Granted Patent
Utility
US 4,511,520 · App. 06/402,759
Method of making perforated films
Inventor:
William E. Bowen
Patented Case
View Patent ↗
Granted: Apr 16, 1985
Filed: Jul 28, 1982
Inventor
William E. Bowen
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.