| 摘要 |
Apparatus for drawing excess fuel vapors from the carburetor of an internal combustion engine utilizes a conduit having an inlet disposed adjacent the carburetor and an outlet in communication with the fuel tank for the engine. A pump in the conduit is controlled by a pressure sensitive switch which is actuated by the engine ignition system. A second conduit communicates the fuel tank with the carburetor and the pump in the first-mentioned conduit is operated to maintain a sufficient pressure head on the tank to force fuel from the tank through the second conduit and into the carburetor. The suction head created by the engine during the operation can be utilized to withdraw fumes from the tank which would otherwise escape into the atmosphere whenever the cap on the tank is removed from filling purposes. Thus a third conduit is provided in communication with the tank and with the suction head of the engine. In order to keep the engine running while fumes are being evacuated from the fuel tank, a fourth conduit is provided which intercommunicates the first and second conduits to cause fuel contained in the latter to be delivered to the carburetor for combination with air to form a combustion mixture. Appropriate valve means is operated by a lever which overlies the cap to the fuel tank so that movement of the lever to a position allowing removal of the cap directs the flow of fluid from the first conduit, through the fourth conduit, and into the second conduit while simultaneously opening the third conduit to withdraw fumes from the tank. The invention also encompases a novel delivery nozzle for supplying fuel to the tank from a storage area, which nozzle includes structure for forming an airtight seal with the tank to cause fuel to be drawn through the nozzle in response to the suction head of the engine which is withdrawing fumes from the tank.
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