Carburetor with acceleration fuel pump
View Patent ↗A combustion engine carburetor with a fuel-and-air mixing passage extending through a body and a float bowl engaged sealably to the body. A vacuum actuated acceleration fuel pump is preferably carried by the float bowl and has a hose-less vacuum channel communicating between the fuel-and-air mixing passage downstream of a throttle valve and a vacuum chamber of the acceleration pump. A hose-less fuel discharge channel communicates between a supplemental fuel chamber of the acceleration pump and the fuel-and-air mixing passage between a venturi and a choke valve in the mixing passage. Preferably, the fuel discharge channel has an injecting bore portion defined by the body and being angled to direct fuel in a downstream direction toward the venturi to promote mixing with air.
1. A combustion engine float bowl carburetor comprising:
a body;
a fuel-and-air mixing passage through the body and having an inlet region and an outlet region;
a vacuum actuated acceleration fuel pump carried by the body;
a hose-less vacuum channel defined by the body and communicating between the acceleration fuel pump and the outlet region of the fuel and air mixing passage;
a float bowl carrying a peripheral surface;
a continuous face carried by the body and engaged sealably to the peripheral surface; and
an elongated recess of the vacuum channel extending longitudinally along, and located laterally between, the peripheral surface and the continuous face.
2. The combustion engine carburetor set forth in claim 1 comprising a hose-less fuel discharge channel defined by the body and communicating between the acceleration fuel pump and the inlet region.
3. The combustion engine carburetor set forth in claim 1 comprising a first bore portion of the vacuum channel extending through the body and communicating between the outlet region and the elongated recess.
4. The combustion engine carburetor set forth in claim 3 wherein the acceleration pump is supported by the float bowl.
5. The combustion engine carburetor set forth in claim 4 comprising:
a resilient diaphragm of the acceleration pump;
a vacuum chamber of the acceleration pump defined between the float bowl and the diaphragm; and
a second bore portion of the vacuum channel defined by the float bowl and communicating between the elongated recess and the vacuum chamber.
6. The combustion engine carburetor set forth in claim 1 comprising a gasket engaged between the peripheral surface and the continuous face.
7. The combustion engine carburetor set forth in claim 6 comprising a hole located through the gasket and communicating between the first bore portion and an end of the elongated recess.
8. The combustion engine carburetor set forth in claim 7 comprising an elongated section of the gasket being flanked and encompassed by a remaining section of the gasket and wherein the elongated section covers and seals the elongated recess of the vacuum channel.
9. The combustion engine carburetor set forth in claim 1 comprising:
a first port defined by the body and communicating with a first end of the elongated recess; and
a second port defined by the float bowl and communicating with an opposite second end of the elongated recess.
10. A combustion engine carburetor having a fuel-and-air mixing passage through a body, a throttle valve in the passage, a venturi upstream of the throttle valve, and a choke valve upstream of the venturi, the carburetor comprising:
a float bowl carried by the body;
a vacuum actuated acceleration fuel pump carried by the body and having a fuel chamber and an actuating vacuum chamber;
a hose-less vacuum channel communicating between the vacuum chamber and the fuel-and-air mixing passage downstream of the throttle valve;
a hose-less fuel discharge channel defined by the body and communicating between the fuel chamber of the acceleration fuel pump and the fuel-and-air mixing passage between the venturi and the choke valve;
a pocket of the vacuum channel defined by the body or the float bowl and communicating with the fuel-and-air mixing passage downstream of the throttle valve; and
a bore portion of the vacuum channel defined by the body and communicating between the pocket and a port in a continuous face of the body which is sealed with a peripheral surface of the float bowl.
11. The combustion engine carburetor set forth in claim 10 comprising:
a resilient diaphragm of the acceleration pump;
a float bowl engaged sealably to the body;
a cover of the acceleration pump engaged to the float bowl;
a vacuum chamber of the acceleration pump defined between the float bowl and the diaphragm; and
a fuel chamber of the acceleration pump defined between the diaphragm and the cover.
12. The combustion engine carburetor set forth in claim 11 wherein the fuel chamber communicates with the fuel-and-air mixing passage upstream of the venturi via the fuel discharge channel.
13. The combustion engine carburetor set forth in claim 12 comprising an injecting bore portion of the discharge channel defined by the body and communicating directly with the fuel-and-air mixing passage upstream of the venturi and wherein the injecting bore portion is angled to spray fuel in a downstream direction and toward the venturi.
14. The combustion engine carburetor set forth in claim 11 comprising a hose-less vacuum channel defined by the body and the float bowl and communicating between the vacuum chamber and the fuel-and-air mixing passage downstream of the throttle valve.
15. A combustion engine carburetor having a fuel-and-air mixing passage through a body, a throttle valve in the passage, a venturi upstream of the throttle valve, and a choke valve upstream of the venturi, the carburetor comprising:
a vacuum actuated acceleration fuel pump carried by the body;
a resilient diaphragm of the acceleration pump;
a float bowl engaged sealably to the body;
a cover of the acceleration pump engaged to the float bowl;
a vacuum chamber of the acceleration pump defined between the float bowl and the diaphragm;
a fuel chamber of the acceleration pump defined between the diaphragm and the cover;
a hose-less vacuum channel defined by the body and the float bowl and communicating between the vacuum chamber and the fuel-and-air mixing passage downstream of the throttle valve;
a hose-less fuel discharged channel defined by the body and communicating between the acceleration fuel pump and the fuel-and-air mixing passage between the venturi and the choke;
a cast pocket of the vacuum channel defined by the body and communicating directly with the fuel-and-air mixing passage downstream of the throttle valve; and
a bore portion of the vacuum channel defined by the body and communicating directly between the cast pocket and a port defined by a continuous face of the body which is sealed to a peripheral surface of the float bowl.