US2437838A - Fuel pump for internal-combustion engines - Google Patents

Description

March 16, 11948. G. E. SEALs 2,437,838

FUEL PUMP FOR INTERNAL;COMBUST-ION ENGINES Filed Dec. 24, 1942 2 sheets-sheet 1 INVENT OR.

March 1e, 194s. G. E. SEALS 2,437,838

I TUEL PUMP FOR INTERNAL-COMBUSTION ENGINES Filed Dec. 24, 1942 2 Sheets-Sheet 2 /a/vcfzy. j?

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Patented Mar. 16, 1948 UNITED STATES 2,437,&8

FUEL PUIWP FOR INTERNAL-COMBUSTION ENGINES Garlin E. Seals, San Antonio, Tex. Application December 24. f942rvSerial No. 470,047

Another object of the invention is to provide a l fuel control arrangement including a multitoothed cam, rotated by a lever, and a plurality of roller followers equal in number to and reciprocated by the teeth of the cam and carried by the plungers of the fuel pump so that varying positions of the cam will determine the lengths of strokes of the pump plungers and consequently the quantity of fuel delivered thereby into the cylinders.

Another object of the invention is to provide a rapid and highly effective scavenging and exhaust system for the cylinders, utilizing as an accelerating medium the air blast of the propeller blades, augmented by a blower in a fresh air chamber serving each cylinder and through which arrangement, a considerable reduction of back pressure from the cylinders is effected and more complete evacuation thereof obtained without requiring a special pump for the purpose.

Still another object of the invention is to provide means embracing the intake ports of each cylinder for introducing fresh air under pressure at an angle upward and this, combined with a deecting device carried by the piston head, very effectively drives out all stale charges through the exhaust ports of the cylinders.

- With the foregoing objects as paramount, the invention has particular reference to certain features of accomplishment, to become manifest as the description proceeds, taken in connection with the accompanying drawings, wherein:

Figure 1 is a perspective view of an engine constructed according to the present invention.

Figure 2 is an elevational view in vertical section.

Figure 3 is a perspective view of the case containing the cam actuating the fuel injectors, with parts broken away.

Figure 4 is a perspective view of one of the fuel injectors partly in vertical longitudinal section.

Figure 5 is a cross section of the crank shaft PATENT GFFICE (Cl. S-3,7)

showing the position of the fuel injector cam, also the fuel control cam.

Figure 6 is a view similar to Figure 5 but-showing the fuel control cam in position for greater/-V 5 fuel injection.

' Figure 7 is a horizontal cross section through the intake and exhaust ports of a cylinder.

Figure 8 is a perspective View of the air intake, a continuation thereof shown in Figure 1, and

Figure 9 is a fragmentary detail view of a blower adapted to accelerate the air intake of the cylinder.

Figure 10 is a view of one of the fuel injector pumps in longitudinal section.

In conventional types of two cycle engines, the burnt gases are evacuated from the cylinder by the injection of the unburnt fuel mixture. On the compression stroke the piston draws in a fresh charge of fuel from the crank case and when the piston is driven down by combustion, the crank case charge is compressed until, near the end of its stroke, the piston uncovers a port in the cylinder through which the fuel from the crank case is forced in. Just prior to this introduction of fuel, the piston uncovers an exhaust port in the opposite side of the cylinder and the burnt gases flow out before the fresh charge enters the cylinder and the incoming gas is directed upward to scavenge the cylinder. The objectionable fea.-

ture of this method of evacuating the cylinders `lies in the fact that the burnt gases are never completely scavenged and the fresh charge of fuel is always more or less diluted by the product of combustion remaining from the' previous charge. This results in loss of power and faulty ignition of the charge. Accordingly, it is the chief object of the present invention to correct the faults which have caused the two cycle engine to be heretofore regarded as unreliable and Vinefflcient.

Continuing with a more detailed description of the drawings, reference is primarily made to Figures 1 and 2 wherein reference numeral 6 is employed to generally denote the engine. As illustrated, the engine has nine cylinders 'l which are air cooled through the provision of fins 8 disposed radially thereon. Each cylinder 1 has a piston 9 reciprocably arranged ltherein provided with a wrist pin I0 to which is connected a connecting rod I I and through which power is transmitted to a crank i2, and to the crank shaft I3. The crank shaft is journaled in bearings' I4 and is adapted to supply power to drive any character of machine' but in the present case, the propeller 55 P of an airplane.

Exhaust ports I5 are provided in the cylinder 1, communicating with an exhaust manifold I8 and exhausting to atmosphere at I1 through accelerating tubes I8 (Fig. 7). The air through the tubes I8 is that blown rearwardly by the propeller P and enters by way of the ared ends I9 of the tubes I8. This exhaust system is highly effective in reducing the back pressure from the cylinder and thus more completely evacuate the same.

For scavenging the cylinder and also for combustion, fresh air enters through the belled end 20 of the riser tube bearing the same character of reference and which is covered by a dust screen 20a. The air flows in the direction of the arrows, past the butterfly valve 2 I, through the chamber 22, which extends completely around the engine and with which the tube 2U communicates, serving as the common means of fresh air supply.

