US2903250A - Fuel feed and charge forming apparatus - Google Patents

Description

Sept; 8, 1959 B. c. PHILLIPS I FUEL FEED AND CHARGE FORMING APPARATUS Original Filed Nov. 30, 1955 3 Sheets-Sheet 1 INVENTOR: 2312mm [.PHILL IFS.

BY M 3 Sept. 8, 1959 B. c. PHiLLIPS 2,903,250

FUEL FEED AND CHARGE FORMING APPARATUS 7 Original Filed Nov. 30, 1955 5 Sheets-Sheet 2 I iNVE'NTOR:

Am LIP. |l\/M B353! [7 HJL 5 B. c. PHILLIPS 2,903,250

FUEL FEED AND CHARGE FORMING APPARATUS 3 Sheets-Sheet 3 J 7 0 w M M 5 Z M 1 2 a I w U 6 w 1 l a w v 2 m m fi 4 22 was n W k W Z M 4 Mm mn2n Ill 6 26 h 0 67 q 35 M NIMUM n w 1 I I 6 L M Q M s H W 6 n M 4 L w 5 06 0 4 2 6 5 H u ZZMZWMZ INVENTOR: Bmmzm L. PHILLIP s.

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Sept. 8, 1959 Original Filed Nov. 30, 1955 TIE-1B United States FUEL FEED AND CHARGE F ORMJNG APPARATUS Bernard C. Phillips, Toledo, Ohio, assignor to The Tillotson Manufacturing Company, Toledo, Ohio, a corporation of Ohio 3 Claims. (Cl. 26'1-37) This invention relates to apparatus for delivering fuel to an internal combustion engine and more especially to an arrangement for feeding fuel to a charge forming device and delivering a fuel and air mixture from the charge forming device. This application is a division of my copeuding application Serial No. 549,978, now Patent No; 2,796,838 issued June 25, 1957.

In the operation of internal combustion engines, particularly of the two cycle type for use with chain-saws, lawn-mowers, and out-board type of marine engines and the like, it is imperative to provide an arrangement for delivering fuel and air mixture to the engine irrespective of the relative position of the engine. For example, engines for operating chain-saws must be capable of operation in extreme angular or even inverted positions and engines utilized for powering lawn-mowers must be capable of operation in extreme angular positions such as are encountered in mowing operations on uneven or hilly terrain. Serious difficulties have been encountered heretofore with fuel feed and charge forming apparatus for engines of this character as conventional type apparatus is wholly unsuited for satisfactory operation in extreme angular and inverted positions of the engines with which the apparatus may be used. For example, a carburetor or charge forming device embodying a float-controlled fuelsupply will not function in an inverted position as the fuel inlet valve would remain in open position permitting flooding of the charge forming device.

A further factor impairing the use of conventional fuel feed and-charge forming apparatus with engines operating in extreme angular or vertical positions is that delivery of fuel by gravity to the charge forming apparatus is rendered inoperative when the fuel supply reservoir is below the charge forming device. Eflorts have been made to pressurize the fuel supply reservoir by means of a hand pump, but such arrangements have been unsatisfactory because of the varying pressures in the fuel supply tank.

The present invention relates to a fuel feed and charge forming apparatus for use with internal combustion engines which is adaptable for successful operation in any position.

An object ofthe invention is the provision of a combined charge forming device and fuel supply means which may be fixedly attached to an internal combustion engine and-which will deliver the requisite fuel and and air mixture to the engine irrespective of the relative position of the engine and charge forming and fuel feeding means.

. Another object of the invention is the provision of-a diaphragm ,type of pumping means in combination with a charge forming device wherein the pulsations or differential pressures existent by reason of the engine operation are utilized to actuate the pump.

.Another'object of the invention is the provision of the diaphragm type fuel pump or liquid feeding device embodying valves formed as integral components of the diaphragmor membrane utilized as a pumping element.

Another object of the invention is the provision of a diaphragm type of fuel feed pump adapted for satisfacatent tory use with carburetors or charge forming devices of diaphragm control or float control fuel flow means.

