US Patent 7364138 Membrane carburetor

A membrane carburetor (1) has a control chamber (13) which is connected via at least one fuel opening (9, 10) to an intake channel (3). The control chamber (13) is delimited by a control membrane (14). A fuel line (54) opens into the control chamber (13) via an inlet valve (15). The inlet valve (15) opens in dependence upon the deflection of the control membrane (14). The membrane carburetor (1) has an acceleration pump (30) which is actuated in dependence upon the position of a throttle element held in the intake channel (3). A good acceleration enrichment and a stable running of the internal combustion engine are achieved when the acceleration pump (30) operates hydraulically on at least one actuating member in the control chamber (13).