Carburetor

A carburetor comprising:

• a body structure through which a vacuum induced primary flow of air passes;
• a throttle valve adjustable to regulate said primary flow of air;
• a flow actuated member positioned along the path of said primary flow of air and which is movable by the air to different positions varying in correspondence with the rate of air flow past said member;
• means for directing fuel and secondary air into admixture with one another in isolation from said primary flow of air to form a combined stream, and then directing said combined stream for induction by vacuum into said primary flow of air, and including a second valve operable to regulate the flow of said secondary air before admixture with the fuel;
• and
• means operable by said flow actuated member to vary the setting of said second valve in response to movement of said flow actuated member by air flowing therepast;
• said second valve including a rotary valve element actable by rotary movement about an axis to variably restrict the flow of said secondary air;
• said means operable by said flow actuated member including a second rotary element actuable rotatively about said axis by said flow actuated member in accordance with movement of the flow actuated member by air flowing therepast, and a connection for transmitting rotary motion from said second rotary element to said rotary valve element and which is adjustable to controllably vary the range of movement of said rotary valve element for a particular range of movement of said flow actuated member.

A carburetor comprising:

• a body structure through which a vacuum induced primary flow of air passes;
• a throttle valve adjustable to regulate said primary flow of air;
• a flow actuated member positioned along the path of said primary flow of air and which is movable by the air to different positions varying in correspondence with the rate of air flow past said member;
• means for directing fuel and secondary air into admixture with one another in isolation from said primary flow of air to form a combined stream, and then directing said combined stream for induction by vacuum into said primary flow of air, and including a second valve operable to regulate the flow of said secondary air before admixture with the fuel;
• and
• means operable by said flow actuated member to vary the setting of said second valve in response to movement of said flow actuated member by air flowing therepast;
• said flow actuated member being mounted for movement essentially along a first axis by air flowing therepast;
• said second valve including a rotary valve element operable by rotary movement about a second axis to regulate the flow of said secondary air;
• said means operable by said flow actuated member including a first connector part movable along said first axis with said flow actuated member, and a second connector part mounted to turn about said second axis with said rotary valve element and having a sliding connection with said first connector part for converting movement of the flow actuated member along said first axis to rotary movement of said rotary valve element about said second axis.

A carburetor comprising:

• a body structure through which a vacuum induced primary flow of air passes;
• a throttle valve adjustable to regulate said primary flow of air;
• a flow actuated member positioned along the path of said primary flow of air and which is movable by the air to different positions varying in correspondence with the rate of air flow past said member;
• means for directing fuel and secondary air into admixture with one another in isolation from said primary flow of air to form a combined stream, and then directing said combined stream for induction by vacuum into said primary flow of air, and including a second valve operable to regulate the flow of said secondary air before admixture with the fuel;
• and
• means operable by said flow actuated member to vary the setting of said second valve in response to movement of said flow actuated member by air flowing therepast;
• said flow actuated member being mounted for movement along a first axis by air flowing therepast;
• said second valve including a rotary valve element operable by rotary movement about a second axis to regulate said secondary flow of air;
• said means operable by said flow actuated member including a rod connected to said flow actuated member and which extends essentially parallel to said first axis and is guided for movement with the flow actuated member essentially parallel to said first axis, and an operative connection between said rod and said rotary valve element for converting movement of said rod parallel to said first axis to rotary movement of the rotary valve element about said second axis;
• said connection including a first connector part carried by said rod and having a slot extending essentially transversely of said first axis, a second connector part received in said slot and movable therealong, a third connector part attached to said rotary valve element for rotation therewith about said second axis, and means attaching said second connector part to said third connector part for adjusting movement relative thereto essentially radially of said second axis.

A carburetor comprising:

• a body structure through which a vacuum induced primary flow of air passes;
• a throttle valve adjustable to regulate said primary flow of air;
• means for directing fuel and secondary air into admixture with one another in isolation from said primary flow of air to form a combined stream, and then directing said combined stream for induction by vacuum into said primary flow of air, and including a second valve operable to vary the flow of said secondary air into admixture with said fuel;
• and
• control means automatically operable, when said throttle valve is moved in an opening direction increasing said primary flow of air to move said second valve in a closing direction enriching said combined stream;
• said control means being operable to move said second valve rapidly from a maximum open position thereof to its most closed position during initial opening movement of the throttle valve.

