Granted Patent
Utility
US 4,382,538 · App. 06/190,923
Valved lined container
Inventor:
Fred B. Wilharm
Patented Case
View Patent ↗
Granted: May 10, 1983
Filed: Sep 26, 1980
Inventor
Fred B. Wilharm
Assignee (at issue)
St. Regis Paper 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.