Mechanical pump

Claim 1

A DIAPHRAGM PUMP, PARTICULARLY FOR PUMPING A VOLATILE LIQUID SUCH AS AUTOMOTIVE FUEL, COMPRISING A PUMP HEAD, A SHEET METAL PUMP BODY SECURED TO SAID PUMP HEAD, A DIAPHRAGM HAVING ITS MARGIN CLAMPED BETWEEN THE PUMP BODY AND THE PUMP HEAD, SAID PUMP BODY HAVING AN END WALL AND AN ANNULAR PERIPHERAL WALL DEFINING WITH THE DIAPHRAGM A PUMPING CHAMBER, SAID BODY FURTHER HAVING A PAIR OF SIDE-BY-SIDE CUP-SHAPED PROJECTIONS EXTENDING FROM ITS END WALL AND OPENING INTO THE PUMPING CHAMBER, AN INTAKE CHECK VALVE IN ONE OF THE CUP-SHAPED PROJECTIONS AND A DISCHARGE CHECK VALVE IN THE OTHER OF SAID CUP-SHAPED PROJECTIONS FOR CONTROLLING THE FLOW OF FUEL INTO AND OUT OF THE PUMPING CHAMBER, A DISCHARGE OUTLET COMMUNICATING WITH SAID OTHER CUP-SHAPED PROJECTION DOWNSTREAM OF THE DISCHARGE CHECK VALVE, A DISCHARGE CAVITY FORMED IN THE OTHER PROJECTION BETWEEN THE DISCHARGE OUTLET AND THE CHECK VALVE, AND MEANS IN THE DISCHARGE CAVITY DOWNSTREAM OF THE DISCHARGE CHECK VALVE FOR DAMPENING PULSATIONS IN PRESSURE OF THE FUEL DELIVERED BY THE PUMP TO THE DISCHARGE OUTLET, SAID MEANS COMPRISING A GENERALLY TRANSVERSE PARTITION ACROSS THE DISCHARGE CAVITY AND HAVING A GENERALLY CENTRAL OPENING THERETHROUGH, A RESILIENT GENERALLY BALL-SHAPED MEMBER REMOVABLY SEATED OVER THE OPENING THEREBY TENDING TO EQUALIZE THE PRESSURE OF THE FUEL BEING DELIVERED BY THE DIAPHRAGM PUMP, AND AT LEAST ONE ADDITIONAL OPENING IN SAID TRANSVERSE PARTITION TO PERMIT THE FLOW OF FUEL THROUGH THE DISCHARGE CAVITY WHEN THE BALL-SHAPED MEMBER IS SEALTED OVER SAID FIRST MENTIONED OPENING.