Carburetor altitude compensation assembly

Claim 2

A carburetor altitude compensation assembly for use on a carburetor having a main metering system for supplying fuel to a primary carburetor bore through means including a main metering orifice and a power piston operated primary main metering rod wherein the power piston is operative in response to engine manifold vacuum to position the primary main metering rod in a fuel enrichment position as the intake manifold vacuum is reduced in response to increased engine loads comprising: fuel supply means including a supplementary metering orifice disposed in parallel with the main metering orifice, a supplementary metering rod located with respect to said supplementary metering orifice and movable therein to control flow therethrough to bypass a selected amount of fuel around said main metering orifice into the carburetor bore, altitude responsive aneroid means responsive to changes in atmospheric pressure due to changes in altitude, means coupling said aneroid means to said secondary metering rod to decrease bypass fuel flow through said supplementary metering orifice upon a reduction in pressure due to an increase in altitude to compensate for enrichment of air-fuel ratio through a carburetor bore as produced by a decrease in air density due to increases in altitude, lockout means coupled to said aneroid means and movable thereby between first and second control positions, said lockout means being positioned by said aneroid means in its second control position in response to a preset altitude to interlockingly engage the power piston to prevent operation thereof into a fuel enrichment position thereby to prevent enrichment of air fuel mixture because of manifold vacuum reductions due to decreases in atmospheric pressure, and thermally responsive means responsive to temperature of air flow into the carburetor bore for conditioning said lockout means to prevent operation thereof into its second control position for permitting operatioN of the power piston into a fuel enrichment mode of operation when cold air flows through the inlet of the bore until the carburetor inlet air temperature reaches a predetermined level at which said bimetal means is operated to condition said lockout means to control the power piston in response to altitude pressure changes.

Claim 3

A carburetor altitude compensation assembly comprising: fuel supply means including a supplementary metering orifice for supplying fuel to a carburetor bore in parallel relationship to fuel flow through a main metering orifice, a supplementary metering rod movable with respect to said supplementary orifice, an air horn on said carburetor including a control chamber therein, pressure responsive aneroid means located within said control chamber having a first portion thereon fixedly secured to said air horn and a second portion thereon movable with respect to said air horn, a bracket secured to said aneroid means for movement therewith, means coupling said supplementary metering rod to said bracket to position said rod within said supplementary metering orifice in accordance with altitude pressure conditions, said supplementary rod having a sea level location with respect to said metering orifice to supply a greater amount of fuel to the engine, a power piston bore within said air horn, a power piston located in said bore having one end thereof exposed to atmosphere, means for exposing the opposite end of said power piston to intake manifold vacuum, said power piston adapted to operate a main metering rod with respect to a main metering orifice for producing an enrichment of fuel supply to an engine upon increases in engine load, lockout means connected to said air horn including a first portion thereon in engagement with said bracket and a second portion thereon movable with respect to said power piston means between a first position and a second position, said second lockout means portion engageable with said power piston means upon a predetermined expansion of said aneroid means to prevent said power piston from moving into a fuel enrichment position to prevent enrichment of the air-fuel mixture upon a decrease in atmospheric pressure, said supplementary metering rod being located by said bracket with respect to said supplementary metering rod to reduce fuel flow to the engine to maintain the predetermined air-fuel ratio upon decreases in atmosphere density to the engine, and temperature responsive means located within said air horn movable with respect to said lockout means and engageable therewith at carburetor inlet air temperatures below a predetermined temperature to position said lockout means in a first control position to allow said power piston means to assume its power enrichment position irrespective of movement of said bracket in response to changes in atmospheric pressure under low temperature conditions.