A further object of the invention resides in a small and compact diaphragm or membrance type of fuel pump in which spring biased valves are eliminated and which may be economically manufactured and utilized wherever differential or pulsating pressures are available for actuating the diaphragm.

Another object of the invention is a provision of fluid pump embodying a pumping member of the diaphragm or the membrance type wherein the valves are integrated components of the diaphragm and which are capable of operation under pulsations of Very high frequency.

An object of the invention resides in a combined charge-forming and fuel-feeding apparatus wherein communication of a variable-volume pumping chamber with an engine crankcase is established through channel means formed in the body of a charge-forming device and wherein a fuel feed channel is incorporated in the chargeforming device for conveying fuel from a pumping chamber to a reservoir or chamber in the charge-forming de vice.

An object of the invention resides in a combination fuel delivery and mixture-forming apparatus for an internalcombustion engine wherein a pumping or pulsating chamber having a flexible wall is connected through a suitable duct with the crankcase of the engine with which the charge-forming apparatus is used whereby the varying pressures in the engine crankcase are utilized for moving the flexible wall, providing a motivating means for flowing liquid fuel from a supply to the charge-forming apparatus.

Another object of the invention resides in the provision of a fuel-feeding apparatus embodying a flexible member or diaphragm for exerting a pumping action, the flexible member or diaphragm being formed with portions functioning as valves or valve means to effect flow of liquid fuel from a supply to a zone at which the fuel is mixed with air or other oxidant to provide a combustible mixture for an internal-combustion engine.

Another object of the invention resides in the provision of a fuel-feeding device wherein components of the device or structure are fashioned in a manner to reduce machine work or machining operations to a minimum, providing an apparatus which may be inexpensively produced in substantial quantities.

Further objects and advantages are within the scope and function of the related elements of the structure, to various details of construction and to combinations of parts, elements per se, and to economics of manufacture and numerous other features as will be apparent from a consideration of the specification and drawing of a form of the invention, which may be preferred, in which:

Figure 1 is a top plan view illustrating one form of combined charge forming device and fuel feed means attached to the crank case of an internal combustion engine of the two cycle type; a

Figure 2 is a vertical sectional view taken substantially on the line 22 of Figure 1;

Figure 3 is a vertical sectional view taken substantially on the line 33 of Figure 1;

Figure 4 is a plan view of a diaphragm forming a component of the fuel feeding means;

Figure 5 is a plan view of a gasket or sealing member for use with the diaphragm illustrated in Figure 4;

Figure 6 is a View taken substantially on the line 6-6 of Figure 2;

Figure 7 is a View taken substantially on the line 7-7 of Figure 2; i

Figure 8 is a sectional view taken substantially on the line 88 of Figure 6;

'Figure9 is a sectional view taken substantially on the line'99 of Figure 7;

Figure is a bottom plan view of the structure shown in Figure 8;

Figurellis a bottomplan view of the structure shown in Figure 9;

Figure 12 is a'fragmentary sectional view taken on the line"-12-12 of'Figure 6;

Figure 13 is a fragmentary sectional View taken substantially on the'line 13-13 of Figure 11',

Figure 14 is a diagrammatic sectional view'through the fuel pump component illustrating the valve arrangement;

Figure 15 is a semi-diagrammatic vertical sectional view of a float controlled charge forming device and fuel feeding means showing the valves in diametrically opposed relation; and

Figure16 is a transverse sectional view taken substantially on the line 16- 16 of Figure 15.

Whilethe fuel'feed and charge forming apparatus has been illu'strated'as particularly constructed for use with an engine of the so-called two cycle type, it is to be understood that the arrangement of the invention may be utilized with other types of internal combustion engine or for other purposes where pulsating pressures are available.

'Referring to the drawings in detail, and initially to Figures 1 through 3 and 14, the charge forming device or carburetor illustrated therein is of the diaphragm type especially constructed for delivering a fuel and air mixture into the crankcase of a two cycle engine of the internal combustion type. The carburetor is inclusive of a'body 10 formed with a mixing passage 12, the latter including a Venturi 14 into which fuel is delivered for admixing with air admitted through an air inlet 16. An air valve 17 mounted upon a shaft 18 is disposed in the inlet'passage 16 for controlling the amount of air admitted to the mixing passage. An arm 20 is secured upon the shaft 18 for manipulating the valve 17.