A carburetor comprising:

• a body structure through which a vacuum induced primary flow of air passes;
• a throttle valve adjustable to regulate said primary flow of air;
• means for directing fuel and secondary air into admixture with one another in isolation from said primary flow of air to form a combined stream, and then directing said combined stream for induction by vacuum into said primary flow of air, and including a second valve operable to vary the flow of said secondary air into admixture with said fuel;
• control means automatically operable, when said throttle valve is moved in an opening direction increasing said primary flow of air to move said second valve in a closing direction enriching said combined stream;
• said control means being operable to move said second valve progressively and gradually in a closing direction through substantially the entire range of opening movement of said throttle valve to maintain a proper air-fuel ratio in different throttle settings;
• and
• a third valve regulating delivery of a portion of the secondary air to the fuel and which is operable automatically and rapidly from a maximum open position thereof to its most closed position during initial opening movement of the throttle valve.

A carburetor comprising:

• a body structure through which a vacuum induced primary flow of air passes;
• a throttle valve adjustable to regulate said primary flow of air;
• means for directing fuel and secondary air into admixture with one another in isolation from said primary flow of air to form a combined stream, and then directing said combined stream for induction by vacuum into said primary flow of air, and including a second valve operable to vary the flow of said secondary air into admixture with said fuel;
• and
• control means automatically operable, when said throttle valve is moved in an opening direction increasing said primary flow of air to move said second valve in a closing direction enriching said combined stream;
• said second valve including a rotary valve element and a second element thereabout;
• said elements containing registering air passages which move to positions of progressively decreasing registry to restrict the flow of secondary air as the throttle valve is opened.

A carburetor comprising:

• a body structure through which a vacuum induced primary flow of air passes;
• a throttle valve adjustable to regulate said primary flow of air;
• means for directing fuel and secondary air into admixture with one another in isolation from said primary flow of air to form a combined stream, and then directing said combined stream for induction by vacuum into said primary flow of air, and including a second valve operable to vary the flow of said secondary air into admixture with said fuel;
• and
• control means automatically operable, when said throttle valve is moved in an opening direction increasing said primary flow of air to move said second valve in a closing direction enriching said combined stream;
• said second valve including a tubular sleeve having a side wall containing an opening, and a rotary valve element within said sleeve containing an air flow passage which moves to positions of decreasing registry with said opening upon rotation of said valve element as the throttle valve is opened;
• said side wall of said sleeve having a groove in its outer surface through which fuel flows about the sleeve for mixture with secondary air at said opening.

A carburetor comprising:

• a body structure through which a vacuum induced primary flow of air passes;
• a throttle valve adjustable to regulate said primary flow of air;
• means for directing fuel and secondary air into admixture with one another in isolation from said primary flow of air to form a combined stream, and then directing said combined stream for induction by vacuum into said primary flow of air, and including a second valve operable to vary the flow of said secondary air into admixture with said fuel;
• control means automatically operable, when said throttle valve is moved in an opening direction increasing said primary flow of air to move said second valve in a closing direction enriching said combined stream;
• said control means being operable to move said second valve progressively and gradually in a closing direction through substantially the entire range of opening movement of said throttle valve to maintain a proper air-fuel ratio in different throttle settings;
• a third valve controlling the flow of a portion of the secondary air to the fuel;
• vacuum actuated means automatically responsive to development of a vacuum condition to move said third valve in an opening direction increasing the flow of secondary air to the fuel;
• and
• a fourth valve for regulating additional secondary air flow to the fuel and which is operable automatically and rapidly from a maximum open position to its most closed position during initial opening movement of the throttle valve.

