Granted Patent
Utility
US 4,366,836 · App. 06/187,910
Valved vent for a liquid drainage system
Inventor:
Frank K. Villari
Patented Case
View Patent ↗
Granted: Jan 4, 1983
Filed: Sep 17, 1980
Inventor
Frank K. Villari
Assignee (at issue)
The Kendall Company LP
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.