The carburetor body '10 is formed with a flange portion 22 which'is adapted to be secured to a boss portion 24 formed on a wall of the crank case 25 of an engine of a two cycle type. A gasket 26'is disposed between the flange 22 and the boss portion'24 and the flange 22 is secured to the boss'by means of bolts 27.

Secured to the body'10-is a member 28 and disposed betweenmember 28 and the body '10 is a flexible diaphragm 30. The body portion "10 has a chamber 32 formed therein, the diaphragm 30 forming one wall of the chamber 32.

A gasket'31is disposed between the member 28 and the carburetor body 10 to effect a seal as well as to prevent or retard transfer of heat between these components. The chamber 32 is adapted to contain fuel to-be delivered into the Venturi'll4 of the mixing passage through a nozzle 36. The nozzle or fuel delivery tube 36 is formed as a part of a fitting 38 threaded into a bore or well 40 formed inthe carburetor body-10. The fitting 38 is formed with a tubular channel (not shown) which conveys-fuel from the well 40 to the nozzle36.

Thelower end ofthe Well is closed by a threaded plug 42. Fuel from the chamber 32 is delivered into the well 4ll-thr0ugh a duct (not shown) in which is disposed an adjustable metering pin 44 having a tapered extremity fitting :into .the duct. The metering pin 44 :is threaded through a fitting 46 and is rotatably adjustable for meteringor'regulating the flow of fuel from the chamber '32 to the well 40. A collar portion-48tformed on the fitting 38.is provided with openings 50.

A duct 52 is arranged between the air inlet passage 16 and the space surrounding the collar48 whereby air'from the air inlet 16 may flow through the openings in the collar portion 48 into thefuel in the nozzle 36. :The air mixes with the fuel within the bore in the fitting so that anemulsion or mixture of air andliquidfuel is discharged from the nozzle 36 into the'VenturiM in order to provide for a more homogeneous mixture delivered into the engine crank case.

A means is provided for :controlling the flow of fuel into the chamber 32. A lever 54 is pivotally supported Within the chamber 30 uponapiii or shaft 56. One arm of the lever engages a member-60 whichextends within a bore formed in a valve member 63, a spring (not shown) being disposed between the member 60 and the valve 63 whereby upwardly =directed rpressure on the member 60 is resiliently transferred*to-the:needle :valve or fuel inlet control valve 63. The valve '63'is of polygonally-shaped cross section and-is slidably .disposed; inaa bore in a fitting 66.

The polygonal-shaped valve 63 facilitates flow of 'fuel along the facets of the valve through interconnecting ducts 64 and 65 intothe chamber 32. The valve member 63 is formed with a cone shaped extremity 69 which cooperates with aseat 70, the-bore-in the-seat being in communication with -a-duct -72. The duct 72 is-in communication with a duct 7 4 which receives fuel-from a-fuel pump chamber in a manner hereinafter-explained.

T he arm -78-of the lever-54 is engaged by a coilspring 80 which rests against a shoulder of a-member -82 the latter being formed with a threaded -portion"84'which is threaded into a bore in'the body l0 and is'adjustableto regulate the pressure of the spring80. The upper-end of thethreaded bore in'the body'lO-isclosed by'means of a plug 86. e

The diaphragm 30 is provided with =a-centr-allydisposed button or member which engages or-contacts-a lower surface of arm 78 of the-lever-54.

The movement of diaphragm 30-is communicated by the lever 54 to thefuel-inlet val-ve*63 for controlling'the flow of fuel into the carburetor chamberorbowl-SZ. The air chamber or pressure equalizing chamber '34 formed in member 28 isvented to the atmosphere bymeans of a passage 41' shown -in-Figure 9,-or the chamber -may be vented into the air inletpassage 16 if' desired. -It is-essential to vent the chamber 3'4-in order to facilitate fiexure or movement'of the diaphragm 30in orderto'accurately control the delivery of fuelinto the chamber 32.

