Key telephone system

Details Key telephone system Key telephone system

1980-08-18

1982-08-31

Brigance, Gerald L.

179 99R, H04Q 520

Patent

active

043474098

ABSTRACT:
A key telephone system comprises a main equipment connected to at least one set of central office (CO) lines and capable of connecting thereto a plurality of key telephones. The main equipment includes a dual tone multifrequency (DTMF) sending circuit common to the key telephones, and the respective key telephones are connected to the main equipment through six wiring cables forming a pair of two-way voice frequency talking circuits and one two-way data transmitting circuit. A plurality of switching matrixes are included in the main equipment for selectively connecting the CO lines and the talking circuits, and also connecting the data transmitting circuit through the DTMF sending circuit to the CO lines and one of the talking circuits in the key telephone, whereby respective functions of hand-free talk-back and off-hook signalling during intercom talking, and speaker monitoring function during CO line talking are performable.

REFERENCES:
patent: 4160131 (1979-07-01), Kaul et al.
patent: 4184054 (1980-01-01), Shibata et al.
patent: 4203011 (1980-05-01), Coviello
patent: 4236049 (1980-11-01), Tanihata et al.

Affiliated with

Also associated with

Rating

Key telephone system does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Key telephone system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Key telephone system will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2185551