Granted Patent
Utility
US 6,401,466 · App. 09/808,452
Door monitor apparatus for interrupting and restoring walk-in refrigeration system operation and alarm monitoring system therefor
Inventor:
Donald Olsen
Patented Case
View Patent ↗
Granted: Jun 11, 2002
Filed: Mar 14, 2001
Inventor
Donald Olsen
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.