Carburetion devices for internal combustion engine

Claim 1

Carburetion device comprising two separate supply circuits for fuel generally mixed with air, namely a main jet circuit for normal operation and an idling circuit both opening into the intake pipe of the device, which idling circuit comprises a mixing channel at which an air supply channel and a fuel supply channel terminate, provided respectively with calibrated orifices adapted to adjust the richness of the air/fuel mixture, and which is provided with an adjustable throttle enabling the user to adjust the flow of mixture which is sucked on idling through said mixing channel by means of an orifice opening into the zone of the intake pipe situated downstream of its main throttle member actuated by the driver, at least when said throttle member is closed, and a bypass passage connected to the mixing channel so as to bypass said adjustable throttle and adapted to be freed, during periods of deceleration, by a closing member which is actuated by a first suction sensitive means sensitive to the suction existing in said zone which is transmitted to it through a member sensitive to the speed of the engine, said speedsensitive member being constituted by a second suction sensitive means sensitive to the suction existing at a point of the intake pipe situated so as to pass from down-stream to upstream of the main throttle member when the latter is slightly opened, said first suction sensitive means being arranged to be subjected to atmospheric pressure when said closing member isolates said bypass passage and said second suction sensitive means being constituted by a capsule containing a spring, said capsule being housed in a chamber connected to said point of the intake pipe.