Pbx dial conference trunk circuit

Claim 1

IN AN AUTOMATIC TELEPHONE SWITCHING SYSTEM, A PRIVATE BRANCH EXCHANGE, AN ATTENDANT''S POSITION AND A PLURALITY OF CUSTOMER STATIONS ASSOCIATED WITH SAID PRIVATE BRANCH EXCHANGE, A CONFERENCE CIRCUIT ALSO ASSOCIATED WITH SAID PRIVATE BRANCH EXCHANGE AND HAVING A PLURALITY OF CONFERENCE PORTS, SAID CONFERENCE PORTS NORMALLY BEING ACCESSIBLE ONLY THROUGH CONNECTION OF SELECTED ONES OF SAID CUSTOMER STATIONS, MEANS UNDER CONTROL OF AN INITIAL ONE OF SAID CUSTOMER STATIONS FOR CONNECTING SAID STATION TO A FIRST OF SAID CONFERENCE PORTS AND FOR CONNECTING OTHER SELECTED STATIONS TO OTHERS OF SAID CONFERENCE PORTS IN TURN, A CENTRAL OFFICE TRUNK TERMINATING AT SAID PRIVATE BRANCH EXCHANGE, CONNECTION OF SAID CENTRAL OFFICE TRUNK BEING CONTROLLED THROUGH SAID ATTENDANT''S POSITION TO THE EXCLUSION OF SAID CUSTOMER STATIONS, AND MEANS CONTROLLED BY SAID INTITIAL ONE OF SAID CUSTOMER STATIONS FOR RENDERING ONE OF SAID CONFERENCE PORTS TEMPORARILY ACCESSIBLE FOR CONNECTION OF SAID CENTRAL OFFICE TRUNK UNDER CONTROL OF SAID ATTENDANT''S POSITION.