Liquid fuel pumps

Claim 1

FOR USE IN SUPPLYING LIQUID FUEL TO INJECTION NOZZLES IN COMMUNICATION RESPECTIVELY WITH THE CYLINDERS OF A MULTICYLINDER INTERNAL COMBUSTION ENGINE, A LIQUID FUEL PUMP COMPRISING IN COMBINATION A HOLLOW BODY PART WHICH IS PROVIDED WITH A PLURALITY OF PORTS ADAPTED TO BE CONNECTED RESPECTIVELY TO THE INJECTION NOZZLES, A CYLINDRICAL DISTRIBUTOR ROTATABLY MOUNTED IN SAID HOLLOW BODY PART, AND ADAPTED TO BE DRIVEN BY THE ENGINE, A HEAD RIGIDLY UNITED WITH ONE END OF SAID DISTRIBUTOR, AND PROVIDED WITH A TRANSVERSELY EXTENDING BORE, AT LEAST ONE PLUNGER SLIDABLY MOUNTED IN SAID BORE, LIQUID FUEL FEED MEANS WHICH IS ADAPTED TO BE OPERATED BY THE ENGINE, AND FROM WHICH LIQUID FUEL IS INTERMITTENTLY FEEDABLE, DURING ROTATION OF SAID DISTRIBUTOR, THROUGH A PART THE LATTER TO SAID BORE FOR CAUSING SAID PLUNGER TO MOVE OUTWARDLY, AN ANNULAR CAM WHICH SURROUNDS SAID HEAD, AND WHICH SERVES TO IMPART INWARD MOVEMENTS TO SAID PLUNGER, DURING ROTATION OF SAID HEAD WITH SAID DISTRIBUTOR, FOR DELIVERING FUEL THROUGH SAID DISTRIBUTOR TO SAID PORTS IN TURN, A STEPPED CYLINDRICAL CHAMBER WHICH IS SITUATED PARALLEL WITH A TANGENT TO SAID ANNULAR CAM, AND WHICH HAS TWO COAXIAL PARTS, ONE OF SAID COAXIAL PARTS BEING WIDER THAN THE OTHER, A FLUID OPERABLE PISTON SLIDABLY ACCOMMODATED IN THE WIDER PART OF SAID CHAMBER, MEANS INTERCONNECTING SAID ANNULAR CAM AND SAID PISTON SO THAT MOVEMENT OF THE LATTER CAUSES ANGULAR MOVEMENT OF SAID ANNULAR CAM TO VARY THE TIMING OF THE DELIVERY OF FUEL BY SAID PLUNGER TO SAID PORTS, A CYLINDRICAL VALVE MEMBER SLIDABLY ACCOMMODATED IN THE NARROWER PART OF SAID CHAMBER, SAID NARROWER PART BEING PROVIDED WITH AN OUTWARDLY EXTENDING PORT WHICH IS CONTROLLABLE BY SAID VALVE MEMBER, A COMPRESSION SPRING DISPOSED BETWEEN, AND ACTING ON, SAID PISTON AND SAID VALVE MEMBER, A SUPPLY PASSAGE THROUGH WHICH FUEL FROM SAID FEED MEANS IS ADMISSIBLE TO THE NARROWER END OF SAID CHAMBER FOR ACTING ON SAID VALVE MEMBER, AND A SECOND PASSAGE WHICH COMMUNICATES AT ITS OPPOSITE ENDS RESPECTIVELY WITH THE WIDER END OF SAID CHAMBER AND THE OUTER END OF THE LAST MENTIONED PORT, AND THROUGH WHICH LIQUID UNDER PRESSURE IS ADMISSIBLE TO, AND DISCHARGEABLE FROM, THE WIDER END OF SAID CHAMBER UNDER THE CONTROL OF SAID VALVE MEMBER, THE LATTER HAVING ASSOCIATED THEREWITH A THIRD PASSAGE FROM WHICH LIQUID UNDER PRESSURE CAN FLOW THROUGH SAID SECOND PASSAGE TO THE WIDER END OF SAID CHAMBER WHEN SAID VALVE MEMBER IS MOVED IN ONE DIRECTION BY A RISE IN THE LIQUID FUEL PRESSURE IN SAID SUPPLY PASSAGE, AND SAID PISTON BEING MOVABLE TOWARDS THE NARROWER PART OF SAID CHAMBER BY THE LIQUID UNDER PRESSURE ADMITTED TO THE WIDER END OF SAID CHAMBER, AND HAVING FORMED THEREIN A FOURTH PASSAGE THROUGH WHICH LIQUID UNDER PRESSURE CAN FLOW FROM SAID SECOND PASSAGE WHEN SAID VALVE MEMBER IS RETURNED TO ITS INITIAL POSITION BY SAID COMPRESSION SPRING FOLLOWING A FALL OF THE PRESSURE IN SAID SUPPLY PASSAGE.