Granted Patent
Utility
US 4,528,696 · App. 06/488,267
Arrangement for providing signalling tones and volume control signals
Inventor:
Robert J. Martin
Patented Case
View Patent ↗
Granted: Jul 9, 1985
Filed: Apr 25, 1983
Inventor
Robert J. Martin
Assignee (at issue)
General Electric Company
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.