US2178902A - Fuel feeding means for internal combustion engines - Google Patents

Description

1939. c. H. CLAUSEN 2.178.902

FUEL FEEDING MEANS FOR INTERNAL COMBUSTION ENGINES Filed Sept. 22; 1957 1 I I'-! 2'4 z '3 83 12 I I I6. I \7 H |5- '2 To 7 20 8 2l M w I y JWm= 4% MW! Patented Nov. 7, 1939 UNITED STATES FUEL FEEDING MEANS FOR INTERNAL COIVIBUSTION ENGINES Carl Herman Clausen, Stockholm, Sweden Application September 22, 1937, Serial No. 165,219

- In Sweden September 18, 1936 '16 Claims. (Cl, 123-139) The present invention refers to an improvement in fuel feeding means for internal combustion engines acting with direct fuel injection, and in which the fuel oil is pumped in into a pressure 5 piping connected with the valve-controlled injection nozzle of the engine. a

In connection with similar fuel feeding means, and for prevention of so called after-dripping through the nozzle and the drawbacks resulting 10 from such occurrences, it has previously been proposed automatically to perform a sudden decrease of pressure within the pressure piping, for instance by a discharge of fuel oil from, or an increase of volume of the said pipe. All of the 5 means hitherto known for such purpose involve the drawback, however, that they do not at all, or in any case rather defectively only, adapt themselves according to the variable .pressure conditions prevailing in the piping between the go fuel pump and the valve-controlled injection nozzle, and therefore the efficiency of said known means will be more or less illusory.

The pressure at hand within the pressure piping during the v injection is mainly a function of 5 the dimensions of said piping, the velocity of the flow of fuel transmitted thereby, and the resistance of the injection nozzle valve itself, such resistance being composed by-the resistance to the flow through the nozzle bores and that of the 30 spring acting on the nozzle valve member. These factors are highly variable both in different engines and also in one and the same engine under different working conditions, and as a result hereof the pressure tending tore-open the nozzle 35 valve and thereby to cause the after-dripping due to the pressure wave arising within the pressure piping after interruption of each separate fuel injection is also highly variable. Hence, a means for automatic decrease of pressure within 40 the pressure piping after interruption of each fuel injection shall also automatically adapt itself to the different pressures which may arise in the piping. 7 According to the invention this result is ob- 45 tained by the provision of a movable control member which is permanently acted upon by the pressure piping pressure for movement in one direction and adapted at its movement caused by said pressurejwhich movement consequently 5 is controlled thereby in respect of velocity and causes an increase of volume of anda decrease of pressure within the pressure piping, to open a return channel from the pressure chamber of the fuel pump to a convenient low pressure cavity, or

' 5 space, so that theinterruption of the-discharge of fuel from the pump into the pressure piping and consequently the magnitude of the pressure decrease within the latter are automatically adapted to different pressure conditions within the pressure piping.

An embodiment of the invention is illustrated in the accompanying drawing to which the following description refers, and in this drawing- Fig. 1 shows the improved fuel feeding means seen in axial section. 10

Fig. 2 shows:a flattened out portion of the inner face of the fuel pump cylinder.

A- pump piston 2 is reciprocably mounted within the cylinder I of the fuel pump, such piston being provided exteriorly with a circumferential recess positioned at a distance below the top face l of the piston and is confined at its upper portion by an inclined control edge 3. In the drawing, the pump piston is shown in its lower end position. Its upper end position is indicated by the dot and dash line X, and a little previous to the arrival of the piston into this last mentioned position during its upward stroke, the circumferential recess 4, establishes connection between the two bores or channel means 5 and 6. The pump piston is both reciprocable, as aforesaid, and turn-able around its axis (manually or by means of governor), and a turning of the same in the direction of the arrow in the drawing will cause the control edge 3 to establish the connection between the bores 5 and 6 more and more early during the upward stroke of the piston, and finally to make such connection permanent. The reference letter It) represents the pressure chamber of the pump, and this chamber is periodically in connection with a suction bore 8 and with an other bore 9.

