Variable venturi downdraught carburettor - has mixing chamber receiving from passage defined by relatively movable venturi elements

摘要

The downdraught variable venturi carburettor has an annular fuel orifice surrounding its mixing chamber, fuel being supplied to the orifice at angularly spaced locations in response to engine operation. A movable venturi is located centrally within the carburettor body, a second venturi defining the orifice being located radially adjacent the first. The venturis define an annular restricted air passage adjacent the fuel dispensing orifice. A throttling device axially moves the first venturi relative to the second this varying the size of the restricted air passage.