Electromagnetically driven pumps, particularly fuel pumps

Claim 1

IN A PUMP, IN COMBINATION, A HOUSING; ELECTROMAGNET MEANS HAVING A COIL AND BEING FIXEDLY MOUNTED IN SAID HOUSING; PISTON MEANS FORMING AN ARMATURE OF SAID ELECTROMAGNET MEANS, SAID ELECTROMAGNET MEANS WHEN ENERGIZED DISPLACING SAID PISTON MEANS FROM ONE END POSITION TO ANOTHER END POSITION ALONG A GIVEN STROKE; SPRING MEANS URGING SAID PISTON MEANS FROM SAID OTHER POSITION IN THE REVERSE DIRECTION OF SAID GIVEN STROKE BACK TO SAID ONE END POSITION WHEN SAID ELECTROMAGNET MEANS IS DEENERGIZED; AN ELECTRICAL CIRCUIT IN WHICH SAID ELECTROMAGNET MEANS IS CONNECTED TO BE SUPPLIED WIT CURRENT THROUGH SAID ELECTRICAL CIRCUIT; AND SWITCHING MEANS CONNECTED TO SAID CIRCUIT AND RESPONDING AUTOMATICALLY TO THE POSITION OF SAID PISTON MEANS FOR ENERGIZING SAID ELECTROMAGNET MEANS WHEN SAID SPRING MEANS DISPLACES SAID PISTON MEANS TO SAID ONE END POSITION THEREOF AND FOR MAINTAINING SAID ELECTROMAGNET MEANS ENERGIZED UNTIL SAID PISTON MEANS REACHES SAID OTHER END POSITION THEREOF, SAID SWITCHING MEANS DEENERGIZING SAID ELECTROMAGNET MEANS WHEN SAID PISTON MEANS REACHES SAID OTHER END POSITION AND MAINTAINING SAID ELECTROMAGNET MENS DEENERGIZED UNTIL SAID PISTON MEANS IS DISPLACED BY SAID SPRING BACK TO SAID ONE END POSITION, SAID SWITCHING MEAN INCLUDING AN ENVELOPE OF NON-MAGNETIZABLE MATERIAL FILLED WITH A PROTECTIVE GAS AND BEING FIXEDLY MOUNTED IN SAID HOUDING, AND A PAIR OF MAGNETIZABLE SWITCHING CONTACT MEMBERS SITUATED IN AN ENVELOPE SAID CONTACT MEMBERS BEING CONSTRUCTED TO AS TO TEND TO STAY IN AN OPEN POSITION AND TO MOVE TO A CLOSED POSITION WHEN SUBJECTED TO THE INFLUENCE OF A MAGNETIC FIELD, SAID SWITCHING MEANS FURTHER INCLUDING A PERMANENT MAGNET FIXED TO SAID PISTON MEANS FOR RECIPROCATION THEREWITH, SAID PERMANENT MAGNET HAVING A MAGNETIC FIELD WHICH IS ONE END POSITION OF SAID PISTON MEANS ACTS ON SAID CONTACT MEMBERS OF MAGNETIZABLE MATERIAL SO AS TO PLACE SAID CONTACTS IN SAID CLOSED POSITION WHERE THEY ENGAGE EACH OTHER.