A pressure valve II is mounted in the extension of the pump pressure chamberv llL-this valve being preferably but not necessarily acted upon by a closing spring means l2. The cavity l3 enclosing said spring 12, and a bore l4 communicating with the former, form the entrance end of the pressure piping leading to the valve-controlled injection nozzle (not shown) A piston-shaped control member I6 is reciprocably mounted within a cylinder bore l5 positioned at one side of the pump cylinder l. The upper end of the bore l5 stands in permanent connection with the-pressure piping l3, H by means of a bore II in the pressure valve housing 22, so that the control member is permanently acted upon by the pressure within said piping, whereas the lower end of the bore, l5 stands in permanent connection, with the channel means 5.

Assuming that the pressure chamber III is filled with fuel oil from the suction bore 8, and

. that the piston 2 is moving upwardly from the I4 will be increased thereby.

lower end position shown, for instance by being acted upon by a cam disc, the fuel oil will at first be pressed, back through the suction bore 8 until the top face I of the pump piston has moved upwards past the said suction .bore and closed the same. Then follows a compression of the 011 within the chamber I 0, and thereafter the oil will flow through the bore 9, a bore I8 connected with the upper portion of the chamber III, an annular exterior .recess I 9 in the control member l6, and through bores 20 in the said member into the channel means 5 and the circumferential recess 4 which latter at this moment is'shut of! from the return bore 6. Due to the increase of .the confined pressure caused by the continued,

upward travel of thepump piston, the control member I6 will move upwardly in the bore, and the pressure within the pressure piping I9,

The upward travelof the control member I6 will be limited either when the top face 1 of the pump piston moves past the bore 9 and closes the latter, or alternatively when the portion 2| of the member I6 positioned beneath the annular recess I9 closes the. bore I8. In case the volume of fuel oil answering to the distance of travel of the pump piston 2 previous to the closing of the bore 9 is greater than the .volume answering to the travel of the control member I6 for closing of the bore I8, the first alternative comes true, but otherwise the second mentioned alternative is valid. In the first mentioned instance, the upward stroke of the member I6 could also be limited by the abutment of said member for instance against the upper end face of the cylinder bore I5, under the provision only that the volume of fuel oil, which is discharged by the pump previous to the closing of the bore 9, is sufliciently great, and this is dependent on the .level of the bore 9 in relation to the level of the suction bore 8.

It would apparently be possible entirely to leave out the bore 9 as far as the effectuation of the movement of the member I Ii is concerned, and to permit the admission of fuel oil to the channel means 5 and the circumferentialrecess 4 to be performed exclusively through the bore I9, until the member I6 has closed the same. The presence, on non-presence, of the bore 9 will consequently beentirely dependent on whether it is desired to permit the portion 2I of the control member I6 to move past the bore I8 for a shorter or longer distance, perhaps with a final limitation of the upward travel of the member I6 by abutment against the face 23. Generally, and on reasons to be understood from the following, it is preferable to maintain the bore 9, however, but is not unavoidably necessary.

When the movement of the control member I6 has been concluded in either of the manners referred to above, the discharge of the fuel oil begins from the pressure chamber III through the valve I I. The reason why such discharge has not previously taken place is that the valve I I is acted upon by the spring I2 and that its area facing the pressure within the cavity I3 is sufficiently greater than the area of the same facing the pressure within the chamber III.

The pressure within the pressure piping I3, I4, which already is increased by the upward travel of the control member I6 and the compression then causedfis now still more increased by the dissure within said piping will charge of fuel oil from the pump through the pressure valve II, and finally the pressure is in creased so much that an injection of fuel into the engine cylinder takesplace.

During the continuation of the upward stroke of the pump piston 2 after the fuel injection (and in dependance on the fuel consumption in the engine cylinder during the prevailing working stroke) and always before the pump piston has arrived at its upper end position X, a connection is established between the bores 5 and 6 through the circumferential recess 4, and thereby the fuel oil confined within the cavities 4, 5, 20 and I9 will get an opportunity to escape to the suction pipe of the pump. The bore Ii may naturally lead into another low pressure cavity, or even to the atmosphere if desired, instead of leading to the suction piping.

Now, the control member I6 is displaced back into its lower end position shown in the drawing under influence from the pressure within the pressure piping I3, I4, and then said member establishes a connection between the pump pressure chamber I 0 and the suction pipe of the pump by means of the bore I8, the recess I9 and the channel means 20, 5, 4 and Ii. The discharge of fuel oil into the pressure piping past the valve II is not concluded until the control member I6 has uncovered a portion of the cross sectional area of the bore I8, which portion is great enough for permitting escape of the whole amount of fuel oil coming from the pressure chamber I0 during the continued upward movement of the pump piston 2 towards the end position X. Until this moment a discharge successively decreasing in volume will continue through the pressure valve II.

