Fuel regulating mechanism and method for a rotary throttle valve type carburetor
First Claim
1. A method of regulating fuel feed from a carburetor to an associated engine in which the carburetor has a rotary throttle valve with a throttle hole disposed in an air intake passage of the carburetor body, and wherein the quantity of air flow in the air intake passage is controlled by at least rotational movement of the throttle valve to thereby vary the opening area of the throttle hole exposed to the carburetor intake passage for controlling air flow therethrough, the throttle valve being cylindrical and rotatable about an axis transverse to the axes of the throttle hole and carburetor air intake passage, the throttle valve also being axially movable along its rotational axis during such rotational movement and a quantity of fuel is released from a fuel jet port of a fuel supply pipe secured to the carburetor body as controlled by the relative position to such jet port of a fuel regulating needle attached to the throttle valve for axial movement therewith, wherein a closing member is non-removably fitted in said carburetor to permanently prevent exterior access to an adjustment portion of the fuel regulating needle located at one end thereof, and the end of the needle opposite said one end is inserted into said fuel supply pipe so that the adjustment of needle regulation of said fuel jet port cannot be made from outside of said carburetor after an idle speed fuel quantity has been set prior to fitment of said closing member, the carburetor further having a bypass air passage for variably communicating the throttle hole of the throttle valve at an upstream portion thereof with an air source comprising ambient atmosphere or the intake air for the carburetor and in bypass relation to the opening area of the throttle hole exposed to a bypass air passage outlet at engine idle setting of the throttle valve, and wherein a bypass air quantity regulating valve is provided in said bypass air passage to variably adjust the quantity of air flowing in the bypass air passage to the throttle hole, and wherein said bypass air passage outlet is constructed and arranged relative to said throttle valve so as to be closed by movement of said throttle valve out of idle setting toward high speed and/or maximum power setting and thereby de-register the throttle hole with said bypass air passage outlet, said method comprising the steps of:
- (a) at initial carburetor-to-engine set-up and calibration, opening the bypass air regulating valve while the engine is running at idle speed to a given open setting of the air flow regulating valve, (b) adjusting the fuel-regulating needle to provide the maximum fuel to air (F/A) mixture ratio permitted by applicable engine exhaust air quality regulations, (c) then permanently setting said fuel needle adjustment by non-removably fitting the closing member to prevent exterior access to an adjustment portion of the fuel needle, (d) then thereafter during subsequent end user operation of the engine closing the bypass air regulating valve only when preparing to crank the engine for starting to thereby provide an enriched fuel-to-air mixture for starting of the engine, and (e) thereafter, upon engine starting and running under its own power, opening the bypass air regulating valve.
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0 Petitions
Accused Products
Abstract
Method of and mechanism for regulating fuel feed from a rotary valve type carburetor to an associated engine. A carburetor bypass air passage variably communicates the throttle valve hole with a bypass air source at engine idle setting of the throttle valve. The bypass air passage outlet is closed by movement of the throttle valve out of idle setting toward high speed. At an initial carburetor-to-engine set-up and calibration, a bypass regulating valve is maintained open while the engine is running at idle speed. Then the fuel-regulating needle is adjusted to maximum fuel to air (F/A) mixture ratio permitted by applicable engine exhaust quality regulations, and then is permanently set and sealed. During subsequent end user operation of the engine, the bypass valve is closed only when preparing to crank the engine for starting to thereby provide an enriched fuel-to-air mixture for starting of the engine. When the engine is running under its own power the bypass valve is maintained open. The bypass branch passage outlet is constructed and arranged relative to travel of the upstream control edge of the throttle valve hole so as to modulate by design the fuel flow versus engine speed during part throttle acceleration due to corresponding travel of the control edge past this bypass outlet.
