Granted Patent
Utility
US 4,212,395 · App. 05/969,224
Multi-angled perforated opening device
Inventor:
Ralph J. Korte
Patented Case
View Patent ↗
Granted: Jul 15, 1980
Filed: Jan 22, 1979
Inventor
Ralph J. Korte
Assignee (at issue)
Champion International Corporation Limited
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.