Granted Patent
Utility
US 4,213,538 · App. 06/055,897
Can end closure
Inventor:
Alfred H. Boardman
Patented Case
View Patent ↗
Granted: Jul 22, 1980
Filed: Jul 9, 1979
Inventor
Alfred H. Boardman
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.