In the chamber'22 there is provided a blower of the well known type suggested in Figure 9 and which consists of interengaging lmpellers 22a, driven by enmeshed gears 22h, the latter in turn, being driven by a large gear 22e, mounted rigidly upon the crank shaft I3. The fresh air delivered by this blower enters passage 23 and inlet ports 24 to the cylinder 1.

Gasoline fuel enters feed pipe 25 from a fuel tank (not shown), through injector 26, flowing through check valves 21 and tube 28 to spray nozzle 29, where it is atomized and thoroughly mixed with the incoming air. A ball check29a is provided in the tube 28 at the point where it enters the spray head and is held under slight tension of a coiled spring to prevent back firing into the line when explosions occur in the cylinder 1, At prearranged points in the' cycle, the electrical current passes through the wire 3I (Fig.

1) from the magneto, distributor 3Ia, timing gears 3Ib, through spark plugs 30 and there creates a spark for ignition.

Reciprocably arranged in the pump cylinder 26 is a plunger 32. This plunger is actuated by a cam 33, shown in detail in Figures 3, 5 and 6, the cam being secured to rotate with the crank shaft 'I3 by means'of the key 34. The cam 33 reciprocates the plunger 32 of the pump by reason of its peripheral engagement with the roller followers 35, one being mounted on the end of each reciprocating plunger rod 32a, and impart thereto an outward radial motion, the rod being returned by a coiled spring 36. There is, of course, one injector for each cylinder, all operated by the same cam 33.

In order to control the supply of fuel to the cylinders. a toothed, circular cam 31 is provided, which is capable of rotation, this being effected by means of a control lever 38. In the-position of this cam, as shown in Figure 5, the roller followers 35 are on the tips of the teeth of this adjustable cam and therefore cam 33 in rotating, will impart lbut slight motion to the injector plunger 32, hence injecting very little fuel, corresponding to an idling position. Figure 6 shows this adjustable cam in a position in which the roller followers 35 run on the tips of the teeth of cam 31 but are under control of cam 33 and therefore the reciprocating motion of the injector plunger is much greater than in the Figure 5 position. In this manner a greater quantity of fuel is injected per cycle. This corresponds to a fully opened throttle accelerating position.

In Figure 3 is shown one fuel injector push rod 32 with spring 35 and a roller bearing on the cam 33. Figure 4 shows the manner in which the fuel from line 25 enters the pump cylinder 26 and upon actuating the plunger 32, it enters the ports a therein, lifting the lower valve 21, against `the resistance of its spring, to continue past the upper valve 21 into the fuel line 28 to enter the cylinder. A fuel return line 36a is provided havlng a ball check 36h therein (Fig. 2) which extends between the line 28, near its top and the fuel supply line 25. This return line is effective to pass fuel back into the supply line in event of clogging of the spray nozzle 29 and possible rupture of the injector line which would present a fire hazard. A screw adjustment 36c is provided in return line 36a to control the tension of the valve spring.

The butterfly valve 2I shown in Flgure2 and which controls the air supply through the tube 20 has a lever 38a which is connected by means of a rod 38h, with the control lever 38 of the toothed cam 31 so that the positions of the butterfly valve, toothed cam 31 and control lever 38 may be synchronously actuated from the cockpit by control rod 38C.

A conventional system of lubrication for the engine is provided. This consists of an oil pump 39 which deliversoil through oil line 40 to the axial passage 4I in the crank shaft I3. Ports 42 provide communication between this passage and the crank shaft bearings and port 43 provides lubrication for the rod bearings. It is further pointed out that oil from the crank case iiows through pipe 44 to the reserve supply or pump from which it returns to the oil pump 39 by way of the pipe 45. v

In operation; a cycle starts by air being forced into tube 20, through dust screen 20a, past butterfiy valve 2|, to the chambers 22 of the fresh air manifold which its pressure is increased by blower 22a and is delivered thereby through cylinder passage 23 andv into the cylinder 1 through intake ports 24. The piston on its upward stroke closes ports 24 and I5, the former first, due to the presence ofan elevation 24a on the head of the piston, confronting the ports 24, and which provides additional time for evacuation through ports I5. In thus moving, the compression stroke is started. Fuel is tnen immediateiy forced into the cylinder through the line 28 and sprayed therein by the nozzle 29, a suilicient quantity of air being mixed with the atomized fuel through compression. It is important at this point to note that the -skirt of the piston is sufficiently long to keep the ports covered while at the top, to prevent communication with the crank case.

When the piston has reached a predetermined point in` its down stroke, a timer passes the current through the spark plugs 30, causing the ignition of the fuel mixture in the customary manner. ,The piston then starts on its downward' onpower stroke. the gases expanding until the exhaust ports I5 are uncovered whence the burnt gases proceed to flow through these ports and' the exhaust manifold I6 and discharge to vertical center line, which roller is raised about midway of the highest tooth of the star cam.