T he fuel is deliveredfrom a pumping chamber through ducts 74 and72,'pastthe needlevalve63'and'through passage 64 into the carburetor chamber or fuel channel 32 when the aspirationeffective through'thefuel nozzle sets up reduced pressure actingonthe-diaphr-agm to compress spring "80 and'adrnit fuel into the'chann'el-or chamber 32. As fuel 'fiows'into'the'chamber32,the pressure therein is raised and the diaphragm 30 is -flexed downwardly as viewed in Figures 2' and -3,-and.the pressure 'of spring 80-swingsthe lever=54:about its'pivot 56 exerting an upwardly acting pressure upon theneedle valve 63 seating the cone-shapedvalveportion69 in-the valve seat 70 and thus interruptingor restricting the -fiow of fuel into the chamber 32.

'In this rnannerfuel-is suppliedtothe'chaniber'32-and the well '40. The'pressure'o'f'the-spring 80 may'be adjusted by manipulation of the threaded member 84..

When air flow ceases in'the'mixing-passage'and Nenturi fuel is no longer-drawn throughthe nozz-le'iifiand'theweight of the fuel on thediaphragm *30 cause's it tolbe flexed downwardly or awayfromthernixing'passage-and, through tilting of the lever' 54, the "fuel 1 inlet'valve 63 is closed.

Disposed in'the outlet zone of the mixing passage 13 is a throttle valve which ,is supportediupona'transversely shaft 96, the shaftibeingrotatable to vary'the' position of the throttle valve 95ffor controllingjthe admounted upon one endof the shaft'96 and has a, threaded opening'to accommodate-awscrew 1-00.- -A stoptmernber;

or pin 16523 iscarriedrbyztheibody :10 andzis I'adapted-tolbe engaged by the screw 104), this arrangement. serving -.to

limit or determine the position of the throttle valve 95 for engine idling conditions.

Means are provided for delivering fuel into the mixing passage for engine idling purposes and low speed operation of the engine. As shown in Figure 2, there is provided an idling orifice 106 and a low speed orifice 108 formed in the wall of the mixing passage. The orifices 106 and 108 are in communication with passages 110 and'112 respectively and these passages are in communication with the fuel chamber 32 through a duct (not shown) leading into the fuel chamber 32. The fuel flow to the idling and low speed orifices may be regulated by means of a needle valve 116.

Means isprovided for regulating the rate of flow of fuel into the well 40 for discharge through the main nozzle 36. As shown in Figure 2, a duct 120 opens into the well 40 and is in communication with the fuel chamber 32. A needle valve portion (not shown) formed at the end zone of a rod or valve member 44 projects into the duct 120 and is provided with a threaded portion 124 cooperating with a threaded bore in the fitting 4-6.

By rotating member 44, the needle portion of the valve may be adjusted in the duct .120 to regulate the fuel flow into the well 40. A ball check valve 126 is disposed in the fitting 38 adapted to close the fuel passage to the main nozzle 36 upon inversion of the carburetor and prevent reverse flow of air from the mixing passage through the main nozzle such as would influence the sub-atmospheric pressure in the fuel chamber 32.

A fuel pumping means is associated with the carburetor construction for delivering liquid fuel into the carburetor fuel chamber 32 from a fuel supply. As shown in Figure 2, a fuel reservoir or supply tank 130 is connected by means of a flexible tube 132 with a tubular projection 134 formed upon a closure member 136. The fuel pumping arrangement includes a pump body con struction formed by components or members 28 and 140, the latter being formed with a circular recess arranged to receive the peripheral edge zone of a fuel filter or strainer 142. A gasket 144 in the recess is engaged by a circular portion 145 of the closure member 136 for retaining the filter .142 in position. As shown in Figure 8, the pump body member 140 is formed with a boss portion 147 having a shoulder 148 engaged by the filter 142. The boss 147 is formed with a threaded bore 149 to receive a threaded member or screw 150, the latter projecting through an opening in the closure member 136 for securing the closure member 136 to the body member 140. A sealing gasket .151 is interposed between the head of the screw and member 136. The projection 134 is formed with a fuel inlet passage 135 which conveys fuel into a chamber 153 provided by the closure member 136. The closure member forms a sump in which Sediment or foreign matter may be collected as it is filtered from the fuel. The strained fuel passes through the filter 142 into an annular chamber 155.

