Granted Patent
Utility
US 4,217,731 · App. 06/037,858
Fire door
Inventor:
Joseph N. Saino
Patented Case
View Patent ↗
Granted: Aug 19, 1980
Filed: May 10, 1979
Inventor
Joseph N. Saino
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.