Fluid pump

Claim 1

A FUEL INJECTION SYSTEM FOR AN INTERNAL COMBUSTION ENGINE COMPRISING A FUEL INJECTION NOZZLE, AN INJECTION PUMP COMPRISING A CASING HAVING A CAVITY THEREIN, AN ELECTROMERIC BODY RECEIVED IN SAID CAVITY AND FORMING A CLOSURE AT ONE END THEREOF, A FIRST SURFACE OF SAID ELASTOMERIC BODY AND THE ENCLOSED PORTION OF SAID CAVITY FORMING A PUMPING CHAMBER, A SOURCE OF FUEL, A FUEL INLET CONDUIT EXTENDING FROM SAID SOURCE OF FUEL TO SAID PUMPING CHAMBER, A FUEL OUTLET CONDUIT INCLUDING A DELIVERY VALVE EXTENDING FROM SAID PUMPING CHAMBER TO SAID INJECTION NOZZLE, AND A DRIVING MEMBER IN ENGAGEMENT WITH A SECOND SURFACE OF SAID ELECTROMERIC BODY, SAID DRIVING MEMBER BEING MOVABLE FOR ALTERNATELY DEFORMING SAID SECOND SURFACE, THE DEFORMATION OF SAID SECOD SURFACE CAUSING ELASTIC DEFORMATION OF SAID FIRST SURFACE FOR VARYING THE VOLUME OF SAID PUMPING CHAMBER AND IMPELLING FUEL FROM SAID PUMPING CHAMBER TO SAID FUEL INJECTION NOZZLE THROUGH SAID FUEL OUTLET CONDUIT, SAID DRIVING MEMBER HAVING SUBSTANTIALLY LESS CROSS-SECTIONAL AREAAT ITS CONTACT WITH A SAID SECOND SURFACE THAN THE CROSS -SECTIONAL AREA OF SAID SECOND SURFACE.