Patent GB-723773-A (GB)
Title: Fuel injectors for internal combustion engines
IPC: F02M59/00
Filed: 1951-06-05
Abstract: 723,773. Fuel injector valves. DUDEK. H. M. June 5. 1951. No. 13333/51. Class 7 (3). [Also in Group XXVIII] A fuel injector valve includes a housing and a ported head the head normally having a valve element seated therein to close its ports the valve element being axially in contact with a valve actuating member which is in turn in axial alignment with a stem means for imparting pressure to liquid fuel after it has been supplied to the housing by axial motion of the stem the stem and the valve actuating member having a fluid coupling therebetween and means for translating axial movement of the valve actuating member in one direction into a reverse direction port opening movement of the valve element. In the fuel injector of Fig. 2 fuel under pressure enters at 17 and a non-return valve is preferably provided to prevent return flow. A stem 6 is reciprocated for example by an arm not shown driven from the crank or cam shaft of the engine in which the injector is employed. It may be driven by an eccentric on the crank shaft. The eccentric may be retarded 10 degrees- 20 degrees with respect to the crank shaft. On downward movement of the stem fuel in a chamber 11 is placed under pressure by a piston 20 and this pressure is transmitted to a space 45 and from the space 45 by means of a passage 50 to a lower chamber 12 of the injector. As the stem moves down the lower end of a portion 61 of the stem, first closes a port 48 and then covers the end of the passage 50. Fuel then trapped in the space 45 forms a link by which a member 26 is forced downwardly and this member forces down a valve actuating member 27 the tapered portion 28 of which co-operates with the furcated upper end of a valve member 25 and lifts this valve member and thus raises the head 36 of the valve member from its seat causing fuel under pressure trapped in the chamber 12 to be injected through orifices 15, 151. When the valve member contacts the lower end of a stem 52 a valve 53 is raised and relieves the pressure in the space 45 and thus allows the valve member to return to its original position in which the valve 36 is closed. By turning the stem 6 the relative position of the members 26 and 27 may be changed since a splined member 30 transmits rotation of the stem to the member 26 and members 26 and 27 are screw threaded at 33. This changes the length of the stem 52 of the relief valve below the member 26. Thus the length of the injection period may be varied and also the timing of the injection. The stem may be either manually or automatically turned for adjustment. The diameter of the stem below the piston 20 may be greater than the diameter above. Fig. 7 shows a modification in which a large quantity of fuel at a high pressure is stored in the lower chamber of the injection valve. The chamber 12 communicates with a surge chamber containing a piston 75 loaded by a heavy spring 77 which forces the piston down during injection. A non-return valve 66 is provided adjacent the fuel inlet 17. The fuel is passed to the top of the piston 20 by means of a byepass 67 (Fig. 11). On upward movement of the piston 20 the fuel is forced into the space 45 through a channel 70. The lower end of the stem is provided with a helical groove so that rotation of the stem varies the moment at which the end of the passage 50 is covered and thus varies the commencement of injection and changes the quantity injected. When a groove 73 registers with this end the pressure in the space 45 is released and the valve 36 closed. The stem is operated by a rocker arm, the furcated end 71, 7<SP>11</SP> of which only is shown. Compressible washers 81, 82 are held against the end of the arm by lock rings 83, 84. The stem may be rotated by an index arm 89 and a governor device may be connected to an arm 93. Relief valves are used in exit lines 18 and these may be set at from 1,000- 5,000 lbs. sq. in. The fuel being injected may be placed under 3,000 to 7,000 lbs. sq. in. pressure.