Granted Patent
Utility
US 4,366,591 · App. 06/205,932
Automatic safety gangplank
Inventor:
Mahlon N. Zimmerman
Patented Case
View Patent ↗
Granted: Jan 4, 1983
Filed: Nov 12, 1980
Inventor
Mahlon N. Zimmerman
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.