US2755818A

US2755818A - Carburetor adjusting mechanism

Info

Publication number: US2755818A
Application number: US398994A
Authority: US
Inventors: Robert R Dietz
Original assignee: Individual
Current assignee: Individual
Priority date: 1953-12-18
Filing date: 1953-12-18
Publication date: 1956-07-24
Anticipated expiration: 1973-07-24

Description

July 24, 1956 DIETZ 2,755,818

CARBURETOR ADJUSTING MECHANISM Filed Dec. 18, 1953 2 Sheets-Sheet 1 Robert A. 0/29)? INVENTOR.

WW 12m United States Patent CARBURETOR ADJUSTING MECHANISM Robert R. Dietz, Havertown, Pa.

Application December 18, 1953, Serial No. 398,994

3 Claims. (Cl. 137-'-637.3)

This invention relates generally to carburetors, and pertains more particularly to mechanism for ad usting the metering system of carburetors of the type shown In the patents to John R. Fish, Nos. 2,214,273 and 2,236,595,

issued September 10, 1940, and April 1, 1941, respectively.

A primary object of this invention is to provide an improved form of metering adjustment mechanism for use in conjunction with carburetors of the type illustrated in the above mentioned patents, wherein the metering adjustment can be accomplished with a minimum of effort by merely manipulating mechanism disposed exteriorly of the carburetor assembly.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

Figure l is a perspective view of a carburetor with portions thereof broken away to show the operating mechanism;

Figure 2 is a side elevational view of a carburetor having the improved attachment positioned thereof, portions of the attachment being broken away to show the relationship of parts;

Figure 3 is a vertical section taken through the carburetor assembly shown in Figure 1 illustrating details of the attachment;

Figure 4 is a vertical section taken substantially along the plane of section line =%4 in Figure 3; and I Figure 5 is a sectional view showing a modified form of adjusting mechanism.

Referring now more particularly to the drawings, the carburetor illustrated includes a barrel portion having a mounting flange portion 12 at its lower end for mounting the carburetor on an intake manifold of an internal combustion engine. The upper end of the barrel is provided with a collar 14 to which an air cleaner mechanism is conventionally secured. A portion 36 of the carburetor body is removable from the remainder of the carburetor, a gasket 18 being provided therebetween, and this body portion forms the gasoline reservoir for the carburetor, suitable float and float valve mechanism being associated therewith, as is conventional. A fitting 20 is provided on the upper surface of the float chamber body, and a gasoline inlet line 22 is connected therewith in a manner well understood in the art.

Referring now more particularly to Figures 1 and 3, it will be noted that the barrel 1! has a pair of diametrically opposed openings therein receiving the throttle shaft member 22, one end portion of which projects into the float chamber and has rigidly afiixed thereto an arm member 24 provided with a fuel passageway 26 opening at its lower end into the fuel feed groove 28 on the side wall 30 of the carburetor. The opposite end of the throttle shaft extends outwardly from the opposite side of the barrel 10 and is provided thereon with an actuating arm member 32 connected by a suitable fitting member 34 to throttle 2,755,818 Patented July 24, '5

linkage member 36 by means of which rotation of the throttle shaft is effected by manipulation of the conven- "barrel ll), as is conventional, and this valve has diametrically opposed

hub portions

42 and 44 received on a portion of the throttle shaft 22 and a sleeve member 46, respectively. Each of the

hub portions

42 and 44 is provided with a radial aperture internally threaded to receive a setscrew member. Normally, in this type of carburetor, the sleeve member 46 is non-existent, this sleeve forming a part of the present invention, and the hub portions of the butterfly valve are rigidly affixed to the throttle shaft 22 by means of setscrews received in the threaded apertures in the hub portions.

In the conventional carburetor structure, it is to be noted that the diameter of the throttle shaft 22 is greater than the width of the central web porion 48 of the butterlly valve 40 and that the throttle shaft is provided with a series of longitudinally spaced openings 50' which communicate with the upstream side 'of the barrel 10in the manner shown most clearly in Figures 1 and 4. In the conventional structure, when it is necessary to change the metering adjustment of the apertures 50 to be more or less uncovered by the central web portion 48 of the butterfly valve, it is necessary to remove the air cleaneron the carburetor, loosen the setscrews and manually rotate the butterfly valve. This method of adjusting the metering of the carburetor is cumbersome, since it necessitates the removal of the air cleaner and manipulation of the setscrew members in the

hub portions

42 and 44 of the throttle valve, and also manipulation of the throttle valve with respect to the throttle shaft to effect the desired fuel setting. Additionally, this method does not lend itself readily to rapid adjustment since it is impractical to make the adjustment while the engine is running, so that it makes it take several trial adjustments of the assembly to effect the desired end result.

