US2094560A - Fuel feeding system - Google Patents

Description

Sept. 28, 1937. HoRToN g 2,094,560

FUEL FEEVDING SYSTEM FiledJuly 5, 1934 4 Sheets-Sheet 25 @aafla sepf.2s,1937. E. C. HOR'TON 2,094,560

- FUELFEEDING SYSTEM Filed July 5, 1934 l4 sheets-sheet 4 9 Y n 65 i f v *l* gnuy: 4 y

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\\\\ INVENTOR Erwmhnron,

ATTORNEYS mv. N

UNITED STATES PArENro1=E FUEL Fsnnmo srs'rm v #Erwin C. Horton, Hamburg, N. Y., kassigner to Y Trico Products Corporation, Buffalo. N. Y.

Application July s, 1934, serial No. mainsL f 4011.111.` (ci. 15s-sai) n i a lower. level than the carburetor 2, thecar-` in the fuel line from thefuel supply tank to the l engine carburetor. Fuel feeding systems of this type heretofore proposed have operated their pumps in part by the low pressure or suction influence of the intake manifold. The suction de-v rived from this source is variable duringengine operation according to the position of the engine throttle, and consequently the operation of-the pump i s likewise variable and the feeding of the fuel tothe engine is spasmodic and unreliable. When the suction is 4high the system may deliver fuel in excess to the engine demands, and when the suction is low the fuelsupplied is insufficient.

The object of the present invention is to provide a fuel feeding systemin which the fuel is supplied in accordance with the requirements whereby greater efficiency in -engine operation and performance is obtained.

More particularly, the'invention resides in a fuel feeding system in .which the delivery of fuel to the carburetor is regulated by the pressure on the pumped fuel. l

Furthenthe invention residesin a fuel feeding 'system in which the pressure on the pumped fuel and the pressure for operating a fluid pressure actuated fuel pump are factors and cooperembodiment of the present invention; i

Fig. 2 is a longitudinal section through the fuel pump element of the'system;

Fig. 3 is a transverse sectional view about on line 3-3 of Fig. 2, showing more particularly the pressure governor;

Fig.`4 is a plan view, partially broken .away and having other parts removed;

Fig. 5 is a view similar to Fig. 3 but taken about on line 5-5 of Fig. 2 and having parts omitted;

Fig.6 is a transverse section showing the valve snap action; l

Fig. 7 illustrates a slight modification in the system;

Fig. 8 is a sectional view of the governor element adapted for the arrangement of Fig. '1;

Fig. 9 illustrates a modified vform of governor for the pump; and

Fig. 10 illustrates a further-modification of the l governor.

Referring more particularly to the drawings, the numeral I designates Athe fuel supply tank of a motor vehicle whichhas an atmospheric vent I' and is usually located to the rear and at `buretor herein shown being of the down draft type having a throttle control 3and 'an intake manifold 4 leading to the combustion chambers i of the engine 5. interposed in they fuelfline be- Atweenthe supply tank Iy andthe carburetor 2 is a pump generally indicated by the numeral 6 and having its inlet port connectedto thefuel supply/,tank byia passage I' and its outletl connected Ito the carburetor 2 bythe passage or conduit 8. The pump unit, according tothe presentrdisclosure, is operated by a. fluid pressure operated motor partand for this purpose communication 'withthe source of pressure may be established by va conduit or connection 9.-,

.l 'I'he pump is illustrated in Figs. 2,through 6 as comprising a central body portion I0 flanked on each side` by cylinder sections II and I2.v Within these cylinders operate the piston heads yor movable fuel displacing walls I3 and Itwhich serve to partition 'wet or pump chambers I5 and I6, at4 the inner sides of the piston heads, from ythrough a strainerr2l and the valved inlet ports 23 and 24 into the wet or pump chambers I5 and I8. This body member AIIJ isalso provided with valved outlet ports 25 and 26 leading respectively from the chambers I5 and ylli and connected to the carburetor 2 by the communicating 'passage Il. Consequently, the reciprocatory movement of the piston unit (I3, I9, I4) will enlarge one Wet chamber as the fuel flows there* with from the supply' tank and ensmall the other wet chamber to expel the' fuel therein'toward the carburetor.

Fluid pressure for operating'the pump may be obtained from any suitable source, such as the intake manifold of the internal combustion en- .gine which provides a very convenient source of supply in a motor vehicle. The two dry or vmotor chambers I'I and I8 are connected by a passage that when the source of suction or low pressure is in .communication with one dry chamber"the higher or atmospheric pressure is in communication with the companion dry chamber. This low pressure in the one dry chamber, at one side of the adjacent piston head, and the pressure of the liquid against the opposite side of said piston head provides the required pressure differential for effecting operation of the piston.

