Granted Patent
Utility
US 4,858,821 · App. 07/270,320
Package and lid with controlled tearing means
Inventor:
Roger G. Bickelhaupt
Patented Case
View Patent ↗
Granted: Aug 22, 1989
Filed: Nov 14, 1988
Inventor
Roger G. Bickelhaupt
Assignee (at issue)
Baxter International Inc.
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.