Monitoring apparatus

Claim 1

APPARATUS FOR MONITORING THE PASSAGE OF ARTICLES THROUGH A MACHINE, COMPRISING A FIRST AND SECOND DETECTOR DEVICE BOTH ARRANGED FOR CTUATION BY THE PASSAGE OF ARTICLES THROUGH THE MACHINE AND SPACED FROM EACH OTHER BY A DISTANCE SUCH THAT A PREDETERMINED NUMBER BY ARTICLES ARE LOCATED THEREBETWEEN DURING CONTINUITY OF ARTICLE FEEDING, A FIRST AND A SECOND ELECTRONIC COUNTER RESPECTIVELY CONNECTED TO SAID FIRST AND SECOND DETECTOR DEVICES FOR ACTUTION THEREBY WHEN ARTICLES ARE DETECTED BY THE DETECTOR DEVICES, SAID COUNTERS EACH HAVING THE SAME RADIX AND BEING SO ARRANGED THAT A PREDETERMINED RELATION IS MAINTAINED BETWEEN THE COUNTS THEREOF DURING CONTINUITY OF ARTICLE FEEDING, AND COMPARING MEANS CONNECTED TO THE COUNTERS AND OPERABLE TO PRODUCE AN OUTPUT SIGNAL WHEN THE RELATION BETWEEN THE COUNTS IS OTHER THAN SIAD PREDETERMINED RELATION THEREBY TO GIVE AN IN DICATION THAT THE NUMBER OF ARTICLES BETWEEN THE DETECTOR DEVICES IS DIFFERENT FROM SAID PREDETERMINED NUMBER, AN ALARM SIGNAL DEVICE OPERABLE BY THE OUTPUT FROM SAID COMPARING MENAS, THE COMPARING DEVICE INCLUDING COINCIDENCE GATES THE OUTPUTS OF WHICH ARE CONNECTED ONE EACH OF A TRIGGER TUBE, THE OUTPUTS FROM SAID TUBES BEING CONNECTED IN COMMON TO A SWITCH ADAPTED TO EFFECT OPERATION OF THE ALARM SIGNAL DEVICE, AND EACH PAIR OF INPUTS OF EACH SAID GATE BEING CONNECTED TO A PREDETERMINED PAIR OF OUTPUTS FROM SAID COUNTERS, EACH COUNTER BEING A DEKATRON COUNTER THE CATHODES OF WHICH ARE PAIRED FOR CONNECTION IN COMMON TO THE GATE APPROPRIATE THERETO, THE TWO CATHODES OF HIGHEST VALUE OF EACH COUNTER BEING PAIRED THROUGH A RECTIFIER TO ENSURE THAT IN EACH COUNTER ON RESETTING OF THE COUNTER THE CATHODE OF HIGHEST VALUE IN CONDUCTING.