59 Citations
43 Claims
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1. A method of regulating fuel feed from a carburetor to an associated engine in which the carburetor has a rotary throttle valve with a throttle hole disposed in an air intake passage of the carburetor body, and wherein the quantity of air flow in the air intake passage is controlled by at least rotational movement of the throttle valve to thereby vary the opening area of the throttle hole exposed to the carburetor intake passage for controlling air flow therethrough, the throttle valve being cylindrical and rotatable about an axis transverse to the axes of the throttle hole and carburetor air intake passage, the throttle valve also being axially movable along its rotational axis during such rotational movement and a quantity of fuel is released from a fuel jet port of a fuel supply pipe secured to the carburetor body as controlled by the relative position to such jet port of a fuel regulating needle attached to the throttle valve for axial movement therewith, wherein a closing member is non-removably fitted in said carburetor to permanently prevent exterior access to an adjustment portion of the fuel regulating needle located at one end thereof, and the end of the needle opposite said one end is inserted into said fuel supply pipe so that the adjustment of needle regulation of said fuel jet port cannot be made from outside of said carburetor after an idle speed fuel quantity has been set prior to fitment of said closing member, the carburetor further having a bypass air passage for variably communicating the throttle hole of the throttle valve at an upstream portion thereof with an air source comprising ambient atmosphere or the intake air for the carburetor and in bypass relation to the opening area of the throttle hole exposed to a bypass air passage outlet at engine idle setting of the throttle valve, and wherein a bypass air quantity regulating valve is provided in said bypass air passage to variably adjust the quantity of air flowing in the bypass air passage to the throttle hole, and wherein said bypass air passage outlet is constructed and arranged relative to said throttle valve so as to be closed by movement of said throttle valve out of idle setting toward high speed and/or maximum power setting and thereby de-register the throttle hole with said bypass air passage outlet, said method comprising the steps of:
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(a) at initial carburetor-to-engine set-up and calibration, opening the bypass air regulating valve while the engine is running at idle speed to a given open setting of the air flow regulating valve, (b) adjusting the fuel-regulating needle to provide the maximum fuel to air (F/A) mixture ratio permitted by applicable engine exhaust air quality regulations, (c) then permanently setting said fuel needle adjustment by non-removably fitting the closing member to prevent exterior access to an adjustment portion of the fuel needle, (d) then thereafter during subsequent end user operation of the engine closing the bypass air regulating valve only when preparing to crank the engine for starting to thereby provide an enriched fuel-to-air mixture for starting of the engine, and (e) thereafter, upon engine starting and running under its own power, opening the bypass air regulating valve. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
(f) adjusting the bypass air regulating valve to increase the air flow regulating opening of the same from the given setting to thereby re-adjust the initial set-up F/A mixture to a different and leaner value for end user engine operation.
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3. The method of claim 1 comprising the further step of:
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(g) providing said bypass air regulating valve in the form of a solenoid-operated valve, and (h) operably coupling the solenoid valve to the engine control system such that the valve automatically is closed for engine start up and opened when the engine begins to run under its own power.
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4. The method of claim 3 wherein step (g) further comprises providing said valve with an adjustable end-limit open stop for adjusting the open setting of the bypass solenoid-operated air regulating valve to thereby increase the air flow regulating opening end limit of the same from the given setting to thereby re-adjust the initial set-up F/A mixture to a different and leaner value for engine operation.
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5. The method of claim 1 wherein the bypass air passage is provided in the form of a tubular conduit extending through a wall of the carburetor to an external connection with the bypass air regulating valve for communicating the same with the bypass air passage outlet within the carburetor.
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6. The method of claim 5 wherein the bypass air regulating valve is provided in the form of a movable flap valve constructed and arranged for controllably opening and closing an open upstream inlet of the tubular conduit.
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7. The method of claim 5 wherein the bypass air regulating valve is provided in the form of a solenoid valve having an armature mounted in the tubular conduit with an armature plunger reciprocable therein and having a valve member at its distal end operable for opening and closing a valve port in a valve disk mounted in the tubular conduit.
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8. The method of claim 5 wherein the bypass air regulating valve is provided in the form of a normally closed valve that is thermally responsive and operably coupled to the engine to sense engine operational heat of a given temperature to thereby open the bypass valve.
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9. The method of claim 3 wherein said bypass passage is provided in the form of a bypass inlet branch passage and a bypass outlet branch passage communicating with the bypass inlet branch passage and terminating at the bypass passage outlet, and wherein the solenoid-operated valve controls flow between the branch passages.
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10. The method of claim 9 wherein the branch passages are provided in the form of drilled passages extending between the carburetor exterior surface and the carburetor intake passage, the inlet opening of the inlet branch passage being located upstream of the throttle valve and the outlet of the outlet branch passage being located for communication with the throttle valve throttle hole in the idle position thereof.
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11. The method of claim 10 wherein the branch passages are communicated with one another via a Welch plug chamber in the carburetor exterior surface that is closed by a Welch plug.
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12. The method of claim 11 wherein the branch passages are drilled parallel to one another and generally perpendicular to the axis of the carburetor air intake passage.
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13. The method of claim 12 wherein the solenoid valve is provided with a needle valve armature having a needle nose at its distal end cooperative with a valve seat formed in one of said branch passages.
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14. The method of claim 13 wherein the valve seat is at the end of the bypass inlet branch passage entering the Welch plug chamber.
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15. The method of claim 9 wherein the outlet of the bypass outlet branch passage is located relative to travel of the upstream control edge of the throttle valve throttle hole so as to modulate the fuel-to-air mixture ratio curve of fuel flow versus engine speed during travel of the control edge past the outlet of the bypass outlet branch passage.
