Time division multiplex transmission systems

Claim 1

A PULSE CODE MODULATION TIME DIVISION MULTIPLEX TELEPHONE SWITCHING SYSTEM COMPRESING A PLURALITY OF TRUNKLINES INCOMING FROM A DISTANT LOCATION TO AN ASSOCIATED LOCAL TRUNK CIRCUIT, MEANS WHEREBY EACH OF SAID TRUNKLINES CARRY A PLURALITY OF TIME POSITIONED CHANNELS, MEANS FOR TRANSMITTING SAMPLES OF INTELLIGENCE IN PULSE CODE MODULATED FORM OVER SAID LINES DURING DISCRETE TIME CHANNELS, THE TRANSMISSION CHARACTERISTICS OF SAIT LINES SOMETIMES CAUSING TIME FLUCTUATIONS OF SIGNALS IN SAID CHANNELS, MEANS ASSOCIATED WITH EACH OF SAID TRUNKS FOR RECEIVING AND STORING THE PULSE CODE MODULATIONS OF SAID SAMPLES IN LOCATIONS CORRESPONDING TO THE TIME POSITIONS OF CHANNELS CARRYING SAID INTELLIGENCE, A LOCAL CLOCK, MEANS FOR CYCLICALLY CONNECTING EACH INCOMING TRUNKLINE TO A CIRCUIT FOR DETECTING SYNCHRONIZATION VARIATIONS BETWEEN INCOMING SIGNALS AND THE OUTPUT OF SAID LOCAL CLOCK, MEANS IN EACH OF SAID TRUNK CIRCUITS FOR EXTRACTING A TIME REFERENCE SIGNAL FROM EACH OF SAID INCOMING SIGNALS, MEANS FOR COMPARING THE OUTPUT OF SAID LOCAL CLOCK TO THE EXTRACTED TIME SIGNAL, AND MEANS FOR RETIMING THE PULSE CODE MODULATIONS OF INCOMING SIGNAL RESPONSIVE TO A DETECTION OF AN EXCESSIVE TIME FLUCTUATION BETWEEN SAID EXTRACTED REFERENCE SIGNAL AND THE OUTPUT OF SAID LOCAL CLOCK, WHEREBY SAID RECEIVED SIGNAL REAPPEARS IN THE PART OF THE TIME CHANNEL THAT IS RESERVED FOR TRANSMISSION OF SAID INTELLIGENCE.