US1639645A - Pressure fuel-feed system for hydrocarbon engines - Google Patents

Description

, 1,639,645 Aug- 23 1927 A, E. BERDON PRESSURE FUEL FEED SYSTEM FOR'HYDROCARBON ENGINES Filed March 26, 1924 Patented Aug. 23, 19.27..

AUNITED STATES PATENT OFFICE.

.ALBERT E. BERDON, OF SOUTH ORANGE, NEW JERSEY, 'ASSIGNOR TO SEJF-FEEDING VAPORIZER CORPORATION, OF NEW YORK, N. Y., A CORPORATION OF NE'W YORK.

PRESSRE FUEL-FEED SYSTEMv FOR HYDROCARBON ENGINES.

Application led March 26, 1924. Serial No. 702,002.

This invention relates broadly to fuel feeding systems for hydrocarbon engines, and more especially to a pressure feed system, adapted for hydrocarbon engines of the automobile, the aeroplane, and similar type en ines and the like.

eretofore -in the` art pumps have been utilized to feed liquid fuel to hydrocarbon engines and a well known system has been to use a pump to servea s'mall tank provided with an overflow back to the main tank and adapted to feed the carburetor by gravity feed. In this old type of system the overflow pipe is objectionable,` more especially in connection with automobile engines, and this system has therefore not been generally used in automobile structures, although it is in quite common use with stationary engines. This system* however possesses the advantage of having a large supply tank located below the level of the carbretor and a very small supply tank above the level of the carburetor, which small tank is continually replenished by the operation of thev pump.4 The organization minimizes the lire hazard due to the fact that only a small supply of fuel is maintained near the engine and above the carburetorand provides a substantially constant head pressure to feed the carburetor. l Pressure supply systems are common in the art in which air pressure is pumped -to themain supply tank to provide a pressure over the fuel in the main supply tank and thereby force the fuel tothe carburetor. This system insures an adequate supply of fuel to the carburetor, but possesses the disadvantage of fire hazard in that if any leakage occurs in the carburetor ioat' control valve whereby the carburetor is flooded the fuel will leak out and run on the lfloor beneath the car and create a ldangerous situation. Furthermore the pressure is variable` and since the main tank must withstand the pressure-it must be extra strongv which adds' to the cost.

The present invention overcomes the diffi-- culties of the known art and at the same time carries forward the advantages of the known art by providingv a novel pumping l apparatus which constantly maintains a smalll supply of fuel to feed the carburetor and which supply is under a predetermined pressure and is furnished accordin to the needs of the carburetor. Broadly, t e present .invention comprises constructions in which a small supply of fuel is under a predetermined pressure andl is replenished as it is used by the carburetor, Withthe replenishing operation taking place through mechanism positively operated mechanically by a moving part of the engine. In a simple form it may comprise a pumping mechanism which is operated 'b `av moving part ofthe engine, for examp e, a valve rod, and which is so constructed that fuel is continually fed to the carburetor conduit bythe pump until a predetermined pressure is reached in the said conduit leading from the pump to the carburetor, at which time the pump ceases to function. The functioning of the pump is proportionate to the reduction in pressure from the predetermined pressure so thata small reduction in pressure will permita proportional pumping operation, thereby maintaining the pressure l in the line to the carburetor substantially constant within relatively narrow limits in which the maximum pressure is substantially a predetermined fixed limit. Having generally set forth the aspects of the invention, it may be stated that the principal object is a fuel feed system for a hydrocarbon engine in which liquid fuel is raised from a main'supply, preferably lo'- cated at a low level, by mechanically operated mechanism which delivers the said fuel to the carburetor under substantially constant pressure. v

Another object of the invention is to provide a system of the character specified in which the maximum pressure on the delivered fuel may be predetermined.

A4 further object of the present invention is a system of the character specified in which a predetermined pressure may be 95. established at which the mechanical driven element of the system ceases to operate.

A still further object of the present invention is a system in `which provision isA made to preventthe back iow of the fuel from the pressure line when the mechanically operated pump ceases to operate.

A still further object of the present invention is a system of the character specified in which constructions are rovided to prevent an overflow of liqui fuel from the main supply tank to the carburetor when the main supply tank is raised above the carburetor, as occurs in an automobile on a steep grade with the enginedown hill.

Another and important object of the present invention is a system substantially as specified in which the delivery of liquid fuel to the carburetor is dependent upon the needs of the carburetor regardless of the speed of operation of the moving part which operates the pump of the system.

