Granted Patent
Utility
US 4,644,688 · App. 06/658,406
Security door
Inventor:
Lawrence Benderoff
Patented Case
View Patent ↗
Granted: Feb 24, 1987
Filed: Oct 5, 1984
Inventor
Lawrence Benderoff
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.