Claim 4

A carburetor altitude compensation assembly comprising: fuel supply means including a supplementary metering orifice for supplying fuel to a carburetor bore in parallel relationship to fuel flow through a main metering orifice, a supplementary metering rod movable with respect to said supplementary orifice, an air horn on said carburetor including a control chamber therein, pressure responsive aneroid means located within said control chamber having a first portion thereon fixedly secured to said air horn and a second portion thereon movable with respect to said air horn, a bracket secured to said aneroid means for movement therewith, means coupling said supplementary metering rod to said bracket to position said rod within said supplementary metering orifice in accordance with altitude pressure conditions, said supplementary rod having a sea level location with respect to said metering orifice to supply a greater amount of fuel to the engine, a power piston bore within said air horn, a power piston located in said bore having one end thereof exposed to atmosphere, means for exposing the opposite end of said power piston to intake manifold vacuum, said power piston adapted to operate a main metering rod with respect to a main metering orifice for producing an enrichment of fuel supply to an engine upon increases in engine load, lockout means connected to said air horn including a first portion thereon in engagement with said bracket and a second portion thereon movable with respect to said power piston means between a first position and a second position, said second lockout means portion engageable with said power piston means upon a predetermined expansion of said aneroid means to prevent said power piston from moving into a fuel enrichment position to prevent enrichment of the air-fuel mixture upon a decrease in atmospheric pressure, said supplementary metering rod being located by said bracket with respect to said supplementary metering rod to reduce fuel flow to the engine to maintain the predetermined air-fuel ratio upon decreases in atmosphere density to the engine, and temperature responsive means located within said air horn movable with respect to said lockout means and engageable therewith at carburetor inlet air temperatures below a predetermined temperature to position said lockout means in a first control position to allow said power piston means to assume its power enrichment position irrespective of movement of said bracket in response to changes in atmospheric pressure under low temperature conditions.

Claim 5

A carburetor altitude compensation assembly for regulating fuel flow between a fuel supply and an intake bore to an engine comprising: means including a main metering orifice communicating the fuel supply with a main fuel well, a supplementary metering orifice communicating the fuel supply with the main fuel well in parallel relationship with the said main orifice, a main metering rod located within said main metering orifice, an air horn having a bore therein, a power piston located within said bore having one end thereof exposed to atmosphere, means for exposing the opposite end of said power piston to intake manifold pressure, means coupling said main metering rod to said power piston for controlling the position thereof within said main orifice in accordance with intake manifold pressure, a supplementary metering rod located in said supplementary orifice, pressure responsive means located on said air horn having a first portion thereof fixedly secured thereto and a second portion thereon movable with respect to the air horn in accordance with changes in altitude of the vehicle, said supplementary metering rod being located within said metering orifice at reduced elevations to provide a bypass flow in conjunction with flow through said main metering orifice to provide a predetermined air-fuel ratio to the engine, said pressure responsive means responding to reductions in air pressure due to increases in altitude to move said supplementary rod with respect to said supplementary orifice to reduce bypass fuel between the fuel supply and the intake bore to maintain a desirable air-fuel ratio upon decreases in air density due to increases in altitude, altitude lockout means operated by said pressure responsive means between a first and second control position, said altitude lockout means engaging said power piston when in its second control position to prevent movement thereof in a direction to cause enriched flow of fuel from the fuel supply to the engine when said pressure responsive means senses a predetermined decrease in pressure due to increases in altitude, and thermally responsive means responsive to a predetermined reduction in temperature of air flow to the engine to disable said lockout means thereby to permit said power piston means to respond to a predetermined reduction in intake manifold pressure to cause fuel enrichment below a predetermined intake air temperature irrespective of changes in altitude.

Claim 6

A carburetor altitude compensation assembly for regulating fuel flow between a fuel supply and an intake bore to an engine comprising: means including a main metering orifice communicating the fuel supply with a main fuel well, a supplementary metering orifice communicating the fuel supply with the main fuel well in parallel relationship with the said main orifice, a main metering rod located within said main metering orifice, an air horn having a bore therein, a power piston located within said bore having one end thereof exposed to atmosphere, means for exposing the opposite end of said power piston to intake manifold pressure, means coupling said main metering rod to said power piston for controlling the position thereof within said main orifice in accordance with intake manifold pressure, a supplementary metering rod located in said supplementary orifice, pressure responsive means located on said air horn having a first portion thereof fixedly secured thereto and a second portion thereon movable with respect to the air horn in accordance with changes in altitude of the vehicle, said supplementary metering rod being located within said metering orifice at reduced elevations to provide a bypass flow in conjunction with flow through said main metering orifice to provide a predetermined air-fuel ratio to the engine, said pressure responsive means responding to reductions in air pressure due to increases in altitude to move said supplementary rod with respect to said supplementary orifice to reduce bypass fuel between the fuel supply and the intake bore to maintain a desirable air-fuel ratio upon decreases in air density due to increases in altitude, altitude lockout means operated by said pressure responsive means between a first and second control position, said altitude lockout means engaging said power piston when in its second control position to prevent movement thereof in a direction to cause enriched flow of fuel from the fuel supply to the engine when said pressure responsive means senses a predetermined decrease in pressure due to increases in altitude, and thermally responsive means responsive to a predetermined reduction in temperature of air flow to the engine to disable said lockout means thereby to permit said power piston means to respond to a predetermined reduction in intake manifold pressure to cause fuel enrichment below a predetermined intake air temperature irrespective of changes in altitude.

