US1526318A - Carburetor - Google Patents

Description

Y Feb; 17,` 1925.

. 1,526,318 M. G. CHANFJLER CARBURETOR Filed Aug. 2, 1920 2 Sheets-Sheet 1 .Ill

Feb. 17, 1925.

M. G. CHANDLER CARBURETOR Filed Aug. 2, 1920 2 Sheets-Sheet 2 Inventor Ud/@0rd /Mmd/f ttor l 3.73

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Seam" Patented Feb.` 17, 192s. f l

lUNITED `STATES MILFonn e.

`1,526,318 PATENT- OFFICE.

cHANnLEn, or CHICAGO, ILLINOIS; AssIeNon, BY MnsNn ASSIGNMENTS,

To cUnrIs '13. cAMP, TRUSTEE, onoAK PARK, ILLINOIS.

' CARBURETOR.

Application-filed August' 2, 1920i Serial N0. 400,693.

To all lwhom t may-concern:

Be itknown that I, MILroRD G. CHAND- LER, acitizen lof the United States, and resi- `new and useful Improvement 'in ACarburetors, of which the. following is a full, clear, concisa-and enact description, reference beinghadto 'the accompanying drawings, forming a part of this specification.

, My linventlon relates to carburetors lfor `'internal combustion engines. The carburetor to which my inventionL is applied is arranged for lifting fuel froma low-level supply tank to the iioat chamber of the car-f buretor by suction derived from the suction of the engine supplied by the carburetor. It is well known that the power output of an internal combustion engine is substantially proportional-to Athe actual pressure of the explosive mixturevin the intake manifold of the engine. The nearer the pressure of this mixture approaches atmospheric pressure, the greater-the power outprut of.

the engine, and the further this pressure falls below atmospheric pressure, the .less` the power output of the engine. The carburetor throttle interposes a restriction to the passage of air into the engine mani-fold, capable of creating a high depression in the manifold, and thus depriving the engine of power.` With the `throttle wide openeyery restriction in -theintake passage creates a certain depression thelpressurey of the i mixture in the intake manifold, and thus deprives the engine of ay portion ofthe power which it would develop were it not for the restricted'intake. My invention vrelates to a carburetor in which means is lprovlded for securing a depresf-xion sufiicientfor lifting fuel from a low-level sup'plytank to the carburetor without unduly restricting the passage leadinginto the carburetor.

. My invention relates further to a means for delivering fuel to the inrushing columnf of air at a point near the middle of' thev column 'so that the distribution of fuel and air willbe substantially uniform. vThis is accomplished, as willbe more fully herein- '5 after pointed out, by arranging the Adis..

charge end of the fuel delivery tube sothat -1t `moves across the air intake opening, at

l 'substantially' one-.half therate that the' v'openingin sinarea' My lnventlon is in the accompanying drawingsin which like reference g vthe several views, in whichdent of Chicago, in' the'county of Cook, and 5 State of Illinois, have invented a certain taken onthe line-4 4 of Figure 1 showingy the mechanism for introducing the yfuelinto the movable delivery nozzle.

l .Figure 5 is a .section taken on a broken lane to show the fuel passageway from the ottom of the oat chamber to the,induc tion passage.y Referring rst to Figure 1, the carburetor `body comprises two maincastings. 6 and 7, `the casting 6 including the principal portion of the induction passage andalso the float or fuel chamber, specially indicated at 8. The casting? is a fillet lying between the -two Wings l() and 11 which constitute partsy of the main casting 6. These two wings are vinternally milled with parallel inner walls, the spacer l7 serving to hold the free ends of the wings `in laccurately spaced relation. Between the wings 10 and l1 is a shoe 14 pivoted at 15,' the shoe having oppo- Isite parallel `faces which clear the inner' side walls of the wings'lO `and ll1v by about 2/1000 yof an inch, 4so that the space back of the shoe is substantially.` enclosed and so that the shoe may act as-a piston swinging about its pivot 15to open and close the' induction passage.- The shoe is preferably made hollow; andfbetween a boss 17` within the hollow` of the shoe andthe spacer v7 is a spring 18 which tends to hold the shoe in the -position to `close the induction passage. The shoe is provided with openings-20 leading between the induction passage and the lspace back of the shoe,.through which the suction of the -induction passage ma be communicated-with Jthe spaeeback o thev shoe for opening the shoe. The `opposite wall 214 of the induction passage is referably formed substantially-semi-cylin rlcally at the point 22 and gradually blends from this semi-circulan cross 1 section into a` straight cro section at the point 23, so that the induction passage has generally flaring Ashape' of substantially th ,sameproportions: a Venturi tube, the shape bemg such that no matter what the position of the shoe may be, the point of least cross-sectional area of the intake passage lies apside wall of the housing 6. By means of a link 29 pivotally attached to the nozzle 27 at 30 and to the shoey 14 at 31, the nozzle is caused to partake of the movement of the shoe to such an extent as to' maintain the delector 33 which is carried by the movable end of the nozzle 27 substantially midway between the shoe 14 andits opposing wall 23 for all positions of the shoe, the purpose of this being to inject the mixture of fuel and air which passes out of the `hollow side of l, the deflector 33 into the middle of the stream of the iioat chamber.

