US1902403A - Combination fuel pump and carburetor - Google Patents

Description

kMach 2l, 1933. w. R. HEwlTT 1.902,403.

COMBINATION FUEL PUMP AND CRBURETOR Filed Sept. 5, 1930 2 Sheets-Sheet l zag/.1. 26 29 25 y/ l A l ILLA 46 7 S ze 63 l 48\ 55 7 I I V 66 sa -e 65- 60 6, f IN VEN TOR.

March 2l, 1933. w. R. HEwlTT COMBINATION FUEL PUMP AND CARBURETOR Filed Sept. 3, 1930 2 Sheets-Sheet 2 i 'l INVENToR.

7 am 7 ATTORNEYS.

Patented Mar. 21,'1933 UNITED STATES WILLIAM B. HEWITT, F NEW' YORK, N. Y.

COMBINATION FUEL PUMP AND CABBUEETOB Application led September 8, 1980. Serial lo. 38,580.5Y

This invention relates to a combination fuel pump and carburetor, and especially to a carburetor which operates on fuel'delivered thereto under pressure.

The development of the internal combustion engine has created a demand for a dependable and adequate fuel supply and in conunction therewith a carburetor or like device. which will insure a uniform and hoo mogeneous mixture of fuel and air.

Recent developments have been along the line of force feed fuel systems such as gear pumps, plunger pumps, e'tc. to insure an adequate fuel supply and while the fuel is under more or lessrpressure while passing through the pump the pressure is relieved when enteringthe 'float chamber of the connected carburetor as thisis usually vented, hence, the suction produced by the air 'in 2o passing through the throat or Venturi tube of the carburetor is depended upon to -with- Adraw the fuel from the float chamber and connected atomizing nozzle and to atomize the fuel, and the pressure previously applied to the fuel is not utilized.

The object of the present invention is to rovide a force feed pump which delivers nel under pressure to a carburetor; to provide a carburetor in which the pressure on the fuel is utilized to raise and dischar e the fuel through the atomizing nozzle; an further, to provide means whereby the pressure on the fuel automatically regulates the pump and maintains the pressure constant.

The u lvention is shown by Way of illustrlatipln 1n the accompanying drawings, in w 1c Fig. 1 is a central, vertical, longitudinal' of the armature plate 18 an Fig. 5' is a cross section of the carburetor taken on line V--V of Fi 2.

Referring to the drawlngsin detail' and particularly Fi 1, A indicates in general a carburetor, an B a force feed fuel pump. The pump employed in thepresent instance is of the I lunger type and is electrically o erated. t consists of a housing which is ivided into a plurality of sections such as indicated at 2, 3, 4, and 5. These, sections are 55 bolted together as shown and enclose the pump cylinder, the valves co-operating therewith, and the mechanism whereby the plungol of the pump is actuated. Thelower housing section indicated at 2 is rovided with a 00 fuel inlet chamber 6 and a 'scharge chamber 7 and ittis also provided with a cylinder 8, an inlet valve 9, and a discharge valve l0, the valves 9 and 10 being of the check valve type as they are spring seated and automatically actuated durin the suction or discharge stroke of the p vunger indicated at 11.

This plunger is extended to pass through the housing sections 3, 4 and 5 and it is guided by partition lates such as shown at 12 and ",9 13. Mounte within the housing section 4 are a pair of electromagnetic coils 14 and 15 which surround core members 16 and 17, and cooperatingv therewith is an armature plate 18 and a flexible diaphragm 19; the dia- 75 phragm being secured between the housmg sections 3 and 4 lwhile the armature plate 18 is secured to the extended stem of the plunger 11. Also secured to the extended stem of the plunger is an adjustable collar 20. This is mounted within the housing section 5 and engages ahelical compressionhspring 21.1 1 t d b T e um un er1 iso erae ymeans p pp g riJthe co-o rating 3 magnets 14 and 1.5. It is according y necessary to provide means for automaticall making and breaking an electric circuit througlllthe same., This is accomplished by provi g a bracket 23 on which is pivotally 9 mounted as at 24 a bell crank having two arms 25 and 26. A spring 27 connects arm 26 with the bracket 23 and a second spring 28 connects the outer end of the arm 25 with a post 29 secured on the upper end of the plunger rod. The partition plate 12 secured to the upper end of the housing section 5 is constructed of insulating material and carries a terminal member 30 which is connected through a wire 31 with a suitable source of current supply. The terminal member is also provided with a contact 32 and this is intermittently engaged by aV contact 33.

