US3409277A - Metering jet adjustable fuel by-pass - Google Patents

Metering jet adjustable fuel by-pass Download PDF

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US3409277A
US3409277A US560242A US56024266A US3409277A US 3409277 A US3409277 A US 3409277A US 560242 A US560242 A US 560242A US 56024266 A US56024266 A US 56024266A US 3409277 A US3409277 A US 3409277A
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fuel
carburetor
orifice
passage
pass
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US560242A
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Donald A Reise
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ACF Industries Inc
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ACF Industries Inc
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    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02MSUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M19/00Details, component parts, or accessories of carburettors, not provided for in, or of interest apart from, the apparatus of groups F02M1/00 - F02M17/00
    • F02M19/02Metering-orifices, e.g. variable in diameter
    • F02M19/025Metering orifices not variable in diameter
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10STECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S261/00Gas and liquid contact apparatus
    • Y10S261/38Needle valves
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10STECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10S261/00Gas and liquid contact apparatus
    • Y10S261/84Tamperproof

Definitions

  • This invention relates to a carburetor.
  • a charge forming device embodying within the fuel system, a metering rod for regulating the flow of fuel between the source thereof and the carburetor mixing conduit.
  • the'rod is disposed within an orifice formed in a passage communicating the carburetor fuel bowl with the fuel nozzle.
  • the metering rod is adjustable in response to the carburetor actuating mechanism for the purpose of providing a more accurate and metered flow of fuel to the mixture conduit.
  • means is provided in the fuel passage communicating the fuel bowl with the fuel nozzle, for passing a second stream" of" fuel to form a by-pass around the metered stream, particularly under engine idle conditions.
  • this by-pass opening is to provide a more accurate flow of fuel under particular carburetor operating conditions and to supplement the flow passing through the main jet as defined by the metering rod.
  • the by-pass opening is preferably provided with a valve element for varying the fuel flow through said by-pass to provide a fine adjustment and consequently a more accurate control over the flow of fuel passing through the nozzle.
  • the metering rod is not the final solution to the problem.
  • the metering rod in normal operation, is merely suspended within an orifice such that one portion of the metering rod end cooperates with the orifice to definean annular opening. Since as a matter economics and convenience the metering rod is normally unguided except for the registration in the orifice, the annular opening provided thereby cannot be accurately predetermined.
  • the present metering rod orifice bypassforms a supplementary flow of fuelwhich is substantially constant under all conditions of carburetor operation.
  • the bypass is so adjusted toafford the necessary amount of fuel to sustain a desirable engine idle speed.
  • FIGURE 1 in the drawing is a vertical, partial cross section of a carburetor embodying the present invention, with portions broken away.
  • FIGURE 2. is a segmentary view in cross section of a portion of the device shown in FIGURE 1.
  • FIGURE 3 is a view similar to FIGURE 2.
  • FIGURES 4 and 5 are views similar to FIGURE 2 illustrating alternative forms of the invention.
  • FIGURE 6 is a view of an end of one form of metering screw.
  • the carburetor together with the presently disclosed fuel bypass means therein, is shown generally and as related to a single barrel unit. It should .be borne in mind however, that the novel concept to be herein described more fully, is not so limited to a single barrel carburetor but may be utilized as well in multibarrel units.
  • the carburetor shown is formed of a plurality of several members including a central body 10 having a lower flanged opening to which is attached a circular neck portion 11 by a plurality of bolts 12.
  • the neck portion includes a peripheral flange 13 having bolt holes therein for engaging the intake manifold of an internal combustion engine.
  • A- gasket 14 is compressed between the respective neck and body portions to form an air tight seal and avoid leakage of air into the air-fuel mixture formed within the carburetor.
  • the upper side of body 10 is provided with a sealing gasket 16.
  • a cover 17 affixed ot the carburetor body by a plurality of bolts 19 forms the device into a unitary member.
  • the body may be formed of any suitable material adapted to the application, and includes a fuel bowl 21 extending substantially the vertical length thereof, defining a fuel holding reservoir 15.
  • Cover 17 is provided with a valve assembly in which a valve 22 is threadably retained, having an inlet 33 opening into fuel chamber 23 and having a strainer 24 disposed therein for removing solids from the fuel stream which would otherwise tend to damage or lodge within the carburetor constricted passages and ports.
  • Valve 22 includes a movable needle element 26 having a conical forward end which engages a peripheral seat 27 thereby defining an annular fiow passage when the needle is displaced from the seat.
