Granted Patent
Utility
US 4,734,933 · App. 06/794,696
Telephone line status circuit
Inventors:
John A. Barsellotti, Douglas Oddy
Patented Case
View Patent ↗
Granted: Mar 29, 1988
Filed: Nov 4, 1985
Inventors
John A. Barsellotti
Douglas Oddy
Assignee (at issue)
Mitel 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.