US1418548A - Fuel-feed system - Google Patents

Description

F. f. EDWARDS.

FUEL FEED SYSTEM.

APPLICATION FILED JAN-6.1921.

Patnted June 6, 1922.

' 3 5HEETSSHEET L F. E. EDWARDS.

FUEL FEED SYSTEM.

APPLICATION FILED JAN. 6, 1921.

Patnted June 6,1922.

3 SHEETS-SHEET 2.

F; E. EDWARDS.

FUEL FEED SYSTEM. 1 APPLICATION FILED JAN. 6, I92]. 1,418,548.. tente June 6, 1922.

s SHEETS-SHEET 3.

a: 59 ta '5 v 7., 6 Q g 57 m W I as g 1 I a FRANCIS E. EDWARDS, 0F CRYSTAL LAKE, ILLINOIS, ASSIGNOR 1'0 STROMBERG MOTOR DEVICES COMPANY, OF CHICAGQILLINOIS, A, CORPORATION OF ILLI- NOIS.

FUEL-FEED srs'rm.

' Specification of Letters ratent. Pate itd June. 6, 1922,

Application filed January 6, 1921. Serial No. 435,347.

To all whom it may concern:

Be it known that I, FRANCIS EJ'EnwARDs, a citizen of the United States, residing at Crystal Lake, in the county of McHenry and State of Illinois, have-invented a certain new and useful Improvement in Fuel- Feed Systems,of which the following is a full, clear, concise, and exact description, reference being had to the accompanying drawings, forming a part of this specifica.

tion.

My invention relates .to fuel feed systems for feeding liquid fuel to the internal combustion engines of automobiles and other vehicles; More particularly, the invention functions to pump the liquid fuel from the supply tank of the automobile to the cars buretor of the engine.

The present application is related to my copending application Serial Number 204,484, filed November 1917 and to numerous related improvement applications which I have filed subsequently thereto, which are directed to developments of the general theory "embodied in the parent application.

According to this general theory, I provide a pumping chamber communicating with a substantially closed air. chamber, which air chamber israpidly diminished and increased in volume to create alternating compressions and rarefactions of air in the pumping chamber with a consequent pumping action on the liquid fuel therein. This pumping chamber has inlet and outlet ports,

controlled by shitable valves, which ports communicate with the tank or other source of supply and with the carburetor respectively.

In the previousiforms I have employed'a reciprocating piston. pump, which is driven is directly responsive to pressure is subject to'damage or to rapid deterioration under the violence o'fexplosion. A further disadvantage ofthe. prior art devices is the fact that they are subject to such rapid operation at high speeds of the engine that they often fail to operate or if they do operate they wear out very quickly. One of the main objects of the invention 1s to provide a pumping mechanism which will operate directly from the engine cylinder preferably on t e compression stroke of the engine without being subjected'to the violence of the explosion stroke.

By this method of operation I am able to secure operation at half of the speed of the engine. The slower operation insures that pump ng will always be performed and the wear 1S reduced. These and other objects Wlll be more apparent from the followingdescription taken in connection with the accompanying drawings in which I have illuspreferred embodiment .ofmy. inven- Figure l is a diagrammatic viewof a fuel feed system embodying my invention:

Figure 2 is a vertical sectional View of the pumping mechanism; and

Figures 3 and 4 are partial sectional views illustrating modifications of the pumping mechanism.

Figure 1 illustrates diagrammatically my invention as employed in a fuel feed system for pumping liquid fuel from the supply tank 1 to the carburetor 2 of the internal combustion engine 3. Though the conception is based primarily upon this particular utility, it' isto be understood that the es sence of the invention may be extended to and include other pumping adaptations.

The pumping mechanism is broadly designated 4 and comprises a fuel pumping chamber 5, and superposed thereon, an impulse pump 6. The inlet port of the pumping chamber 5 is connected with the tank 1 by means of the pipe 7. The discharge port of the pumping chamber 5 communicates by means of the pipe 8 with the float chamber 9 of the carburetor 2. Communication between the pumping chamber 5 and the float chamber 9 is, of course, under the control of a float controlled valve (not shown) in the float chamber 9. The impulse pump}; is arranged to receive its pumping impulses througha pipe 11 which connects with the top of one of the cylinders 12 of the internal combustio-n'engine 3.' The pipe 11 has any suitable connection with the upper area of the cylinder 12, preferably a connection which may be made with facility, such as through a spark plug, a 'valve plug or the cylinder plug 13 as illustrated.

