Private branch exchange telephone system with dial transfer facilities

Claim 1

IN AN AUTOMATIC TELEPHONE SYSTEM, A PRIVATE BRANCH EXCHANGE, A PLURALITY OF CENTRAL OFFICE TRUNKS TERMINATING AT SAID PRIVATE BRANCH EXCHANGE, A PLURALITY OF EXTENSIONS AT SAID PRIVATE BRANCH EXCHANGE, MEANS FOR COMPLETING A CONNECTION OVER ONE OF SAID CENTRAL OFFICE TRUNKS BETWEEN AN OUTSIDE STATION AND A FIRST ONE OF SAID EXTENSIONS STATIONS, MEANS FOR TEMPORARILY INTERRUPTING SAID CONNECTION BY SPLITTING SAID ONE CENTRAL OFFICE TRUNK BETWEEN THE OFFICE END AND THE LINE END, A TRANSFER TRUNK AT SAID PRIVATE BRANCH EXCHANGE, MEANS ACTIVATED BY SAID FIRST ONE OF SAID EXTENSIONS FOR SEIZING SAID TRANSFER TRUNK AND FOR COMPLETING A CONNECTION OVER SAID OFFICE END OF SAID ONE CENTRAL OFFICE TRUNK AND SAID TRANSFER TRUNK FROM SAID FIRST EXTENSION TO A SECOND ONE OF SAID EXTENSIONS, MEANS ACTIVATED BY EITHER SAID FIRST OR SAID SECOND EXTENSION FOR RESTORING SAID FIRST-MENTIONED CONNECTION WHEREBY TO JOIN SAID OUTSIDE STATION AND SAID FIRST AND SECOND EXTENSIONS IN A CONNECTION FOR CONVERSATION, AND MEANS CONTROLLED BY SAID SECOND EXTENSION AND EFFECTIVE UPON SAID FIRST EXTENSION GOING ON HOOK FOR COMPLETING A CONNECTION OVER SAID TRANSFER TRUNK AND THE OFFICE END OF SAID CENTRAL OFFICE TRUNK FROM SAID SECOND EXTENSION TO A THIRD OF SAID EXTENSIONS.