Automatic control for hydraulically driven diaphragm-operated compressors and pumps subjected to very high pressures

Claim 1

IN COMBINATION WITH A FLUID-DELIVERY MACHINE INCLUDING A CHAMBER, A DIAPHRAGM SUBDIVIDING SAID CHAMBER INTO AN OPERATIVE CHAMBER CONTAINING THE FLUID TO BE DELIVERED AND AN ACTUATING CHAMBER AND A HYDRAULICALLY CONTROLLED PISTON ADAPTED TO EXECUTE PERIODICALLY A FORWARD STROKE FEEDING A DRIVING FLUID INTO THE CONTROL CHAMBER TO URGE THE DIAPHRAGM INTO THE OPERATIVE CHAMBER AND A RETURN STROKE SUCKING THE DRIVING FLUID BACK TO URGE THE DIAPHRAGM REARWARDLY, THE PROVISION OF MEANS TAPPING OFF A SAMPLE OF THE LOW PRESSURE DRIVING FLUID AT A SELECTED MOMENT DURING THE DELIVERY PERIOD BEFORE THE DIAPHRAGM REACHES ITS OUTERMOST POSITION, MEANS OF STORING SAID SAMPLE, AND MEANS COMPARING THE PRESSURE OF THE STORED SAMPLE WITH THE ACTUAL PRESSURE OF THE DRIVING FLUID AT OTHER MOMENTS AND ADAPTED TO STOP THE FORWARD STROKE OF THE HYDRAULIC PISTON WHEN SAID ACTUAL PRESSURE HAS RISEN ABOVE THE STORED PRESSURE BY A PREDETERMINED AMOUNT.