Selective calling system

Claim 1

A SYSTEM OF CALLING A PLURALITY OF REMOTE STATIONS OVER A SINGLE COMMUNICATION CHANNEL WHERE EACH REMOTE STATION INCLUDES A RECEIVER UNIT TUNED TO TWO DISTINCT TONE FREQUENCIES ONE OF WHICH IS COMMON TO ALL REMOTE STATIONS FROM A CENTRAL STATION INCLUDING A TRANSMITTER UNIT COMPRISING, IN COMBINATION, AT SAID CENTRAL STATION (A) A PLURALITY OF TONE GENERATOR MEANS EACH NORMALLY INOPERATIVE BUT OPERABLE WHEN SET INTO OPERATION TO COUPLE A PREDETERMINED TONE FREQUENCY TO SAID TRANSMITTER UNIT, (B) A PLURALITY OF SELECTING MEANS ONE FOR EACH OF SAID PLURALITY OF REMOTE STATIONS AND HAVING A NORMAL NON-ACTUATED CONDITION OF OPERATION AND AN ACTUATED CONDITION OF OPERATION, (C) A PLURALITY OF STORAGE MEANS ONE OF EACH OF SAID PLURALITY OF SELECTING MEANS AND EACH OPERABLE FROM ITS NORMAL NON-STORAGE CONDITION TO A STORAGE CONDITION IN RESPONSE TO ITS CORRESPONDING SELECTING MEANS BEING AT LEAST TEMPORARILY OPERATED TO ITS ACTUATED CONDITION OF OPERATION, (D) A PLURALITY OF CODING MEANS ONE FOR EACH OF SAID PLURALITY OF SELECTING MEANS AND ITS CORRESPONDING STORAGE MEANS AND EACH OPERABLE TO SELECT CONCURRENTLY FOR OPERATION A PARTICULAR NUMBER OF SAID PLURALITY OF TONE GENERATOR MEANS LESS THAN THE PLURALITY, (E) MEANS RESPONSIVE TO EACH OF SAID PLURALITY OF CODING MEANS ONLY IN ITS OPERATIVE CONDITION FOR SETTING INTO OPERATION THE PARTICULAR NUMBER OF SAID TONE GENERATOR MEANS SELECTED CONCURRENTLY BY THE OPERATING CODING MEANS, (F) CIRCUIT MEANS FOR COUPLING CONTROL ENERGY TO EACH CODING MEANS FOR RENDERING IT OPERABLE UPON OPERATION OF ITS CORRESPONDING STORAGE MEANS TO ITS STORAGE CONDITION AND ACCORDING TO PARTICULAR ONES OF SAID PLURALITY OF STORAGE MEANS EACH BEING IN ITS NON-STORAGE CONDITION WHILE SAID MEANS IS NON-RESPONSIVE AND THE RESTORING ITS STORAGE MEANS TO ITS NON-STORAGE CONDITION, (G) TIMING MEANS SET INTO OPERATION RESPONSIVE TO SAID MEANS UPON INITIAL OPERATION THEREOF FOR SUCCESSIVELY MEASURING FIRST AND SECOND TIME INTERVALS AND THEREAFTER MEASURING SUCCESSIVELY A PLURALITY OF SECOND TIME INTERVALS ONE FOR EACH ADDITIONAL CODING MEANS RENDERED OPERABLE. (H) CONTROL CIRCUIT MEANS RESPONSIVE TO SAID TIMING MEANS DURING MEASUREMENT OF SAID FIRST TIME INTERVAL AND SAID MEANS IN ITS RESPONSIVE CONDITION FOR SETTING A GIVEN ONE OF SAID PLURALITY OF TONE GENERATOR MEANS INTO OPERATION AND THEREAFTER RESPONSIVE TO SAID TIMING MEANS DURING MEASUREMENT OF EACH SECONE TIME INTERVAL AND TO SAID MEANS IN ITS RESPONSIVE CONDITION FOR SETTING INTO OPERATION THE PARTICULAR NUMBER OF TONE GENERATOR MEANS CORRESPONDING TO THE CODE MEANS THEN OPERATING, SAID CONTROL CIRCUIT MEANS BEING EFFECTIVE UPON MEASUREMENT OF EACH SECOND TIME INTERVAL TO INTERRUPT THE COUPLING OF CONTROL ENERGY TO SAID PLURALITY OF CODING MEANS, WHEREBY THE LAST OPERATED CODING MEANS IS RENDERED INOPERATIVE CAUSING SAID MEANS TO BE RENDERED NONRESPONSIVE, (I) SAID TRANSMITTER UNIT INCLUDING MEANS FOR TRANSMITTING THE COMMON TONE FREQUENCY TO ALL REMOTE STATIONS AND COMBINING CONCURRENTLY APPLIED TONE FREQUENCIES INTO THE SECOND OF SAID TWO DISTINCT TONE FREQUENCIES FOR TRANSMISSION OVER SAID SINGLE COMMUNICATION CHANNEL TO THE CORRESPONDING REMOTE STATION.