A carburetor comprising:

• a body structure through which a vacuum induced primary flow of air passes;
• a throttle valve adjustable to regulate said primary flow of air;
• means for directing fuel and secondary air into admixture with one another in isolation from said primary flow of air to form a combined stream, and then directing said combined stream for induction by vacuum into said primary flow of air, and including a second valve operable to vary the flow of said secondary air into admixture with said fuel;
• control means automatically operable, when said throttle valve is moved in an opening direction increasing said primary flow of air to move said second valve in a closing direction enriching said combined stream;
• said control means being operable to move said second valve progressively and gradually in a closing direction through substantially the entire range of opening movement of said throttle valve to maintain a proper air-fuel ratio in different throttle settings;
• a third valve controlling the flow of a portion of the secondary air to the fuel;
• vacuum actuated means automatically responsive to development of a vacuum condition to move said third valve in an opening direction increasing the flow of secondary air to the fuel;
• and
• thermostatic means operable in response to a low temperature to prevent movement of said third valve in said opening direction by said vacuum actuated means.

A carburetor comprising:

• a body structure through which a vacuum induced primary flow of air passes;
• a throttle valve adjustable to regulate said primary flow of air;
• means for directing fuel and secondary air into admixture with one another in isolation from said primary flow of air to form a combined stream, and then directing said combined stream for induction by vacuum into said primary flow of air, and including a second valve operable to vary the flow of said secondary air into admixture with said fuel;
• and
• control means automatically operable, when said throttle valve is moved in an opening direction increasing said primary flow of air to move said second valve in a closing direction enriching said combined stream;
• said body structure containing a passage through which said primary flow of air passes;
• said throttle valve being a butterfly valve mounted for pivotal movement about an axis disposed essentially transversely of said passage between an essentially closed position disposed generally transversely of said passage and an open position;
• said control means including an element positioned to be engaged by said butterfly valve in its most closed position for deflection thereby and operable upon such deflection to open said second valve.

A carburetor comprising:

• a body structure through which a vacuum induced primary flow of air passes;
• a throttle valve adjustable to regulate said primary flow of air;
• means for directing fuel and secondary air into admixture with one another in isolation from said primary flow of air to form a combined stream, and then directing said combined stream for induction by vacuum into said primary flow of air, and including a second valve operable to vary the flow of said secondary air into admixture with said fuel;
• and
• control means automatically operable, when said throttle valve is moved in an opening direction increasing said primary flow of air to move said second valve in a closing direction enriching said combined stream;
• said control means including an element engageable and displaceable by said throttle valve in its most closed position to actuate said second valve;
• said element being constructed to limit closing movement of the throttle valve and thereby determine its most closed position and prevent movement of the throttle valve beyond that position.

A carburetor comprising:

• a body structure through which a vacuum induced primary flow of air passes;
• a throttle valve adjustable to regulate said primary flow of air;
• means for directing fuel and secondary air into admixture with one another in isolation from said primary flow of air to form a combined stream, and then directing said combined stream for induction by vacuum into said primary flow of air, and including a second valve operable to vary the flow of said secondary air into admixture with said fuel;
• and
• control means automatically operable, when said throttle valve is moved in an opening direction increasing said primary flow of air to move said second valve in a closing direction enriching said combined stream;
• said body structure containing a passage through which said primary flow of air passes;
• said throttle valve being a butterfly valve mounted to pivot about an axis disposed essentially transversely of said passage and which is disposed generally transversely across said passage in an essentially closed position of the throttle valve;
• said control means including a vertically extending pin guided for vertical longitudinal movement in said body structure and having a lower end projecting to a location for engagement and upward displacement by an edge portion of said butterfly valve in said essentially closed position;
• said second valve including an enlarged head formed at an upper end of said pin and engageable with a seat in a lower position of the pin and head to essentially close off said flow of secondary air.

A carburetor comprising:

• a body structure through which a vacuum induced primary flow of air passes;
• a throttle valve adjustable to regulate said primary flow of air;
• means for directing fuel and secondary air into admixture with one another in isolation from said primary flow of air to form a combined stream, and then directing said combined stream for induction by vacuum into said primary flow of air, and including a second valve operable to vary the flow of said secondary air into admixture with said fuel;
• control means automatically responsive to development of a vacuum condition to move said second valve in an opening direction;
• and
• thermostatic means operable to prevent movement of said second valve in said opening direction at low temperature and permit movement of the second valve in said opening direction at a higher temperature.