Claim 7

A carburetor altitude compensation assembly for regulating fuel flow between a fuel supply in a carburetor and an air fuel supply bore therein to the engine to maintain fuel supply to the bore in accordance with changes in the air density flowing therethrough so as to control air-fuel ratios therein comprising: a pair of metering orifices each having the inlet thereof in communication with the fuel supply, means for communicating the outlets of each of the orifices with the carburetor bore, said metering orifices being in parallel flow relationship with one another, an air horn assembly located above said metering orifices including a bore therein, a power piston located within said bore, means communicating one end of said power piston with atmosphere and the opposite end thereof with a vacuum source responsive to changes in engine load, a first metering rod carried by said power piston and movable thereby with respect to one of said metering orifices to provide a first control of fuel flow to the bore, said power piston locating said first metering rod in a part throttle position and a fuel enrichment position in accordance with changes in vacuum conditions acting thereon, a second metering rod located in the other of said metering orifices, pressure responsive means located within said air horn including means thereon movable with respect to said air horn in accordance with changes in pressure due to changes in vehicle altitude, means coupling said second metering rod to said pressure responsive means, said pressure responsive means positioning said second rod with respect to said other metering orifice between a reduced altitude position and an increased altitude position, said first metering rod and said second metering rod providing a predetermined quantity of fuel flow from the supply to the carburetor bore when the vehicle is at a predetermined base altitude to produce a predetermined air-fuel ratio in the bore, said pressure responsive means responding to decreases in pressure due to increases in altitude to cause movement of said second rod to reduce fuel flow through said other metering orifice to reduce fuel flow into the throat in accordance with reductions in air density because of increased altitude to control the air-fuel ratio so as to prevent excessive fuel enrichment due to increased altitude, a lockout lever pivotally connected to said air horn having a first portion thereon coupled to said pressure responsive means and a second portion thereon movable between first and second control positions, said lockout lever in its second control position engaging said power piston to prevent movement thereof into its fuel enrichment position to prevent excessive flow of fuel from the Fuel supply to the bore when said pressure responsive means senses a predetermined increase in altitude, and temperature responsive means for maintaining said lockout lever in its first control position to permit fuel enrichment flow from the fuel supply to the carburetor bore in response to predetermined reduced inlet air temperatures at the inlet throat of the bore.

Claim 8

A carburetor altitude compensation assembly for regulating fuel flow between a fuel supply in a carburetor and an air fuel supply bore therein to the engine to maintain fuel supply to the bore in accordance with changes in the air density flowing therethrough so as to control air-fuel ratios therein comprising: a pair of metering orifices each having the inlet thereof in communication with the fuel supply, means for communicating the outlets of each of the orifices with the carburetor bore, said metering orifices being in parallel flow relationship with one another, an air horn assembly located above said metering orifices including a bore therein, a power piston located within said bore, means communicating one end of said power piston with atmosphere and the opposite end thereof with a vacuum source responsive to changes in engine load, a first metering rod carried by said power piston and movable thereby with respect to one of said metering orifices to provide a first control of fuel flow to the bore, said power piston locating said first metering rod in a part throttle position and a fuel enrichment position in accordance with changes in vacuum conditions acting thereon, a second metering rod located in the other of said metering orifices, pressure responsive means located within said air horn including means thereon movable with respect to said air horn in accordance with changes in pressure due to changes in vehicle altitude, means coupling said second metering rod to said pressure responsive means, said pressure responsive means positioning said second rod with respect to said other metering orifice between a reduced altitude position and an increased altitude position, said first metering rod and said second metering rod providing a predetermined quantity of fuel flow from the supply to the carburetor bore when the vehicle is at a predetermined base altitude to produce a predetermined air-fuel ratio in the bore, said pressure responsive means responding to decreases in pressure due to increases in altitude to cause movement of said second rod to reduce fuel flow through said other metering orifice to reduce fuel flow into the throat in accordance with reductions in air density because of increased altitude to control the air-fuel ratio so as to prevent excessive fuel enrichment due to increased altitude, a lockout lever pivotally connected to said air horn having a first portion thereon coupled to said pressure responsive means and a second portion thereon movable between first and second control positions, said lockout lever in its second control position engaging said power piston to prevent movement thereof into its fuel enrichment position to prevent excessive flow of fuel from the Fuel supply to the bore when said pressure responsive means senses a predetermined increase in altitude, and temperature responsive means for maintaining said lockout lever in its first control position to permit fuel enrichment flow from the fuel supply to the carburetor bore in response to predetermined reduced inlet air temperatures at the inlet throat of the bore.