During its return stroke towards the lower end position, the control member I6 causes an increase ofvolume of the cavity I3, such volume increase resulting in a decrease of pressure within the -.pressure piping for prevention of afterdripping in the injection nozzle. This decrease of pressure is delayed to a certain extent, however, by the continued oil discharge through the pressure valve I I, such discharge being interruptedsure remaining until the next working stroke of I the fuel pump will therefore be dependent on the magnitude of the continued discharge through the pressure valve II, and secondarily such magnitude will be dependent on the smaller or greater rapidity of the by the. member I6. ment of the member I6 depends in its turn upon the amount of pressure within the pressure piping I3, I4, and this means that in case said pressure is higher, the member 16 will move more rapidly than in case the pressure .is lower. In other words, a higher pressure within the pressure piping results in a greater absolute decrease of pressure within the said piping than does a lower pressure therein, and thereby one of the most important results ofthe invention is obtained.

The. absolute decrease of pressure within the pressure piping will therefore adapt itself to the number of revolutions of the engine, as the presbe higher at a higher speed of the engine than at a lower engine speed. The decrease of pressure will also be amplified (which is desirable since the differences in pressure within the pressure piping will be very great at variable number of revolution of the engine) uncovering of the bore I 8 The rapidity of displacedue to the fact that the pump piston 2 will more rapidly establish a communication between the bores 5 and 6 at greater engine speeds than at smaller ones, so that the member It will sooner begin its return movement to the lower end position and open the return channel means at the bore I8 ,at an earlier stage, whereby the continued discharge through the pressure valve H will cease more rapidly.

When the bore 9 is present, the decrease of pressure may be still more amplified at increased numbers of revolution of the engine when giving this bore an upwardly diverging cross sectional shape and by connecting the upper portion of the same with an annular groove 9' in the cylinder wall, if desired. The suction bore 8 may simultaneously be given an upwardly converging cross sectional area, and both of these arrangements may be understood from Fig. 2 in the drawing.

. When the fuel pump is provided with a slide valve controlled suction inlet, a greater velocity of the slide valve (in the embodiment shown in the drawing this valve is formed by the pump piston itself) will cause the fuel feeding and the increase of pressure within the pressure chamber Ill caused by such feeding to begin already before the pump piston has closed the suction bore 8 by means of its top face 1, and thisbelng due to a throttle action arising at the suction bore, such throttling action being amplified by the embodiment of the bore 8 just described. This fuel feeding results obviously in that the control member It begins its upward travel earlier than in case the speed of travel of the slide valve (piston 2) is lower. On the other hand, the throttle action is retarded at the bore 9 due to its upwardly diverging cross sectional area, and this means that the control member l6 (provided that its movement is not stopped by abutment) will move upwardly to a greater distance at higher; .than at lower numbers of revolution of the engine, so that a greater increase of volume of the chamber l3 and the pressure piping as a whole will occur at greater than at lower engine speeds, when the said member l8 subsequently returns to its bottom position.

The actual decrease of pressure within the pressure piping will be smaller, however, than at first sight is to be supposed when considering the foregoing, and as pointed out above this is due to that the return channel means from the pressure chamber i0 is not opened until the portion 2| of the control member l6 .begins to uncover the bore i8. This means that how far the member l6 has ever travelled upwardly in the cylinder bore l5, the decrease of pressure within the pressure piping will always and only correspond to the difference between the volume of fuel oil ad-- ditionally introduced into the pressure piping through the valve H, and the amount of volumewith which the pressure piping is increased when the control member It moves back into a position uncovering the bore l8. This smaller decrease of pressure relatively tothe increase of volume of the pressure piping is more advantageousthan a decrease of pressure which is directly proportional with the said increase of volume, among others since it causes a pressure reduction process which is extended in respectof time, and this results in a softer, or smoother, pressure reducing process. By means of a suitable dimensioning of the control member IE, it is simultaneously open to provide for that the absolute de crease of pressure will be substantially proportional with the number of revolutions of the engine to the whole range of speeds of the same, so that the pressure remaining within-the pressure piping at the intervals between two consecutive fuel injections will be substantially constant.