  • Fuel reservoir contains fioat 35 which is pivoted on arm 34 at a pivot point 36 such as a shaft or similar member, carried on a downwardly depending portion of cover 17. Lowering of the float will permit needle element 26 to be displaced from its corresponding seat by the pressure of the fuel in fuel chamber 23. The fiow of fuel into reservoir 15 will continue until such time as the fuel level will cause the float 35 to rise sufiiciently thereby positioning needle element 26 into its seat and thus precluding further fuel flow.
  • the carburetor consists of a mixture conduit 37 having an air inlet 38 at the upper end thereof which may be connected to an air filter or the like.
  • the air inlet or air horn is further provided with a choke valve 39 carried on a choke valve shaft 41 which is pivotally disposed in the air horn.
  • Mixture conduit 37 is provided with a plurality of coaxially disposed venturis 42, 43, and 44 respectively, suspended from a wall of the mixture conduit.
  • the lower or neck portion of the carburetor is provided with a movable throttle 46 mounted to a throttle shaft 47, one end of which protrudes from the carburetor to operably engage a suitable actuating mechanism.
  • the carburetor includes a fuel nozzle 48 having an inlet disposed in the main nozzle passage 49 and having a constricted end opening into the upper venturi 42.
  • An air bleed passage 51 includes a constricted portion 52 for delivering a limited air stream to nozzle 48.
  • the carburetor main fuel system comprises reservoir 15 which normally maintains a predetermined level of fuel.
  • An intermediate passage communicates the fuel reservoir 15 with a fuel sump 53.
  • Sump 53 is formed at the lower end of an upright cavity 54 in the carburetor body.
  • Sump 53 and cavity 54 are disposed generally concentrically, the sump portion having a smaller diameter than the cavity thereby defining a peripheral shoulder 56.
  • a gasket or other sealing member 57 is compressibly urged against shoulder 56 by an orifice plate 58 which is in turn urged against the gasket by a tubular retainer 59 slidably, although closely received within the cavity 54 and maintained in place by cover 17 bearing against the upper end of said retainer.
  • Orifice plate 58 is provided with a plurality of openings including orifice 61 which may be shown in FIGURE 3, be provided with tapered inlet and outlet ports.
  • a second orifice or opening 62 is spaced from orifice 61 and defines a supplementary or by-pass passage for fuel normally passing through the orifice 61.
  • Fuel passing from the sump 53 will normally traverse the orifice plate and enter the main nozzle passage 49 prior to discharge through nozzle 48.
  • orifice 61 is provided with a suspended metering rod 63.
  • the metering rod is formed at the lower end, with a plurality of decreasingly sized diameters which sequentially are disposed within the orifice 61 to define variable openings for passage of fuel from sump 53 into main nozzle passage 49.
  • Metering rod 63 although not completely shown, extends through the carburetor cover 17 and may be engaged by a linkage connected to throttle shaft 47 or by other means to regulate the position of the metering rod within the orifice 61 thus providing optimum fuel fiow therethrough in accordance with the engine operating conditions.
  • the supplementary, or calibrating orifice 62 is provided with, or cooperative with a valve member 66 to be hereinafter described in greater detail, whereby a variable opening is formed in the by-pass to supplement main fuel flow.
  • Tubular member 59 is provided with a second longitudinal chamber 67 formed therein and terminating at the cover 17.
  • this elongated chamber 67 may extend through the cover plate 17 for providing access to the valve element 66 for adjusting the latter either by a screw driver or other similar tool.
  • a plug 68 wedged in chamber 67 provides a closure to the latter for avoiding leakage of air into the carburetor or discharge of fuel therefrom.
  • the carburetor idle fuel system comprises an elongated chamber 71 containing an idle jet 72. Jet 72, is communicated by an idle passage '73 formed in cover 17, with an elongated connecting passage 74 which opens into an idle chamber 76, the latter is communicated with mixing conduit 37 at a point above the throttle plate 46 when the latter is in closed position. Passage 77 communicated with idle chamber 76 opens into an adjustable idle jet port 78 which is communicated with mixture conduit 37 at a point downstream of throttle 46. Idle adjusting screw 79 is threadably carried in the idle port and is normally adjusted to give optimum fuel feed to the engine when the latter is at idle speed and throttle 46 is in closed position.
  • valve element 66 a threaded set screw or the like carried in the orifice 62.
  • the valve element 66 as shown is provided with an elongated slot 81 extending longitudinally thereof, the slot having a cross section as to define a uniformly decreasing cross sectional area as the slot progresses toward one end of the valve element.
  • the valve element is provided with a generally triangular shaped slot having the largest or widest portion thereof at the lower end of the valve element and decreasing gradually toward the upper end to a virtually negligible opening.
  • FIGURE 4 illustrates another alternative embodiment of the invention wherein valve element 86 is shown cooperatively disposed with respect to a supplementary orifice 87 formed within orifice plate 88. In this instance, however, the valve element 86 is threadably retained within the carburetor body portion 89 and particularly within the access passage 91.
