Pulse responsive receiver having plural delay stages in accordance with a particular pulse code

Claim 1

A SELECTIVE-CALL-SYSTEM RECEIVER WHICH IS SELECTED BY RESPONDING TO A STARTING PULSE FOLLOWED BY A GROUP OF SELECTOR PULSES WHOSE MUTUAL TIME SPACINGS SERVE AS SELECTION CRITERIA, COMPRISING A PLURALITY OF SUCCESSIVE PULSEDELAY STAGES CORRESPONDING IN NUMBER TO THE NUMBER OF SELECTION CRITERA AND HAVING DELAY TIMES CHARACTERIZING THE RECEIVER, A SIGNAL GENERATOR STAGE FOLLOWING THE LAST OF SAID PULSE-DELAY STAGES, A PLURALITY OF COINCIDENCE GATES CONNECTED BETWEEN EACH STAGE AND THE SUCCESSIVE STAGE, PULSE FORMING MEANS CONNECTED TO EACH PULSE-DELAY STAGE FOR GENERATING A GATING PULSE WHICH OPENS EACH COINCIDENCE GATE FOR A GIVEN TIME INTERVAL IN RESPONSE TO THE OUTPUT OF A PULSE FROM THE PRECEDING PULSE-DELAY STAGE, SELECTOR PULSE INPUT MEANS CONNECTED TO THE FIRST OF SAID PULSE-DELAY STAGES AND TO ALL OF SAID COINCIDENCE GATES FOR PASSING SELECTOR PULSES THROUGH SAID GATES ONLY WHEN THE TRAILING EDGES OF THE SELECTOR PULSES OCCUR DURING SAID GATING PULSES, WHEREBY A SIGNAL CAN ACTUATE THE SIGNAL GENERATOR STAGE ONLY WHEN THE SELECTOR PULSE TIME-SAPCING CORRESPONDS TO THE DELAY TIMES CHARACTERIZING THE RECEIVER.