US1796634A - Carburetor - Google Patents

Description

Mafch 17, 1931. R s CE 1,796,634

CARBURETOR Filed Nov. 29, 1926 Patented Mar. 17, 1931 entran sr IEERCIVAL S. TICE, OF CHICAGO, ILLINOIS GARBURETOR Application led November 29, 1926. Serial No. 151,287.

The purpose of this invention is to provide an improved construction in a carburetor for an internal combustion engine. The

invention consists in the elements and features ofconstruction shown and described as indicated in the claims.

In the drawings Figure 1 is atop plan View of a carburetor embodying this invention. Figure 2 Ais a section at the line 2-2 on Figure 1.

Figure 3 is a section at the line 3-3 on Figure 2. f

Figure 4 is a plan view of a blank from which the foot-carrying lever is formed.

Referring to the drawings for specic description of the construction by which the purpose of the invention is accomplished: The carburetor shown in Figure 1 has its fuel mixture conduit, 1, discharging at the engine intake and provided intermediately in its course with a constricting sleeve, 2,

hereinafter called the throat sleeve and which may be somewhat of venturi form, and with a throttle valve, 3, between said throat sleeve and the engine intake, constituting therefor a posterior throttle.

The fuel element of the fuel mixture is -derived from a fueLchamber shown as a levelgoverning chamber or float bowl,f 5, to which the fuel is supplied from a main tank l or like source not shown, by gravity or other l pressure through the inlet passage, 5, the admission of the fuel to the fuel chamber, 5, being .controlled by a valve, 6, seating u wardly at a port through the valve seat, and having a` flat stem, 6, lfor guidance of the valve in the slideway leading to the seat which is at the upper end of a cylindrical bore forming a vertical passage through a boss, 12, which projects from the ca plate, 13, which forms the' side'lwall of t e oat chamber opposite the fuel mixture conduit, 1.

The float, 10, of'cork or the like, is open through from side to side, forming a gap as seen at 10, to stride the boss, 12, and also an oppositely projecting boss, 15, which projects from the opposite wall of the float bowl for accommodating certain fuel passages hereinafter described.

This float is mounted on a horizontal arm, 16, of the lever, 16, 17, which is fulcrumed on the boss, 12, by means of fork arms, 16a, 16a, which stride the boss. The lever is formed from a flat blank as seen in flat form in Figure 4, having struck and folded out from the middle portion of its Width at one end the arm, 17, extending in general at right angles to the arm, 16. The arm, 16, is bowed upward at 16", in a gap, 10a, of the float for reaching so the lower end of the stem, 6a, of the valve, 6, for upholding the valve to its seat at the-high position of the float. The lever arm, V17, is similarly bowed at 17", for bearing against the end of the stem, 19, of a diaphragm, 20, which closes a small pressure chamber, 21, at the inner end of a passage, 22, which leads from the fuel supply connection, 24, from which the fuel inlet, 5a, also leads to supply the float bowl through duct, 23.

Upon considering the construction as thus far described, it will be understood that the chamber, 20, may be dimensioned relatively to the port through the valve seat, 7, and that the lever arms, 16 and 17, may be so propor- 75 tioned to each other and with respect to the chamber, 20, and port, 7, that the fluid pressure of the fuel supply, tendingto open the valve and fill the float bowl for'ffbuoying up the float, shall be balanced by fluid pressure acting on the diaphragm, 20, and through, the stein, 19, on the depending lever arm, 17, tending to uphold the Valve to its seat; and it will be understood that the valve will tend to open for inlet of fuel only by virtue of itsv weight and that of the float carried on the horizontal arm, 16, of the lever, inopposition to the pressure from the diaphragm, 20; and that liquid will continue ,to flow into the float bowl only until itfis filled' to a depth at which the float is buoyed up and its weight taken off the lever arm, 17; from which it will re sult that the height of the fuel in the float bowl for its discharge to the fuel mixture conduit, will never exceed that which is measured by the weight of the valve and float, and will therefore be quite independent of the pressure by which the fuel is fed to the float bowl from the main tank; and consequently the pressure by which the fuel is delivered ,division hereof, are not from the float bowl for discharge in the fuel mixture conduit, will not be subject to variation as the pressure from the main supply tank varies as it does, due to the varying depth of liquid in the main supply tank from which it is fed by gravity to the carburetor.

