| US 7,568,472 B2 | ||
| Controlling evaporative emissions in a fuel system | ||
| John C. Woody, Caro, Mich. (US) | ||
| Assigned to Walbro Engine Management, L.L.C., Tucson, Ariz. (US) | ||
| Filed on Jul. 15, 2008, as Appl. No. 12/173,148. | ||
| Application 12/173148 is a division of application No. 11/881476, filed on Jul. 27, 2007, granted, now 7,424,884. | ||
| Application 11/881476 is a division of application No. 11/135242, filed on May 23, 2005, granted, now 7,263,981. | ||
| Prior Publication US 2008/0276911 A1, Nov. 13, 2008 | ||
| Int. Cl. F02M 5/10 (2006.01); F02M 5/12 (2006.01) | ||
| U.S. Cl. 123—517 [123/437] | 13 Claims |
| 1. A fuel pump of a fuel system including a fuel tank and a carburetor adapted for use with an internal combustion engine,
comprising:
a carburetor having a mixing passage, a fuel bowl, a fuel nozzle communicating the mixing passage with the fuel bowl to supply
fuel from the fuel bowl to the mixing passage when the engine is operating, and a float in the fuel bowl responsive to the
level of liquid fuel in the fuel bowl to open and close a valve to supply fuel from the fuel tank to the fuel bowl; and
an accumulator pump comprising a diaphragm disposed within an interior of the fuel pump to divide the interior into a fuel
reservoir on a reservoir side of the diaphragm and an oppositely disposed actuation chamber on an actuation side of the diaphragm;
a biasing member to yieldably bias the diaphragm;
a fuel inlet to the fuel reservoir and communicating with the fuel bowl;
an inlet check valve in communication with the fuel inlet;
a fuel outlet from the fuel reservoir and communicating with at least one of the fuel tank or fuel bowl;
an outlet check valve in communication with the fuel outlet; and
the biasing member moving the diaphragm to withdraw liquid fuel from the fuel bowl and into the fuel reservoir substantially
during shutdown of the internal combustion engine.
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