In the present invention, the valves for controlling flow of liquid fuel into and away from the fuel chamber 168 in the pumping means are integrally formed with the diaphragm 160 as component parts thereof. As particularly shown in Figures 2, 4 and 14, the valves 176 and 178 are formed by punching or removing material of the diaphragm providing spaces 179 and 180, the valves 176 and 178 being shaped as tongues adapted to be flexed at the hinge or zone of juncture with the remainder of the diaphragm. The valve 178 controls the inlet passage of the fuel chamber 168 and valve 176 controls the outlet or discharge passage from the fuel chamber.

The chamber 155 adjacent the filter screen 142 is in communication with a fuel passage 180 for conveying fuel to the zone of the inlet valve 178. The member 28, adjacent the zones of the valves 17 6 and 178 is formed with spaces or recesses 182 and 183 to facilitate flexure or movement of the valves. A passage 185 is arranged to convey fuel from the zone of valve 178 into the pumping chamber 168. A passage 187 is arranged to convey fuel from the chamber 168 to a zone adjacent the outlet valve 176. 1

The chamber 182 is in communication with the fuel reservoir 32 in the carburetor body through the medium of passages 74, 72 and 64.

For purpose of illustration, Figure 14 is a section through the pump structure, the section being of an expanded character to better illustrate the valves and fuel passages in the fuel pumping apparatus. Disposed between the body member of the pumping arrangement and the carburetor body 10 is a diaphragm or pumping element'160 and a gasket 162.

The diaphragm or membrane is formed of impervious flexible material such as synthetic rubber or cloth impregnated or coated with a material which is resistant to the deleterious effects of hydrocarbon fuels. A Celluloid-like material known as Mylar has been found to be satisfactory. The diaphragm is preferably of a thickness of from three thousandths of an inch to forty thousandths of an inch. The pump body member 140 and member 28 are secured to the carburetor body 10 by means of screws 164, the screws passing through openings in the diaphragm 160 and the gasket 162. The central zone of the pump body 140 adjacent the diaphragm is formed with a spherically-shaped recess or depression providing a fuel chamber 168 and the body portion 28 of the pump is formed with a spherically-shaped recess or depression forming a pumping chamber 170, the diaphragm 160 forming an intermediate wall of each of the chambers 168 and 170.

The pumping chamber is arranged to be connected with a source of periodically or intermittently varying or differential pressure whereby the diaphragm 160 is flexed to exert a pumping action in the fuel chamber 168. In the embodiment shown in Figures 1 through 3 and 14, the pumping chamber 170 is connected with the crank case of the engine through a passage in the carburetor body. As the engine is of the two-cycle type, the pressure in the engine crank case alternately increases and decreases during each revolution of the crankshaft. As shown inFigure 2, the pumping chamber 170 is in com munication with a passage 172 formed in member 28 which is in registration with a passage 174 formed in the carburetor body 10, the passage 174 being in communication with the interior of the crank case 25 of the engine.

Through the medium of these passages, the varying pressures existent in the crankcase during engine operation are effective in the chamber 170 to flex the pumping diaphragm 160.

When the pressure within the chamber 32 is reduced through the discharge or delivery of fuel from the charnber 32 into the mixing passage through the main nozzle 36 or through the idling and low-speed orifices 106 and 108, the lever 54 swings in a clock-wise direction as viewed in Figure 3 about the axis of pivot shaft 56, which movement causes valve 63 to move away, from its seat 70 to facilitate flow of fuel from the fuel chamber 168 of the pumping means into the reservoir 32. The flow of liquid fuel into the carburetor chamber 32 and the fuel chamber 68 only takes place when the engine is in operation whereby the variable pressure in the crank case of the engine is effective to flex the pumping diaphragm 160. So long as the fuel inlet control valve 63 is in open position, fuel flow into the carburetor reservoir chamber 32 continues until an amount of fuel is introduced into .the chamber 32 sufficient to partially satisfy the sub-atmospheric pressure existing in the chamber 32, causing the diaphragm to move downwardly whereby the pressure of spring 80 is effective against the arm 78 of the lever to cause the lever to swing in a counter-clockwise direction as viewed in Figure 3 to move the valve 63 into its seat 70 and interrupt the flow of fuel into the carburetor chamber.

