Hydraulically actuated diaphragm pump

Claim 1

A HYDRAULICALLY ACTUATED DIAPHRAGM PUMP COMPRISING, IN COMBINATION, HOUSING MEANS DEFINING A PRESSURE CAVITY, A DIAPHRAGM EXTENDING ACROSS SAID CAVITY TO FORM A FLEXIBLE PARTITION SEPARATING THE CAVITY INTO A PUMPING CHAMBER AND A HYDRAULIC ACTUATING CHAMBER, A PUMP INTAKE SPRING CONNECTED TO ACT ON SAID DIAPHRAGM TO URGE THE LATTER IN A DIRECTION TO EXPAND SAID PUMPING CHAMBER AND CONTRACT SAID ACTUATING CHAMBER, POSITIVE STOP MEANS COACTING WITH SAID DIAPHRAGM TO POSITIVELY LIMIT MOTION THEREOF IN PUMP CHAMBER CONTRACTING AND EXPANDING DIRECTIONS, MEANS DEFINING AN ENCLOSED PLENUM SPACE COMMUNICATING WITH SAID ACTUATING CHAMBER AND FORMING THEREWITH A PUMP ACTUATING SPACE, A RECIPROCABLE DISPLACEMENT ELEMENT MOVABLE WITHIN SAID PLENUM SPACE TO EFFECT ALTERNATE CONTRACTION AND EXPANSION THEREOF, A PRESSURE RELIEF VALVE COMMUNICATING WITH SAID PUMP ACTUATING SPACE TO RELIEVE EXCESS PRESSURE THEREIN, A GAS-LIQUID DISCRIMINATING CHECK VALVE INCLUDING MEANS DEFINING A VALVE CAVITY LOCATED ABOVE SAID ACTUATING SPACE, MEANS DEFINING AN INNER VALVE PASSAGE HAVING AN INNER END OPENING INTO THE UPPERMOST PORTION OF SAID HYDRAULIC ACTUATING SPACE AND HAVING AN OUTER END OPENING INTO THE BOTTOM OF SAID VALVE CAVITY, SAID INNER VALVE PASSAGE BEING POSITIONED SO THAT THE ELEVATION OF EVERY PORTION THEREOF IS AT LEAST EQUAL TO THAT OF SAID INNER END THEREOF, MEANS DEFINING AN OUTER VALVE PASSAGE OPENING INTO THE TOP OF SAID VALVE CAVITY, A LIQUID RESERVOIR EXTENDING ABOVE SAID CHECK VALVE AND BEING CONNECTED TO SAID OUTER VALVE PASSAGE FOR CONTINUOUSLY SUPPLYING LIQUID THERETO; SAID CHECK VALVE INCLUDING A CHECK VALVE DISC MOVABLY DISPOSED IN SAID VALVE CAVITY AND BIASED BY GRAVITY TO MOVE BETWEEN AN UPPER, VALVE CLOSED POSITION IN WHICH THE VALVE DISCS CLOSES SAID OUTER PASSAGE AGAINST THE OUTFLOW OF FLUID THERETHROUGH AND A LOWER, VALVE OPEN POSITION; SAID DISC BEING SLOTTED ON THE UNDERSIDE THEREOF AND BEING DIMENSIONED IN RELATION TO SAID CAVITY TO PROVIDE WHEN THE DISC IS IN THE LOWER POSITION THEREOF PASSAGE SPACE AROUND THE VALVE DISC FOR THE INFLOW OF FLUID FROM SAID OUTER PASSAGE INTO SAID HYDRAULIC ACTUATING SPACE, A VALVE ACTUATING TANG ON SAID VALVE DISC EXTENDING INTO ONE OF SAID PASSAGES FOR BOTH THE UPPER AND LOWER POSITIONS OF THE VALVE DISC, AND SAID TANG BEING DIMENSIONED IN TRANSVERSE SECTION TO PROVIDE LIMITED PASSAGEWAY SPACE EXTENDING THROUGH SAID ONE PASSAGE PAST SAID TANG FOR ALLOWING EITHER THE INFLOW OF LIQUID THROUGH SAID CHECK VALVE INTO SAID ACTUATING SPACE OR THE ESCAPE OF GAS FROM SAID ACTUATING SPACE THROUGH SAID CHECK VALVE WHEN SAID DISC IS IN ITS LOWER POSITION AND TO RESPOND TO AN INCIPIENT OUTFLOW OF LIQUID FROM SAID ACTUATING SPACE THROUGH SAID CHECK VALVE TO MOVE SAID VALVE DISC TO SAID UPPER POSITION THEREOF.