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US 2003/0111743 A1Published application
Starting assembly for a carburetor
AssigneeWalbro Japan, Inc.
InventorsShinichi Ohgane, Takashi Horikawa, Katsushi Habu, Takeshi Sakaguchi, Hiraku Watanabe, Hiroaki Ishii
Life of this patent
Estimating the term…
Abstract
A starting device for a rotary throttle valve-type carburetor enables adjustment of the quantity of air and fuel delivered to an engine to facilitate the cold start of the engine. The starting device changes the position of the throttle valve prior to starting the engine to adjust the fuel and air mixture delivered to the engine as desired to facilitate starting and initial warming up of the engine.
Claims50
A carburetor, comprising:
- a body having an air intake passage, and a throttle valve chamber communicated with the air intake passage;
- a rotary throttle valve slidably and rotatably received in the throttle valve chamber between idle and wide open positions to control the delivery of a fuel and air mixture to the engine, and having a through hole to control the flow of air from the carburetor;
- a fuel nozzle carried by the body and through which fuel flows prior to being discharged from the carburetor;
- a start shaft carried by the carburetor body for movement between first and second positions;
- an actuator operably associated with the start shaft for movement in response to movement of the start shaft from its first position to its second position to cause movement of the throttle valve in a direction increasing both the quantity of air flow through the throttle valve through hole and the effective flow area of the fuel nozzle compared to the air flow through the throttle valve through hole and the effective flow area of the fuel nozzle when the throttle valve is in an idle position.
2 more elements
A carburetor, comprising:
- a body having an air intake passage, and a throttle valve chamber communicated with the air intake passage;
- a rotary throttle valve slidably and rotatably received in the throttle valve chamber between idle and wide open positions to control the delivery of a fuel and air mixture to the engine, and having a through hole to control the flow of air from the carburetor;
- a fuel nozzle carried by the body and through which fuel flows prior to being discharged from the carburetor;
- a needle carried by the throttle valve for reciprocation relative to the fuel nozzle to change the effective flow area of the fuel nozzle and thereby control the delivery of fuel from the carburetor;
- a start shaft carried by the carburetor body for movement between first and second positions;
- a cam operably associated with the start shaft and adapted to axially move the throttle valve away from its idle position to move the needle relative to the fuel nozzle and increase the effective flow area of the fuel nozzle permitting an increased fuel flow through the nozzle;
- and
- a push rod associated with the start shaft for movement relative to the throttle valve when the start shaft is moved from its first position to its second position to rotate the throttle valve away from its idle position to increase the effective flow area of the hole in the throttle valve and permit increased air flow therethrough, whereby movement of the start shaft from its first position to its second position axially and rotatably displaces the throttle valve to change the fuel and air mixture delivered from the carburetor compared to that delivered from the carburetor when the throttle valve is in its idle position.
5 more elements
The carburetor of clam 29 wherein the cam shaft is eccentrically disposed relative to the start shaft.
A carburetor, comprising:
- a body having an air intake passage, and a throttle valve chamber communicated with the air intake passage;
- a rotary throttle valve slidably and rotatably received in the throttle valve chamber between idle and wide open positions to control the delivery of a fuel and air mixture to the engine, and having a valve shaft, a hole through the valve shaft to control the flow of air from the carburetor, and an air passage formed at least in part in the valve shaft that is in communication with the air intake passage during at least a portion of the throttle valve movement away from its idle position;
- a fuel nozzle carried by the body and through which fuel flows prior to being discharged from the carburetor;
- a needle carried by the throttle valve for reciprocation relative to the fuel nozzle to change the effective flow area of the fuel nozzle and thereby control the delivery of fuel from the carburetor;
- a start shaft carried by the carburetor body for movement between first and second positions;
- and
- a cam operably associated with the start shaft and adapted to axially move the throttle valve away from its idle position to move the needle relative to the fuel nozzle and increase the effective flow area of the fuel nozzle permitting an increased fuel flow through the nozzle whereby the movement of the throttle valve when the start shaft is rotated to its second position communicates the air passage of the throttle valve with the air intake passage to permit increased air flow through the carburetor.
4 more elements
A carburetor, comprising:
- a body having an air intake passage, a throttle valve chamber communicated with the air intake passage, and an opening;
- a rotary throttle valve slidably and rotatably received in the throttle valve chamber between idle and wide open positions to control the delivery of a fuel and air mixture to the engine, and having a valve shaft, and a hole through the valve shaft to control the flow of air from the carburetor,
- a fuel nozzle carried by the body and through which fuel flows prior to being discharged from the carburetor;
- a needle carried by the throttle valve for reciprocation relative to the fuel nozzle to change the effective flow area of the fuel nozzle and thereby control the delivery of fuel from the carburetor;
- a start shaft carried by the body adjacent at least in part to the opening and moveable between first and second positions, the movement of the start shaft causing at least a portion of the start shaft to pass near the opening to communicate contaminants in the area of the start shaft with the opening;
- and
- a cam operably associated with the start shaft and adapted to axially move the throttle valve away from its idle position to move the needle relative to the fuel nozzle and increase the effective flow area of the fuel nozzle permitting an increased fuel flow through the nozzle.
4 more elements
Dependencies are inferred from the claim text.