A carburetor comprising:

• a body structure through which a vacuum induced primary flow of air passes;
• a throttle valve adjustable to regulate said primary flow of air;
• means for directing fuel and secondary air into admixture with one another in isolation from said primary flow of air to form a combined stream, and then directing said combined stream for induction by vacuum into said primary flow of air, and including a second valve operable to vary the flow of said secondary air into admixture with said fuel;
• control means automatically responsive to development of a vacuum condition to move said second valve in an opening direction;
• said control means including a lever mounted for pivotal movement upon development of said vacuum condition and operable upon such pivotal movement to move said second valve in an opening direction;
• and
• thermostatic means operable to limit pivotal movement of said lever in a direction opening said second valve at low temperature and permit pivotal movement of the lever in a direction opening said second valve at a higher temperature.

A carburetor comprising:

• a body structure through which a vacuum induced primary flow of air passes;
• a throttle valve adjustable to regulate said primary flow of air;
• means for directing fuel and secondary air into admixture with one another in isolation from said primary flow of air to form a combined stream, and then directing said combined stream for induction by vacuum into said primary flow of air, and including a second valve operable to vary the flow of said secondary air into admixture with said fuel;
• control means automatically responsive to development of a vacuum condition to move said second valve in an opening direction;
• said control means including a lever mounted for pivotal movement relative to said body structure;
• said second valve including a valve element carried at a first end of said lever and extending at least partially across a secondary air inlet and acting to vary the effective open area of said inlet upon pivotal movement of the lever;
• said control means including a plunger exposed to and actuable by said vacuum condition and acting against a second end of the lever to pivot the lever in a direction opening said second valve upon development of the vacuum condition;
• thermostatic means responsive to a change in temperature;
• and
• a unit actuable upwardly and downwardly by said thermostatic means and acting at a low temperature to block pivotal movement of said lever in a direction opening said second valve.

A carburetor comprising:

• a body structure through which a vacuum induced primary flow of air passes;
• a throttle valve adjustable to regulate said primary flow of air;
• means for directing fuel and secondary air into admixture with one another in isolation from said primary flow of air to form a combined stream, and then directing said combined stream for induction by vacuum into said primary flow of air, and including a second valve operable to vary the flow of said secondary air into admixture with said fuel;
• control means automatically responsive to development of a vacuum condition to move said second valve in an opening direction;
• and
• thermostatic means operable at a low temperature to block opening movement of said second valve;
• said thermostatic means including a third valve acting at said low temperature to admit a supplementary flow of air to a location downstream of said throttle valve and acting upon an increase in temperature to block off said supplementary flow of air.

A carburetor comprising:

• a body structure through which a vacuum induced primary flow of air passes;
• a throttle valve adjustable to regulate said primary flow of air;
• means for directing fuel and secondary air into admixture with one another in isolation from said primary flow of air to form a combined stream, and then directing said combined stream for induction by vacuum into said primary flow of air, and including a second valve operable to vary the flow of said secondary air into admixture with said fuel;
• thermostatic control means automatically operable under cold start conditions to actuate said second valve in a manner restricting the flow of said secondary air and thereby enriching said combined stream, and automatically operable upon an increase in temperature to actuate said second valve in a manner reducing the restriction to said secondary air and thereby leaning said combined stream;
• and
• a third valve actuable by said thermostatic control means to control flow of supplementary air to a location downstream of said throttle valve in accordance with temperature changes;
• said third valve being positioned to block opening movement of said second valve under cold start conditions.

A carburetor comprising:

• a body structure through which a vacuum induced primary flow of air passes;
• a throttle valve adjustable to regulate said primary flow of air;
• means for directing fuel and secondary air into admixture with one another in isolation from said primary flow of air to form a combined stream, and then directing said combined stream for induction by vacuum into said primary flow of air, and including a second valve operable to vary the flow of said secondary air into admixture with said fuel;
• thermostatic control means automatically operable under cold start conditions to actuate said second valve in a manner restricting the flow of said secondary air and thereby enriching said combined stream, and automatically operable upon an increase in temperature to actuate said second valve in a manner reducing the restriction to said secondary air and thereby leaning said combined stream;
• a lever mounted for pivotal movement and carrying said second valve at an end thereof;
• and
• a third valve controlling delivery of supplementary air to a location downstream of said throttle valve and which is actuable by said thermostatic control means at low temperature to deliver said supplementary air and at higher temperatures to restrict supplementary air;
• said third valve being positioned to block pivotal movement of said lever in a direction to open said second valve at said low temperature.