:Underthiscondition further flexureand pumping action of'ithe diaphragm 7160 continues until suflicient fuel flows into the chamber 168 to equal or balance the'pumping pressures reflective :in the pumping: chamber 17 0.

As J fuel :is discharged into the mixing passage 14 from the reservoir of fuel channel 32,='the=diaphragm is drawn upwardly, moving the lever54 to open the inlet valve 63'to admit more fuel'until the'proper supply'of fuel is replenished in'the reservoir 32. Thus, during engine operationythe pumping means is effective to deliver fuel to ;the carburetor inaccordance with the engine requirements. Through this arrangement fuel is supplied to the carburetor in any-position of the latter including inverted position whereby the combination'is particularly useable with engines for powering chain saws, lawn mowers and the like wherein-carburetors are moved into various positions.

As :shownin Figure 5'ithe gasket 162 is formed with a circularopening 190-substantially equal to the span or diameter of the chamber 168 in order to accommodate the movements of the diaphragm 160. The gasket 162 is also formed with generally triangularly shaped openings 19 1 and "-192 to accommodate movements of the valves 176 and 178. Dowels or pins 193 in member 140 serve 'to positionthe diaphragm 160 and gasket 162 in proper position and pins 19'5 in'member '28 position the member in properrelation-on the carburetor body 10.

The- valves 176 and 178 areflexed at high speeds as two cycle-engines with which the arrangement may be used operate atspeeds up to 8,000 'R.P'.M. or more. Hence under high speed engine operation the outletvalve tendsto beheld-open by reason of the inertia of the fluid moving 'through the valveport or passage. The pump body 28 at the outlet valve recess 182 is formed with a plurality of recesses 1 94 which are disposed above the outlet valve 178.

"Through this arrangement the column of fuel in the passage 74'=in member'28 and passage-74.in-the carburetor body 10iseffective-onthehpper surface of the valve 178ito-assistinurging the valve'toward aclosed position in.the'-periods 'betweensuccessi-vepumping pulsations impressed upon the'diaphragm by differential pressures in the crankcase ofthe engine.

Figures Hand .16 illustrate the pumping arrangement embodiedina carburetor wherein the fuel in-the carburetoris maintained in the bowl or chamber through the use of a float controlled inlet valve. In this form of construction, the :inletand outlet valves of the pump may the :disposed in diametrically opposed relation as shown:in Figure 16 or inany other desired relation.

With particular reference to Figure 15, thereis illustrated a carburetoribody 200 formed with a'fuel reservoir, chamber or bowl v202, the body being provided with a centraliboss portion 204 bored to accommodate a-fitting 206 having passages-through which fuel from the reservoir 202:is.conveyed to a-main nozzle 208 for discharge into ainixing passage 210. The carburetor is secured to a boss portion 212 :formed on the engine crankcase 25', the boss portion :having apassage 216 in registration with theamixing-passa'ge2l0 for conveying fuel and air mixture into the engine crankcase.

:Disposed in the mixing passage 210 is a throttle control or'val-ve218 and-anair inlet valve 220, which constructionsiare similar'to those shown-in Figure 2. Low speedand idlingorifices 226 and 224 are in communication :with 'fuelzin'the reservoir through a passage 230 and a tubularrduct .232 formed within a needle valve member 2'34,theilatter.having a valve-'por-tion 235 cooperating with the fitting .206 for regulating the admission of fuel into a well :236 formed .in the fitting 206.

The needle'valve 234'isprovided with a manipulating means ior g rip member 238 for rotating the valve 234 to :regulate the flow of fuel from the reservoir or chamber1202 into'the fuel well for discharge through the main orifice or nozzle 208. The idling and low-speed 8 orifices 224 and 226 receive fuel-through-the duct .232 in the valve member 234. Air may-be-mixed wither bled into the 'fuel prior to its discharge from the'orifices 224 and 226 through passages 240-and 242, a rotatable valve member 244 being provided for controlling the amount of air mixed with the fuel.