As the cam 33 turns with the crank shaft thevarious rollers, as shown, roll around the circular periphery until the cam depression 46 is reached, whence the -roller follows the depression until intercepted by the toothed cam. The degree to which the roller moves inwardly or follows this depression indicates the size of the fuel charge, thus a slight movement of the rollers would constitute a slight charge and a large movement of the rollers inward would result in a heavy charge.

As this is a two stroke cycle, nine power strokes are produced each revolution instead of nine power strokes every two revolutions, as in the conventional aviation engine. Moreover, the engine herein described further differs from the conventional in that it incorporates the principles of both the Diesel and other types of gasoline engines, and although it embraces the two cycle principle, it does not receive lubricant or fuel through the crank case in the manner of most types of two cycle engines but rather, is fed in such a way that the fuel is never mixed with oil nor the oil diluted by fuel. The lubricating system is in no wise hindered by fuel induction.

It is further important to observe that by virtue of the flared tubes i9, which enter the exhaust manifold i6, it is possible in scavenging, to establish in the manifold I6 a partial vacuum which is effective to aid in evacuating the cylinder by drawing foul gases through exhaust ports i5 as they are acted upon by the blast oi' air entering the ports 24.

Manifestly, the construction as shown and described is capable of some modification and such modification as .nay be construed to fall within the scope and meaning of the appended claims is also considered to be within the spirit and intent of the invention.

What is claimed is:

1. A fuel pump including a body having a valve controlled restriction intermediate its ends, a plunger reciprocably arranged in said body below said restriction having a valve controlled axial fuel passage, a fuel supply line in communication with said body below said plunger, an actuating rod on said plunger, a cam adapted to axially move said rod, an oscillatabie, multi-toothed cam in juxtapositioned relation to said first cam, and manually actuated means for oscillating said multi-toothed cam to vary the degree 0i' displacement of said plunger-rod effected by said cam.

2. A fuel injector pump comprising a tubula body having a reciprocable plunger therein provided with an axial fuel passage, a Spring retained valve in said plunger, a spring retained valve in said body above said plunger, a rotatable cam operative to reciprocate said plunger, an osciliatabie cam having a plurality of regularly spaced, peripheral teeth, and manually movable in relation to the void in said rotatable 'cam to vary the degree of displacement of said plunger to correspondingly vary the volume of fuel passing through said injector.

3. In a fuel injector pump, a cylindrical body having an axial fuel passage, a rotatable cam having a peripheral void, a plunger reciprocably disposed in the axial passage of said cylindrical body and actuated by said, cam, valvesin control of the fuel propelled by said plunger, a toothed cam oscillatably mounted in juxtapositioned relation to said rotatable cam and manually controlled whereby its teeth will be movably disposed in the void of said rotatable cam for controlling the effect of the latter on said plunger to vary the volume of fuel pumped thereby.

4. In a fuel injector pump, a tubular body, a plunger in said body having an axial fuel passage, valves in control of said passage, a plunger' rod, a rotatable cam for actuating said plunger rod to reciprocate said plunger, an oscillatable, multi-toothed cam adjacent said rotatable cam whose teeth are engageable with said rod at predetermined positions of said cams for variably controlling the displacement of said plunger by said cam to correspondingly vary the quantity of fuel pumped by said plunger, and means for manually operating said multi-toothed cam.

5. A fuel injector pump comprising a tubular body having a restriction in its axial passage and a plunger reciprocably mounted therein below said restriction', a spring retained valve in said plunger, a spring retained valve in control of said restricted passage, a rotatable cam for reciprocating said plunger, and manually operated, multi-toothed cam, oscillatably disposed in juxtapositioned relationship with said rotatable cam for increasing and decreasing the degree of displacement of said plunger as effected by said cam, and manual means for operating said oscillatable cam.

6. A fuel pump comprising a tubular body having a reciprocable plunger therein, a camadapted to actuate said plunger, an oscillatable cam having peripheral, regularly spaced teeth adjacent said cam for controlling the stroke of said plunger as effected bysaid cam, valve means in said tubular body to control the fuel propelled therethrough by said plunger and means for manually operating said oscillatable cam.

GARLIN E. SEALS.

REFERENCES CITED 5 The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 903,774 Remington Nov. 10, 1908 903,902 Simmons Nov.'17, 1908 1,112,339 Teun Sept, 29, 1914 1,139,898 Newcomb May 18, 1915 1,613,854 St. Clair Jan. 11, 1927 1,753,759 Stalker Apr. 8,'1930 1,859,541 Thaheld May 24, 1932 1,917,791 Bellanca July 11, 1933 1,929,885 Gosslau Oct. 10, 1933 1,938,271 Woolson Dec. 5, 1933 1,966,771 Thaheld July 17, 1934 2,162,683 Tobin June 13, 1939 FOREIGN PATENTS Number Country Date l 294,327 Great Britain 1928 362.749 Great Britain 1931 688,991 France 1930 785,391 France 1935

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