tacts 32 and 33, arm 25, bracket 23 and terminal 34. It then passes through wire 35, the connected magnetic coils 14 and 15 and returns to Ithe source of supply through the wire 31a. A. circuit thus established ener- .gizes the' cores 16 and 17 and the armature plate is accordingly attracted and as it is secured to the plunger ,pump 11 this will be raised as shown in Fig. 1, thereby producing a suction stroke causing'valve 9 to open and admit fuelto the cylinder. During upward movement of the plunger 11 post 29 on the upper end of the plunger rod is raised to a position where spring 28 exerts an upward pull on the bell crank 25. Contacts 32 and 33 are separated the-moment this occursas arm will instantly swing upwardly where its movement is checked by a stop member 38. The circuit is thus broken through the magnetic coils and spring 21, which was compressed during the up ward movement of the plunger, will now exert its pressure to reverse the movement of the plunger and cause discharge of the liquid admitted to the cylinder. Valve 9 will accordingly close and valve 10 will open causing the fuel to enter the discharge passage 7. The housing 2 is extended as shown in Fig'. land forms the base for the carburetor. It also forms a combination fuel and air receiving chamber indicated at 40v as a partition member 41 is introduced between the fuel discharge passage 7 and the chamber 40. In actual practice if the mechanism shown is installed on an automobile wires 3l and 31a will be connected in the ignition circuit so that when the ignition switch is closed the.

pump will immediately start operation and build up a pressure in the chamber 40 of the on wire 31 passes through terminal 30, conl spring 21. `This pressure may be varied by adjusting the position of the collar 20. Suflice it to say, that? when a predetermined pressure is obtained in the chamber 40 the pump will cease operation, this being due to the. A

fact that a loose fit is maintained between the plunger 11 and the cylinder 8 so that fuel under pressure may leak by the plunger into the chamber 3a. The pressure on the fuel will naturally be the same as that in the chamber 40. This pressure is exerted on the diaphragm 19 and as the pressure increases it gradually forces the diaphragm upwardly and as the diaphragm is secured to the plunger 11 this willbe raised upwardly and a position will finally be assumed where the spring actuated bell crank 25 will cease to function and remain in elevated position in engagement with the stop member 38. However, the moment the pressure drops below a. predetermined pressure spring 21 forces the plunger Vdownwardly and when a certain position is assumed the spring actuated bell crank will again function and intermittently make and break the circuit. The bell crank lever is nothing more or less than a spring actuated snap type of switch, spring 27 being so connected as to assume a position at one side or another of the pivot* 24 as the lever oscillates, while the position of the spring 28 is controlled by the position of the plunger. In the position shown in Fig. 1, the pull of the spring 28 is upwardly and it pulls levers 25 and 26 to a position where spring 27.passes beyond the pivotal center 24, thuscompleting the upward movement, the downward movement being obtained when the plunger lever returns to lowered position where the pull of the spring 28 becomes downwardly and where it swlngs the levers 25 and 26 to a position where springl 27 passes to the opposite side of center 24, thus completing the` downward movement of the levers in closing position.

The carburetor generally indicated at A consists of a number of housing sections indi cated at 2a, 42 and 43, these sections being secured together by means of bolts as shown. The upper housing section 43 contains a butterfly or throttle valve 44 secured on a cross shaft 45. It also contains an adjustable needle valve 46 and a housing 47 in which is journaled a multiple orifice valve 4i. Thehousing 47 is provided with an extension 49 which passes through the housing 42 `and downwardly into the housing 2a which forms an extension of the housing 2. The extension 49 has an inlet passage 50 formed therein which terminates ina tube 51 which extends downwardly into the fuel contained in 'the chamber 40. The upper end of the housing i is provided with an orificel 52 which aligns with the needle valve 46 andrby raisin or` lowering the needle valve the amount of nel discharged may be controllc i. Valve 48 is provided with a number of radially disposed passages or discharge orifices of varying diameter as indicated at 53 and with a large passage 54. The valve is secured on a cross shaft 55 which extends through the s'ide of the housing section 43 and which is rotated as will hereinafter be described.

By rotating shaft 55 and the valve 48 secured thereon any one ofthe graduated ori` fices 53 may be moved into alignment with the discharge orifice or nozzle 52 while the larger opening 54 will register with the inlet 50. The quantity of fuel discharging through the nozzle or orifice 52 may thus also be varied by bringing one or another of the graduated orifices 53 into re ister with the nozzle and the quantity may urther be regulated by increasing or decreasing the pressure in chamber 40 through adjustment of the collar 2O on the plunger rod.

Air is admitted to the carburetor through openings formed in the exterior wall of the housing 42. A ring 61 having similar openings formed therein surrounds the housing section 42. This ring functions as a choke as b rotating it the amount of air admitted t rough the openings 60 may be increased or decreased. The ring will accordingly be connected with the usual choke operatmg mechanism on an automobile and as such may be adjusted by the driver. Air entering the openings 61 of the choke and the openings 60 formed in the housing 42 enters a chamber 63 formed within the housing section 43. The air passages 60 are angu arly positioned as shown in Fig. 2l and the air admitted to the chamber 63 will thus enter tangentially so as to cause a swirling motion. This is important as chamber 63 forms the mixing chamber of the carburetor and as the air ,enters with a swirling motion a more uniform homogeneous mixture lis insured. Interposed between the housing 47 and the top plate 65 of the housing section 42 is a disc 66, see Figs. 2 and 5. This disc has openings 67 formed therein which during rotation of disc 66 moves into and out of register with the openings 60, hence regulating the amount of air admitted to the mixing chamber. The disc 66 has a beveled gear segment 67 attached to its upper surface and this segment intermeshes with bevel gear pinion 68 secured on shaft 55. This shaft also has a gear segment 69 secured on its outer end which terminates in a lever 70. Shaft 45 carrying the throttle valve is also provided with a gear segment 71 and motion etween shaft 55 and 45 is obtained by an intermeshing intermediate gear 72. The lever will be referred o as the throttle lever and may be connected with a foot or hand throttle mechanism in the usual manner.

