Telephone conference bridge system

Claim 1

A telephone conference bridge system for interconnecting a plurality of telephone lines in a conference connection comprising a line interface circuit connected between said telephone lines and a conference bridge circuit, a tone transmitter/receiver connected to said line interface circuit, and a computer connected to said line interface circuit and said tone transmitter/receiver, said line interface circuit having means for detection of incoming calls on said lines and, via said tone transmitter/receiver, indicating each said detection to said computer, said computer storing information regarding the busy/idle status of said telephone lines and controlling relay means in said interface circuit for connecting each line having an incoming call to the bridge circuit, said relay means being driven by relay drivers actuated by the computer via a peripheral interface adapter, wherein an incoming call on a line is detected by a ring detector in the line interface circuit, said ring detector sending a signal to the computer via a peripheral interface adapter to indicate the existence of the incoming call, said computer causing the tone transmitter/receiver to send tone signals to an incoming caller and only connecting the caller to the bridge system upon receipt of a predetermined reply sequence of tones, one of said lines being designated a "Chairman's Port" and said interface circuit having means whereby only the Chairman's Port can make outgoing calls from the bridge system by connecting said one of said lines to another one of said lines, a predetermined tone code via the Chairman's Port causing the computer to block all idle lines after a conference is established.