Referring now to the detailed construction 'of the pumping mechanism, as shown in Figure 2, it will be noted that the impulse pump 6 comprises a relatively large cylinder 14 and a relatively small cylinder 15, which is integral therewith and superposed in axial alignment on the large cylinder 14. A compound piston 16, consisting of a large piston 17 and a small piston 18, reciprocates in the cylinders 14 and 15. Both pistons are hollow, in the interior of the small piston 18 being closed off from the under side or interior of the large piston by the solid heabl or wall indicated at 19. The hollow interior of the small piston 18 has communication with the upper area of the large cylinder 14,. above the piston 17 through a series of ports 2121 located adjacent the bottom of the piston 18. In the operation of the impulse pump the compound piston 16 does not move higher than the full line position and therefore the ports; 21 are always free to conduct the pressure fluid from the hollow interior ofthe small piston 18 to the upper area'of I pipe line 11, this union being of any suitable type capable of maintaininga tight joint against the compression and explosion pressures from the engine. The nipple 25 is also drilled to provide an upwardly inclined restricted passage 27 which opens into he cylinder space above the small piston 1 The piston as an entirety is normally urged up-- ward into the full line position by a helical compression spring 28, which is confined in the lowerair chamber 30 of the large cylinder714 and bears against the hollow piston 1 The large cylinder 14 is open at the bot-' tom and is provided with a radial flange 29, to which is bolted orotherwise fastened the flanges 31 and 32 of the upper and lower halves 33 and 34 of the pumping chamber 5. The upper section 33 is provided with a second series of annularly valve port 35 which affords vcommunication between the interior of the pumping chamber 5 and the air chamber 30 of the large I cylinder 14. This valve port is governed by a Valve 36 which is controlled by the level of the fuel in the pumping chamber under the action of the float 37. Thefloat may be guided by a vertical stem 38 or by any other suitable means. The inlet and outlet flow of the liquid fuel through the pumping chamher" 5 occurs through inlet and outlet ports 39 and 41 which are controlled by disk check valves 42 and 43. Theinlet valve 42. cooperates with the valve seat formed in the integral extension 44, which forms a valve compartment. The inlet pipe 7 has connection through a union45, which threads into the extension'44 andcommunicates with the under side of the valve 45. The motion of the valve 42 is limited by a surrounding valve cage 46, which prevents displacement of the valve.

The exhaust valve 43 cooperates with a valve seat in a similar extension 47, into which screws the union 48 of the discharge pipe 8. The valve 43 is provided with an upwardly extending stud 49' which is adapted to contact with the screw plug 51 and prevent displacement of the valve.

To support the pumping mechanism, the cylinder casting 14 is provided with a lat- .erally extending bracket 52 which is adapted to be connected to the bottom of the inlet housing 53 of the carburetor float chamber as'illustrated in Figure 1. I also contemplate supporting the pumping mechanism above the float chamber if such situation is preferable.

The operation 7 of the embodiment thus far described is as follows:

- With the starting of the internal combustion engine3, part of the contents of the engine cylinder isforced into the pipe 11. This raises the pressure in the pipe 11 and in the pumping element. The body of air or gas contained in the pipe 11' and the connected pumping element 6 constitutes in effect an elastic connecting rod for trans- 1 mitting energy from the gas in the'cylinder 12 to the compound piston 16. As I have previously remarked, the pressure pulsations to which this column of mixture is subjected are of widely varying degree. The pressure of explosion is usually several times that of the pressure of compression and it is. therefore desirable that means he provided to reduce the effect of the explosion pressure. The pressure produced by the compression stroke in the engine cylinder 12 enters the impulse pump when the piston member is at the upward limit of its stroke (as shown in Figure 2). Consequently. this compression pressure has access to the upper surface of the small piston 18 through the passage 27, and also to the. upper surface of the large 50 i of exhaust so as to insure the upward movepiston 17 through the ports 22/ and 21. In the normal running of the engine this compression pressure is built up very rapidly and from the fact that it is effective upon both piston areas it quickly depresses the piston member 16. The lower limit of the piston stroke is defined by that position where thepiston'is balanced by the spring pressure from thefspring 28'. It will be apparent that simultaneously with the depression of the piston member 16 communication between. the column of the mixture and the large piston 17 is interrupted by the solid wall of the small piston 18 moving down across the passage 24:. Therefore, when ignition occurs in the cylinder 12, immediately after this severing of communication', the explosion pressure will not-have access to the large piston 17 but only to the head of the sniallpiston 18. The relatively small area of the small piston 18 reduces the effectiveness of the explosionpressure and substantially equalizes the pumping effort of the two pressures. The effectiveness of this explosion pressure upon the small piston 18 is furthermore reduced by the restricting action of the small passage 27. The energy produced by the -explos1on pressure is therefore only sufficient tohold the piston member 16 in the positionto which it has been depressed by the compression pressure, or at the most, to force the piston member down slightly further against the compression of the spring 28, It will hence be :seen that the differential piston areas on the compound piston 16 equalize or substantlally equalize the pumping effortof the two different pressure pulsations and avoid the hammering action which would result 1f the explosion pressure were effective uponthe large piston 17.

\Vith the beginning of exhaust, the pressure sharply diminishes and drops to a rarefied condition during the intake of the engine. This reduqtion of pressure during both the exhaust and intake periods immediately results in the quick ralsing of the piston member 16 under the compression of the spring 28. The compression of this spring is made to exceed the sllght pressure it -ment of the piston member 16. during exhaust. The rapidity of'the upward stroke of the piston member 16' creates a slight pressure in the top of the small cylinder 15. This pressure has restricted" escape through the restricted passage 27 and hence produces dash-pot action in the small cyl nder 15- thereby bringing the piston to rest without vibration or jar. It will be obvious that a positive stop for limiting the'upward stroke of the pistonmay be provided- 1f desired. The cycle of the impulse pump from this upper position is a repetition of that just re-' cited.

piston member 16.

After an interval of running, the column of mixture may become largely composed of combusted gases, due to incomplete exhaustion of the pipe line and impulse pump but this does not affect the operation as these combusted gases .still constitute an effective elastic medium between the engine and the From the foregoing description it will be apparent that-the impulse pump recipro- It will be seen that the body of air en- I trapped in the air chamber 30 and .in the upper part of the pumping chamber 5, will be alternately compressed and rarefied by the reciprocation of the piston member 16. The 'suction impulses quickly raise the liquid fuel from the tank 1, which is usually situated at a lower level, through the pipe 7, and check valve 42 into the pumping chamber 5. As soon as sufiicient liquid fuel has been drawn into the pumping chamber 5, it is discharged through the outlet check valve 43 into the bottom of the carburetor float chamber 9 until thisfloat chamber is filled to v the required levelwhereupon the float control valve therein shuts off the admission of further fuel from the pumping chamber 5.

Continued operation of the impulse pump continues to draw fuel into the "pumping chamber 5,: thereby raising the level in the. chamber until a predetermined maximum level is attained, whereupon the raising of the fioat 37 seats the valve 36 and prevents the entrance of the pumping impulses into the chamber 5. I

It' will be noted that the valve 36 is arranged to open inwardly. Thus compression impulsesin the air chamber 30 tend to i open the valvewhile suction impulses tend tity of the compression impulses leaks past to close it. Asa result a-considerable quanthe valve 36, building up sufficient pressure in the pumping chamber 5 to overcome the head of the column of liquid extending to the elevated float chamber.. It will be apparent therefore that irrespective of whether the pumping mechanism is supported above or below the carburetor float chamber sufficient pressure is always trapped in the pump'-' ing chamber 5 to force the liquid fuel tothe carburetor float chamber instantaneouslywith the opening of the float controlled valve therein. v

In Figure 3, I have illustrated modified means for discontinuing the pumping operation when the fuel rises to a predetermined maximum level in the pumping chamber 5.