  • access passage 91 is provided with a constricted threaded portion which terminates at shoulder 92.
  • Orifice 87 is disposed in vertical alignment with access passage 91 that the valve element 86 may correctly seat within the conical seat 93 formed at the exit at orifice 87. The valve element 86 may thereby rotate as to advance or withdraw the valve element from position with the seat 93 thereby defining the annular opening formed to regulate the secondary flow of fuel which by-passes main orifice 94.
  • valve member 97 may be readily adjusted from a point external to the carburetor in such manner as to position the forward point 101 within the conically shaped seat 102 in the lower face of the orifice plate 103.
  • Valve member 97 is of course provided with a suitable circumferential seal 104 to suitably define a fluid tight barrier particularly since the adjusting means is at the lower side of the carburetor and will be immersed in fuel at all times.
  • the metering rod 63 it is preferable that the metering rod 63 to permitted to descend sufficiently into the main orifice to seat and form tight annular seal.
  • the by-pass passage formed by valve member 66 will constitute the sole source of fuel supplied from the carburetor Sump 53 into the main nozzle passage 49.
  • the fuel bypass adjustment might be utilized to obtain a desired carburetor flow test curve at any of several settings of the metering rod.
  • the bypass adjustment might be calibrated at engine idle, or at any other intermediate step of the metering rod.
  • the selecting of the exact point of by-pass adjustment is of course preferably at that section of the carburetor flow curve considered to be most critical.
  • the use of the by-pass valve arrangement thereby not only simplifies the carburetor structure but also permits a suitable adjustment to the carburetor to insure uniformity of a particular type of unit in accordance with the size of internal combustion engine to which it is associated.
  • the problem of replacement of an entire orifice plate 58 is readily accomplished by merely removing the elongated retainer 59 so as to permit removal of the orifice plate and the insertion of a different size plate should the engine require the latter.
  • the adequate means may be provided within the Well or at the peripheral shoulder 56 to properly align the orifice plate with the respective elongated chambers 54 and 67 positioned thereabove.
  • the flat orifice plate may be made irregularly shaped such as in the form of a triangle, hexagon or other geometric shape which would permit insertion within the carburetor wall only in the proper position.
  • a charge forming device for an internal combustion engine including a body:
  • a fuel system communicating said reservoir with said mixing conduit and including:
  • adjustable bypass means including a secondary fuel port communicating said nozzle inlet with said fuel reservoir

Description

Nov. 5, 1968 D. A. RElSE 3,409,277
METERING JET ADJUSTABLE FUEL BY-PASS Filed June 24, 1966 2 Sheets-Sheet 1 49 27 1% fifl ,72 /6 wk fi ,0 f A 66 I v -57 M F c. l.
-67 j? 2/ 4? v 66 j i /5 56 57 62 2 5a 55 .2. I. 53 F IISVENTOR 56 DONALD A. REISE 55 F l 0.3. fl
ATTORNEY Nov. 5, 1968 D. A. REISE 3,409,277
METERING JET ADJUSTABLE FUEL BY-PASS Filed June 24, 1966 2 Sheets-Sheet 2 FIGS.
X W /03 g /0/ INVENTOR FIG. 5. DONALD A. REISE ATTORNEY ABSTRACT OF THE DISCLOSURE "A carburetor having a main fuel metering jet and a main fuel metering rod is further provided with an auxili'ary adjustable main fuel supply port which port is rendered non-accessible after final adjustment of the operative size of said port to prevent unauthorized change of the size after final calibration.
This invention relates to a carburetor.
It relates in particular to a charge forming device embodying within the fuel system, a metering rod for regulating the flow of fuel between the source thereof and the carburetor mixing conduit. Following normal carburetor construction in which a metering rod it utilized, the'rod is disposed within an orifice formed in a passage communicating the carburetor fuel bowl with the fuel nozzle. The metering rod is adjustable in response to the carburetor actuating mechanism for the purpose of providing a more accurate and metered flow of fuel to the mixture conduit. According to the' present invention, means is provided in the fuel passage communicating the fuel bowl with the fuel nozzle, for passing a second stream" of" fuel to form a by-pass around the metered stream, particularly under engine idle conditions.
The function of this by-pass opening is to provide a more accurate flow of fuel under particular carburetor operating conditions and to supplement the flow passing through the main jet as defined by the metering rod. The by-pass opening is preferably provided with a valve element for varying the fuel flow through said by-pass to provide a fine adjustment and consequently a more accurate control over the flow of fuel passing through the nozzle.
