Control apparatus

Claim 1

APPARATUS FOR AUTOMATICALLY CONTROLLING A DIMENSION OF A PLASTIC MATERIAL PRODUCED BY A MACHINE IN CONTINUUS LENGTHS COMPRISING: ELECTRICALLY ENERGIZED MOTOR MEANS FOR ADJUSTING SAID MACHINE TO CORRECT A DEVIATION OF SAID DIMENSION FROM THE DESIRED DIMENSION OF ACID MATERIAL; AN ELECTRICAL CIRCUIT COMPRISING FIRST AND SECOND PNEUMATIC-PRESSURE-OPERATED SWITCHES FOR ENERGIZING SAID MOTOR MEANS TO CORRECT POSITIVE AND NEGATIVE DEVIATIONS RESPECTIVELY; A GAS RESERVOIR PNEUMATICALLY CONNECTED WITH SAID PNEUMATIC-PRESSURE-OPERATED SWITCHES; MEANS FOR PROVIDING A FIRST PNEUMATIC PRESSURE REPRESENTATIBE OF THE MAGNITUDE AND THE SENCE OF SAID DEVIATION; MEANS FOR PROVIDING A SECOND PNEUMATIC PRESSURE REPRESENTATIVE OF ZERO MAGNITUDE OF SAID DEVIATION; A FLOW RESISTANCE MEMBER; AND A TWO-WAY VALVE ADAPTED TO CONNECT SAID RESERVOIR EITHER WITH SAID MEANS FOR PROVIDING SAID FIRST PNEUMATIC PRESSURE, OR THROUGH SAID FLOW RESISTANCE MEMBER WITH SAID MEANS FOR PROVIDING SAID SECOND PNEUMATIC PRESSURE; SAID ELECTRICAL CIRCUIT BEING ADAPTED (1) TO MAINTAIN SAID RESERVOIR IN CONNECTION WITH MEANS FOR PROVIDING SAID FIRST PNEUMATIC PRESSURE UNTIL SAID DEVIATION EXCEEDS A PREDETERMINED MAGNITUDE, (2) THEREUPON TO ENERGIZE SAID MOTOR MEANS THROUGH ONE OF SAID PNEUMATICPRESSURE-OPERATED SWITCHES AND SIMULTANEOUSLY TO ACTUATE SAID VALVE TO CONNECT SAID RESERVOIR THROUGH SAID FLOWRESISTANCE MEMBER WITH SAID MEANS FOR PROVIDING SAID SECOND PNEUMATIC PRESSURE, (3) TO MAINTAIN SAID RESERVOIR IN CONNECDTION WITH SAID MEANS FOR PROVIDING SAID SECOND PNEUMATIC PRESSURE FOR A PERIOD OF TIME SUFFICIENT FOR SAID MOTOR MEANS TO ADJUST SAID MACHINE TO CORRECT SAID DEVIATION AND FOR A PREDETERMINED PERIOD OF TIME THEREAFTER, AND (4) THEREUPON TO ACTUATE SAID VALVE TO CONNECT SAID RESERVOIR WITH SAID MEANS FOR PROVIDING SAID FIRST PNEUMATIC PRESSURE.