A carburetor comprising:

• a body structure through which a vacuum induced primary flow of air passes;
• a throttle valve adjustable to regulate said primary flow of air;
• means for directing fuel and secondary air into admixture with one another in isolation from said primary flow of air to form a combined stream, and then directing said combined stream for induction by vacuum into said primary flow of air, and including a second valve operable to vary the flow of said secondary air into admixture with said fuel;
• thermostatic control means automatically operable under cold start conditions to actuate said second valve in a manner restricting the flow of said secondary air and thereby enriching said combined stream, and automatically operable upon an increase in temperature to actuate said second valve in a manner reducing the restriction to said secondary air and thereby leaning said combined stream;
• a lever mounted for pivotal movement and carrying said second valve;
• and
• a third valve actuable upwardly and downwardly by said thermostatic control means and operable in an upper position at low temperature to pass supplementary air to a location downstream of the throttle valve and in a lower position at an increased temperature to restrict said supplementary air;
• said third valve in said upper position being location to block downward movement of a second end of said lever and thereby prevent pivotal movement of the lever in a direction opening said second valve.

A carburetor comprising:

• a body structure through which a flow of air passes along a path;
• a throttle valve adjustable to regulate said flow of air;
• and
• two elements forming between them a restriction through which said air flows to locally increase the velocity of the air at said restriction;
• a first of said elements being movable relative to the body structure and relative to the second of said elements by the force of air flowing therebetween, in a relation varying the width of said restriction in accordance with the rate of flow of air through the restriction;
• said second element containing fuel passages means through which fuel flows within said second element and discharging fuel into the air flowing through said body structure for admixture therewith;
• said first element being movable essentially along a predetermined axis relative to said body structure and said second element, with said restriction between the elements being essentially annular;
• said passage means within said second element forming a circular series of openings through which the fuel is emitted into said flow of air at a location closely adjacent said first element.

A carburetor comprising:

• a body structure through which a flow of air passes along a path;
• a throttle valve adjustable to regulate said flow of air;
• and
• two elements forming between them a restriction through which said air flows to locally increase the velocity of the air at said restriction;
• a first of said elements being movable relative to the body structure and relative to the second of said elements by the force of air flowing therebetween, in a relation varying the width of said restriction in accordance with the rate of flow of air through the restriction;
• said second element containing fuel passage means through which fuel flows within said second element and discharging fuel into the air flowing through said body structure for admixture therewith;
• said first element moving essentially along a predetermined axis relative to said second element to vary said restriction;
• said passage means in said second element including an essentially annular recess formed in said second element and receiving said fuel, a plate disposed across a downstream side of said recess and forming a restriction or restrictions through which the fuel flows, and an essentially annular structure at a downstream side of said plate and containing a circular series of openings near said first element and near said restriction for emitting fuel into said flow of air.

A carburetor comprising:

• a body structure through which a flow of air passes along a path;
• a throttle valve adjustable to regulate said flow of air;
• two elements forming between them a restriction through which said air flows;
• a first of said elements being movable relative to the body structure and relative to the second of said elements by the force of air flowing therebetween, in a relation varying the width of said restriction in accordance with the rate of flow of air through the restriction;
• and
• an operative connection between said throttle valve and said first element operable in response to opening movement of said throttle valve to move said first element in a direction opening said restriction independently of the actuation of said first element by air flowing therepast;
• said body structure containing a passage through which said flow of air passes;
• said throttle valve being a butterfly valve having a shaft connected to the butterfly valve and mounted to turn therewith about an axis disposed essentially transversely of said passage;
• said operative connection including pins connected to said first element and projecting into recesses in said shaft and adapted to be actuated by the shaft for displacing said first element in an opening direction relative to said second element in response to rotation of the throttle valve and shaft about said axis in a direction opening the throttle valve.