Claim 9

A carburetor altitude compensation assembly for regulating fuel flow from a fuel supply in a carburetor to an air fuel bore therein comprising: a pair of metering orifices located in the base of a fuel supply in the carburetor, an air horn cover on said carburetor including a chamber therein having an aneroid element therein, means for fixedly connecting the top of the aneroid with respect to the air horn, a guide rod on the opposite end of said aneroid, a guide slot in said air horn receiving said guide rod for defining a maximum altitude stop, a control lever having a base connected to said guide rod extending outwardly thereof including opposite end portions thereon bent upwardly with respect to the base of said aneroid, a spring element having one end thereof fixedly secured to the base of said control lever and the opposite end thereof underlying one end of said control lever including a rod support portion thereon, an adjustment screw threadably received in said one end of the said control lever engageable with said spring element for adjustably positioning said rod support portion vertically with respect to said control lever, a first metering rod connected to said spring element portion depending downwardly from said control lever, one of said metering orifices located below said rod and cooperating therewith to provide a predetermined flow area from the fuel supply to the carburetor bore at a predetermined base altitude, said aneroid element responding to increases in altitude to move said bracket in a direction to cause said first rod to move within said orifice to produce a predetermined reduction of fuel flow in accordance with increases in altitude, air bleed valve means in said air horn for bleeding air into a secondary fuel metering system, valve operator means carried by the opposite end of said control lever to increase air flow through said bleed when the rod is in a reduced flow position thereby to further control air-fuel ratio so as to prevent altitude responsive enrichment thereof, a lockout lever pivotally secured to said air horn having a tang thereon located in contact with said one end of said control lever to be moved thereby so as to cause pivotal movement of said lockout lever, a bimetal element connected to said lockout lever, a stop surface on said air horn casting engageable with said bimetal to control pivotal movement of said lockout lever in accordance with the inlet air temperature to the carburetor, a bore in said air horn located on one side of said aneroid, a power piston located in said bore having one end thereof exposed to atmosphere, means for exposing the opposite end of said power piston to a load responsive vacuum source on an engine to cause said power piston to move between a normal fuel supply position and a fuel enrichment position upon changes in vacuum produced by increases in engine load, a second metering rod connected to said power piston for movement therewith, said second metering rod movable with respect to the other of said metering orifices to produce a first control of fuel flow from the fuel supply to the carburetor bore when the power piston is in its normal fuel supply position and to increase fuel flow from the fuel supply to the bore when the power piston is in its fuel enrichment position, said lockout lever having a second portion thereon movable with respect to said power piston, said control lever in response to a predetermined decrease in pressure positioning said lockout lever to locate said second portion thereon in interlocked relationship with said power piston to prevent movement thereof into its fuel enrichment position thereby to preveNt fuel enrichment flow to the carburetor bore when the aneroid senses a predetermined pressure decrease, said bimetal engaging said stop to prevent movement of said lockout lever into interlocked relationship with said power piston when air flow to the carburetor is below a predetermined temperature, said bimetal flexing away from said stop surface above said predetermined temperature to permit pivotal movement of said lockout lever in response to pressure changes in air temperature to the bore is above said predetermined temperature.