As hinted at in the foregoing, the total amount of fuel fed out fromv the fuel pump is increased at increasing engine speed, especially if the pump is provided with a slide valve controlled suction intake, and this is due to the throttling coaction between the top face I of the pump piston and the suction bore 8, which means that the capacity of the pump is increased withincreasing engine speeds, and reduced with decreasing engine speeds. Now, as well known, the actual conditions are that the amount of air sucked in during each working cycle of the engine is decreased with increasing number of revolutions, and increased with decreasing engine speed. Therefore, the maximum capacity of the fuel pump ought to increase with decreasing engine speed, as otherwise the result would be that the engine, when running at low speed and with relatively greater cylinder charge caused thereby, cannot reach its maximum effect otherwise possible, and this is due to a too small admission of fuel oil-a disadvantage which is especially to be noted in enof injection, as the greater volume of the cavity l3 must be filled again can begin.

' The same results as described in both of the preceding paragraphs may at least approximately be obtained in case the pressure valve, in a manner known per se, is constructed so that it gets an increased working stroke, or distance of elevation from the seat, when the speed of the engine and that of the fuel pump is increased, such before the next injection increase of the working stroke of the valve being substantially proportional with the increase of the'engine speed. This modification has nat urally its specific importance when the bore 9 is not at hand. It is easily to be understood that a variable distance of elevation of the pressure valve body will also result in a variable discharge from the pressure pipe through said valve and back to the pressure pressure valve has closed. Without additional explanations it is also obvious that this variable return flow will result in effects of the same kind as described above.

The pressure valve H shown in Fig- 1 is exactly of such a construction'that its distance of elevation from the seat is increased with an increasing speed of the pump piston 2. For the chamber l0 before the has been obtained, the raising of the pressure forth and back piston itself but may be valve from its seat will continue. The maximum distance of elevation of the valve ll may naturally be limited by means of an abutment positioned in any convenient manner.

Since the control member [6 must always perform a certain movement towards its lower end position, whereby the volume of the pressure piping is increased, the essential advantage appearing under all working conditions of the engine is that the volumetrical decrease of pressure will always occur previous to the hydrostatical decrease of pressure, which concludes the pressure decreasing process, this advantage being not at hand in connection with the devices previously known for the purpose of causing an increase of volume of the pressure pipe. As will be apparent without explanations, a hydrostatical decrease of pressure cannot take place until a certain portion of the bore l8 has been uncovered, such uncovering causing the volumetrical decrease of pressure. This sequence of the steps of the pressure decreasing process results in that the otherwise unavoidable pressure waves 'which oscillate within the pressure piping as a continuation of the first pressure wave arising in the direction towards the pressure valve ll at the closing of the injection nozzle valve, are retarded by a resilient fluid cushion instead of being repelled by a non-resilient wall, as will be the case when the pressure decreasing process is of a volumetrical nature only, orif it is concluded volumetrically, respectively. It is apparent that the aforementioned hydrostatical pressure wave damping effect assists in the rapid elimination of the non-desirable pressure wave oscillations within the pressure piping after conclusion of each fuel injection, and the result in practice is that it is not to be feared that the fuel shall trickle out (after-dripping) through the injection nozzle due to such pressure oscillations, even if the injection nozzle valve should not be perfectly tight.

The constructional embodiment of the apparatus according to the invention may naturally be varied in many ways within the scope of the latter. The construction of the control member may be modified, and the said member and the pressure valve II- may be mounted one above the other etc. Spring means having a retarding action on the movements and thereby also an influence on the pressure decreasing process and on the control of the volumes may be mounted at one or both sides of the control member l6. Throttle members, or valves, having a retarding influence on the fuel oil flows may be mounted in one or more of the channel means leading to the cylinder I 5 for the control member. The circumferential recess 4 and its control edge 3 must not necessarily be provided in the pump at hand in'a separate piston slide, and also in other respects it may be constructively modified or replaced by some common mechanically controlled valve member.

What I claim and desire to secure by Letters Patent is:

1. In a fuel feeding means for'internal com-' bustion engines, a fuel piston pump for' feeding fuelinto a pressure piping leading to an injection nozzle of the engine, a control member, a cylinder in which said member is movable, a conduit connecting said cylinder to said' pressure piping, a second conduit-connecting said cylinder to the pressurechamber of said pump, a third conduit having periodic communication with a low pres-i third conduit and erated by said cation between said second and third conduits and being movable in said cylinder by variations in pressure existing in said piping and said pump pressure chamber.

