Granted Patent
Utility
US 4,619,425 · App. 06/284,150
Pulse code system for railroad track circuits
Inventor:
Harry C. Nagel
Patented Case
View Patent ↗
Granted: Oct 28, 1986
Filed: Jul 17, 1981
Inventor
Harry C. Nagel
Assignee (at issue)
American Standard Inc.
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.