US1874875A - Carburetor - Google Patents

Description

AUZ- 30, 1932. R. F. BRAcKE f 1,874,875

` cARBUREToR Filed July 25, 1929 2SheetS-Sheet l f www fw/www4 Aug. 30, 1932. l R. F. BRACKE 1,874,875

cARUREToR Filed July 25. 1929 2 Sheets-Sheet 2 Patented Aug. 30, 1932 vUhuru STATES PATENT fol-Fica noms r. mexx, or rumors, Assioma- 'ro ovarian.' cam.V or smeer, :ammore UABBUBITOB animaba mea my as,

My invention relates to .improvements in carburetors.

An object 'of my invention is to provide an improved carburetor for..internal com'- bustion engines.

Another object is to provide a carburetor which because of its unusual compactness and ease of manipulation, is particularly adapted for use on portable engines such as are used to drive mechanical household appllliances, or smallrmachinery in home orl s op.

Another object is to provide a carburetor' which does not choke up and sto Another object is toprovideA a carburetor having particularlyl novel means for maintaining the fuel discharge nozzle under the proper depression to assure the ow of fuel thereto.v

Another object is to provide'a carburetor which has but few .parts and which may be manufactured at a relatively low cost.`

Other objects andV advantages will hereinafter appear.

An' embodiment of my invention is illustrated in the accompanying drawings formina part o f this specificatign'wher'ein:

c ig. 1 is a side elevation of a two-cycle portable gasoline engine equipped with my improved carburetor;

t Fig.,2 is an end elevation ofthe carbure,-A

Fig. 3 is a sectional view along the line 3-3 of Flgure 2;

Fig. 4 is an enlarged sectional view along the' line 4-4 of Figure 2;

Figure 5 is an enlarged 4sectional view along the line 5-5 of Figure-.3, and

-, Figure 6 is an enlarged view of a part" of4 the mechanism as illustrated in .Figure 3.

ing into the passage fue is erst" icas. semi I. saam.

e 'The carburetof selected for mit-maan herein is designed for use on a small line engine such as used for drivin w rl g machines and similar small .mac ery in the private home or shop.`

In general the carburetor compriscsal die cast body A having an induction passage B; one endof which 1s ada ted for communication'with the inlet mamfold of the engine C and the other end of which is open to atmosphere. A fuel nozzle D in the form of a suction multiplying Venturi tube discharg-v from the tank E directly thereto where it umtes with the air streams passing throu hA the nozzle and passage B to form a proper y` B functions to lift fuell proportioned fuel mixture. 'A choke F is employed for startin the engine and functions automatically as t e en 'ne cranking pedal G is operated. The car uretor also is provided with a valve H operable automatically to admit air to the passage B when the choke i F is closed and the engine has started to run. An air valve J of novel construction is einployed tocontrol the condition of depression in vthat portion of the passage B, with which the nozzle Dcommunicates. l

The induction passage B is uninterrupted throughout its length exce t for air valve J. This valve is placed imme 'atel beneath the discharge orifice of the vnozz e ,D and is pressed against its seat 10 by a ringlltov close the passage B. The' valve yields to the differential in pressure between atm here and engine manifold suction to permlt the induction of air through the passage B. Anl

upstandingstem 12centrally located upon' the 'valve carries at its upper end a disc 13 which rests slightly abovev the discharge orifice of the nozzle D when the valve is closed.- The disclpartiall isolates that region of the passage imme iately abovejthe valve and surrounding the orifice ofthe nozzle D from the upper section of the passage which sec# tio'n is normally at atmospheric pressure so that a sufficient depression is maintained in the nozzle region of the passage to assure the sub'ection of thefuel nozzle to depression -s ciently low to induce the elevation of fuel from the tank E thereto.

The fuel in passing from the tank E to the fuel nozzle is first conducted through a strainer cap which is disposed at the lower end of a tube 16 extending within the tank and 5 which communicates at its upper end with assages 17 within the body of the carburetor y a detachable fitting 18. This ttingis employed to permit the ready lremoval of the tube and strainer cap for cleaning. The paso sages 17 communicate with an adjustable needle valve 18a which is set by movement of a wing lever 19 to control the quantity of fuel occur during the compression stroke of the y en ne.

Iii order tofacilitate lthe starting of the `engine C by providing a rich fuel chargel the choke F is employed. This choke comprises a shutter 30 which lis pivoted about a sleeve 31 within which the needle valve 18a is mount- 1 ed so that it may be rotated upon its mounting to ventlrely close the inlet opening 33 of the induction passage B and thereforel causes a 35 rich fuel discharge such as is necessary in first Starting the engine. An arm 35 formed integral with the shutter 30 is mechanicallyconnected by a link 36 to the cranking pedal G beyond its fulcrum 37. Thus when the cranking `pedal is depressed to crank the engine the choke F. closes.

The cranking pedal G may be constructed for either foot or hand actuation and has formed at its'remote end a segmental gear 39 which meshes with a gear 40 carried by and connected with the engine shaft 41 through suitable mechanism.

In order to prevent the engine from becoming choked after it has fired and started to run under its own power, should the operator retain his foot or hand upon the starting crank pedal .thus holding the choke closed, a valve I-I which under all normal conditions remains closed, will open by atmospheric pressure to admit air in suiiicient quantities to prevent the engine from becoming choked up and stopping. I have therefore provided a foolproof starting choke mechanism with which successful initial engine operation is assured though the operator may know nothing about its presence or function.

