Internal combustion engine carburettor - has vent valve diaphragm subject to pressure in venture and at throttle

摘要

The i.c. engine carburettor has a float chamber vent valve controlled by the pressure in the intake. This frees or shuts an opening to atmosphere and one to the intake, being actuated by a diaphragm cell. The diaphragm (16) in the cell (17) is subjected on the one hand via a oipe (20) to the pressure in the venturi (3) and that of a spring (19), and on the other via a further pipe (23) to the pressure in the intake (1) near the throttle butterfly (2). As the butterfly is opened, the mouth (25) of the latter pipe (23) can change from downstream to upstream of it.