Other and further objects of the present invention will in part be obvious and will in part be pointed out hereinafter in the specification following by reference to the accompanying drawings forming a part of this application.

Realizing that the present invention may be embodied in constructions other than those herein specifically shown and described, it is desired that the disclosure herewith shall be considered as illustrative and not in the limiting sense.

Throughout the drawings like parts are indicated by like characters, and

Figure 1 is a diagrammatic view illustrating the invention as applied to a hydrocarbon engine ofthe automobile type;

Figure 2 is a sectionalview through one form of pumping apparatus adapted for use in connection with the present invention;

Figure 3 is an elevational view of the device shown in Figure 1; and

Figure 4 is a plan view of the device shown in Figures 2 and 3. y

Referring now more especially to Figure 1, which diagrammatically illustrates the whole system a main tank 1 open to atmosphere is connected by a suitableconduit- 2 to a mechanical pump 4, which is operated by some moving part of a hydrocarbon englne 5,. for example, one of the valvev rods 6. Thls pump 4 is connected by a suitable conduit l7 to a carburetor 8 in such manner that as the valve rod 6 reciprocates in its operation it will operate an actuating lever 9 vof the pump 4 and thereby actuate the pump to draw gasoline from the main tank l to deliver said fuel to the carburetor 8 under a constant predetermined pressure, as w1ll now be explained by reference to a more detailed description of t e mechanical pumping apparatus. Upon reference to Figures 2 to 4 inclusive, which illustrate the preferred form of mechanical pump, it will be observed that a diaphragm pump has been chosen in order to avoid sliding packed jo1nts in the fuel line. Other Ytypes of pumplng apparatus may be utilized without departing from the invention, but the diaphragm type of pump is preferred.` Referring to the details of the pump illustrated, it will be noted that a body' portion 10 is constructed to carry the operating valves and is provided on t-he inlet side with an inlet connection 11 which is arranged on its inner end with a valve seat against whichvan inlet valve 12 is normally seated by means of a light spring 14. The body portion l0 is cut away, preferably, around the valve 12 and inlet connection to provide a space 15 in which the valve 12 may operate and also to provide a liquid seal which tends to obviate air pockets. This space 15 leads by means of a conduit 16 to a pumping recess 17 in the upper part of the body portion, 'which pumping recess at the opposite side of the body portion leads to an outlet collar 18 that is provided with a seat against which an outlet valve 19 is normally seated by a light spring 20. This outlet valve 2() and the end of the outlet collar 18 which is provided with a valve seat, are also surrounded with an annular space 21', allowing clearance for thevalve operation, and likewise providing a liquid seal for the valve. This outlet space 21 communicates with an conduit 7 leading from the carburetor. The body poltion 10 of the pump is adapted to carry a cover portion 24 which may be attached to the body portion' by machine screws 25 or the like, and this cover portion 24 ,is also provided with a recess 26 vopposite to the pumping recess 17 in the body portion 10. A diaphragm 27 of the ordinary type, preferably corrugated, is mounted between the body portion 10 and the cover portion 24 and is adapted to be flexed back and forth in the spaces formed by the recesses 17 and 26 to provide the pumping action.

'outlet conduit 22 that connects with the loo y An operating stem 28 is operatively connected with the diaphragm 27 as by means of suitable washers 29 and 30 and is adapted to be guided at its free end by an adjustable guide or collar 31 which preferably is Screw threaded in an extension 32 on the cover 24. A spring 34 surrounds the operating stem 28 and is compressed bet-Ween the adjustable guide 31'and the washer 29. The guide 31 is adjustable in the extension 32 in order to predetermine the amount of compression of the spring 34 for the purpose hereinafter described. The upper end of the stem 28 is connected by an extensible spring 35 with the actuatinglever 9 which is pivoted atl 36 to a bracket 37 that is` mounted on the cover portion 24. The mounted relatively to the engine so that the other end of this actuating lever 9 is in operative relation to the valve rod 6 as previously stated, and this operative relation preferably comprises a bifurcated end 38 on the lever 9 extending around the valve rod 6 pump is and above an adjustable collar 39 on 'the valve rod 6 so that the lever 9 is raised by 'the collar 39 as the valve rod 6 moves up'- Wardly, but is lowered by the action of the compression spring 34 which is carried b the operating stem 28, as the valve rod 6 1s lowered.

