Patent ID: 6758461
Filing Date: 2004-07-06
Classification: F02M,Y10S

Abstract:
A fuel-air mixture device comprising:a primary air passage having an inlet, an adjustable throttle mounted on a rotary shaft arranged transversely of said primary air passage and an outlet; a secondary air passage having an inlet from said primary air passage between its inlet and its adjustable throttle and an outlet to said primary air passage between its adjustable throttle and its outlet; a variable orifice nozzle for introducing fuel to said primary air passage, said nozzle having a mouth for dispensing fuel into said secondary air passage upstream of its outlet; a tapered needle arranged radially of said primary air passage and positioned in said mouth to provide variability of said orifice by axial movement of said needle, said needle being arranged transversely of said primary air passage with its small diameter end directed towards said primary air passage, the arrangement being such that in use, said fuel mixes with air flowing through said secondary air passage prior to mixing with air flowing in said primary air passage; a linkage mechanism for controlling the position of said needle to the position of said adjustable throttle in said primary air passage for adjustment of said orifice of said nozzle; an actuator for said tapered needle acted on by said linkage, with said needle extending between said actuator and said fuel dispensing mouth of said nozzle, the arrangement being such that as said throttle is opened, said needle is moved away from said primary air passage and out of said mouth of said nozzle to match fuel flow from said nozzle to said position of said adjustable throttle; and an apertured vaporisation block having a plurality of air passageways through said block, which subdivide a longitudinal portion of said primary air passage between said fuel introduction position and said outlet, the arrangement being such that fuel, air flowing through the secondary air passage and air flowing through said primary air passage all pass through said air passages for mixture of the fuel and the air; and wherein said linkage maintains a cam plate carried on said transverse, throttle-carrying shaft and having a cam surface directed towards said primary air passage, with said actuator for said tapered needle bearing against said cam plate.