US1784481A - Carburetor - Google Patents

Description

Dec. 9, 1930. y

G. M. BICKN ELL CARBURETOR 2 Sheets-Sheet l Filed May 5, 1927 ec. 9, 1930. G. M. BlcKNELL 1,784,48

CARBURETOR Filed May 5, 1927 2 sheets-sheet 2 I Patented Dec. 9, 1930 UNITED STATES PATENT OFFICE GEORGE M. BICKNELL, OF ST. LOUIS, MISSOURI, ASSIGNOR '.llOV CARTER CARBURETOR CORPORATION, OF ST. LOUIS, MISSOURI, A CORPORATION OF DELAWARE CARBURETOR i Application. led May 5, 1927. Serial No. 189,034.

Reference is had to the accompanying drawings which illustrate the preferred form of the invention; though it is to be understood that the invention is not limited to 5 the exact details of construction shown and described, as it is obvious that various modifications thereof within the scope of the claims will occur to persons skilled in the art.

In said drawings:

Figure 1 is a view partly in central vertlcal section and partly in elevation of a carburetor constructed in accordance with this invention;

Fig. 2 is a view in elevation looking from the right in Fig. l;

Fig. 3 is a front elevation of the carburetor shown in Fig. 1, parts being broken away to show other parts more clearly;

Fig. 4 is a plan view of the carburetor shown in Fig. 1; and

Fig. 5 is a fragmentary view showing the lever forming a part of the operating connection between the choke and throttle valves of the carburetor shown in the other views.

This invention relates to carburetors of the type in which the air inlet can be restricted in order to provide a richer mixture for use in starting or warming the motor, and it is an object of this invention to provide an improved carburetor of the type described in which the proper throttle valve opening to prevent stalling of the motor will be automatically provided for each settin of the choke valve. It is also an object o this invention to provide an improved carburetor of the typedescribed having a connection between the choke and throttle valves which will open the throttle suiiciently to prevent stalling of the motor for each setting of the choke valve and -which will permit of the operation of the throttle valve independently of the choke valve.

As is well known, when starting an inter- A nal combustion engine, such as is used in automobiles, it is often advantageous, especially if the engine be cold, to partly open the clar- -buretor throttle valve and to close or practically close the carburetor choke valve which 60 is often placed in the main air passage of the carburetor. Opening thevthrottle valve will allow the mixture from the carburetor to be drawn more readily into the intake manifold of the engine, and closing the choke valve will restrict the air passage and cause a richer mixture to be drawn from the carburetor. After the motor is started and while it is warming up, it is also advantageous to have the carburetor throttle open l slightly more than is necessary for idling the 6o engine in order to prevent the engine stalling. This is due to the fact that the low air veloci-v ties occurring with the throttle closed are insuliicient to properly vaporize the fuel in a cold motor.u A slight additional opening e5 of the throttle will cause the motor to run at a greater speed andto use air in sufficient volume to cause the partially closed choke valve to affect the mixture ratio. To provide for the control of the engine during this 7o warming up period, controls are located convenient to the riders seat to regulate both` the carburetor choke and throttle valves, but in order to secure the best results from the engine at various speeds before it is. thoroughly warm, these controls should be properly set with respect to each other. .In order to maintain the proper relative settings of the valves, this inventionP provides for the interconnection of these valves in such a manner that when the choke valve is closed or partially closed, thethrottle valve Will be opened slightly more than is necessary for the idle engine speed, the relation of the settings of the two valves being -such as to give the correct throttle opening to prevent stalling of lthe motor at the di'erent positions of the choke valve thus simplifying the operation of starting and running a cold motor as the operator will have but a single control` to handle in starting and warming the engine.

As shown in the drawings, the carburetor constituting this invention comprises a body 1 having an air inlet 2 leading to a main air chamber 4 from which a discharge leads 95 through the ve turi 6 to the mixing chamber 8 and thencel a A the throttle valve 10 to the mixture out et 12, the mixture outlet bein connected to the inta-ke manifold (not shown) of an internal combustion engine. To the adj acent the throttle valve 10, and being controlled by a valve 30.