The efficiency and desirability of metering rods in charge forming carburetors, has long been known and proven to be most desirable. The metering rod arrangement regardless of'how it is controlled whether from the carburetor orifice to define a variable opening for passage of fueltherethrough.
' To meet the ever increasing and acute demands of industry, it has been necessary to provide means for more accurately regulating the passage of fuel that enters the carburetor mixing conduit. More particularly there is an ever urgent need for regulating the combustible air fuel mixture for the purpose of minimizing the amount of unburned hydrocarbons which are passed to the atmosphere in the course of the operation of the engine. This creation of excessive hydrocarbon, commonly referred to as a smog condition, results in a large part from .an overly rich air fuel mixture being directed from the carburetor tothe engine. In view of the diverse accessories which the ordinary automobile engine is required to operate, suchxas the air conditioning system, power steering, etc.,
United States Patent" it has become increasingly difficult to assure a concise and proper fuel flow to the carburetor mixtrue conduit under all circumstances.
Although the use of a metering rod does go a considerable distance in providing fuel control, the metering rod is not the final solution to the problem. For one thing, and as shown in FIGURE 1, in normal operation, the metering rod is merely suspended within an orifice such that one portion of the metering rod end cooperates with the orifice to definean annular opening. Since as a matter economics and convenience the metering rod is normally unguided except for the registration in the orifice, the annular opening provided thereby cannot be accurately predetermined.
Toward overcoming the above noted problem, of an in ability to provide a sufficiently accurate fuel flow, the present metering rod orifice bypassforms a supplementary flow of fuelwhich is substantially constant under all conditions of carburetor operation. As an example, even when the metering rod is positioned such as to cut oif the flow of fuel from the fuel bowl to the nozzle, the bypass is so adjusted toafford the necessary amount of fuel to sustain a desirable engine idle speed.
vA further circumstance prompting the development of the fuel bypass arrangement, arose from the desire for a multi use carburetor arrangement having a basically standard construction. In order to adapt to a number of different size engines however, it is necessary that the fuel flow characteristics of the carburetor be regulated in accordance with the engine requirements. The present arrangement permits ready interchange of parts particularly of fuel metering plate containing the respective primary and bypass fuel passages. Further, the presently disclosed arrangement provides a simple means for adjusting the fuel bypass either prior to assembly of the carburetor, or subsequent to assembly thereof. It is found that for the most accurate calibration of any carburetor the latter is preferable adjusted to its final setting while under simulated conditions such as on a test stand in which fuel flow is regulated in accordance with the air flow passing therethrough. The resulting mixture is thereby immediately indicated thereby dictating possible further adjustment of the carburetor jets.
FIGURE 1 in the drawing is a vertical, partial cross section of a carburetor embodying the present invention, with portions broken away.
FIGURE 2. is a segmentary view in cross section of a portion of the device shown in FIGURE 1.
FIGURE 3 is a view similar to FIGURE 2.
FIGURES 4 and 5 are views similar to FIGURE 2 illustrating alternative forms of the invention.
FIGURE 6 is a view of an end of one form of metering screw.
Referring to FIGURE 1 the carburetor, together with the presently disclosed fuel bypass means therein, is shown generally and as related to a single barrel unit. It should .be borne in mind however, that the novel concept to be herein described more fully, is not so limited to a single barrel carburetor but may be utilized as well in multibarrel units. The carburetor shown is formed of a plurality of several members including a central body 10 having a lower flanged opening to which is attached a circular neck portion 11 by a plurality of bolts 12. The neck portion includes a peripheral flange 13 having bolt holes therein for engaging the intake manifold of an internal combustion engine. A- gasket 14 is compressed between the respective neck and body portions to form an air tight seal and avoid leakage of air into the air-fuel mixture formed within the carburetor.
The upper side of body 10 is provided with a sealing gasket 16. A cover 17 affixed ot the carburetor body by a plurality of bolts 19 forms the device into a unitary member.
The body may be formed of any suitable material adapted to the application, and includes a fuel bowl 21 extending substantially the vertical length thereof, defining a fuel holding reservoir 15. Cover 17 is provided with a valve assembly in which a valve 22 is threadably retained, having an inlet 33 opening into fuel chamber 23 and having a strainer 24 disposed therein for removing solids from the fuel stream which would otherwise tend to damage or lodge within the carburetor constricted passages and ports. Valve 22 includes a movable needle element 26 having a conical forward end which engages a peripheral seat 27 thereby defining an annular fiow passage when the needle is displaced from the seat.
