Methods and apparatus for transmitting records

Claim 1

APPARATUS FOR THE SIMULTANEOUS TRANSMISSION OF A PLURALITY OF FUNCTIONS OF A COMMON INDEPENDENT VARIABLE COMPRISING TRANSMITTING MEANS, MEANS FOR SUPPLYING TO SAID TRANSMITTING MEANS A PLURALITY OF SIGNALS CORRESPONDING RESPECTIVELY TO SAID FUNCTIONS, SAID TRANSMITTING MEANS COMPRISING MEANS FOR PRODUCING IN RESPONSE TO THE FIRST MENTIONED SIGNALS A PLURALITY OF FREQUENCY-MODULATED SIGNALS EACH OF WHICH CORRESPONDS TO ONE OF SAID FIRST MENTIONED SIGNALS, AND COMPRISING MEANS FOR MIXING SAID FREQUENCY-MODULATED SIGNALS, MEANS PROVIDING A TRANSMISSION LINK RECEIVING THE MIXED FREQUENCY-MODULATED SIGNALS AND TRANSMITTING THEM TO A POINT REMOTE FROM SAID TRANSMITTING MEANS, MEANS AT SAID POINT RECEIVING THE SIGNALS SO TRANSMITTED, MIXING THE LAST MENTIONED SIGNALS WITH A FIXED AUDIO FREQUENCY SIGNAL, AND RECORDING THE SO MIXED SIGNALS IN A SINGLE RECORD CHANNEL, MEANS FOR REPRODUCING THE SIGNALS FROM SAID CHANNEL, MEANS SEPARATING THE INDIVIDUAL SIGNALS THEREOF, MEANS DEMODULATING SAID FREQUENCY-MODULATED SIGNALS AND ALSO THE SIGNAL PROVIDED AT SAID FIXED FREQUENCY TO PROVIDE RESPECTIVE VARIABLE AMPLITUDE SIGNALS CORRESPONDING THERETO, AND MEANS RECORDING SIMULTANEOUSLY A PLURALITY OF SIGNALS EACH OF WHICH CORRESPONDS RESPECTIVELY TO THE DIFFERENCE OF AMPLITUDE OF THE AMPLITUDE SIGNAL DERIVED FROM SAID SIGNAL PROVIDED AT SAID FIXED FREQUENCY AND THE AMPLITUDE OF ONE OF SIGNALS DERIVED FROM THE FREQUENCY-MODULATED SIGNALS.