To aid in starting the motor, there is provided a choke valve 32 which surrounds the stand pipe 22 and is operated by a yoke 34 carried on a shaft 36 to take a position such as is shown in dotted lines in Fig. 1, in whichit more or less restricts the opening to the venturi 6, thereby causing a restrict: on in the air inlet passage leading to the intake manifold and causing a greater decrease in the pressure ian the mixing chamber 8. thus increasing the suction on the port 28. The shaft 36 has its ends j ournaled in the walls of the body l and has one end projecting beyond the walls and provided with a crank arm 38 secured thereon. The throttle valve 10 is' mounted on a shaft 40 having its ends ournaled in the walls of the body andrhaving one end projecting v beyond the body walls and carrying a crank 42 secured thereon. The crank 42 is provided with a projection 44 having threaded openings therein at right angles to each other, in one of which is positioned a set screw 46 whichY projects beyond the projection 44 and 1s adjusted in its opening to engage with a laterally projecting ange portion 54 of lever 52 hereinafter described, said flange 54 resting against a lug 48 formed integral with the body wall when the throttle valve 10 is in its fully closed position the screw 46 serving as an adjustable stop for the valve and being held in its adjusted position by a set screw 50 positioned in the other opening.

Pivotally mounted on the shaft 40, between the crank 42 and the bodyl 1, is a lever 52 which extends in both directions from the shaft 40, and at one end is provided with a laterally projecting flange portion 54 which is interposed between the face of the lug 48 and the set screw 46. To the other end of the lever 52 there is pivotally connected an adjustable link 56 which has its other end pivotally connected to the crank 38, the connection of the link 56 to the crank 38 being such that the operation of the crank 38 will provide for a slight Imovement of the link 56 which will be communicated to the lever 52. Operation Vof the lever 52 will, through engagement of the flanged portion 54 with .the set screw 46 cause the crank 42 and shaft 40 to be operated, rotating the throttle valve 10. The lever arms through which themotion of the crank 38 is communicated to crank 42 are so proportioned and arranged with respect to each other as to provide a proper opening of the throttle valve 10 for each position of the choke valve 32 and the arrangement is such that operating the choke valve 32 to restrict the air passage will cause a corresponding proportional opening of the throttle valve 10.

It will `be noted that the connection of the lever 52 to the crank 42 is such that the crank 42 may be operated to open the throttle valve 10 'to a greater extent than it is opened by the operation of the chokel valve 32 without changing the setting of the choke valve 32 and that upon the closing of the throttle valve 10. the connection between the choke and throttle valves will serve to prevent the fully closing of the throttle valve while the choke valve is 1n a partly closed position but that the choke valve may be returned to the fully opened position re ardlessgof thesetting of the throttle valve. t will also be noted that the connection between the two valves in no way interferes with the usual operation of the throttle valve while the choke valve is in the fully opened position. It will also be noted that this construction insures a correct throttle valve opening for each position of the choke valve and that should the engine start to die or stall as a result of too lean a mixture, operation of the choke valve to supply a richer 'mixture also operates the throttle valve thereby automatically making the action of the choke valve more effective and speeding up the engine by the operation of a single con- 1 trol.

What is claimed is:

1. In a carburetor, a throttle valve and shaft rotatably supporting said valve, a crank v loo for operating said shaft, a choke valve, a Y

crank for operting said choke valve, a lever loosely mounted on said shaft and operatively engaging said throttle valve operating crank and adjustable means connecting said tle valve shaft, and adjustable means conl necting said lever and the choke valve oper-'"1 ating crank for actuating the throttle valveupon movement of the choke valve crank.

3. In a carburetor having throttle and' choke valves', shafts on whlch said valves r are mounted and cranks on said shafts for actuating said valves, means for effecting simultaneous opposite operation of the 'throttle and choke valves respectively comprising a lever journaled on said throttle valve 'shaft for actuating the throttle valve crank, and a link connecting the lever and choke valve crank and operative by the choke valve crank to actuate the lever, said link being adjustable whereby the relative open and closed positions of the throttle and choke valves respectively may be varied.

