Charge forming apparatus with variable air-fuel ratio control

Claim 1

Charge forming apparatus including a body member having an air induction passage defined therein provided with throttle means arranged for regulating the rate of air flow therethrough, said body member having fuel passage means defined therein including a fuel channel extending into said air induction passage, said fuel channel including an exposed gap facing substantially upstream of said air induction passage permitting impingement of an air stream upon a fuel stream in said fuel channel for deflecting fuel from said fuel channel into said induction passage in proportion to air flowing in said induction passage, forming an air and fuel mixture therein, wherein the improvement comprises an intermittently movable shield mounted for overlapping a portion of said gap defining a variable exposed gap length, including a spring connected between said body member and said shield, resiliently supporting said shield in a selected position with respect to said fuel channel gap, and drive means operatively coupled with said shield for displacing said shield from said selected position thereby changing the length of said exposed gap, said drive means being remotely operable for controlling the position of said shield with respect to said gap providing variable adjustment of the ratio of fuel and air in said induction passage.