Granted Patent
Utility
US 4,640,428 · App. 06/772,277
High gas barrier plastic closure
Inventor:
Long F. Chang
Patented Case
View Patent ↗
Granted: Feb 3, 1987
Filed: Sep 3, 1985
Inventor
Long F. Chang
Assignee (at issue)
Owens-Illinois 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.