Granted Patent
Utility
US 5,230,017 · App. 07/789,689
Communication line monitoring system
Inventor:
Robert Alexander
Patented Case
View Patent ↗
Granted: Jul 20, 1993
Filed: Nov 8, 1991
Inventor
Robert Alexander
Assignee (at issue)
British Technology Group USA 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.