Disposed withinthe fuel reservoir or bowl 202 .is an annularly shaped float member 250 which is of a type to be buoyantly supported by the 'fuelcontained within the chamber 202. Secured to the float member 250'is an arm or lever 252 pivotally supported on a shaft 254 secured to the body-of the carburetor. The body of the carburetor is formed with a boss 256'bored to accommodate a fitting 258 in which is moveably mounted a fuel inlet control valve member 260. The valve member 260 has a comically-shaped valve portion 262 which-cooperates with an opening in the fitting 2'58to control the-flow of fuel into the reservoir 202.

The fuel pumping or feeding mechanism illustrated in Figures 15 and 16 is similar to the fuel pump mechanism hereinbefore described and shown in Figure 2. The carburetor body shown in Figure 15 is formed with a chamber 265 of a spherical sector shape, a diaphragm forming a wall of the chamber 265 being configurated to provide inlet and outlet valves 176' and 178. The chamber 265 provides a pumping chamber and is connected with the crankcase of the engine through a passage 268 formed in the carburetor body 200 and passage 270 formed in the boss portion 212 of the engine crankcase wall structure. I

The pump construction includes -a pump body 28 formed with a fuel chamber 168, fuel inlet passages 180' and and a fuel outlet passage 187'.

Thecarburetor body 200 is formed with'a fuel passage 275 which conveys fuel from the chamber 168' into a region adjacent the fuel inlet control valve 262. The fuel strainer 142' and the closure 136' are of the same construction as the corresponding elements shown in Figure 2.

In the operation of the arrangement shown in Figures 15 and 16, when the engine is operating, fuel is discharged into the mixing passage 210 from the nozzle 208 at normal engine speeds and from the orifices 224 and 226 at low or idling speeds. As the fuel level in the chamber 202 is thereby lowered, the float 250 swings downwardly about the shaft 254 opening the'fuel control valve 260. Under the influence of differential pressure pulsations in the engine crankcase, which are-communicated to the pumping chamber 265 through passage 270, the diaphragm is vibrated causing fuel from the chamber 168 to fiow past the outlet'valve 178' of thediaphragm through the passage 275 into the chamber 202. In this manner the fuel level in the carburetor chamber 202 is maintained substantially constant. As fuel is delivered from the chamber 168' to the carburetor, the upward movements of the diaphragm establish suction or reduced pressure in the chamber 168' causing fuel from a supply tank (not shown) to flow through the passage 180' past the inlet valve 176' into the chamber 168'. Through this arrangement, the engine during operation is continuously supplied with fuel.

It will be apparent that the invention provides a simple, yet compact and efiicient fuel feeding means or pump which, combined with the carburetor construction, forms a unitary device occupying comparatively small space adapted to operate at high etficiency. The pump arrangement may be operated from any source of pulsating pressures to feed liquids or gases for other purposes.

It is to be understood that the diaphragm of the fuel feeding means or pump may be formed of any suitable material providing a flexible impervious membrane. When the material of the pumping diaphragm is sufiiciently resilient to form an effective seal between the components shaped to provide the pumping and fuel 9 chambers, the gasket 162 may be eliminated from the assembly.

It should be noted that the fuel pump is disposed whereby several heat barriers retard or prevent heat from the engine being transferred to the fuel in the fuel chamber in the pump. With particular reference to Figure 2, it will be apparent that the gasket 26, body 10, diaphragm 30, member 28, gasket 162 and pumping diaphragm 160 serve to retard transfer of heat to the fuel in the chamber 168.

-It is apparent that, within the scope of the invention, modifications and different arrangements may be made other than is herein disclosed, and the present disclosure is illustrative merely, the invention comprehending all variations thereof.