Claim 2

A SYSTEM OF CALLING A PLURALITY OF REMOTE STATIONS OVER A SINGLE COMMUNICATION CHANNEL WHERE EACH REMOTE STATION INCLUDES A RECEIVER UNIT TUNED TO TWO DISTINCT TONE FREQUENCIES ONE OF WHICH IS COMMON TO ALL REMOTE STATIONS FROM A CENTRAL STATION INCLUDING A TRANSMITTER UNIT COMPRISING, IN COMBINATION, AT SAID CENTRAL STATION (A) A PLURALITY OF TONE GENERATOR MEANS EACH NORMALLY INOPERATIVE BUT OPERABLE WHEN SET INTO OPERATION TO COUPLE A PREDETERMINED TONE FREQUENCY TO SAID TRANSMITTER UNIT, (B) A PLURALITY OF SELECTING MEANS ONE FOR EACH OF SAID PLURALITY OF REMOTE STATIONS AND HAVING A NORMAL NON-ACTUATED CONDITION OF OPERATION AND AN ACTUATED CONDITION OF OPERATION, (C) A PLURALITY OF STORAGE MEANS ONE OF EACH OF SAID PLURALITY OF SELECTING MEANS AND EACH OPERABLE FROM ITS NORMAL NON-STORAGE CONDITION TO A STORAGE CONDITION IN RESPONSE TO ITS CORRESPONDING SELECTING MEANS BEING AT LEAST TEMPORARILY OPERATED TO ITS ACTUATED CONDITION OF OPERATION, (D) A PLURALITY OF CODING MEANS ONE FOR EACH OF SAID PLURALITY OF SELECTING MEANS AND ITS CORRESPONDING STORAGE MEANS AND EACH OPERABLE TO SELECT CONCURRENTLY FOR OPERATION A PARTICULAR NUMBER OF SAID PLURALITY OF TONE GENERATOR MEANS LESS THAN THE PLURALITY, (E) MEANS RESPONSIVE TO EACH OF SAID PLURALITY OF CODING MEANS ONLY IN ITS OPERATIVE CONDITION FOR SETTING INTO OPERATION THE PARTICULAR NUMBER OF SAID TONE GENERATOR MEANS SELECTED CONCURRENTLY BY THE OPERATING CODING MEANS, (F) CIRCUIT MEANS FOR COUPLING CONTROL ENERGY TO EACH CODING MEANS FOR RENDERING IT OPERABLE UPON OPERATION OF ITS CORRESPONDING STORAGE MEANS TO ITS STORAGE CONDITION AND ACCORDING TO PARTICULAR ONES OF SAID PLURALITY OF STORAGE MEANS EACH BEING IN ITS NON-STORAGE CONDITION WHILE SAID MEANS IS NON-RESPONSIVE AND THE RESTORING ITS STORAGE MEANS TO ITS NON-STORAGE CONDITION, (G) TIMING MEANS SET INTO OPERATION RESPONSIVE TO SAID MEANS UPON INITIAL OPERATION THEREOF FOR SUCCESSIVELY MEASURING FIRST AND SECOND TIME INTERVALS AND THEREAFTER MEASURING SUCCESSIVELY A PLURALITY OF SECOND TIME INTERVALS ONE FOR EACH ADDITIONAL CODING MEANS RENDERED OPERABLE. (H) CONTROL CIRCUIT MEANS RESPONSIVE TO SAID TIMING MEANS DURING MEASUREMENT OF SAID FIRST TIME INTERVAL AND SAID MEANS IN ITS RESPONSIVE CONDITION FOR SETTING A GIVEN ONE OF SAID PLURALITY OF TONE GENERATOR MEANS INTO OPERATION AND THEREAFTER RESPONSIVE TO SAID TIMING MEANS DURING MEASUREMENT OF EACH SECONE TIME INTERVAL AND TO SAID MEANS IN ITS RESPONSIVE CONDITION FOR SETTING INTO OPERATION THE PARTICULAR NUMBER OF TONE GENERATOR MEANS CORRESPONDING TO THE CODE MEANS THEN OPERATING, SAID CONTROL CIRCUIT MEANS BEING EFFECTIVE UPON MEASUREMENT OF EACH SECOND TIME INTERVAL TO INTERRUPT THE COUPLING OF CONTROL ENERGY TO SAID PLURALITY OF CODING MEANS, WHEREBY THE LAST OPERATED CODING MEANS IS RENDERED INOPERATIVE CAUSING SAID MEANS TO BE RENDERED NONRESPONSIVE, (I) SAID TRANSMITTER UNIT INCLUDING MEANS FOR TRANSMITTING THE COMMON TONE FREQUENCY TO ALL REMOTE STATIONS AND COMBINING CONCURRENTLY APPLIED TONE FREQUENCIES INTO THE SECOND OF SAID TWO DISTINCT TONE FREQUENCIES FOR TRANSMISSION OVER SAID SINGLE COMMUNICATION CHANNEL TO THE CORRESPONDING REMOTE STATION.