Carburettor with integral accelerator pump - has cylindrical secondary fuel chamber containing piston actuated by throttle to feed fuel to main venturi

摘要

The carburettor for combustion engine consists of a choke tube n12) with a main venturi (14) and a throttle butterfly (16). A float chamber (18) communicates with the venturi feed tube (22) through jets (20). A passage (54) feeds fuel to a cylindrical chamber (25) which contains a piston (42) held in position by springs (44, 52). A lever (28), connected to the butterfly (16), actuated a rod (26) and piston (40) sliding inside the main piston (42). The bore in which it slides is grooved. When the accelerator is gently depressed, the rod and pistons descend slowly, allowing fuel to pass from the bottom to the top of the chamber through the grooves. When the accelerator is sharply depressed, the fuel cannot pass in time and it is forced into the main venturi tube (22).