In operation my improved carburetor re quires little attention, namely, the adjustment of the needle valve 18a, by movement ofthe w'ing lever 19 to meet speed and load conditions.

In starting the engine the operator has only to depress the cranking pedal G, whereupon movement of the segmental gear 39 therewith causes the engine shaft 41 to rotate. By the same movement of pedal G Athe choke F will close the induction passage inlet 33 to cause a rich fuel charge to be drawn into the engine manifold, thus causing the engine to fire and run under its own power.

If now the operator should continue to hold the pedal G depressed either through thoughtlessness or without knowledge of the fact that the choke is thus held closed, the increased depression in the induction passage B caused by the running engine will result in theopening of valve H by atmospheric vpressure to admit sufficient air to prevent the Y engine from choking -up and stopping.

At all times during operation of the carburetor that region of the-passage B surrounding the fuel nozzle D is maintained at a higher depression than the osterior section of the passage because o the disc 13. This simple arrangement ermits the disposition of the nozzle D to t e rear of the air valve J instead of in front of it as in the present known types of carburetors emply'- mg a Venturi tube for the fuel nozzle. e arrangement makes for a very simple yet eficient fuel lifting mechanism which ma be maintained at very low cost and whic is highly compact.

I claim:

1. 'A carburetor having an induction passage adapted for communication at one end with the intake manifold of an internal combustion engine and open vto atmosphere at the other end, a fuel nozzle discharging into said passage, a 4choke for closing said open end of said passage to induce a rich fuel discharge for starting the engine and means operable automatically upon the increase 1n engine manifold suction as the engine runs under its own power for admitting suilicient air to said passage to sustain engine operation only when the choke is left in closed posi'- tion after the engine l1" s started- 2. In a carburetor, having an induction passage, the outlet ofA which is adapted` for communication with the intake manifold of an internal combustion engine and the inlet of which is open to atmosphere, an air valve in said passage adjacent to its outlet and arranged to yield to the diferentialin pressure atopposite sides thereof, a fuel nozzlehav` ing its discharge orifice communicating with said passage immediately behind said .valve and means associated with the valve forming a partially closed chamber;ladjace1r1tfthenozzle for causing a relativelyhigher depression in that region of the passage'immediately surrounding the discharge orifice of'fsaid nozzle than exists in the remaining .portion of 130.-

nuwe

l the passagejbetween the valve and the pas-` c Ain said passage adjacent toits outlet and arranged to yie d to the differential in pressure at opposite sides thereof, a fuel nozzle having its discharge orifice commumcat 'with v said passage immediatel 'behind said valve operation.

and means associated wit the vvalve forming a partially closed chamber adjacent the n ozzle for causinga relatively higher depression in that region of the p e immediately surrounding the discharge orifice of said nozzle than exists in the remaining rtion of the passage betweenthe valve an the passage inlet, said means also serving as a stabilizer for said valve to prevent the valve from chatterin inV response to slight fluctuation in mani old suction.

4. In a carburetor having anA induction v passage, the outlet of which is adapted for communication with the intake manifold of an internal combustion e 'ne and the inlet of which is open to atmosp ere, an air valve in said passa adjacent to its outlet and arranged to yie d to the diiferentialin pressure said ontleend @gamble bythe diffemnii in pressure atjopposite' sides thereof, a fuel noz-- zle dischargin l in said passage immediately behind said va ve and adisc integral with said valve and spacedtherefroiil said disc lyin across said assage between tbe discharge en of said fue nozzle and the assa e inlet to forma partially-,closed cham r a jacent the nozzle whereb the same is maintained at ahi'gher depression than' the remaining ortion of the passage during the normal car uretor operation. v In 'tness whereof, I hereunto subscribe my name this 15th da of July 1929.

a e Ro RT F. isRAcKE.

at opposite sides thereof, a fuel nozzle havinv its discharge orifice communicating with sai passage immediately behind said. valve, andv a disc ofless diameter than said passage dis- Eosed arallel to said valve and carried therefion4 Y y, said disc lying between said fuel nozzle discharge orifice and said eassa inlet to form a partially closed cham r a jacent the nozzle whereby that region of the passage surrounding said nozzle orificeis maintained at a higher de ression thanV the remaining section thereo during Anormal carburetor 5. In a carburetor including an induction passa e having its outlet end communicating with t e intake manifold of an internal combustion engine and its inlet end open to atmosphere, an air valve in saidvpassage adjacent said outlet end operable b the differential in ressure at opposite sids thereof, a fuel nozz e dischar -'ng in said passage ininiediately behind said valve and means associated with said valve for partially closing said passage adjacent the fuel nozzle for causing a relatively higher depression in that portion of the passage between said valve and its associated means surrounding the discharge end of the fuel nozzle` than exists in iosf usA

6.' In a carburetor including aninduction passage having its inlet end open to atmosphere and its outlet end communicating with the intake manifold of an internal combustion engine, an airvalve in said passage adjacent CERTIFICATE or connection.

Patent No. 1,814, 87s; August so, 1932.

' i nouEn'r einem l t is hereby certified-that error appears'in the printed specification of the above numbered patent requiring correction as follows: Pnge 2, line 47, after Y'suitable" insert the wordratchet; and that the said Letters Patent should he fread with this 'correction therein that the same may conform to the record'of the 'case inthe Patent Office.V

,e (Seal) Signed and sealed this 29th day of November, A. D. 1932.

M.- J. Moore, Acting Commissioner of Patents.

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