Granted Patent
Utility
US 4,282,408 · App. 06/088,219
On-hook/off-hook detector circuit
Inventor:
Olgerts Stauers
Patented Case
View Patent ↗
Granted: Aug 4, 1981
Filed: Oct 25, 1979
Inventor
Olgerts Stauers
Assignee (at issue)
Western Electric Company, 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.