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16. The method of claim 9 wherein the bypass branch passages are drilled at opposite acute angles to the carburetor air intake passage axis and intersect one another at a vertex valve seat that opens to a valve mounting hole in the exterior surface of the carburetor body, and the body of the solenoid-operated valve is threadably mounted in the mounting hole and has an armature carrying a valve member cooperable with the vertex valve seat for opening and closing the bypass passage.
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17. A method of regulating fuel feed from a carburetor to an associated engine in which the carburetor has a rotary throttle valve with a throttle hole disposed in an air intake passage of the carburetor body, and wherein the quantity of air flow in the air intake passage is controlled by at least rotational movement of the throttle valve to thereby vary the opening area of the throttle hole exposed to the carburetor intake passage for controlling air flow therethrough, the throttle valve being cylindrical and rotatable about an axis transverse to the axes of the throttle hole and carburetor air intake passage, the throttle valve also being axially movable along its rotational axis during such rotational movement and a quantity of fuel is released from a fuel jet port of a fuel supply pipe secured to the carburetor body as controlled by the relative position to such jet port of a fuel regulating needle attached to the throttle valve for axial movement therewith, wherein a closing member is non-removably fitted in said carburetor to permanently prevent exterior access to an adjustment portion of the fuel regulating needle located at one end thereof, and the end of the needle opposite said one end is inserted into said fuel supply pipe so that the adjustment of needle regulation of said fuel jet port cannot be made from outside of said carburetor after an idle speed fuel quantity has been set prior to fitment of said closing member, the carburetor further having a bypass air passage for variably communicating the throttle hole of the throttle valve at an upstream portion thereof with an air source comprising ambient atmosphere or the intake air for the carburetor and in bypass relation to the opening area of the throttle hole exposed to a bypass air passage outlet at engine idle setting of the throttle valve, and wherein said bypass air passage outlet is constructed and arranged relative to said throttle valve so as to be closed by movement of said throttle valve out of idle setting toward high speed and/or maximum power setting and thereby de-register the throttle hole with said bypass air passage outlet, said method comprising the steps of:
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(a) at initial carburetor-to-engine set-up and calibration maintaining the bypass air passage open while the engine is running at idle speed, (b) during the conditions of step (a) adjusting the fuel-regulating needle to provide the maximum fuel to air (F/A) mixture ratio permitted by applicable engine exhaust air quality regulations, (c) then permanently setting said fuel needle adjustment by non-removably fitting the closing member to prevent exterior access to an adjustment portion of the fuel needle, (d) then thereafter during subsequent end user operation of the engine closing the bypass air passage only when preparing to crank the engine for starting to thereby provide an enriched fuel-to-air mixture for starting of the engine, and (e) thereafter, upon engine starting and running under its own power, reopening the bypass air passage. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24)
(f) providing a bypass air regulating valve for the bypass air passage operable to vary the air flow in the same to thereby re-adjust the initial set-up F/A mixture to a different value by and for end user engine operation.
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19. The method of claim 17 comprising the further steps of:
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(g) providing a bypass air regulating solenoid valve constructed and arranged for opening and closing the bypass air passage, and (h) operably coupling the solenoid valve to the bypass passage and to the engine control system such that the valve automatically closes the bypass passage for engine start up and opens the bypass passage when the engine begins to run under its own power.
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20. The method of claim 19 wherein step (g) further comprises providing said bypass air regulating valve with an adjustable end-limit open stop for adjusting the open setting of the valve to thereby vary an air flow regulating opening end limit of the same to thereby adjust the F/A mixture to a prepared value for engine running operation.
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21. The method of claim 17 wherein the bypass air passage is provided in the form of a tubular conduit extending through a wall of the carburetor to an external connection with a source of bypass air for communicating the same with the bypass air passage outlet within the carburetor.
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22. The method of claim 21 wherein a bypass air regulating valve is provided in the form of a movable flap valve constructed and arranged for controllably opening and closing an open inlet of the tubular conduit communicating with the source of bypass air.
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23. The method of claim 21 wherein the bypass air regulating valve is provided in the form of a solenoid valve.
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24. The method of claim 21 wherein the bypass air regulating valve is provided in the form of a normally closed valve that closes the bypass passage and is thermally responsive and operably coupled to the engine to sense engine operational heat of a given temperature to thereby open the bypass valve and thus the bypass passage.