In this form, the intake into the pumping chamber 5 occurs through an intake port 52, which is placed in axial alinement with the float 37, the intake check valve 53 is confinedin a valve cage 54, which is arranged to guide the lower end of a float operated stem which extends down through the center of the float 37. At its upper end the stem is guided in a bored cap 56 formed in the top of the pumping chamber, and is provided with spaced collars 57 between which engage theconventional form of weighted levers 58 -58. These levers have intermediate pivots upon depending brackets 59, which -extend down from the top of the pumping chamber 5. Communication between the air chamber and the pumping chamber 5 is by way of'an open port 61 in the top of the pumping chamber 5. When the fuel level rises toa predetermined maximum in the pumping chamber 5, the float 37 engages the weighted ends of the lever 58, thereby thrusting. the stem downward and positively holding the intake check valve 53 upon its seat. Thereafter the suction impulses are ineffective for raising fuel.

reached. This atmospheric vent is pro-' vided by a diagonal rib or the like 62 in the the ca from t e top upper section 33' of the pumping chamber, which rib is drilled or cored to provide the atmospheric inlet 63. A hole 64 is drilled coextensive-with the inlet 63,'in the flange 32 of the lower chamber section 34'. The passage 63 intersects a vertical bore 65 in like extension 66, which projects of the float chamber. Communications between the bore 65 and the interiorof the pumping chamber 5 is governed by a valve 67 under the control of the float 37. The valve 67 is actuated by a similar arrangement of weighted levers 58', having their inner ends engaging between collars 57, on the stem of the valve 67. The levers 58 are pivoted on 9. depending bracket member 68,.extending down from the top of the float chamber 5. The compression and rarefaction impulses created in the air chamber 30 have access to the pumping chamber 5 through the open port 61'. When; the fuel rises to its predetermined of the carburetor, it will be apparent that there would be no tendency for the fuel in the pumping chamber to discharge by gravity to the float chamber, and therefore if there were an entire cessation of .the pumping impulses in the pumping chamber the apparatus would become inoperative. This condition is avoided, however, by the action of the valve 67, which operates analogous to that of the valve 36 of Figure 2. It will be noted that the valve 67 isarranged to open inwardly whereby compression impulses in the pumping chamber tend to close it while suction impulses tend to open it. This will tend to trapa sufiicient amount of pressure in the pumping chamber to overcome the head ofthe column of liquid extending up to the float chamber of the carburetor. I alsocontemplate closing the intake check valve by extending the stem of the valve 67 downwardly to the intake port, similarly to Figure 3, in addition to relieving the pressure pulsations through the atmospheric vent. There is no possibilit of the operation of the device being inter ered with by the development of a pressure condition higher or lower than the average pressure condition in the closed air chamber constituting the chamber 30 and pumping chamber 5, for the reason that such high or low pressure condition is soon dissipated by the leakage past the large piston 14, which acts as a breather.

Numerous modifications will be at once apparent to those skilled in the art, but I intend that these modifications shall-be construed as included in the spirit and scope of the appendedclaims.

I claim:

v 1. In a fuel feed system for internal combustion engines, a pumping chamber for pumping the fuel from the tank or other source of supply to the carburetor of the engine, an impulse pump adapted for connection to oneof the cylinders of said engine,

said impulse pump operating said pumpingv chamber, and means in said impulsepump for reducing the effect of the explosion impulse from said cylinder.

2. In a fuel feed system forinternal combustion engines, a pumping chamber for pumping the fuel from the tank or, other source of supply to the carburetor of the engine, an impulse pum adapted for connection to. one of the cyllnders otsaid engine,

- the different pressure pulsations from cylinder.

3. In a fuel feed systemfor internal combustion engines, a pumping chamber for pumping the fuel from the tank to the carburetor of the engine, an air chamber communicating with said pumping chamber, an impulse pump adapted for connection to one of the cylinders of said engine, said impulse pump producing compressions and rarefactions of the air in said air chamber and means in said impulse pump for substantially equalizing the pumping effort of the different pressure pulsations from said cylinder. I

4-. In combination, a pumping chamber having inlet and outlet valves for liquid to be pumped, a substantially closed air chamber enclosing a body of air and communicatpump for pro ucing compressions and rare- .factions in said body of air, said impulse pump being connected to a source of variable pressure pulsations, and means for equalizing the pumping effort of said variable pressure pulsations.

