US1803315A - Carburetor - Google Patents

Description

Patented May Y5, 1931 UNITED STATES PATENT OFFICE CARL BREER, OF DETROIT, MICHIGAN, ASSIGNOR TO CHRYSLER CORPORATION, F HIGHLAND PARK, MICHIGAN, A CORPORATION ,OF DELAWARE CARBURETOR.

Application filed VMay as,

This invention relates to carburetion and more particularly to a means-for enriching the fuel supplied'to an internal combustion engine when starting.

When starting or warming up a cool engine it is often desirable to enrich the mixture. This is usually accomplished by the use of a choke which cuts off the amount of air supply increasing the suction on the car- 1Q buretor nozzle and thereby supplying more fuel through the nozzle.

The present invention provides a means for an additional supply of fuel when the choke is closed. This additional supply of fuel la is atomized when it reaches the main body of the carburetor thus producing an ideal rich mixture.

One of the objects of the invention is to provide a means for supplying additional 2c fuel dependent on the amount of suction as determined by the use of a choke.

Another object is'the construction and arrangement of parts whereby the flow of the mixture is opposed by the velocity of the air passing through the carburetor when theair inlet thereof is open. As one practical adaptation for accomplishing this result, a

passage for directing the fuel into the mixing chamber, is angularly positioned so that 3c the air velocity may oppose the flow of mixture through this passage during normal operation of the carburetor7 and so that suction created between the choke and throttle, when the carburetor is conditioned for starting, may feed fuel from said passage.

These and other objects will more fully appear from the following specification and claims taken in connection with the accompanying drawing, in which:

. The figure shows a sectional view of a cari buretor showing the application yof the device Referring to the drawing the reference Vnu.-

meral 2 indicates a carburetor body ,provided with the usual float or fuel reservoir chamber 4, mixing chamber 6 and throttle passage 8. The float chamber 4 is shown provided with a fuel inlet 10 regulated by a needle valve 12 and float 14 of the usual construction. A passage 16 leading from the float chamber 4 communicates with the mixing 1926. Serial No. `111,892.

chamber 6. A nozzle 18 is shown as an extension of the passage 16 for atomizing the fuel under suction through the throttle passage.` The usual venturi 2O for increasingr the pull on` the fuel is shown anda throttle valve 22 is shown to regulate the amount of atomizedV fuel to be supplied to an internal combustion engine.

Air is Vsupplied to the mixing. chamber 6 throughthe opening 24. A choke valve 26 is 60 shown adapted to cut off the supply of air, when closed, to increase the suction onV the nozzle 18. It will be understood that under running conditions, with the choke lin an open position, the proper proportions of air and gasoline are supplied to the manifold i and engine, not shown; but when the choke isclosed and the amount of air cut off, as in starting a cold motor, a rich mixture is supplied not sufficiently atomized` due to the insuflicient supply of air.

The present invention aims to overcome this difhculty by supplying a rich atomized fuel tothe mixing chamber thereby reducing the suction on the nozzle and consequently supplying a rich, highly atomized fuel to the engine whenthe choke is closed rather than a poorly atomized mixture. I

As one desirable means of accomplishing this result a well 28 is shownV adjacent the so ioat chamberprovided with an opening 30 for the admission of fuel. level is an enlarged portion 82 and leading therefrom is an opening or vent 34 opening to atmospheric pressure which may be pro- 85 tected against the admission of dirt by a cover or protection 36. A passage shown as a tube 38 leading from the enlarged portion 32 of the well opens into the mixing chamber. The opening in this tube is larger than the vent 34 andV asthe suction is increased in the mixing chamber, a vacuum is v.formed in the enlarged portion 32 whereby gasoline and air are drawnvthrough the tube 38first being atomized in the enlarged portion 32 by 95 a turbulent action; the latter` forming a secondary mixing chamber.

The tube 38 is shown downwardly inclined at a predetermined angle and its discharge end is located in the path of the air which 1w Above the fuel l is admitted through the opening 24twhen the choke 26 is open as to oppose the flow of mixture through the tube 38 when the choke is open, The location of the discharge end of the tube 38 also causes a mixture of fuel and air to be fed from the chamber 32 to the mixing chamber 6 by the suction Which is created in the mixing chamber when the choke 26 is closed.

In the operation of the device, upon closing of the choke 26 and with the throttle 22 partly open when starting, a vacuum is created in the main body of the carburetor suiiicient to pull fuel and air through the tube 38 enriching the mixture to the engine with a fuel highly atomized. Due to the added enriching the engine Will start more easily giving smoother` running and more flexibility during the Warming up period.

It Will be obvious that various changes may be made in the arrangement, combination and construction of the various parts of my improved device, without departing from the spirit of my invention and it is my intention to cover by my claims such changes as may be included Within the scope thereof.

What I claim is:

1. In a carburetor comprising a float chamber, a mixingchamber provided with an inlet for the admission of air, means for supplying fuel from said float chamber to said mixing chamber, a Well open to atmospheric pressure for receiving a supply of fuel from said float chamber, an enlarged portion in said Well and above the fuel level, a passage having an opening larger than the opening to atmospheric pressure and connecting said enlarged portion and said mixing chamber, and a choke, the outlet of said passage being` in the path of the air admitted through said inlet When said choke is open for opposing the flow of fuel through said passage.A

2. In a carburetor comprising a float chamber, a mixing chamber provided with an opening for the admission of air, means for supplying fuel from said float chamber to said mixing chamber, a Well communicating with said float chamber and open to atmospheric pressure for receiving a supply of fuel, a tube having its discharge end located for the reception of the air admitted through said openings so that the velocity of the air passing through the carburetor may oppose the iioW of mixture through said tube, from said Well to said mixing chamber and means for restricting` the flow of air to said mixing chamber.

3. In a carburetor comprising a main mixing chamber and a fuel reservoir, a fuel nozzle in said mixing chamber communicating With said fuel reservoir, an auxiliary mixing chamber having a restricted air inlet there- 1n, and an auxiliary fuel inlet in said main mixing chamber communicating With said auxiliary mixing chamber, the discharge end of said auxiliary fuel inlet being larger than said restricted inlet and located so as to build up a back pressure in said auxiliary mixing chamber when the flow of air through said main mixing chamber is capable of feeding sufficient fuel from said fuel nozzle.

4. In a carburetor comprising a mixing chamber having an air inlet and an air outlet, a source of fuel, a nozzle in said mixing chamber communicating with said source of fuel, a choke valve in said air inlet, and means communicating With said source of fuel for injecting air and fuel into said mixing chamber when said carburetor is conditioned for starting, said means being adapted to be rendered inoperative by the air admitted through said inlet when said choke is open.

CARL BREER.

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