Granted Patent
Utility
US 4,802,191 · App. 07/019,129
Data transmission using a transparent tone-in band system
Inventors:
Joseph P. McGeehan, Andrew Bateman
Patented Case
View Patent ↗
Granted: Jan 31, 1989
Filed: Feb 26, 1987
Inventors
Joseph P. McGeehan
Andrew Bateman
Assignee (at issue)
NATIONAL RESEARCH DEVELOPMENT 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.