A carburetor comprising:

• a body structure through which a vacuum induced primary flow of air passes;
• a throttle valve adjustable to regulate said primary flow of air;
• a flow actuated member positioned along the path of said primary flow of air and which is movable by the air to different positions varying in correspondence with the rate of air flow past said member;
• means for directing fuel and secondary air into admixture with one another in isolation from said primary flow of air to form a combined stream, and then directing said combined stream for induction by vacuum into said primary flow of air, and including a second valve operable to regulate the flow of said secondary air before admixture with the fuel;
• control means for automatically actuating said second valve to vary the flow of said secondary air upon actuation of said throttle valve varying said primary flow of air;
• a diffuser structure containing a passage through which said combined stream is directed between said second valve and the point of admixture of the combined stream with said primary flow of air, said passage having a restriction for increasing the velocity of said combined stream and thereby enhancing intimate intermixture of the fuel and secondary air;
• said passage of the diffuser structure having a first portion tapering downstream, a second portion beyond said first portion forming said restriction, and a third portion beyond said restricted second portion and flaring to a progressively increasing diameter;
• said diffuser structure having a tubular portion containing said tapering first portion of said passage and which faces toward said second valve to receive fuel and secondary air therefrom;
• means forming a chamber containing said tubular portion of said diffuser structure and having a side wall extending about and spaced radially from said tubular portion and an end wall spaced from an end of the tubular structure;
• and
• an additional air inlet for admitting air into a space radially between said tubular portion of said diffuser structure and said side wall of said chamber for entry into said tapering portion of said passage with said fuel and secondary air.

A carburetor comprising:

• a body structure through which a vacuum induced primary flow of air passes;
• a throttle valve adjustable to regulate said primary flow of air;
• a flow actuated member positioned along the path of said primary flow of air and which is movable by the air to different positions varying the width of a restriction through which the air flows in correspondence with the rate of air flow past said member;
• and
• means for directing fuel and secondary air into admixture with one another in isolation from said primary flow of air to form a combined stream, and then directing said combined stream into said primary flow of air for intimate intermixture therewith;
• said means forming a plurality of circularly spaced passages through which said fuel and secondary air flow at a location closely adjacent said restriction;
• said passages having open sides.

A carburetor comprising:

• a body structure through which a vacuum induced primary flow of air passes;
• a throttle valve adjustable to regulate said primary flow of air;
• a flow actuated member positioned along the path of said primary flow of air and which is movable by the air to different positions varying the width of a restriction through which the air flows in correspondence with the rate of air flow past said member;
• and
• means for directing fuel and secondary air into admixture with one another in isolation from said primary flow of air to form a combined stream, and then directing said combined stream into said primary flow of air for intimate intermixture therewith;
• said means forming a plurality of passages through which said fuel and secondary air flow closely adjacent said restriction and which have tapering first portions and flaring second portions downstream of said first portions;
• said flaring second portions of said passages having open sides.

A carburetor comprising:

• a body structure through which a vacuum induced primary flow of air passes;
• a throttle valve adjustable to regulate said primary flow of air;
• a flow actuated member positioned along the path of said primary flow of air and which is movable by the air to different positions varying the width of a restriction through which the air flows in correspondence with the rate of air flow past said member;
• means for directing fuel and secondary air into admixture with one another in isolation from said primary flow of air to form a combined stream, and then directing said combined stream into said primary flow of air for intimate intermixture therewith;
• and
• a second member forming said restriction with said first mentioned member and relative to which said first mentioned member is movable to vary the restriction;
• said members having opposed surfaces tapering in a downstream direction to reduced ends and forming between them at least a portion of said restriction;
• said means being constructed to introduce said combined stream into said flow of primary air at essentially said reduced downstream ends of said surfaces;
• said means forming a plurality of circularly spaced passages near said reduced downstream ends of said surfaces and closely adjacent said restriction and through which said fuel and secondary air flow for intimate intermixture with said primary flow of air;
• said passages having first portions tapering to reduced restricted regions and having flaring second portions downstream of said first portions,
• said flaring second portions of said passages having open outer sides.

A carburetor comprising:

• a hollow first member through which a vacuum induced flow of air passes;
• a throttle valve contained at least partially within the interior of said first member and operable to regulate said flow of air therethrough;
• said first member having a side wall containing at least one opening through which said flow of air passes outwardly from the interior to the exterior of said first member downstream of the throttle valve;
• a flow actuated member extending about said hollow first member and forming therewith a restriction at the exterior of said first member through which said air passes after flow through said opening;
• said flow actuated member being movable relative to said first member by said flow of air to different positions varying the width of said restriction in correspondence with the rate of air flow through the restriction;
• and
• means for introducing fuel into said flow of air.

