Granted Patent
Utility
US 4,331,509 · App. 06/166,371
Digester strainer locking assembly
Inventor:
John F. Oettinger
Patented Case
View Patent ↗
Granted: May 25, 1982
Filed: Jul 7, 1980
Inventor
John F. Oettinger
Assignee (at issue)
ESCO GROUP LLC
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.