Pressure regulator for a petrol injection system

Claim 1

A pressure regulator for the petrol circuit of an internal combustion engine injection system provided with intake ducts and injectors disposed in said intake ducts, said circuit comprising a petrol tank, a pump and a delivery duct connected to said injectors, the regulator comprising a casing provided with a first duct for petrol inlet and connected to said delivery duct, a second duct for petrol discharge and connected to said tank, and a third duct connected to at least one engine intake duct, the regulator also comprising a valving member engaged with a sized port disposed in said petrol discharge duct, said valving member being connected to a diaphragm, one face of which is subjected to the inlet petrol pressure, its other face being subjected to a pressure which is a function of the engine intake pressure, the regulator being characterised in that said valving member is also operationally connected to an aneroid capsule also subjected to said pressure which is a function of the engine intake pressure, said third duct having a sized port, and there is a fourth duct connected to atmosphere and having a manually adjustable variable port wherein pressure of petrol to said injectors is a controlled function of intake pressure and atmosphere pressure reacting on both said diaphragm and said aneroid capsule.