Granted Patent
Utility
US 4,274,351 · App. 06/118,680
Can end closure
Inventor:
Alfred H. Boardman
Patented Case
View Patent ↗
Granted: Jun 23, 1981
Filed: Feb 5, 1980
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.