Pneumatic leak test panel

Claim 1

IN A LEAK TEST INSTRUMENT FOR DETECTING LEAKS IN A TEST PART, A SOURCE OF PRESSURE, A PRESSURE RECORDING INSTRUMENT, A TEST SIGNAL PRODUCING MEANS, CONDUIT STRUCTURE INCLUDING A FIRST CIRCUIT PORTION INTERCONNECTING SAID PRESSURE SOURCE AND THE TEST PART AND A SECOND CIRCUIT PORTION COMMUNICATING WITH SAID SOURCE AND SAID SIGNAL PRODUCING MEANS, PRESSURE REGULATOR VALVE MEANS FOR MAINTAINING A FIRST TEST PRESSURE IN SAID SECOND CIRCUIT PORTION AND A HIGH PRESSURE IN SAID FIRST CIRCUIT PORTION, A BALANCE VALVE MEANS FOR INTERRUPTING AND ESTABLISHING COMMUNICATION BETWEEN SAID CIRCUIT PORTIONS, A RAPID FILL VALVE MEANS IN SAID FIRST CIRCUIT PORTION FOR ESTABLISHING AND INTERRUPTING DISTRIBUTION OF SAID HIGHER PRESSURE TO SIAD PART, DUMP VALE MEANS IN SAID FIRST CIRCUIT PORTION FOR ESTABLISHING AND INTERRUPTING COMMUNICATION BETWEEN SAID PART AND AN EXHAUST REGION, SAID DUMP VALVE MEANS BEING ADAPTED TO BE MOVED TO AN OPEN CIRCUIT POSITION UPON MOVEMENT OF SAID RAPID FILL VALVE MEANS TO A CLOSED CIRCUIT POSITION, MEANS FOR CLOSING SAID DUMP VALVE MEANS AND OPENING SAID BALANCE VALVE MEANS WHEN THE PRESSURE IN SAID PART APPROACHES THE PRESSURE IN SAID SECOND CIRCUIT PORTION, SAID TEST SIGNAL PRODUCING MEANS RESPONDING UPON MOVEMENT OF SAID BALANCE VALVE MEANS TO AN OPEN CIRCUIT POSITION TO A VARIATION IN THE PRESSURE DIFFERENTIAL IN SAID CIRCUIT PORTIONS TO PRODUCE A TEST SIGNAL PRESSURE THAT IS PROPORTIONAL TO SUCH PRESSURE DIFFERENTIAL, AND A CONNECTION FORMING A PART OF SAID SECOND CIRCUIT PORTION BETWEEN SAID SIGNAL PRODUCING MEANS AND SAID RECORDING INSTRUMENT WHEREBY SAID INSTRUMENT RESPONDS TO SAID SIGNAL PRESSURE.