In the operation of 4the device, it will be observed that as the engine turns over and the valve rod 6 is reciprocated, the adjustable collar 39 on the valve rod 6 will contact with and will raise the` outer end of the actuating lever 9 so that it acts as a lever of thev second class to pull on the extensible spring 35. The pull of the spring 35 vis communicated to the operating stem 38 and thereby tends to raise the stem and compress the compression spring 34. This causes the diaphragm 27 to be flexed upwardly and produce apartial vacuum whereby atmospheric pressure in the main tank, whichis open to atmosphere, causes liquid fuel to How through the conduit 2 past the inlet valve` 12 and into the pumping space 17 in the body portion beneath the upwardly flexed diaphragm 27. As the valve rod 6 lowers on its return stroke, the adjustable collar 39 is lowered away from the louter, end of the lever 9 so-that the pull onthe extension spring 35 is relieved and the full force of the compression spring 34 now acts on the diaphragm to produce pressure on the fuel beneath the diaphragm in the'space 17. This action assists the light spring 14 in closing the inlet valve 12 and also overcomes the pressure of the light spring 20 to open thc Y outlet valve 19, 'thereby driving the fuel from the recess 17 into the conduit 7 leading to the carburetor. This action continuesas the engine continues to turn over until a sufficient amount of liquid is supplied to the carburetor to cause the carburetor float in the float chamber to close the carburetor inlet valve thereby closing the conduit from the pump to the carburetor, stopping the flow of fuel to the carburetor. y As the engine continues to run the valve rod 6 will again,

f' through the collar 39, raise the operating arm 9, which again in turn will Hex .the dia-v phragm 37 in an upward direction and on the return stroke the compression spring 34 will again tend to force the diaphragm downward. Now that the fuel line leading to the carburetor is substantially closed and is filled with liquid fuel, this fuel in the closed conduit tends to resist the return of the diaphragm to normal. 'The diaphragm will therefore stand stationary. As soon, however, as a small amount of gasoline is released from the conduit into the float chamber of the carburetor by the float valve, the diaphragm under the influence of thel springe 34 will lower iproportionately and on the next'upstroke ofthe valve rod 6 the fuel necessary to fill the void follows that during the voperation of the engine the fuel on the outlet side ofthe pump, namely, that in the conduit line leading to the carburetor', is maintained substantially under a predetermined pressure. It will be understood that the extension spring 35 is -of vsuch strength as to overcome the maximum compression. which may be applied to the compression spring 34. After the feed line to the carburetor has become filled with gasoline and momentarily there is no fuel feeding into the float chamber of the carburetor and while the diaphragm 27 is being maintained substantially stationary, and movement in an upward direction by the outer end of the lever 9 is allowed by the extension of the extension spring 35, so there is always an excess of motion to insure prompt action of the diaphragm. This ac'- tion -will occur when the washer 29 on the operating stem 28 contacts with vthe stop 40 on the cover 24, which stop fixes the upper limit of movement of the diaphragm. Movement of the diaphragm is limited by the contactiifg of the end 41 of the operating stem 28 with the bottom of the recess 17, which comprises a lower limit stop for the diaphragm and consequently relieves the diaphragm of abnormal. downward stress action of the spring 34, when the pumping chamber 17 is empty.

It will be observed that the inlet valve 12 actsxto hold the pressure established in the feed line conduit leading to thel carburetor, A aswell or to perform its normal pumping function; and that while the outlet valve 19 performs its normal pumping function it also operates to prevent an overflow from the' main tank Where 'the main tank is elevated, but in practice the pump is usually located at a point so high that the main tank is `not likely to bel raised .above it and the outlet valve elfect'ually blocks any siphoning action that might tend to occur where the main tank is elevated above the carburetor.

From the foregoing it will be observed that the present system comprises an arrangement of parts whereby a relatively small amount of liquid fuel is maintained under a'predetermined pressure by positively mechanicallyoperated constructions, which automatically functions to supply the carbureto.` according to its requirements.

Having thus described my invention what I claim is:

In combination, a fuel supply source and a fuel receiving element, a pumping mechanism disposed 'between the two comprising a chamber having a diaphragm therein, arod 5 secured to said diaphragm, a spring connected to said rod and an operating mechanism secured to said spring for exing said diaphragm in one direction, a spring disposed around said rod and having fixed bearings at either end thereof, whereby when 10 said latter spring is compressed it may Hex said diaphragm in the opposite direction and inlet and outlet passages connecting said chamber with said fuel supply source and said fuel receiving element.

ALBERT E. BERDON. i

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