Granted Patent
Utility
US 4,458,821 · App. 06/448,064
Tamper-indicating closure
Inventor:
Efrem M. Ostrowsky
Patented Case
View Patent ↗
Granted: Jul 10, 1984
Filed: Dec 9, 1982
Inventor
Efrem M. Ostrowsky
Assignee (at issue)
Ethyl Molded Products 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.