Granted Patent
Utility
US 5,867,560 · App. 08/653,185
Remote hang-up detector
Inventor:
Robert W. Frankland
Patented Case
View Patent ↗
Granted: Feb 2, 1999
Filed: May 24, 1996
Inventor
Robert W. Frankland
Assignee (at issue)
Rockwell International Corporation
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.