Under normal engine operation, fuel is drawn from the tank 28 and conducted through line 29 by a mechanically or electrically actuated pump 31. Pressurized fuel is then discharged into line 32 and thence to the fuel inlet 33 communicated through a strainer 24 with fuel chamber 23. Fuel reservoir contains fioat 35 which is pivoted on arm 34 at a pivot point 36 such as a shaft or similar member, carried on a downwardly depending portion of cover 17. Lowering of the float will permit needle element 26 to be displaced from its corresponding seat by the pressure of the fuel in fuel chamber 23. The fiow of fuel into reservoir 15 will continue until such time as the fuel level will cause the float 35 to rise sufiiciently thereby positioning needle element 26 into its seat and thus precluding further fuel flow.
Internally, the carburetor consists of a mixture conduit 37 having an air inlet 38 at the upper end thereof which may be connected to an air filter or the like. The air inlet or air horn is further provided with a choke valve 39 carried on a choke valve shaft 41 which is pivotally disposed in the air horn.
Mixture conduit 37 is provided with a plurality of coaxially disposed venturis 42, 43, and 44 respectively, suspended from a wall of the mixture conduit.
The lower or neck portion of the carburetor is provided with a movable throttle 46 mounted to a throttle shaft 47, one end of which protrudes from the carburetor to operably engage a suitable actuating mechanism. The carburetor includes a fuel nozzle 48 having an inlet disposed in the main nozzle passage 49 and having a constricted end opening into the upper venturi 42. An air bleed passage 51 includes a constricted portion 52 for delivering a limited air stream to nozzle 48.
Referring to FIGURES 1 and 2, the carburetor main fuel system comprises reservoir 15 which normally maintains a predetermined level of fuel. An intermediate passage communicates the fuel reservoir 15 with a fuel sump 53.
Sump 53 is formed at the lower end of an upright cavity 54 in the carburetor body. Sump 53 and cavity 54 are disposed generally concentrically, the sump portion having a smaller diameter than the cavity thereby defining a peripheral shoulder 56. A gasket or other sealing member 57 is compressibly urged against shoulder 56 by an orifice plate 58 which is in turn urged against the gasket by a tubular retainer 59 slidably, although closely received within the cavity 54 and maintained in place by cover 17 bearing against the upper end of said retainer.
Orifice plate 58 is provided with a plurality of openings including orifice 61 which may be shown in FIGURE 3, be provided with tapered inlet and outlet ports. A second orifice or opening 62 is spaced from orifice 61 and defines a supplementary or by-pass passage for fuel normally passing through the orifice 61.
Fuel passing from the sump 53 will normally traverse the orifice plate and enter the main nozzle passage 49 prior to discharge through nozzle 48. As is known in the prior art, orifice 61 is provided with a suspended metering rod 63. The metering rod is formed at the lower end, with a plurality of decreasingly sized diameters which sequentially are disposed within the orifice 61 to define variable openings for passage of fuel from sump 53 into main nozzle passage 49.
Metering rod 63, although not completely shown, extends through the carburetor cover 17 and may be engaged by a linkage connected to throttle shaft 47 or by other means to regulate the position of the metering rod within the orifice 61 thus providing optimum fuel fiow therethrough in accordance with the engine operating conditions.
The supplementary, or calibrating orifice 62 is provided with, or cooperative with a valve member 66 to be hereinafter described in greater detail, whereby a variable opening is formed in the by-pass to supplement main fuel flow.
Tubular member 59 is provided with a second longitudinal chamber 67 formed therein and terminating at the cover 17. Alternatively, this elongated chamber 67 may extend through the cover plate 17 for providing access to the valve element 66 for adjusting the latter either by a screw driver or other similar tool. A plug 68 wedged in chamber 67 provides a closure to the latter for avoiding leakage of air into the carburetor or discharge of fuel therefrom.
The carburetor idle fuel system comprises an elongated chamber 71 containing an idle jet 72. Jet 72, is communicated by an idle passage '73 formed in cover 17, with an elongated connecting passage 74 which opens into an idle chamber 76, the latter is communicated with mixing conduit 37 at a point above the throttle plate 46 when the latter is in closed position. Passage 77 communicated with idle chamber 76 opens into an adjustable idle jet port 78 which is communicated with mixture conduit 37 at a point downstream of throttle 46. Idle adjusting screw 79 is threadably carried in the idle port and is normally adjusted to give optimum fuel feed to the engine when the latter is at idle speed and throttle 46 is in closed position.