5. In combination, a pumping chamber having inlet and outlet valves for liquid to be pumped, a substantially closed air chamber enclosing a body of air and communicating with pumping chamber, an impulse pump for produping compression and rarefactions in' said body of air, said impulse pump adapted for cdnnection to a source of variably pulsating pressure, and means in said impulse pump for exposing differential areas to said variably pulsating pressure. i 6. In. combination, an internal combustion engine, a carburetor therefor, a source of fuel for said carburetor, pumping mechanism for pumping the fuel from said source of fuel to said carburetor, said pumping mechanism comprising an impulse pump connected to one of the cylinders of said internal combustion engine, said impulse pump adapted to be operated by the pressure pulsations from said cylinder, a piston memer in said impulse pump having different piston areas, and means for exposing one piston area to the compression pressure from said cylinder and another piston area to the explosion pressure.

7. In combination, an internal combustion engine, a carburetor therefor, a source of fuel for said carburetor, 'pumping mechanism for pumping the fuel from said source of fuel to said carburetor, an impulse pump for actuating said pumping mechanism, sa1d.

impulse pump being connected to one of the cylinders of said engine'and adapted to be 6 operated by the pressure pulsations thereing with said umping chamber, an impulse from. a compound piston member in said impulse pump comprising a relatively large piston and arelatively small piston, and means for exposing the relatively large piston to the compression pressure from said cylinder and the relatively small piston to the explosion pressure. p

8. In a fuel feed system for internal (Ornbustion engines, a pumping chamber for pumping the fuel from the tank or other source of supply to the carburetor of the. engine, a substantially closed air chamber enclosing a body ofair and communicating With said pumping chamber, an impulse pump adapted for connection to one of the cylinders of said engine, said impulse pump producing compressions and rarefactions in said body of air, means in said impulse pump for reducing the pumping efi'ort during the explosion impulse from said cylinder and float controlled means Within said pumping chamber for controlling the application of the pumping impulses to the liquid in said pumping chamber.

9. In a fuel feed system for internal combustion engines, a pumping chamber for pumping the fuel from the tank or other source of supply to the carburetor of the engine, a substantially closed air chamber enclosing a body of air and communicating With said pumping chamber, an impulse 1 pump adapted for connection to one of the cylinders of said engine, said impulse pump producing compressions and rarefactions in said body of air, means in said impulse pump for substantially equalizing the pumping effort of the different pressure pul-. sations from said internalcombustion enginefand float controlled means in said pumping chamber for controlling the intake of fuel into said pumping chamber.

10. In a fuel feed system for an internal combustion engine, a pumping chamber having inletand outlet valves for pumping the fuel from the tank to the carburetor of the 110 engine, a substantially closed air chamber enclosing a body of air communic'atingwith the upper part of said pumping chamber, an impulse pump adapted for connection to one of the cylinders of said engine, said impulse 115 pump producing compressions and rarefactions in said body of air, said impulse pump comprising a compound piston having differential areas adapted to be exposed to the municating with the top of said pumping chamber an impulse pump for producing compressions and rarefactions in said body of air, a mixture chamber connecting said impulse pump with one of the cylinders of said internal combustion engine and enclosing a column of mixture therein, said impulse pump comprising relatively large and relatively small cylinders in axial alinement, a compound piston having large and small pistons reciprocatingfin said cylinders, an admission passage communicating with said column of mixture and opening into said small cylinder, and an admission port in the wall of the small piston connecting said column of mixture with said large cylinder, said admission port adapted to be closed by the movement of said piston under the compression pressure in said column of mixture.

12. In a fuel feed system ofinternal combustion engines, a pumping mechanism for pumping the fuel from the tank or other source of supply to the carburetor of the engine, said pumping mechanism comprising an impulse pump adapted for connection to one of the cylinders of said engine, said impulse pump adapted to operate under the pressure pulsations from said cylinder, at half the speed of the engine.

In witness whereof I hereunto subscribe my name this 3rd dayof January A. D. 1921.

FRANCIS EDWARDS.

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