A voice/data switch (13) for selectively connecting an audio communication terminal device (15), such as a telephone, or a piece of electronic data communication equipment (17), such as a telephone facsimile device or a computer, to a Telco line (19) is disclosed. The voice/data switch (13) includes...http://www.google.es/patents/US4821312?utm_source=gb-gplus-sharePatente US4821312 - Voice/data switch