2. In a fuel feeding means for internal combustion engines, a fuel piston pump for feeding fuel into a pressure piping leading to an injec-" tion nozzle of the engine, a control member, a

cylinder in which said member is movable, a

conduit connecting said cylinder to said pressure piping, a second conduit connecting said cylinder to the pressure chamber of said pump, a third conduit connected to said cylinder having communication with a low pressure area, said control member having a port therein adapted to interconnect said second and third conduits, means operated by said pump controlling said said control member controlling the communication between said second and third conduits and being movable in said cylinder by variations in pressure existing in said piping and said pump pressure chamber whereby a decrease in pressure within the pressure piping may be secured in accordance with the pressure conditions prevailing therein. I

3. In a fuel feeding means for internal combustion engines, a fuel piston pump having, a

pressure chamber, aduct leading from said chamber to the pressure piping leading to an injection nozzle of an engine, a cylinder, a conduit con: necting said cylinder to said pressure piping, a second conduit connecting said cylinder and said pressure chamber, a third conduit connecting said cylinder to a low pressure area and a control member movable in said cylinder in response to pressure conditions existing in said pressure piping and said pressure chamber.

4. In a fuel feeding means for internal combustion engines, a fuel piston pump having a pressure chamber, a duct leading from said chamthe reciprocations of said pump.

5. In a fuel feeding means for internal combustion engines, a fuel piston pump having a pressure chamber, a duct leading from said chamber to the pressure piping leading to an injection nozzle ,of an engine, a cylinder, a conduit connecting saidcylinder to said pressure piping, a second conduit connecting said cylinder and said pressure chamber, a third conduit connecting said cylinder to a low pressure area, a control member movable in said cylinder in response to pressure conditions existing in said pressure piping and said pressure chamber and a slide valve oppump controlling-said third conduit.

bustion engines, a fuel piston pump having a pressure chamber, a duct leading from said chamber to' the pressure piping leading to an injection nozzle of an engine, a cylinder, a conduit connectingsaid cylinder to said pressure piping, a second conduit connecting said cylinder and said pressure chamber, a third conduit connecting said cylinder to a low pressure area, a control member movable in said cylinder in response to pres- 6. In a fuel feeding means for internal comsaid second and third conduits during a portion of said control members movements.

'7. In a fuel feeding means for internal compiston pump having a bustion engines, a fuel pressure chamber, a'duct leading from said chamher to the pressure piping leading to an injection nozzle of an engine, a cylinder, a conduit connecting said cylinder to said pressure piping, a

second conduit connecting said cylinder and said pressure chamber, a third conduit connecting said cylinder to a low pressure area, a control member movable in said cylinder in response to pressure conditions existing in said pressure piping and said pressure chamber, a slide valve operated by said pump controlling said third conduit and a port in said control member interconnecting said second and third conduits when said control member has been moved by the pressure existing in said pressure piping in order to connect said pressure chamber with said low pressure area at the conclusion of the fuel injection.

8. In a fuel feeding means for internal combustion engines, a fuel piston pump having a, pressure chamber, a duct leading from said chamber to the pressure piping leading to an injection nozzle of an engine, a cylinder, a conduit con- I necting said cylinder to said pressure piping, a second conduit connecting said cylinder and said pressure chamber, a third conduit connecting said cylinder to a low pressure area, a control member movable in said cylinder in response to. pressure conditions existing in said pressure piping and said pressure chamber, means controlling said third conduit periodically in synchronism with said pump and means on said control member for closing said second conduit shortly after the start of the compression stroke of said pump.

9. In a fuel feeding means for internal combustion engines, a fuel piston pump for feeding fuel into a pressure piping leading to an injection chamber for "said said nozzle of the engine, a pressure pump, a conduit connecting said chamber to -pressure piping, means connecting said chamber with a low pressure area and means operative by the pressure in said chamber for closing said means connecting said chamber with a low pressure area.