Referring to FIGURE 3, the shown embodiment of the invention utilizes as valve element 66 a threaded set screw or the like carried in the orifice 62. The valve element 66 as shown is provided with an elongated slot 81 extending longitudinally thereof, the slot having a cross section as to define a uniformly decreasing cross sectional area as the slot progresses toward one end of the valve element. Referring particularly to FIGURE 6, the valve element is provided with a generally triangular shaped slot having the largest or widest portion thereof at the lower end of the valve element and decreasing gradually toward the upper end to a virtually negligible opening. Thus by advancing or rotating the threaded valve element 66 within the threaded orifice 62, it is possible to vary proportionately the cross sectional opening of the fuel passage defined by the triangular slot 81. For example, and referring to FIGURE 3, as the valve element 66 is rotated to withdraw the same from the orifice plate. The fuel passage formed between slot 81 and the walls of orifice 62 will increase in size and allow a greater fuel flow through the orifice. Elongated chamber 67 is thus disposed preferably in substantial alignment With valve element 66 in order that the adjusting tool may be inserted within the elongated chamber 67 with the plug 68 removed. After needed adjustment, plug 68 is of course, inserted within the chamber 67 and sufficiently expanded or upset to form the necessary fluid tight seal.
FIGURE 4 illustrates another alternative embodiment of the invention wherein valve element 86 is shown cooperatively disposed with respect to a supplementary orifice 87 formed within orifice plate 88. In this instance, however, the valve element 86 is threadably retained within the carburetor body portion 89 and particularly within the access passage 91.
As shown in FIGURE 4, the lower end of access passage 91 is provided with a constricted threaded portion which terminates at shoulder 92. Orifice 87 is disposed in vertical alignment with access passage 91 that the valve element 86 may correctly seat within the conical seat 93 formed at the exit at orifice 87. The valve element 86 may thereby rotate as to advance or withdraw the valve element from position with the seat 93 thereby defining the annular opening formed to regulate the secondary flow of fuel which by-passes main orifice 94.
In a further embodiment of the invention, as shown in FIGURE 5, the basic principal of bypassing the main orifice by means of a supplementary adjustable fuel flow regulator it is shown, wherein the adjustable valve element 97 is threadably retained in the lower portion of the fuel sump 98. In this embodiment of the invention it is, of course, unnecessary to provide an access passage through the carburetor body in alignment with the secondary or by-pass passage 99. Thus, the valve member 97 may be readily adjusted from a point external to the carburetor in such manner as to position the forward point 101 within the conically shaped seat 102 in the lower face of the orifice plate 103. Valve member 97 is of course provided with a suitable circumferential seal 104 to suitably define a fluid tight barrier particularly since the adjusting means is at the lower side of the carburetor and will be immersed in fuel at all times.
It is clear from the foregoing description of the invention as related to the carburetor herein described, that it is possible to obtain a greater degree of accuracy in carburetor calibration in the instance of a use of metering rods incorporated into the carburetor structure. Among the advantages to be derived from the adjustable fuel bypass about the main metering rod orifice, is the feature of more accurate carburetor calibration particularly to minimize the effects of unburned hydrocarbons which result from accessively rich fuel particularly at engine idle. It is clear that in this latter mentioned condition it is unnecessary for the fuel metering rod 63 to be fabricated with a great degree of accuracy so as to form a precise annular passage with the corresponding Orifice in the Orifice plate 58. To the contrary, it is preferable that the metering rod 63 to permitted to descend sufficiently into the main orifice to seat and form tight annular seal. Thus the by-pass passage formed by valve member 66 will constitute the sole source of fuel supplied from the carburetor Sump 53 into the main nozzle passage 49. Thus the fuel bypass adjustment might be utilized to obtain a desired carburetor flow test curve at any of several settings of the metering rod. For example, the bypass adjustment might be calibrated at engine idle, or at any other intermediate step of the metering rod. The selecting of the exact point of by-pass adjustment is of course preferably at that section of the carburetor flow curve considered to be most critical.
The use of the by-pass valve arrangement thereby not only simplifies the carburetor structure but also permits a suitable adjustment to the carburetor to insure uniformity of a particular type of unit in accordance with the size of internal combustion engine to which it is associated.
Further, it is understood that the problem of replacement of an entire orifice plate 58 is readily accomplished by merely removing the elongated retainer 59 so as to permit removal of the orifice plate and the insertion of a different size plate should the engine require the latter. It should be mentioned that both for the initial insertion of the orifice plate 58 and for subsequent replacement thereof, the adequate means may be provided Within the Well or at the peripheral shoulder 56 to properly align the orifice plate with the respective elongated chambers 54 and 67 positioned thereabove. To this end the flat orifice plate may be made irregularly shaped such as in the form of a triangle, hexagon or other geometric shape which would permit insertion within the carburetor wall only in the proper position.
It is clear from the foregoing description that the carburetor utilizing the herein described bypass fuel passage possesses many advantages heretofore lacking in similar carburetor construction. It is also understood that certain modifications and changes may be made in the physical structure of the described device Without departing from the spirit and substance of the invention as defined in the claims appended hereto.
