Air valve type carburetor

Claim 2

An air valve type carburetor of the type wherein an air valve and a throttle valve are provided in an air passage, the degree of opening of said air valve being controlled by a negative pressure appearing between said air valve and said throttle valve, and an orifice communicating with a float chamber is opened into said air passage, while a needle valve for metering the flow rate of fuel passing through said orifice is provided on said air valve, said air valve type carburetor comprising a nozzle disposed in the air passage between said air valve and said throttle valve and directly communicated with the float chamber through a channel, wherein a check valve is provided in said channel communicating said nozzle with the float chamber, said check valve having the negative pressure between the air valve and throttle valve acting directly thereon through said channel, said channel being normally closed but opened under a high negative pressure created between the air valve and throttle valve when said throttle valve is opened abruptly, thereby allowing fuel to flow through said nozzle into said air passage.

Claim 3

A carburetor according to claim 1, wherein said nozzle is located closer to said throttle valve than to said needle valve so as to assure sufficiently high negative pressures to open said check valve upon abrupt opening of said throttle valve.

Claim 4

A carburetor according to claim 1, wherein said channel extends uninterruptedly between said check valve and said float chamber.

Claim 5

A carburetor according to claim 1, wherein a biasing means of said check valve closes said check valve during steady state high speed operation and acceleration with an opened throttle due to a reduction in said high negative pressure shortly after said abrupt opening, said orifice including means for supplying sufficient fuel for optimizing said steady state high speed operation and acceleration once the fuel flow through the orifice has overcome the inertial lag which prevents sufficient immEdiate fuel flow through said orifice due to delays inherent in the response of said air valve to said abrupt opening of said throttle and in the flow through said orifice once opened.

Claim 6

A carburetor according to claim 4, wherein said channel extends uninterruptedly between said check valve and said float chamber.

Claim 7

An air valve type carburetor arrangement comprising: an air passage means for supplying a fuel and air mixture to an engine, a movable throttle valve arranged in said air passage means for controlling the flow of fuel and air mixture to said engine, a movable air valve extending into said air passage for controlling the opening in said air passage in response to the negative pressure at a location in said air passage between said throttle valve and said air valve, a float chamber for holding a supply of fuel, a main fuel orifice communicating with said air passage at a location directly adjacent said movable air valve, main fuel orifice control means for controlling the opening in said main fuel orifice in response to movement of said air valve, a secondary fuel nozzle communicating with said air passage at a location between said air valve and said throttle valve, a channel directly connecting said secondary fuel nozzle with said float chamber, and check valve means arranged in said channel, said channel and secondary fuel nozzle directly communicating the negative pressure in said air passage at the location of said secondary fuel nozzle with said check valve means, said check valve means being operable only in the event of a predetermined excessively high negative pressure in said air passage at the location of said secondary fuel nozzle, which excessively high negative pressure occurs only during a short time period immediately after abrupt opening of said throttle valve to accelerate the engine; whereby additional fuel is supplied to said air passage to assist in the acceleration by way of said secondary fuel nozzle in direct and immediate response to opening of said throttle valve.

Claim 8

An air valve type carburetor arrangement comprising: an air passage means for supplying a fuel and air mixture to an engine, a movable throttle valve arranged in said air passage means for controlling the flow of fuel and air mixture to said engine, a movable air valve extending into said air passage for controlling the opening in said air passage in response to the negative pressure at a location in said air passage between said throttle valve and said air valve, a float chamber for holding a supply of fuel, a main fuel orifice communicating with said air passage at a location directly adjacent said movable air valve, main fuel orifice control means for controlling the opening in said main fuel orifice in response to movement of said air valve, a secondary fuel nozzle communicating with said air passage at a location between said air valve and said throttle valve, a channel directly connecting said secondary fuel nozzle with said float chamber, and check valve means arranged in said channel, said channel and secondary fuel nozzle directly communicating the negative pressure in said air passage at the location of said secondary fuel nozzle with said check valve means, said check valve means being operable only in the event of a predetermined excessively high negative pressure in said air passage at the location of said secondary fuel nozzle, which excessively high negative pressure occurs only during a short time period immediately after abrupt opening of said throttle valve to accelerate the engine; whereby additional fuel is supplied to said air passage to assist in the acceleration by way of said secondary fuel nozzle in direct and immediate response to opening of said throttle valve.

Claim 9

An arrangement according to claim 6, wherein said main fuel orifice includes means for supplying sufficient fuel for optimizing said steady state high speed operation and acceleration once the fuel flow through the orifice has overcome the inertial lag related to the difference in weight of air and fuel and the response of said air valve which prevents sufficient immediate fuel flow through said orifice after an abrupt movement of said air valve and corresponding abrupt adjustment of said orifice by said fuel orifice control means occurring immediately after said abrupt opening of said nozzle.

Claim 10

An arrangement according to claim 6, wherein said channel extends uninterruptedly between said check valve and said float chamber.

Claim 11

An arrangement according to claim 6, wherein said check valve means includes a biasing means for closing said check valve means during steady state high speed operation and acceleration with an opened throttle due to a reduction in said high negative pressure at said nozzle which occurs shortly after said abrupt opening of said throttle valve.

Claim 12

An arrangement according to claim 9, wherein said main fuel orifice includes means for supplying sufficient fuel for optimizing said steady state high speed operation and acceleration once the fuel flow through the orifice has overcome the inertial lag related to the difference in weight of air and fuel and the response of said air valve which prevents sufficient immediate fuel flow through said orifice after an abrupt movement of said air valve and corresponding abrupt adjustment of said orifice by said fuel orifice control means occurring immediately after said abrupt opening of said nozzle.

Claim 13

An arrangement according to claim 10, wherein said channel extends uninterruptedly between said check valve and said float chamber.

Claim 14

An arrangement according to claim 10, wherein said main fuel orifice control means is a needle valve attAched to said air valve and extending into said main fuel orifice.

Claim 15

An arrangement according to claim 12, wherein said secondary fuel nozzle is located closer to said throttle valve than to said needle valve so as to assure sufficiently high negative pressure to open said check valve upon abrupt opening of said throttle valve.

Claim 16

An arrangement according to claim 13, wherein said channel opens into a bottom portion of said float chamber, and wherein said needle valve extends downwardly into said float chamber.

Claim 17

An arrangement according to claim 14, wherein said air valve is provided with a control passage extending into said air passage for communicating the negative pressure in said air passage with said air valve to control movement of said air valve.

Claim 18

An arrangement according to claim 15, wherein said control passage is positioned intermediate said needle valve and said secondary fuel nozzle along the length of said air passage.

Claim 19

An arrangement according to claim 16, wherein said channel extends uninterruptedly between said check valve and said float chamber.

Claim 20

An arrangement according to claim 16, wherein said check valve means includes a spring biased ball controlling the opening in said channel.

Claim 21

An arrangement according to claim 18, wherein said air valve includes an oil damper means for dampening the movement of said air valve.