Claim 10

A carburetor altitude compensation assembly for regulating fuel flow from a fuel supply in a carburetor to an air fuel bore therein comprising: a pair of metering orifices located in the base of a fuel supply in the carburetor, an air horn cover on said carburetor including a chamber therein having an aneroid element therein, means for fixedly connecting the top of the aneroid with respect to the air horn, a guide rod on the opposite end of said aneroid, a guide slot in said air horn receiving said guide rod for defining a maximum altitude stop, a control lever having a base connected to said guide rod extending outwardly thereof including opposite end portions thereon bent upwardly with respect to the base of said aneroid, a spring element having one end thereof fixedly secured to the base of said control lever and the opposite end thereof underlying one end of said control lever including a rod support portion thereon, an adjustment screw threadably received in said one end of the said control lever engageable with said spring element for adjustably positioning said rod support portion vertically with respect to said control lever, a first metering rod connected to said spring element portion depending downwardly from said control lever, one of said metering orifices located below said rod and cooperating therewith to provide a predetermined flow area from the fuel supply to the carburetor bore at a predetermined base altitude, said aneroid element responding to increases in altitude to move said bracket in a direction to cause said first rod to move within said orifice to produce a predetermined reduction of fuel flow in accordance with increases in altitude, air bleed valve means in said air horn for bleeding air into a secondary fuel metering system, valve operator means carried by the opposite end of said control lever to increase air flow through said bleed when the rod is in a reduced flow position thereby to further control air-fuel ratio so as to prevent altitude responsive enrichment thereof, a lockout lever pivotally secured to said air horn having a tang thereon located in contact with said one end of said control lever to be moved thereby so as to cause pivotal movement of said lockout lever, a bimetal element connected to said lockout lever, a stop surface on said air horn casting engageable with said bimetal to control pivotal movement of said lockout lever in accordance with the inlet air temperature to the carburetor, a bore in said air horn located on one side of said aneroid, a power piston located in said bore having one end thereof exposed to atmosphere, means for exposing the opposite end of said power piston to a load responsive vacuum source on an engine to cause said power piston to move between a normal fuel supply position and a fuel enrichment position upon changes in vacuum produced by increases in engine load, a second metering rod connected to said power piston for movement therewith, said second metering rod movable with respect to the other of said metering orifices to produce a first control of fuel flow from the fuel supply to the carburetor bore when the power piston is in its normal fuel supply position and to increase fuel flow from the fuel supply to the bore when the power piston is in its fuel enrichment position, said lockout lever having a second portion thereon movable with respect to said power piston, said control lever in response to a predetermined decrease in pressure positioning said lockout lever to locate said second portion thereon in interlocked relationship with said power piston to prevent movement thereof into its fuel enrichment position thereby to preveNt fuel enrichment flow to the carburetor bore when the aneroid senses a predetermined pressure decrease, said bimetal engaging said stop to prevent movement of said lockout lever into interlocked relationship with said power piston when air flow to the carburetor is below a predetermined temperature, said bimetal flexing away from said stop surface above said predetermined temperature to permit pivotal movement of said lockout lever in response to pressure changes in air temperature to the bore is above said predetermined temperature.