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25. A method of regulating fuel feed from a carburetor to an associated engine in which the carburetor has a rotary throttle valve with a throttle hole disposed in an air intake passage of the carburetor body, and wherein the quantity of air flow in the air intake passage is controlled by at least rotational movement of the throttle valve to thereby vary the opening area of the throttle hole exposed to the carburetor intake passage for controlling air flow therethrough, the throttle valve being cylindrical and rotatable about an axis transverse to the axes of the throttle hole and carburetor air intake passage, the throttle valve also being axially movable along its rotational axis during such rotational movement and a quantity of fuel is released form a fuel jet port of a fuel supply pipe secured to the carburetor body as controlled by the relative position to such jet port of a fuel regulating needle attached to the throttle valve for axial movement therewith, wherein a closing member is non-removably fitted in said carburetor to permanently prevent exterior access to an adjustment portion of the fuel regulating needle located at one end thereof, and the end of the needle opposite said one end is inserted into said fuel supply pipe so that the adjustment of needle regulation of said fuel jet port cannot be made from outside of said carburetor after an idle speed fuel quantity has been set prior to fitment of said closing member, the body of the carburetor further having a bypass air passage for variably communicating the throttle hole of the throttle valve at an upstream portion thereof with an air source comprising ambient atmosphere or the intake air for the carburetor and in bypass relation to the opening area of the throttle hole exposed to a bypass air passage outlet at engine idle setting of the throttle valve, and wherein said bypass air passage outlet is constructed and arranged in the carburetor body relative to said throttle valve so as to be closed by movement of said throttle valve out of idle setting toward high speed and/or maximum power setting and thereby de-register the throttle hole with said bypass air passage outlet, said method comprising the steps of:
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(a) at initial carburetor-to-engine set-up and calibration maintaining the bypass air passage open while the engine is running at idle speed, (b) during the conditions of step (a) adjusting the fuel-regulating needle to provide the maximum fuel to air (F/A) mixture ratio permitted by applicable engine exhaust air quality regulations, and (c) then permanently setting said fuel needle adjustment by non-removably fitting the closing member to prevent exterior access to an adjustment portion of the fuel needle. - View Dependent Claims (26, 27, 28, 29, 30)
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- 31. In a rotary throttle carburetor in which a rotary throttle valve, movable from an idle position to an open throttle position, is positioned in a carburetor body bore oriented transverse to an air hole in said throttle valve having an inlet and an outlet, said carburetor body having a throttle passage registering with said throttle valve air hole and a permanently adjusted fuel regulating needle for varying the jet port of a fuel jet with throttle rotary movement, wherein the improvement comprises a bypass air passage extending through a wall of said carburetor body and having an outlet registering with said throttle passage in the idle position and closed by the rotary throttle when rotated from idle toward wide open throttle (W.O.T.) position, said bypass passage having an upstream end open to a source of bypass air to establish an air bleed at the idle setting of the rotary throttle valve to provide a maximum permissible ratio of fuel to air (F/A) mixture at engine idle speed mode of operation despite the needle being raised to provide a corresponding increased opening in the jet port at the needle idle setting.
- 40. In a fuel regulating mechanism for a carburetor in which a throttle valve having a throttle hole is disposed in an air intake passage of a carburetor body, and wherein the quantity of air flow in the air intake passage is controlled by movement of the throttle valve to thereby vary the opening area of the throttle hole exposed to the intake passage upstream of the throttle valve, and a quantity of fuel controlled by a relative position of a fuel regulating needle attached to the throttle valve to a fuel jet port of a fuel supply pipe secured to the carburetor body due to movement of the throttle valve, and wherein the throttle valve is cylindrical and rotatable about an axis transverse to the axes of the throttle hole and carburetor air intake passage and wherein the throttle valve is movable along the axis transverse to the axes of the throttle hole and carburetor air intake passage for controlling air flow through the carburetor air intake passage, and wherein a bypass air passage is provided in the carburetor body variably communicating the throttle hole of the throttle valve at an upstream portion thereof with the intake passage of the carburetor body in bypass relation to the opening area of the throttle hole exposed to the air intake passage at engine idle setting of the throttle, wherein a closing member is non-removably fitted in said carburetor to permanently prevent exterior access to an adjustment portion of the fuel regulating needle located at one end thereof, and the end of the needle opposite said one end is inserted into said fuel supply pipe so that the adjustment of needle regulation of said fuel jet port cannot be made from outside of said carburetor after an idle speed fuel quantity has been set prior to fitment of said closing member and wherein said bypass air passage has an outlet constructed and arranged relative to said throttle valve so as to be closed by movement of said throttle valve out of idle setting toward high speed and/or maximum power setting to thereby de-register the throttle hole with said bypass air passage outlet, the improvement in combination therewith wherein said bypass air passage is constructed and arranged so as to be maintained open when said adjustment of needle regulation is being set and also during engine running at idle speed.
Specification