The valves are shiftable so as to transpose the suction and atmospheric connections with respect to the motor or dry chambers and such shifting of the valves is accomplished during the final portion of each stroke of the piston, According to the present disclosure the valves are connected to a pivoted valve shifting member 36 which in turn is connected by a spring 31 to a second pivoted member 38. This member 38 is connected to the piston through a link 39 which has a play connection with the piston, so that movement of the latter to the left in Fig. 2 will be independent of the valve snap action (36, 31, 38) Vuntil the piston engages the shoulder 40 of the link and moves the member 38 to the left thereby to bring the spring 31 beyond the pivotal mounting of member 36 to effect a snapping of the valve shifting lever 3S tov reverse the valve connections. Likewise return movement of the piston, or to the right in Fig. 2, will be independent of the valve snap action until the shoulder 4| of the piston contacts with the shoulder 42 on the link 38 and moves the latter with its connected lever 38 to the right sufficient to return the spring across a dead center position and thereby cause the valve shifting lever 36 together with the connected valves to be snapped back to the position shown in Fig. 2 to thereby re-establish the fluid communications illustrated therein. The valve snap action is conveniently housed within the cylinder and to accommodate the same such cylinder may be extended or enlarged over that of cylinder |2.

Means are provided for controlling the application of operating pressure (suction herein)k to the pump in such manner as to insure amore reliable pumping action. This controlling means or governor is preferably responsive in its functioning to the pressure on the fuel being pumped to the carburetor so that the engine demands will always be primarily regarded by the system and thereby insure ample fuel to maintain efficient operation of the engine.

The governor element here shown comprises a valve 45-engageable with a valve seat 46 through which communication with the vsource of suction is established by the passage 41 as a continuation of the conduit or passage 9. A spring 48 tends to urge the governor valve from its seat and is more or less counteracted by the pressure differential acting in the opposite direction on the valve. The valve may be supported by a diaphragm 49 which serves to increase the surface over which the pressure differential will normally act. Consequently, as the suction becomes excessive the valve 45 will be moved closer to its seat and thereby throttle or restrict the size of the passage through or over the seat. This valving actionaccordingly governs or regulates the degree of suction for the suction passage 32, the latter leading from the chamber 50 surrounding the valve seat and of which chamber the diaphragm constitutes a wall.

The opposite side of this movable wall or diaphragm 49 is acted upon by the pressure on the outowing fuel. To this end the pressure on the fuel outflowing from the pump is transmitted to the diaphragm 49. According to the present disclosure a wet chamber 5| is provided in communication with the fuel outlet, as by a branch outlet passage 52. The chamber 5| is closed on one side by the diaphragm 49 so that the latter really constitutes a partitioning wall separating the chambers 50 and 5|. As the back pressure on the outiiowing fuel increases, as when the output is greater than is being accommodated by the carburetor, then the pressure differential acting on the diaphragm 49 and its valve 45 will likewise increase and counteract the outward urge of the spring 48 to move the valve closer to its seat for throttling the suction acting on the piston.

'Ihus with an empty carburetor, as when the fuel system has run dry, the fuel pump will continue to operate at its full capacity until the carburetor has had its supply replenished and the back pressure on the fuel in the communicating passage between the pump outlet and the carburetor increases sufliciently to throttle the suction supply, whereupon the pump will retard or cease depending upon the pressure differential acting upon the diaphragm.

If desired, the pump 6 may be mounted on or adjacent the supply tank and the governor 45' separately disposed closer to the intake manifold or source of suction, as illustrated in Fig. 1. This kwill provide for a more sensitive governor action,

since by this arrangement the governor does not have the Weight of the pump output in conduit 8 acting to increase the pressure differential on the diaphragm 49. In this embodiment the fuel conduit 8 connects the pump to the governor chamber 5| while the suction conduit 32 provides communication between the governor chamber 50 and the valve chamber 28.

The operation is believed to be obvious from the foregoing, the fuel in tank flowing into the connected wet chamber under the urge of atmos- 'pheric pressure and against one of the piston heads whose opposite side is open to the source of suction. This results in a movement of the piston head toward the low pressure chamber and exerts a, pull on the trailing piston head for eX- pelling the fuel to the carburetor. When this pump stroke is completed the automatic valve mechanism shifts the valves 34 and 35 to transpose the suction and atmospheric connections whereby the pump will move in a reverse direction. This pumping action will continue until the demands of the engine have been supplied whereupon the velocity of the pump outflow will be retarded` and the pressure increase in chamber 5| sufficient to counteract the spring 48 and move the valve 45 closer to its seat so as to throttle the suction influence on the pump. Obviously when the engine demands more fuel, which will relieve the abnormal pressure in chamber 5|, the valve 45 will open so that the pumping action will resume its normal operation.

The pump illustrated in Fig. 2 may be mounted directly on the engine block or crank case and for this purpose is provided with ears 43 through which fastening bolts 44 extend. The inlet and outlet fuel ports of the pump are rendered easily accessible by having them open toward one side of the body portion |0 and providing such side with a removable plate 53. Such platemay be provided with keeper elements or pins 54 restricting the opening movements of the inlet valves 55 and outlet valves 56 and is shown as being secured in its operative position by a single fastening element 51.