Claim 11

A carburetor altitude compensation assembly for regulating fuel flow from a fuel supply in a carburetor to an air fuel bore therein comprising: a pair of metering orifices located in the base of a fuel supply in the carburetor, an air horn cover on said carburetor including a chamber therein having an aneroid therein, means for fixedly connecting the top of the aneroid with respect to the air horn, a guide rod on the opposite end of said aneroid, a guide slot in said air horn receiving said guide rod for defining a maximum altitude stop, a control lever having a base connected to said guide rod extending outwardly thereof including an end portion thereon bent upwardly with respect to the base of said aneroid, a spring element having one end thereof fixedly secured to the base of said control lever and the opposite end thereof underlying one end of said control lever including a rod support portion thereon, an adjustment screw threadably received in said one end of the said control lever engageable with said spring element for adjustably positioning said rod support portion vertically with respect to said control lever, a first metering rod connected to said spring element portion depending downwardly from said control lever, one of said metering orifices located below said rod and cooperating therewith to provide a predetermined flow area from the fuel supply to the carburetor bore at a predetermined base altitude, said aneroid element responding to increases in altitude to move said bracket in a direction to cause said first rod to move within said orifice to produce a predetermined reduction of fuel flow in accordance with increases in altitude, a lockout lever pivotally secured to said air horn having a tang thereon located in contact with said one end of said control lever to be moved thereby so as to cause pivotal movement of said lockout lever, bimetal means for controlling pivotal movement of said lockout lever in accordance with the inlet air temperature to the carburetor, a bore in said air horn located on one side on said aneroid, a power piston located in said bore having one end thereof exposed to atmosphere, means for exposing the opposite end of said power piston to a load responsive vacuum source on an engine to cause said power piston to move between a normal fuel supply position and a fuel enrichment position upon changes in vacuum produced by increases in engine load, a second metering rod connected to said power piston for movement therewith, said second metering rod movable with respect to the other of said metering orifices to produce a first control of fuel flow from the fuel supply to the carburetor bore when the power piston is in its normal fuel supply position and to increase fuel flow from the fuel supply to the bore when the power piston is in its fuel enrichment position, said lockout lever having a second portion thereon movable with respect to said power piston, said control lever in response to a predetermined decrease in pressure positioning said lockout lever to locate said second portion thereon in interlocked relationship with said power piston to prevent movement thereof into its fuel enrichment position thereby to prevent fuel enrichment flow to the carburetor bore when the aneroid senses a predetermined pressure decrease, said bimetal means operative to prevent movement of said lockout lever into interlocked relationship with said power piston when air flow to the carburetor is below a predetermined temperature, said bimetal means flexing above said predetermined temperature to permit pivotal movement of said lockout lever in response to pressure changes when air temperature to the bore is above said predetermined temperature.

Claim 12

A carburetor altitude compensation assembly for regulating fuel flow from a fuel supply in a carburetor to an air fuel bore therein comprising: a pair of metering orifices located in the base of a fuel supply in the carburetor, an air horn cover on said carburetor including a chamber therein having an aneroid therein, means for fixedly connecting the top of the aneroid with respect to the air horn, a guide rod on the opposite end of said aneroid, a guide slot in said air horn receiving said guide rod for defining a maximum altitude stop, a control lever having a base connected to said guide rod extending outwardly thereof including an end portion thereon bent upwardly with respect to the base of said aneroid, a spring element having one end thereof fixedly secured to the base of said control lever and the opposite end thereof underlying one end of said control lever including a rod support portion thereon, an adjustment screw threadably received in said one end of the said control lever engageable with said spring element for adjustably positioning said rod support portion vertically with respect to said control lever, a first metering rod connected to said spring element portion depending downwardly from said control lever, one of said metering orifices located below said rod and cooperating therewith to provide a predetermined flow area from the fuel supply to the carburetor bore at a predetermined base altitude, said aneroid element responding to increases in altitude to move said bracket in a direction to cause said first rod to move within said orifice to produce a predetermined reduction of fuel flow in accordance with increases in altitude, a lockout lever pivotally secured to said air horn having a tang thereon located in contact with said one end of said control lever to be moved thereby so as to cause pivotal movement of said lockout lever, bimetal means for controlling pivotal movement of said lockout lever in accordance with the inlet air temperature to the carburetor, a bore in said air horn located on one side on said aneroid, a power piston located in said bore having one end thereof exposed to atmosphere, means for exposing the opposite end of said power piston to a load responsive vacuum source on an engine to cause said power piston to move between a normal fuel supply position and a fuel enrichment position upon changes in vacuum produced by increases in engine load, a second metering rod connected to said power piston for movement therewith, said second metering rod movable with respect to the other of said metering orifices to produce a first control of fuel flow from the fuel supply to the carburetor bore when the power piston is in its normal fuel supply position and to increase fuel flow from the fuel supply to the bore when the power piston is in its fuel enrichment position, said lockout lever having a second portion thereon movable with respect to said power piston, said control lever in response to a predetermined decrease in pressure positioning said lockout lever to locate said second portion thereon in interlocked relationship with said power piston to prevent movement thereof into its fuel enrichment position thereby to prevent fuel enrichment flow to the carburetor bore when the aneroid senses a predetermined pressure decrease, said bimetal means operative to prevent movement of said lockout lever into interlocked relationship with said power piston when air flow to the carburetor is below a predetermined temperature, said bimetal means flexing above said predetermined temperature to permit pivotal movement of said lockout lever in response to pressure changes when air temperature to the bore is above said predetermined temperature.