By imparting a swinging movement to the valve 48 the amount of fuel discharging through the atomizing nozzle or orifice 52. During gradual opening of the throttle valve 44 through means of vthe throttle lever 70 the smallest orifice in valve 48 will first align with the atomizing nozzle 52. In this position the openings 67 in the valve 66 only partially registers with the air inlets 60,

ence a small quantity yof air enters and mixes with a proportional amount of fuel; thorough mixing being insured bythe swirling action of the air and the mixture finally discharges by the throttle valve and is de livered to the manifold of an engine in the usual manner. Further rotation of the shafts 45 and 55lby means of the lever brings the next graduated opening 48 into register with the atomizing nozzle and causes further opening of the air inlet poits 60, hence a larger amount of fuel and air is admitted and mixed to be delivered to the engine, and

as the quantity of fuel and volume of air is L at all times proportioned to varying engine speeds and loads a uniform and homogeneous mixture is insured. Atomization being insured first by swirling action of the air, and. secondl by the atomizing action obtained by disc arging the fuel through the nozzle 52 under ressure.

When t e ignition switch or electric circuit through wires 31 and 31a is closed the pump immediately starts operating and as such builds up a predetermined or desired pressure in the chamber 40, this pressure be ing cushioned by air which is trapped above the fuel. The moment the engine is started and the throttle opened fuel under pressure is delivered to the atomizing nozzle and the air pressure in the chamber 40 will accordingly tend to drop. This is not the case, however, as the capacity of the pump is suflicient to maintain the pressure desired. The pump merely ceasing operation when a predetermined pressure is exceeded or merely slowing down to take care of the pressure required.

The pump and carburetor shown in the present instance are connected with any suitable source of fuel supply through an inlet pipe 6a. An adequate supply of fuel in chamber 40 is insured due to the automatic operation of the pump and better atomization of the fuel is insured due to the fact tha*y it is delivered to the atomizing nozzle under pressure and, it is further due to the swirling action on the incoming air in the mixing chamber. A uniform mixture is also e. Le

insured due to the mechanical or metering control of air and fuel and as the carburetor is provided with an adjustable needle valve and the pump with a pressure control the richness of the mixture may be increased or decreased as conditions ma demand.

While certain features of t e present invention are more or less specifically described, I wish it understood that various changes may be resorted to within the scope of the appended'claims. Similarly, that the materials and finishes of the several parts employed may be such as the manufacturer may ecide, or varying conditions or uses may demand.

Having thus described my invention, what I claim and desire to secure by Letters Patent is 1. In a device of the character described, a carburetor having a chamber formed therein for the reception of air and fuel under pressure, an atomizing nozzle in communicatio'n therewith, an intermediate valve to reg-V ulate and to close the flow of fuel under pressure to the nozzle, a pump whereby fuel under pressure is delivered to the chamber, and means whereby the pressure on the fuel in said chamber automatically regulates the pump to maintain a constant pressure.

2. In a device of the character described, a carburetor having a chamber formed therein for the reception of air and fuel under pressure, an atomizing nozzle in communication therewith, an intermediate valve to regulate and to close the iiow of fuel under pressure to the nozzle, a pump whereby fuel under pressure is delivered to the chamber, means whereby the pressure on the fuel in said chamber automatically regulates the pump to maintain a constant pressure, and other means for varying said re'ssure.

3. A carburetor comprising a housing having a combination a1r and fuel receiving chamber formed therein to receive fuel under pressure, an atomizing nozzle in communication with said chamber, an intermediate valve to regulate and close a flow of fuel under pressure through the nozzle, an air inlet controlling valve, means whereby said valves are simultaneously operated to gradually increase or decrease the flow of air and fuel at a uniform rate so as to maintain a uniform mixture, a needle valve controlling the dis charge of fuel from the atomizing nozzle, lrlldl means for varying the pressure on the 4. In a carburetor having a liquid fuel chamber and a mixing chamber, a single spray nozzle communicating between said c ambers, and `a rotary valve disposed between the li uid fuel chamber and the spray aving a dplurality of openings' nozzle and of raded size forme therein and adapted to brought'into registry with the spray nozzle by rotation of the valve.

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