The governor element 45', Figs. '7 and 8, may be mounted directly on the intake manifold, in

' differential on opposite sides thereof f to actv which event the suction passage 41 may open directly into the manifold ychamber through the connecting nipple 9'. The atmospheric vent I for the fuel supply tank I may open into the supply tank through themounting base of the pump 6 where the latter is mounted directly upon the tank.

In the foregoing it will be noted that the governor element 45 (45') is responsive jointly to the output pressure of the pump on the one side, in cooperation with the sub-atmospheric pressure in themaniiold passage on the other side. In the embodimentsy illustrated in Figs. 9 and 10, the suction throttling valve is responsive to the output pressure of the pump acting on the one side, and while the diaphragm IIIll is open to the atmosphere the throttling valve is itself subjected to the col operating suction influence so that the suction and liquid pressure act jointly against the spring pressure.

Like in the embodiment illustrated in Fig. 3,v

the chamber I is closed at one side bythe diaphragm 49a (Fig. 9), the chamber S0 at the opposite. side of the diaphragm being open to the atmosphere through vent`6 I. The valve element 62 cooperates with its seat 63 to throttle the communication between the suction passage Ila and the motor suction passage 32a. The valve vis provided with a stemportion 64 slidably. mounted in the adjacent wall of chamber 60 and held in contact with the diaphragm 498L by spring 65 which urges the valve to an open position. The valve stem 64 isprovided with a snug sliding fit in the chamber wall and may if necessary be provided with packing (not shown) Fig. illustrates the governor valve in the form i of a ball 'I0 which is normally urged to an open position by the spring 1I, a stem 'I2 being slidably interposed between the ball and the: diaphragm 49a in a manner somewhatA similar to the valve stem 64 in Fig. 9. The ball valve may be of a sufficient size to provide a certain pressure against the spring 1I and assist the pump output pressure. This is also true of the embodiment illustrated in Fig. 9, since in both embodiments the valves will be subjected to the suction influence tending to draw them to their lseats against the tension of their springs and in cooperation with the pressure of the delivered fuel acting on the remote side of the diaphragm.

`In these modified forms the pump will supply fuel to the carburetor or engine until the pressure at the output or outflow side of the engine builds up sufiiciently to counteract and overcome the spring pressure whereupon the suction or low pressure. passage to the motor side of the pump will be throttled until the engine fuel demand is increased.

` pump to the intake manifold for providing operating pressure for the pump, and means responsive to the difference in the pressures on the fluids in the two lines for regulating the operation of the pump to proportion the output of the pump in accordance with the demand of the engine.

2. A liquid fuel pump operable by fluid pressure, such, for instance, as the variable suction influence maintaining in the intake'manifold of a motor vehicle internal combustion engine, comprising a motor chamber, piston means operating back and forth therein, a fuel outlet line leading from the pump, a fluid pressure line leading to the motor chamber by which pressure may be utilized to actuate the pump, valve mechanism F for operatively connecting the pressure lineiand the outside atmosphere to the motor chamber to provide the required'uid pressuredifferential in one direction to effect operation of said piston means and the pump on the liquid expelling stroke of thelatter, means for effecting return movement of said piston means, and means in said pressure line responsive to the difference in the pressures of the fuel outlet line and the pressure line for restricting the flow capacity of the pressure line to aA substantially predetermined degree, whereby the differential pressure action on the piston means to operate the fuel pump is determined against `becoming excessive and the pressure on the fuel in `the outlet line'is maintained below a predetermined maximum. l

3. A combined fuel pump and regulator having a motor chamber, and piston means operating back and forth therein, a suction line leading to themotor chamber by which suction may be utilized to actuate the pump, valve mechanism for operatively connecting the suction line and the outside atmosphere to the motor chamber to provide the required fluid pressure differential in one direction to effect operation of said piston' means and -the lpump on the liquid expellingv stroke of the latter, means for effecting return movement of said piston means, and pressure responsive regulator means in said suctionlin'e for restricting the passage of fluid through said suction line to a substantially predetermined degree, said pressure responsive regulator means being subjected to the pressureon the fuel at the' delivery side of the pump and responsive to such pressure for regulating the degree of suction permitted for the operation of the pump, whereby the differential pressure action on the piston means to operate the fuel pump is determined f y 4. A liquid fuel pump having a motor chamber, piston means operable back and forth therein, a pressure line leading to the motor chamber by which pressure may be utilized to actuate the pump, valve mechanism for operatively connecting the pressure line and the outside'atmospherel to the motor chamber toprovide the required fluidpressure differentialin one direction to effectxoperation of said piston means and said pump on the liquid expelling stroke of the latter, means for effecting return movement of said piston means, said pump having a delivery line leading to a. point of consumption at a higher plane relative to the pump, and means for regulating the 'supply of pressure through the pressure line to the motor chamber, said regulating means embodying a pressure responsive mem-4 ber acted upon on one side by the pressure `on the fuel adjacent such point of rconsumption in the relatively higher plane and on the opposite side by the pressure maintaining in the pressure line, said pressure responsive member being movable by a predetermined differential between n the two pressures.

ERWIN HORTON.

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