I claim:.
1. A charge forming device for an internal combustion engine including a body:
(1) A fuel reservoir formed in the body.
(2) a mixture conduit in said body having an air inlet,
(3) a throttle movably positioned in said mixture conduit for regulating the passage of air fuel mixture therethrough,
(4) a fuel system communicating said reservoir with said mixing conduit and including:
(A) a fuel nozzle having a discharge end opening into said mixture conduit and having an inlet,
(B) means including a removable insert forming a fuel passage communicating said fuel nozzle inlet with said reservoir,
(C) an orifice disposed in said removable insert and an elongated removable retainer holding said insert in position,
(D) a suspended metering rod having a metering end disposed in said orifice, said metering rod being reciprocably movable to define a variable annular opening in said orifice,
(E) adjustable bypass means including a secondary fuel port communicating said nozzle inlet with said fuel reservoir,
(F) alignment means for aligning said orifice with said metering rod,
(G) valve means for adjusting said adjustable bypass means,
(H) an access passage in alignment with said valve means, and
(I) obstructing means for said access passage to prevent further access to said valve means after adjustment thereof.
References Cited UNITED STATES PATENTS 1,579,600 4/ I926 Durante 261-51 1,586,601 6/ 1926 Booty 261-50 2,084,607 6/ 1937 Bicknell 261--5l X 2,186,480 1/1940 Ensign 261-51 X 2,341,694 2/1944 Coffey 261-51 X 2,914,307 11/ 1959 Eickmann.
3,086,757 4/1963 Smith 26151 X 3,330,543 7/ 1967 Mennesson.
3,343,820 9/1967 Elliott 261-51 X HARRY B. THORNTON, Primary Examiner.
T. R. MILES, Assistant Examiner.
US560242A 1966-06-24 1966-06-24 Metering jet adjustable fuel by-pass Expired - Lifetime US3409277A (en)

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Cited By (22)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3753555A (en) * 1970-06-08 1973-08-21 Zenith Carburetter Co Ltd Carburetors
US3779530A (en) * 1970-03-31 1973-12-18 Zenith Carburetter Co Ltd Carburetors
US3807707A (en) * 1973-01-02 1974-04-30 H Johnson Exterior adjustment metering jet insert plate for carburetors and carburetor modifying method
US3859397A (en) * 1973-06-18 1975-01-07 Gen Motors Corp Carburetor altitude compensation assembly
US4003968A (en) * 1973-06-01 1977-01-18 Borg-Warner Corporation Charge forming method and apparatus
US4052490A (en) * 1976-05-10 1977-10-04 Ford Motor Company Carburetor with manually adjustable fuel supply
US4084562A (en) * 1972-08-08 1978-04-18 Robert Bosch Gmbh Fuel metering device
US4100663A (en) * 1977-04-29 1978-07-18 Crum James R Carburetor, kit and tool for use therein
US4175103A (en) * 1978-04-17 1979-11-20 General Motors Corporation Carburetor
FR2424417A1 (en) * 1978-01-16 1979-11-23 Gen Motors Corp PERFECTED CARBURETOR AND PROCESS FOR CALIBRATING THIS CARBURETOR
US4178332A (en) * 1978-01-11 1979-12-11 General Motors Corporation Carburetor and method of calibration
US4234523A (en) * 1978-01-11 1980-11-18 Hitachi, Ltd. Adjustment prevention mechanism for carburetor
US4251471A (en) * 1978-09-27 1981-02-17 Pierburg Gmbh & Co. Kg Carburetor for internal combustion engines with an acceleration pump
US4271095A (en) * 1978-08-21 1981-06-02 Toyo Kogyo Co., Ltd. Idle adjusting device for a carburetor
US4277423A (en) * 1980-02-13 1981-07-07 Noguez Robert W Fuel calibration device for carburetor
US4373502A (en) * 1980-10-16 1983-02-15 Miletech, Inc. Fuel control system
US4374785A (en) * 1981-01-21 1983-02-22 Miletech, Inc. Metering device for fuel control system
US4461731A (en) * 1981-11-24 1984-07-24 Pollution Controls Industries, Inc. Carburetor
US4663090A (en) * 1985-09-11 1987-05-05 Pollution Controls Industries, Inc. Fuel control system for a carburetor
US5034163A (en) * 1986-07-16 1991-07-23 Outboard Marine Corporation Modular side-draft carburetor