The drawings' show the course of the fuel from the float bowl to the discharge in the fuel mixture conduit for admission and admixture with the air in the ordinary operation of the engine running under load with a wide open throttle; and they also show the course of the fuel for discharge in the fuel mixture conduit under idling conditions.

The course in the first instance is by way of an annular passage, 43, encompassing the throat sleeve, 2, and the discharge being from a plurality of ports in a bridge, 45, which extends diametrically across the throat of the sleeve.

The course in the second instance is by way of a second annular passage, 50, which also encompasses the sleeve, the discharge being by way of diametrically opposite ports, 58, opening just above the ends of the bridge, 45.

This part of the structure and certain fuelimpelling and otherwise feed-regulating devices partly shown in the drawings rendering the fuel flow adjustable to engine requirements under varying running conditions, being reserved for an application to be filed as a claimed in this application and need not be further described here.

I claim ,-1. In an apparatus of the character indicated, in combination with a chamber connected for receiving liquid fuel under pressure from a source of supply, a valve seating against the inflow of said liquid fuel; a float in the\ chamber connected for holding the valve seated at a predetermined high level of liquid in the chamber; and a pressure-responsive device otherI than said valve, and connections through which saiddevice is exposed to the 'supply pressure, and means transmitting said pressure to the'valve in the direction for holding it seated against the fuel pressure tending to open it. f

2. In the construction defined in claim 1, the pressure-responsive device and transmitting means comprising a chamber in communication with the supply source and having a yielding Wall exposed toward the first mentioned chamber, and lever means in said chamber operatively associated With said yielding Wall and with the valve for transmitting the inward movement of the yielding wall to the valve in valve-seating direction.

3. In the construction defined in claim 1, the pressure-responsive device and transmitting means comprising a chamber in communication with the supply source and having a yielding wall exposed towardthe firstl mentioned chamber, and vlever means and connections yin said chamber operatively associated with said yielding wall and with the valve for transmitting the inward movement of the yielding Wall to the valve in valve-seating direction, the arms of the lever being proportioned with respect to the valve area and the area of said moving wall to cause the pressure transmitted for holding the valve seated to substantially counter-balance the fuel pressures tending to open the valve.

4. In an apparatus of the character indicated in combination with a chamber connected for receiving liquid under pressure from a source of supply; a valve for controlling liquid access to said chamber, seating against the pressure from the source; a pressure-transmitting device exposed to the supply, and means in said chamber for applying the pressure transmitted by said device to the valve in the direction for holdingthe same seated against the liquid supply pressure tending to open it, and a float in the chamber for seating said valve connected with said pressure-applying means to hold the valve seated.

5. In a carburetor and the like for an internal combustion engine in combination with a fuel mixture conduit, a fuel chamber connected for discharge of fuel into the fuel lmix- .ture conduit and connected for receiving fuel under pressure from a fuel source; a valve seating against fuel inflow pressure; a float in the chamber connected for holding the valve seated.at a predetermined high level of fuel in the chamber; a pressure-responsive device other than said valve, and connections through which said device is exposed to the fuel supply pressure, and lmeans transmitting said pressure to the valve in the direction for holding it seated against the fuel supply pressure tending to open it.

6. -In a carburetor for an internal combustion engine in combination `with a fuel mixture coduit; a fuel chamber connected -for discharge of fuel into the fuel mixture conduit and for receiving fuel under pressure from a fuel source; a valve controlling ac'- cess of fuel to said chamber seating against the pressure from the fuel source; a pressuretransmitting device exposed to the fuel supply pressure, and means in said chamber fol` applying the pressure transmitted by said device to the valve in the direction for holding said valve seated against the supply pressure tending to open it, and a float in the chamber for seating said valve and connected with said pressure-applying means.

In testimony' whereof, I have hereunto set my hand at Chicago, Illinois, this 18th day of November, 1926.

. ,PERCIVAL S. TICE.

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