4. In a carburetor having a throttle valve, a shaft mounting the same, a crank mounted on the shaft and adjustable to vary the norl mal position of the throttle valve, a choke valve, a shaft mounting the choke valve, a crank secured to the shaft, an adjustable link secured to the choke valve crank and a lever connected to said link and pivotally mounted on said throttle valve shaft, said'lever being operatively connected to the throttle valve crank and causing simultaneous opposite operation of said choke valve and throttle valve.

5. In a carburetor having a throttle valve, a shaft mounting the same, a crank mounted on the shaft and ad'ustable to vary the normal position of the t rottle valve, a lever pivotally mounted on said shaft and engaging said crank, a choke valve, a shaft mounting the choke valve, a crank secured to the shaft, and adjustable means secured to the choke valve crank and connected to said lever causing simultaneous opposite operation of said choke valve and throttle valve, said throttle valve being capable of opening movement independently of the choke valve.

6. In a carburetor, a throttle valve, a choke valve, shafts on Which said valves are mounted, cranks carried by said shafts and operating said valves, a lever loosely mounted on Said throttle valve shaft and operatively connected to said throttle valve operating crank, a link connecting said lever and choke valve operating crank for opening said throttle valve when said choke is closed, and said throttle valve operating means openingsaid throttle valve independently of said choke valve.

7. In a carburetor, a throttle valve, a choke valve, shafts on which said valves are mounted, cranks carried by said shafts and operating said valves, a lever loosely mounted on said throttle valve shaft and operatively connected to said throttle valve operating crank, a link connecting sai'dleve'r and choke valve operating crank forti opening said throttle valve when said chokeiis closed, and said 'throttle valve operatiiig means opening said throttle valve independently of said choke valve, said lever permitting continued opening of said throttle valve independently of said choke valve.

8. In a carburetor, a throttle valve, a choke valve, shafts on which said valves are mounted, cranks carried by said shafts and operating said valves, a lever loosely mounted on said throttle valve shaft and operatively connected to said throttle valve operating crank, a link connecting said lever and choke valve operating crank for opening said throttle valve when said choke is closed, said valves being independently operated to open position.

9. In a carburetor, a throttle valve, a shaft rotatably supporting said valve, a crank for operating said shaft, a choke valve, a crank for operating said choke valve, a lever loosely mounted on said shaft and operatively engaging said throttle valve operating crank upon movement of said lever in one direction, and a link connecting said lever and said choke valve o erating crank.

'10. In a car uretor, means forming a mixying'chamber, a standpipe discharging into said mixing chamber, a fuel nozzle discharging into said standpipe, an air inlet port for said standpipe, a venturi surrounding the upper end of said standpipe and forming an annular secondary air inletportfor said mixing chamber, an outlet passage for said mixing chamber,c a valve controlling said passage, a valve controlling said secondary air inlet port, and means operable by closing the secondary air inlet port for opening the outlet valve of the mixing chamber.

l1. In a carburetor, a throttle valve, a choke valve, shafts on which said valves are mounted, cranks carried by said shafts and operating said valves, a lever loosely mounted on said throttle valve shaft and operatively connected to said throttle valve operating crank, a link connecting said lever and choke valve operating crank for opening said throttle valve when said choke is closed.

l2. In a carburetor, a throttle valve, a standpipe forming a primary air passage, means forming a secondary air passage, a choke valve slidably mounted on the standpipe and controlling the secondary air passage, a lever for operating the choke valve, and means including a lost motion connection mounted on and carried by the carburetor for opening said throttle valve as the choke valve is closed.

13. In a carburetor, means forming a mixing chamber, a throttle valve controlling the outlet of said mixing chamber, primary and secondary air passages leading to said mixing chamber, a venturi at the entrance of said secondary air passage to the mixing chamber, a fuel nozzle discharging into said primary air passage, a valve controlling said secondary air passage, and means for partially opening said throttle When said secondary valve is closed.

,In Witness whereof I have hereunto set my hand.

GEORGE M. BICKNELL.

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