep 6, 1983
Filed: Dec 22, 1980
Inventor
Duane A. Krueger
Assignee (at issue)
American Can 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.