of incomin air. v

Fuel is elivered to the ports 35 in the nozzle Venturi tube 28 through a passage 36 which leads to the lower part of the float chamber 8, this passage being provided with a plug 37 having a properly sized opening through it to furnish the right amount-of fuel for a combustible mixture. The upper space of the float chamber v8 is maintained at a depression below atmosphere for the purpose of lifting fuel to the float chamber from a low level supply tank. The depression for this purpose is derived from the throat of a very small Venturi tube 39, shown in section in Figure 3, through a communicating passage 40 which connects between the annular space 40 around the vacuum Venturi tube, and the upper space The Venturi tube 39 is drilled eccentrically, so that when rotated within the housing 4l, the discharge e-nd of the Venturi tube will be caused to change its position ywith respect to the pivot 15 upon which the shoe 14 is supported. The shoe is provided with a cam 43 which is cut so that its edge 44 intersects the discharge opening of the Venturi tube 39. The rotation of the Venturi tube 39 causes the edge of the cam to cut off greater or less proportions ofthe opening to permit greater or less amounts of air to pass through the Venturi tube. By the rotation of this tube, the mixture may be made rich or lean, since the amount of air passing through this small Venturi tube controls the amount of suction on top of the fuel in the oat chamber. The ater the suction on the top of the fuel m the float chamber, the less the fuel- Landais e feeding differential and, therefore, the leaner suit the particular engine supplied by the carburetor. The spring 18. and other parts of the carburetor are selectedto give a substantially constant proportionality of fuel and ain-,but if this proportionahty is not exactly what is desired to provide a perfect mixture under all conditions, then the richness at certain engine speeds can be governed by slight changes in the sha of the cam edge 44, as very few thousan ths of an inch taken from or added to this cam changes the mixture proportions a noticeable amount.

The Venturi tube 39 is also provided with an opening 46 adapted to register with an opening 47 when the Venturi tube is rotated to an extreme position. When these two openings 46 and 47 register, an atmospheric communication is completed to a point behind the shoe 14 which relieves the suction back of the shoe and causes the shoe to partially close. vThis may be done in starting a cold engine, at which time an extremely rich mixture is needed.`

In the operation of this carburetor, the suction produced by the rotation of the engine draws air through lthe nozzle Venturi tube 28 which in turn draws a mixture of fuel into this nozzle through the openings 35. This mixture of fuel and air is carried through the movable nozzle 27 and discharged into the induction passage just above the deiiector 33.

causes a flow of air through. the small Venturi tube 39, thus creating a suction on the surface of the fuel in the float chamber for lifting fuel from the low level supply tank to the float chamber. Mechanism within the fioat chamber of ordinary construction maintains a substantially constant level of fuel therein. When the throttle 25 is ol ned to a. greater extent than .that for i ling an engine, the increased suction in the induc- At the same time,v the suction within the induction passagetion Ipassage of the carburetor is communicated through the passage 2O to a point behind the Yshoe 14 and thus causes the shoe to open to such an extent that the suction in the induction passage is prevented from increasing as rapidly as it otherwise would, this being controlled by the pressure of the spring 18 which tends to hold the shoe in its closed position. The openings 20 each being located at the point of high local depression in the induction passage, the suction behind the shoe 14 will increase much more rapidly than the rate of increase of suctiony in the largest art of the induction passage, thus vsubstantially overcoming the gradually increasing resistance of the sprin 18 as it becomes more and morecompresse Bv reason of this action, the suction in the induction passage of the carburetor at a point just anterior to the throttle 25. is prevented from very materially increasing `as the ,volume of air through the induction passage increases. It is necessary that the suction in the induction passage increase t0 some extent to insure stability in the moving part-s of the carburetor, but it is desirable Ifor securing the'best power results that the depression in the induction passage be not` too greatly increased for the higher engine demands As the shoe 14 opens to its various positions, the swinging nozzle 27'is caused to follow so that the fuel is delivered at the central part of the stream of incoming air, there being substantiall the. same space maintained` between'the eiector 33 and the surface 23, as between the deflector 38 and the shoe 14 for all positions of the shoe.

This feature of my invention providingA means for ldelivering fuel to the central part of the incoming stream of air is in no wise limited to a carburetor for lifting fuel from a low level sup-ply tank, and may be used with a carburetor in which the upper surface of the float chamber is open to atmosphere as well as in the present type of carburetor in which the upper space of the float chamber is sealed against external at-- mos here.

A though my invention is shown and described with respect to the details illustrated on the accompanying drawings, it is to be understood that I do not wish to be unduly limited thereto, certain modifications being possible without departing from the spiritor scope of my invention.

I claim:

. 1. In a carburetor, the combination with an inductionpassage having a fixed wall, of

.abpivoted shoe constituting an opposite mov-l a e wall, a fuel delivery tube pivoted with- 1n the induction passage and-extending toward the anterior opening'into the induction passage, a deflector carried on the endof said tube, and means to Cause said tube and its deieetorv to move about its pivot to hold lsaid deflector and the movable end of the tube substantially midway between the xed wall ,of the induction chamber and said pivoted shoe for all of the various positions of said pivoted shoe.

, closed by a part of said Venturi tube, said Venturi tube being rovided with means for opening said secon passage when the Venturi tube is rotated to a predetermined position, and Imeans for delivering fuel to `said induction passage. 3. In a carburetor, the combination with an induction passage, means for varying the size of the opening through said passage, a fuel and air delivery port located 'at substantially 'the' most constricted point in said passage, a Venturi tube for creating a mixture of fuel and air, and a tubular connection extendin from said Venturi .tube in a downward direction to said fuel and air deliveryl port, substantially vas described.

4. Ina carburetor, the combination with an induction chamber of a primary mixture passageway lying longitudinally within the induction chamber, a Venturi tube serving as a fuel nozzle discharging into said primary mixture passageway, a discharge orice `for said passageway where the .primary mixture discharges into the induction chamber, the point at which the primary mixture enters the primary mixture passageway being nearer the engineto-be served bythe carburetor than the point at which the primary mixture discharges from the discharge

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