Automatic control system

Claim 1

IN A CONTROL, IN COMBINATION, A HOUSING HAVING TWO SECTIONS, A DIAPHRAGM BOUND BETWEEN SAID SECTIONS TO DIVIDE THE INTERIOR OF SAID HOUSING INTO TWO FLUID CHAMBERS, A SEPARATE SUPPLY PASSAGE FOR ADMISSION OF PRESSURIZED FLUID INTO EACH CHAMBER TO PLACE SAID DIAPHRAGM IN NORMALLY COUNTERPOISED POSITION, A DISCHARGE PASSAGE FROM AT LEAST ONE SAID CHAMBER, A CONTROL MEANS FOR SAID DISCHARGE PASSAGE COMPRISING A VALVE CLOSURE THEREFOR, TRIP MEANS IN SAID ONE SAID CHAMBER OPERATIVELY ASSOCIATED WITH SAID VALVE CLOSURE TO OPEN IT IN RESPONSE TO A DROP IN PRESSURE IN THE SUPPLY PASSAGE TO SAID ONE SAID CHAMBER HAVING SAID DISCHARGE PASSAGE LEADING THEREFROM, MEANS TO RESTRAIN SAID TRIP MEANS FROM TRIPPING SAID VALVE CLOSURE OPEN, AND MEANS OPERATIVELY ASSOCIATED WITH SAID DIAPHRAGM UPON THE MOVEMENT THEREOF AWAY FROM SAID NORMALLY COUNTERPOISED POSITION TO REMOVE SAID RESTRAINING MEANS TO RELEASE SAID TRIP MEANS TO TRIP THE VALVE CLOSURE IN SAID ONE SAID CHAMBER SUPPLIED BY SAID LASTMENTIONED SUPPLY PASSAGE UPON OCCURRENCE OF SAID DROP.