I claim:

1. In combination, a body formed with a passage adapted to accommodate air flow, said body having a recess formed therein, a disc-like member formed with a recess, a first diaphragm formed of flexible material disposed between said body and said member and extending across said recesses and forming therewith a first liquid receiving chamber and a clearance space to accommodate movements of said first diaphragm, said recess forming a clearance space being vented to the atmosphere, an element disposed adjacent the disc-like member, said member and element each being formed with a cavity, a second diaphragm disposed between said member and element and extending across said cavities forming therewith a second liquid receiving chamber and a pumping chamber, a duct establishing communication between said first liquid receiving chamber and the passage for conveying liquid into the passage under the influence of reduced pressure set up by air flow through the passage, liquid conveying channel means between said first and second liquid receiving chambers, valve means in said channel means, means responsive to movements of said first diaphragm controlling the valve means to regulate the admission of liquid from the second liquid receiving chamber into said first liquid receiving chamber, said element being formed with inlet and outlet ports for said second liquid receiving chamber, said pumping chamber being adapted to be connected with a source of varying fluid pressure for actuating said second diaphragm for pumping liquid from a supply into the second liquid receiving chamber, and valve means integrally formed on said second diaphragm for controlling the flow of liquid through said inlet and outlet ports.

In combination, a body formed with a passage adapted to accommodate air flow, said body having a recess formed therein, a disc-like member formed with a recess, a first diaphragm formed of flexible material disposed between said body and said member and extending across said recesses and forming therewith a first liquid receiving chamber and a clearance space to accommodate movements of said first diaphragm, said recess forming a clearance space being vented to the atmosphere, an element disposed adjacent the disc-like member, said member and element each being formed with a cavity, a second diaphragm disposed between said member and element and extending across said cavities forming therewith a second liquid receiving chamber and a pumping chamber, a duct establishing communication between said first liquid receiving chamber and the passage for conveying liquid into the passage, liquid conveying channel means between said first and second liquid receiving chambers, valve means in said channel means, means responsive to movements of said first diaphragm controlling the valve means to regulate the admission of liquid from the second liquid receiving chamber into said first liquid receiving chamber, said element being formed with inlet and outlet ports for said second liquid receiving chamber, means for securing said body, member and element in fixed relation, said pumping chamber being adapted to be connected with a source of varying fluid pressure for actuating said second diaphragm for pumping liquid from a supply into the second liquid receiving chamber, and valve means associated with said second diaphragm for controlling the flow of liquid through said inlet and outlet ports.

3. In combination, a body formed with a passage adapted to accommodate air flow, said passage being formed with a Venturi, said body having a recess formed therein, a disc-like member formed with a circular recess, a first diaphragm formed of flexible material disposed between said body and said member and extending across said recesses and forming therewith a first liquid receiving chamber and a clearance space to accommodate movements of said first diaphragm, said recess forming a clearance space being vented to the atmosphere, an element disposed adjacent the disc-like member, said member and element each being formed with a cavity, a second diaphragm disposed between said member and element and extending across said cavities forming therewith a second liquid receiving chamber and a pumping chamber, a duct establishing communication between said first liquid receiving chamber and the passage for conveying liquid into the passage, liquid conveying channel means between said first and second liquid receiving chambers, valve means in said channel means, means responsive to movements of said first diaphragm controlling the valve means to regulate the admission of liquid into said first liquid receiving chamber, said element being formed with inlet and outlet ports for said second liquid receiving chamber, said pumping chamber being adapted to be connected with a source of varying fluid pressure for actuating said second diaphragm for pumping liquid from a supply into the second liquid receiving chamber, valve means associated with said second diaphragm for controlling the flow of liquid through said inlet and outlet ports, said element being formed with a recess, a strainer extending across the recess in the element, a circular closure for the recess in the element being formed with a tubular elbow-shaped portion to admit liquid from a supply into the recess in the element, and means securing the closure to the element whereby the closure is rotatably adjustable for changing the relative position of the elbow-shaped portion.

References Cited in the file of this patent UNITED STATES PATENTS 109,678 Shearer Nov. 29, 1870 2,496,688 Armstrong Feb. 7, 1950 2,634,684 Alvarez et a1. Apr. 14, 1953 2,713,854 Conover July 26, 1955 2,796,838 Phillips June 25, 1957 2,801,6 1 Anderson et al. Aug. 6, 1957

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