Granted Patent
Utility
US 4,941,575 · App. 07/344,972
Sift-proof carton and blank therefor
Inventor:
Herbert Friedman
Patented Case
View Patent ↗
Granted: Jul 17, 1990
Filed: Apr 27, 1989
Inventor
Herbert Friedman
Assignee (at issue)
Ivy Hill Corporation
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.