A carburetor comprising:

• a body structure through which a vacuum induced primary flow of air passes;
• a throttle valve adjustable to regulate said primary flow of air;
• a flow actuated member positioned along the path of said primary flow of air at a location downstream of said throttle valve and which is movable by said air to different positions varying the width of an essentially annular restriction through which the air flows;
• fuel delivery means for directing fuel and secondary air into admixture with one another in isolation from said primary flow of air to form a combined stream, and then directing said combined stream for induction by vacuum into said primary flow of air;
• said fuel delivery means including a second valve operable to regulate the flow of secondary air before admixture with the fuel in a manner enriching said combined stream when the flow of secondary air is reduced;
• and
• automatic actuating means operable by said flow actuated member, upon movement thereof in an opening direction increasing the width of said restriction, to progressively close said second valve and thereby enrich said combined stream;
• said fuel delivery means being constructed to direct said combined stream of fuel and secondary air into said primary flow of air at a location downstream of said throttle valve and directly adjacent said essentially annular restriction in all positions of said flow actuated member and in a generally annular pattern corresponding generally to that of said essentially annular restriction, to intimately intermix the combined stream of fuel and secondary air with the primary flow of air at essentially the maximum velocity of the primary flow of air as it passes the flow actuated member.

A carburetor comprising:

• a body structure through which a flow of air passes along a path;
• a throttle valve adjustable to regulate said flow of air;
• a flow actuated member positioned along said path and which is movable by the air in an opening direction progressively increasing the width of a restriction through which the air flows in correspondence with the rate of air flow past said member;
• means yieldingly urging said flow actuated member to a closed position preventing air flow through said restriction;
• and
• an operative connection between said throttle valve and said flow actuated member operable in response to opening movement of said throttle valve to move said flow actuated member from said closed position to a partially open position independently of the actuation of said member by air flowing therepast;
• to enable clearing of a flooded condition;
• said member being free, after clearing of the flooded condition, for movement in said opening direction by air flowing therepast independently of said operative connection, and being free for movement farther in said opening direction by air flowing therepast than by said operative connection;
• said operative connection including a cylindrical shaft connected to said throttle valve and mounted to turn about an axis disposed essentially transversely of said passage, and pins connected to said flow actuated member, and projecting into recesses in said shaft;
• said recesses in the shaft having inner wall surfaces lying essentially in a plane which contains said axis and which is disposed essentially diametrically with respect to said shaft;
• said pins having end surfaces which engage said inner wall surfaces of said recesses and which are cammed thereby in a relation displacing said flow actuated member in said opening direction upon rotation of the throttle and shaft about said axis in a direction opening the throttle valve.

A carburetor comprising:

• a body structure through which a vacuum induced primary flow of air passes;
• a throttle valve adjustable to regulate said primary flow of air;
• a fuel inlet;
• said body structure having a portion with a surface containing a secondary air inlet opening;
• means for directing fuel from said fuel inlet, and secondary air which enters said secondary air inlet opening, into admixture with one another in isolation from said primary flow of air to form a combined stream, and then directing said combined stream for induction by vacuum into said primary flow of air;
• a lever mounted for pivoting movement relative to said body structure at a location adjacent said surface which contains the secondary air inlet opening and about an axis extending essentially pependicular to said surface;
• a valve element carried by said lever at a location offset from said axis and closely adjacent said surface and which, upon pivotal movement of the lever, swings essentially parallel to said surface and transversely across said opening to positions extending different distances across said opening, to thereby vary the effective size of the opening and the rate of flow of secondary air therethrough;
• and
• means for pivoting said lever to vary the flow of secondary air into admixture with said fuel;
• said means for pivoting the lever including control means responsive to development of a vacuum condition to swing said lever in a direction opening said valve element carried thereby, and thermostatic means operable under cold start conditions to prevent swinging movement of the lever in a direction opening said valve element carried thereby.