The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 06, 2004
Filed:
Sep. 25, 2002
Matthew A. Braun, Caro, MI (US);
Masatoshi Endo, Miyagi-ken, JP;
David L. Speirs, Cass City, MI (US);
Walbro Engine Management LLC, Cass City, MI (US);
Abstract
A fuel-air mixture control apparatus for adjusting the mixture of fuel and air that a carburetor provides to an internal combustion engine. A mixing passage provides a fuel-air mixture to one or more combustion chambers of an internal combustion engine. A main fuel supply passage provides fluid communication between a fuel source and the mixing passage through a main fuel nozzle. An idle fuel supply passage provides fluid communication between a fuel source and the mixing passage through an idle fuel nozzle. An idle fuel ratio control valve adjusts the proportion of fuel drawn into the mixing passage through the idle fuel supply passage to the flow rate of air drawn into the mixing passage. The idle fuel supply passage is in fluid communication with the main fuel nozzle. Vacuum pressure induced by flow rates across the main fuel nozzle, which exceed a predetermined flow rate, precludes idle fuel flow into the mixing passage. As such, the position of the idle fuel ratio control valve cannot affect the fuel air mixture at throttle settings that provide a flow of fuel and air equal to or exceeding the predetermined value. A main fuel flow ratio control valve adjusts the proportion of fuel drawn into the mixing passage through the main fuel supply passage to the flow rate of air drawn into the mixing passage.