Granted Patent
Utility
US 4,691,375 · App. 06/617,733
Data transmission using a transparent tone-in band system
Inventors:
Joseph P. McGeehan, Andrew Bateman
Patented Case
View Patent ↗
Granted: Sep 1, 1987
Filed: Jun 6, 1984
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.