10. In a fuel feeding means for internal combustion engines, a fuel piston pump for feeding fuel into a pressure piping leading to an injection nozzle of the engine, a pressure chamber for said pump, a conduit connecting said chamber to said pressure piping, means connecting said chamber with a low pressure area and means operative by the pressure in said chamber for closing said means connecting said chamber with a low pressurearea, and then reopening the same upon the conclusion of the fuel injection.

11. In a fuel feeding means for internal combustion engines, a fuel piston pump having a pressure chamber, a duct leading from said chamber to the pressure piping leading to an injection nozzle of an engine, a cylinder, a conduit connecting said cylinder to said pressure piping, a second conduit connecting said cylinder and said pressure chamber, a third conduit connecting said cylinder to a low pressure area, a control member movable in said cylinder in response to pressure conditions existing in said pressure piping and said pressure chamber, a groove provided in the outer 75 face of said control member, said groove being elled a certain adapted upon movements of said control member to be brought into and out of register with said second conduit and said control member having a passage connecting said groove,with said third conduit.

12. In a fuel feeding means for internal combustion engines, a fuel piston pump having a- 1 pressure chamber, a duct leading from said chamber to the pressure piping leading to an injection nozzle of an engine, acylinder, aconduit connecting said cylinder to said pressure piping, a second conduit connecting said cylinder and said pressure chamber, a third conduit connecting said cylinder to a low pressure area, a control member movable in said cylinder in response to pressure conditions existing. in said pressure piping and said pressure chamber, a fourth conduit'connecting said pressure chamber with said cylinder and said fourth conduit having permanent communication with said third conduit and adapted to be closed when the pump has travelled a certain distance at the beginning of its working stroke.

13. In a fuel feeding bustion engines, a fuel means for internal com, piston pump having a pressure chamber, a duct leading from said chamber to the pressure piping leading to an injection nozzle of an engine, a cylinder, a conduit connecting said; cylinder to said pressure piping; a second conduit connecting said cylinder and said pressure chamber, a third conduit connecting said cylinder to a low pressure area,

a control member movable in said cylinder in response to pressure conditions existing in said pressure piping and said pressure chamber, means for periodically closing said third conduit to disconnect-said cylinder from said low pressure area, a fourth conduit interconnecting said pressure chamber and said cylinder, said fourth conduit communicating at all times with said third conduit and adapted to be closed by saidpump piston when said pump piston has travdistance at the beginning of its working stroke, and said fourth conduit being so positioned and dimensioned that before being closed by said pump piston a sufliciently great quantity of fuel oil will have passed ,therethrough for causing a displacement of said control member a longer distance than needed for moving 1 said control member in order to disconnect said second and third conduits.

14. In a fuel feeding means for internal combustion engines, a fuel piston pump having, a pressure chamber, a duct leading from said chamber to the pressure piping leading to an injection nozzle of an engine, a cylinder, a conduit connecting said cylinder to said pressure piping, a second conduit'connecting said cylinder and said pressure chamber, a third conduit connecting said cylinder to a low pressure area, a control member movable in said cylinder in response to pressure conditions existing in said pressure piping and said pressure chamber, means for periodically closing said third conduit from said low pressure area and opening the same at the conclusion of the fuel injection, a groove provided in said control member adapted upon movement of saidcontrol member to be brought into and out of connection withsaid second conduit, a port interconnecting said groove and said third conduit, a fourth conduit interconnecting said pressure chamber and said cylinder and being in permanent communication with said third conduit, said fourth conduit being so located that it is closed by the pump piston when it has verging in bustion claim 14, a suction intake for the pressure chamber of said pump which is adapted to be opened and closed by the movements of the pump piston, said intake havinga cross sectional area conthe direction of the working stroke of piston and said intake being so posito becompletely closed by the piston slightly previous to the complete closing of said fourth conduit by said pump piston.

16. In a fuel feeding means for internal comengines, .a fuel piston pump having a pressure chamber, a duct leading from said chamber to the pressure piping leading to an injection nozzle of an engine, a cylinder, 9. conduit connecting said cylinder to said pressure piping, a second conduit connecting said cylinder and said pressure chamber, a third conduit connecting said cylinder to a low pressure area, a control member movable in said cylinder in response topressure conditions existing in said pressure piping and said pressure chamber, a pressure valve provided in said duct, a seat there- .pfor and said pressure valve being so constructed that its distance of elevation from said seat is increased with an increase of the speed of the fuel piston pump.

CARL HERMAN CLAUSEN.

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