US1933378A - Carburetor - Google Patents

Description

Cet. 31, 1933. 1 M MILLER ET AL 1,933,378-

CARBURETOR Filed NOV. 23, 1931 TORNEY- Patented Oct. 31, 1933 1,933,378 CARBURETOR J eptha man,

' Aviation Corporation,

poration of Delawarev Application November 23, 1931 Serial No. 576,898

v claims. (ci. zelalii This invention relates to carburetors,

and

more particularly todevices for controlling the \ow of fuel in carburetors.

An object of the invention is to provide an improved means for controlling the flow of fuel to the nozzle of the carburetor at starting,v

acceleration, at low speeds, and at high speeds.

o combined acceleration pump and A further object of the invention is to upon the acceleration pump and economizer.

. A further object of the invention is to provide an improved economizer controlled by the position of the throttle.

Further objects and advantages of the invention will be apparent from the following description, taken in connection with the appended drawing, in which:

Figure 1 is a side elevation of a carburetor embodying the invention, away to disclose the construction.

Figure 2 is an enlarged sectional view o and Figure 3 is on the line 3-3 of Figure 2.

The invention is illustrated as applied to a parts being broken f the economizer;

Aan enlarged sectional view taken down draft plain tube carburetor, but it will be understood that it may be applied to other types as well. The carburetor illustrated prises a body portion forming a vertical sageway for air and lwith fuel by buretor also comprises com- P21S- fuel, controlled by a choke valve 12 and a throttle valve 14 and supplied means of a main nozzle 16. The-cara float chamber 18 of any suitable construction, and within the float chamber is mounted a combined acceleration pump and economizer 20 constructed in accordance with this invention.

The device 20 comprises a movable cylinder or cup 22 closed at its upper end by a head 24, which head is connected to an operating rod 26, this rod being pivoted at 28 to a lever 30 which is pivoted at 29 to the body of the carburetor and urged upwardly by a leaf spring 32. A rod 34 is connected at its upper end to lever at 31 and at its lower end to a crank arm 36 which is fixed to the shaft of throttle 14. The mechanism thus far described is disclosed and -claimed in the application of Don Cole, Serial No. 290,393,

tiled July 5, 1928.

The connection 31 is preferably forme dby Mackenzie Miner and wiuera Good- South Bend, Ind., .assignors to Bendix South Bend, Ind., a corin lever 30 and securing nuts 38 thereto, so that when the throttle is opened the lever 30 is forced downwardly, thereby causing the cup 22 to be depressed, but when the throttle is closed the lever 30 need not move upwardly since there is no positive connection for upward movement of the lever. The spring 32 urges lever 30 upwardly at all times, thereby tending to close the throttle valve 14.

The cup 22 is provided with a movable piston 40 which has a relatively loose t therein and is urged upwardly by a compression spring 41. The pistonI is provided with a conical valve seat 42 at its upper end, and has a central bore which slidably engages a stern 43 fixed to the base of the iioat chamber. The stem `43 has a conical head adapted to cooperate with valve seat 42 and provided with radial passageways 44 communicating with an axial bore 46 which in turn communicates through ducts 48 with a passageway 50 leading to the main nozzle 16.

The lower portion of stem 43 is provided with a central bore 52v within which is threaded a member 54 which extends upwardly within the 4bore 46 and closesthe upper end thereof. The upper end of member 54 is cup-shaped, its outer surface being spaced from the inner wall of stem 43 to permit fuel to pass therebetween, and its inner surface is adapted to receive a coiled compression spring 56 which acts upon a valve stem 58 slidably mounted within a bore in the mem-v ber 54. The lower end of valve stem 58 is provided with a conical portion 60 terminating in a disk 62, a cooperating valve seat being formed in bore 52. The member 60 thus controls the communication of bore 52 with a passageway 64 leading through a metering oriiice 66 to passageway 50 and thence to the main nozzle.

Radial passageways 68 (Figure 3) lead from bore 52 to the exterior of stem 53, thus communicating with the float chamber below the level of fuel therein.

It can now be seen that if the throttle is opened cup 22 is depressed,.and any liquid which is contained within the cup will transmit pressure to the upper end oii the same downwardly against the force of spring 41, thereby opening the valve ports V44 and permitting the `discharge of liquid therethrough and through the ducts 48 and passageway 50 tothe nozzle 16.

If the cup 22 is held down, the spring 41 gradually moves the piston 40 upwardly, expelling fuel the piston 40 and force until the valve seat 42 closes the ports 44 and thus 22 extends above the liquid level in the floatchamber, and the cylinder in operation may become filled with liquid up to or above said level. The stem 26 passes loosely through a hole in the float chamber cover, to permit pivot 28 to follow its arcuate path.

A carburetorconstructed as aforesaid tends to give a mixture which becomes too lean at wide open throttle, and the economizer above described is accordingly provided to open the auxiliary passageways 68 for fuel between the float chamber 18 and the nozzle 16 when the throttle valve approaches its wide open position. The economizer is brought into operation when the inner surface of head 24 contacts with the upper end of valve stem 58 and moves it 4downwardly against the force of spring 56. This permits fuel to ow from the float chamber through radial passageways 68, bore 52, passageway 64, metering orifice 66, and passageway 50 to the main nozzle.

While the invention has been described with particular reference to a specific embodiment thereof, it is not our intention to limit it to such embodiment, or otherwise except in accordance with the appended claims.

We claim:

1. Fuel supply means for a carburetor having a fuel reservoir and a fuel nozzle, comprising a member extending into the fuel reservoir and having a bore communicating with the nozzle, a fuel container reciprocable thereon, a yielding piston between said member and said container, a conduit in said member communicating with the reservoir and the nozzle, a valve in the conduit, and means operative upon movement of the fuel container to a predetermined position to open said valve.

2. Fuel supply means for a carburetor having a fuel reservoir and a fuel nozzle, comprising a stationary member extending into the reservoir,I

said nozzle but not with said container, a valve controlling said second bore, and means operative upon movement of the container to a predetermined position to open said valve.

3. Fuel supply means for a carburetor having a fuel reservoir and a fuel nozzle, comprising a member extending into the reservoir, a bore in said member communicating with the fuel nozzle, a second member movable with respect to the rst mentioned member to form a pump chamber and force fuel through said bore, a second bore in said first mentioned member communieating with said reservoir and said nozzle but not with said pump chamber, and a valve controlling lthe second bore and. adapted to be opened by relative movement between said flrst mentioned member and said second member.

4. Fuel supplymeans for a carburetor having a fuel nozzle, comprising a fuel reservoir, a member in said reservoir, a bore in said member communicating with said fuel nozzle, a second member in the reservoir movable with respect to the first mentioned member to form a pump chamber and force fuel through said bore, a second bore in said first mentioned member communieating with said reservoir and with said fuel nozzle but not with said pump chamber, a metering restriction in said second bore, and control means for the second bore operative in accordance with the relative positions of said rst mentioned member and said second member.

5. Fuel supply means for a carburetor having a fuel reservoir and a mixing chamber, comprising a fixed stem in said reservoir having an aperture communicating with the mixing chamber, a cylinder reciprocable on the stem to force fuel through said bore, a yielding piston interposed between the stem and cylinder and controlling the ow of fuel through said bore, a 'second bore in said stem communicating directly with the reservoir and communicating with the mixing chamber, and a valve yieldingly mounted in said stem and having a valve stem .projecting into the path of the cylinder to be actuated thereby.

JEPTHA MACKENZIE MILLER. WIILARD B. GOODMAN.

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