Carburetor and method of operation - Patent Review 4217314

Claims

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A carburetor comprising an induction passage, a throttle in said induction passage, a fuel passage, a metering apparatus reciprocable between a lean position and a rich position and including a metering element effective to restrict fuel flow through said fuel passage in said lean position and to permit increased fuel flow through said fuel passage in said rich position, said metering apparatus further including a force producing piston member responsive to the pressure in said induction passage downstream of said throttle for biasing said metering apparatus toward said lean position, and a force producing spring member having a bias opposing the bias of said piston member and effective to move said metering apparatus to said rich position when said pressure is above a predetermined level, and wherein said carburetor also comprises a solenoid coil and said metering apparatus also includes a solenoid armature which upon energization of said coil has a bias supplementing the bias of one of said force producing members and opposing the bias of the other force producing member, whereby said metering apparatus is disposed in a position determined by energization of said solenoid coil when said pressure is below a certain level and in said rich position when said pressure is above said certain level.

2. A carburetor comprising an induction passage, a throttle in said induction passage, a fuel passage, a metering apparatus reciprocable between a lean position and a rich position and including a metering element effective to restrict fuel flow through said fuel passage in said lean position and to permit increased fuel flow through said fuel passage in said rich position, said metering apparatus further including a force producing piston member responsive to the pressure in said induction passage downstream of said throttle for biasing said metering apparatus toward said lean position, and a force producing spring member having a bias opposing the bias of said piston member and effective to move said metering apparatus to said rich position when said pressure is above a predetermined level, and wherein said carburetor also comprises a solenoid coil energized according to a duty cycle and said metering apparatus also includes a solenoid armature which upon energization of said coil has a bias supplementing the bias of one of said force producing members and opposing the bias of the other force producing member, whereby when said pressure is below a certain level said metering apparatus is disposed in said lean position during a portion of the duty cycle and in said rich position during the remainder of the duty cycle, and whereby when said pressure is above said certain level said metering apparatus is continuously disposed in said rich position.

3. A carburetor comprising an induction passage, a throttle in said induction passage, a fuel passage, a metering apparatus reciprocable between a lean position and a rich position and including a metering element effective to restrict fuel flow through said fuel passage in said lean position and to permit increased fuel flow through said fuel passage in said rich position, said metering apparatus further including a piston responsive to the pressure in said induction passage downstream of said throttle for biasing said metering apparatus toward said lean position, and a spring having a bias opposing the bias of said piston and effective to move said metering apparatus to said rich position when said pressure is above a predetermined level, and wherein said carburetor also comprises a solenoid coil energized according to a duty cycle and said metering apparatus also includes a solenoid armature which during energization of said coil has a bias supplementing the bias of said spring and opposing the bias of said piston, whereby when said pressure is below a certain level said metering apparatus is disposed in said rich position when said coil is energized and in said lean position when said coil is not energized, and whereby when said pressure is above said certain level said metering apparatus is disposed in said rich position both when said coil is energized and when said coil is not energized.

4. A carburetor comprising an induction passage, a throttle in said induction passage, a fuel passage, a metering