US5055238A (en) * 1989-06-30 1991-10-08 Shinagawa Diecast Industrial Corp. Diaphragm carburetor
US5441673A (en) * 1992-01-30 1995-08-15 Andreas Stihl Carburetor for an internal combustion engine

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US1579600A (en) * 1924-11-26 1926-04-06 Durante Frank Carburetor
US1586601A (en) * 1920-12-20 1926-06-01 Philip C Booty Carburetor
US2084607A (en) * 1933-03-25 1937-06-22 Carter Carburetor Corp Automatic choke for carburetors
US2186480A (en) * 1938-02-21 1940-01-09 Ensign Carburetor Co Ltd Carburetor
US2341694A (en) * 1940-10-12 1944-02-15 Carter Carburetor Corp Carburetor
US2914307A (en) * 1955-09-29 1959-11-24 Acf Ind Inc Carburetor construction
US3086757A (en) * 1960-01-05 1963-04-23 Acf Ind Inc Carburetor
US3330543A (en) * 1964-10-12 1967-07-11 Sibe Liquid fuel feed devices for internal combustion engines
US3343820A (en) * 1965-10-20 1967-09-26 Holley Carburetor Co Carburetor

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1586601A (en) * 1920-12-20 1926-06-01 Philip C Booty Carburetor
US1579600A (en) * 1924-11-26 1926-04-06 Durante Frank Carburetor
US2084607A (en) * 1933-03-25 1937-06-22 Carter Carburetor Corp Automatic choke for carburetors
US2186480A (en) * 1938-02-21 1940-01-09 Ensign Carburetor Co Ltd Carburetor
US2341694A (en) * 1940-10-12 1944-02-15 Carter Carburetor Corp Carburetor
US2914307A (en) * 1955-09-29 1959-11-24 Acf Ind Inc Carburetor construction
US3086757A (en) * 1960-01-05 1963-04-23 Acf Ind Inc Carburetor
US3330543A (en) * 1964-10-12 1967-07-11 Sibe Liquid fuel feed devices for internal combustion engines
US3343820A (en) * 1965-10-20 1967-09-26 Holley Carburetor Co Carburetor

Cited By (22)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3779530A (en) * 1970-03-31 1973-12-18 Zenith Carburetter Co Ltd Carburetors
US3753555A (en) * 1970-06-08 1973-08-21 Zenith Carburetter Co Ltd Carburetors
US4084562A (en) * 1972-08-08 1978-04-18 Robert Bosch Gmbh Fuel metering device
US3807707A (en) * 1973-01-02 1974-04-30 H Johnson Exterior adjustment metering jet insert plate for carburetors and carburetor modifying method
US4003968A (en) * 1973-06-01 1977-01-18 Borg-Warner Corporation Charge forming method and apparatus
US3859397A (en) * 1973-06-18 1975-01-07 Gen Motors Corp Carburetor altitude compensation assembly
US4052490A (en) * 1976-05-10 1977-10-04 Ford Motor Company Carburetor with manually adjustable fuel supply
US4100663A (en) * 1977-04-29 1978-07-18 Crum James R Carburetor, kit and tool for use therein
US4178332A (en) * 1978-01-11 1979-12-11 General Motors Corporation Carburetor and method of calibration
US4234523A (en) * 1978-01-11 1980-11-18 Hitachi, Ltd. Adjustment prevention mechanism for carburetor
FR2424417A1 (en) * 1978-01-16 1979-11-23 Gen Motors Corp PERFECTED CARBURETOR AND PROCESS FOR CALIBRATING THIS CARBURETOR
US4175103A (en) * 1978-04-17 1979-11-20 General Motors Corporation Carburetor
US4271095A (en) * 1978-08-21 1981-06-02 Toyo Kogyo Co., Ltd. Idle adjusting device for a carburetor
US4251471A (en) * 1978-09-27 1981-02-17 Pierburg Gmbh & Co. Kg Carburetor for internal combustion engines with an acceleration pump
US4277423A (en) * 1980-02-13 1981-07-07 Noguez Robert W Fuel calibration device for carburetor
US4373502A (en) * 1980-10-16 1983-02-15 Miletech, Inc. Fuel control system
US4374785A (en) * 1981-01-21 1983-02-22 Miletech, Inc. Metering device for fuel control system
US4461731A (en) * 1981-11-24 1984-07-24 Pollution Controls Industries, Inc. Carburetor
US4663090A (en) * 1985-09-11 1987-05-05 Pollution Controls Industries, Inc. Fuel control system for a carburetor
US5034163A (en) * 1986-07-16 1991-07-23 Outboard Marine Corporation Modular side-draft carburetor
US5055238A (en) * 1989-06-30 1991-10-08 Shinagawa Diecast Industrial Corp. Diaphragm carburetor
US5441673A (en) * 1992-01-30 1995-08-15 Andreas Stihl Carburetor for an internal combustion engine

Also Published As

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