To overcome this cumbersome method of adjusting the metering system of the carburetor, the boss 52 on the carburetor barrel it) which is normally apertured to journal the throttle shaft 22 is reamed out or otherwise enlarged to receive the previously mentioned sleeve 46 and the hub 4d of the throttle valve 49 is also reamed out to receive an inner end portion of this sleeve in the manner shown most clearly in Figure 3. One of the setscrew members 54 is then replaced in the hub 44 to rigidly affix the throttle valve it) to the sleeve 46, the other setscrew being omitted in the hub portion 42 such that the butterfly valve is, in effect, journaled on the throttle shaft 22. The sleeve 46 projects outwardly through the boss 52 and its outer end receives an arm member 56 whose split upper end 58 surrounds the sleeve and is clampingly engaged thereon by virtue of the clamping screw 66 extending through the ears 62 at the upper end of the arm 56. The lower end of the arm is formed as a gear segment having the teeth 64 thereon, in the manner shown most clearly in Figures 1 and 2. A second arm member 66 has its split upper end 68 surrounding the throttle shaft 22 and clampingly engaged thereon by virtue of the clamping screw 70 engaging through the cars 72 in a manner similar to the first mentioned arm. The lower end of this second arm is provided with the laterally projecting, spaced parallel leg members 74 which are positioned below the gear segment teeth 64 and these legs are apertured to receive a shaft 76 to which the worm gear 78 is suitably feathered. One end portion of the shaft 76 is provided with a hand wheel portion 80, and it is to be understood that the legs 74 normally frictionally engage on the shaft 76 to such an extent that the unit is self-locking. The worm gear 78, of course, meshes with the gear segment teeth 64 and it will be manifest that by manipulation of the shaft 76 and consequently the worm gear 78, relative rotation between the throttle shaft 22 and the butterfly valve 40 will be effected such as to change the amount the apertures 50 are covered or uncovered by the central portion 48 of the butterfly valve. Accordingly, it will be manifest that metering adjustment of the carburetor is thus efiected without removal of the air cleaner or any other associated carburetor mechanism, and that the adjustment may be effected very rapidly and while the engine is running to produce the most accurate setting of the metering holes 50.

Referring now more particularly to Figure 5, wherein a modified form of adjusting mechanism is shown, it will be seen that in addition to the previously described adjusting mechanism, one of the end plugs 38 has been removed from the throttle shaft 22 and this end portion of the throttle shaft enlarged and internally threaded to receive the metering needle 82. The outer end of the metering needle is provided with a hand wheel portion 84 and the inner end 86 is of reduced diameter corresponding to the internal diameter of the throttle shaft such that manipulation of the metering needle 82 may effect the blocking off of one or more of the metering holes 50 in the throttle shaft, Figure 5 illustrating a position in which all of the metering holes have been blocked off. In this manner, a finer adjustment of the metering mechanism may be effected than is otherwise produced by the provision of the previously described assembly alone.

From the foregoing, the construction and operation of the device will be readily understood and further explanation is believed to be unnecessary. However, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction shown and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the appended claims.

What is claimed as new is as follows:

1. In a carburetor, a barrel, a throttle shaft projecting diametrically through said barrel and having one end journaled therein, a sleeve rotatably received on said throttle shaft and journaling an intermediate portion thereof in said barrel, a butterfly valve disposed within said barrel having diametrically opposed hub portions receiving a portion of said shaft and an inner end portion of said sleeve respectively, said butterfly valve being fixed to said sleeve, said throttle shaft being hollow and having a plurality of apertures between the hub portions of said of said barrel, a second arm fixed to said throttle shaft adjacent the first arm, a gear segment formed on the free end of said first arm, a worm gear rotatably carried by the free end of said second arm in mesh with said segment, and means for rotating said worm shaft to effect relative rotation between said throttle shaft and butterfly valve.

2. In a carburetor, a barrel, a throttle shaft projecting diametrically through said barrel and having one end journaled therein, a sleeve rotatably received on said throttle shaft and journaling an intermediate portion thereof in said barrel, a butterfly valve disposed within said barrel having diametrically opposed hub portions receiving a portion of said shaft and an inner end portion of said sleeve respectively, said butterfly valve being fixed to said sleeve, said throttle shaft being hollow and having a plurality of apertures between the hub portions of said butterfly valve, a first arm fixed to said sleeve externally of said barrel, a gear segment formed on the free end of said first arm, a second arm fixed to said throttle shaft adjacent the first arm, a pair of laterally extending spaced legs on the free end of said second arm, a worm gear rotatably received between said legs in mesh with said segment, and means for rotating said worm shaft to effect relative rotation between said throttle shaft and butterfly valve.

3. In a carburetor, a barrel, a throttle shaft projecting diametrically through said barrel and having one end journaled therein, a sleeve rotatably received on said throttle shaft and journaling an intermediate portion thereof in said barrel, a butterfly valve disposed within said barrel having diametrically opposed hub portions receiving a portion of said shaft and an inner end portion of said sleeve respectively, said butterfly valve being fixed to said sleeve, said throttle shaft being hollow and having a plurality of apertures between the hub portions of said butterfly valve, a first arm fixed to said sleeve externally of said barrel, a second arm fixed to said throttle shaft adjacent the first arm, and means connecting said arms for effecting relative rotation between said throttle shaft and butterfly valve.

FOREIGN PATENTS 1 444,625 France 1912