Automatic positioning servosystem

Claim 1

AN ARTICLE POSITIONING APPARATUS, WHICH COMPRISES, A BASE, AN ARTICLE SUPPORTING CARRIAGE MOVABLY MOUNTED ON SAID BASE, A PLURALITY OF DETENT BARS HAVING ACCURATELY SPACED NOTCHES FORMED THEREIN AND CONNECTED TO THE CARRIAGE FOR MOVEMENT THEREWITH, SAID BARS BEING DISPLACED FROM ONE ANOTHER SUCH THAT THE NOTCHES ARE POSITIONED IN OVERLAPPING RELATIONSHIP, A SERVO-MOTOR CONNECTED TO THE CARRIAGE FOR MOVING THE CARRIAGE AND BARS, MEANS MOUNTED ON SAID BASE ALONG THE PATH OF MOVEMENT OF THE CARRIAGE FOR PRODUCING A VOLTAGE REPRESENTATIVE OF THE LOCATION OF THE CARRIAGE, A VOLTAGE SOURCE FOR PRODUCING A VOLTAGE REPRESENTATIVE OF A DESIRED LOCATION OF THE CARRIAGE, A SERVO AND NULL NETWORK CONNECTED TO THE VOLTAGE PRODUCING MEANS AND THE VOLTAGE SOURCE FOR COMPARING THE VOLTAGES THEREFROM AND PRODUCING A DIFFERENTIAL VOLTAGE TO DRIVE THE SERVO-MOTOR TO POSITION THE CARRIAGE WITHIN THE LIMITS OF ONE OF THE NOTCHES WHICH DEFINES AN EXACT DESIRED LOCATION, A DETENT PIN ASSEMBLY ASSOCIATED WITH EACH DETENT BAR AND MOUNTED ON THE BASE OVER SAID BARS, A DETENT PIN MOUNTED IN EACH ASSEMBLY FOR ADVANCEMENT INTO ENGAGEMENT WITH AN ASSOCIATED BAR TO ACCURATELY POSITION THE CARRIAGE, AND MEANS OPERABLE AFTER THE POSITIONING OF THE CARRIAGE WITHIN THE LIMITS OF SAID ONE NOTCH FOR DISCONNECTING THE SERVO-MOTOR FROM THE CARRIAGE AND SELECTIVELY OPER-