Granted Patent
Utility
US 3,980,839 · App. 05/530,960
Maintenance monitor for telephone switching systems
Inventor:
Alan G. Hutcheson
Patented Case
View Patent ↗
Granted: Sep 14, 1976
Filed: Dec 9, 1974
Inventor
Alan G. Hutcheson
Assignee (at issue)
Lynch Communications Systems, 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.