Fuel supply system for internal combustion engines

A fuel supply system for an internal combustion engine comprising:

• a fuel pump for pumping fuel from a fuel tank to a fuel distributor;
• a pressure regulator connected between the fuel pump and the fuel distributor to respond to pressure of the fuel pumped by the fuel pump, to return fuel back to said fuel tank as a function of the pressure of the pumped fuel,
• a pressure reducer between the pressure regulator and the fuel distributor to reduce the pressure of the fuel delivered to the fuel distributor to a value lower than the pressure of the fuel at the pressure regulator,
• a fuel line connecting said fuel pump to said fuel distributor via said pressure regulator and said pressure reducer, and a branch line connecting said fuel line to a return line to said fuel tank via said pressure regulator,
• said pressure regulator including a variable volume storage chamber for receiving fuel pumped by said fuel pump,
• a displaceable member defining separated first and second chambers of variable volume, one of said chambers being said storage chamber and being connected to the fuel line to receive the fuel pumped by the fuel pump and the other of said chambers being connected to said return line, and
• a regulator valve responsive to change of volume of said storage chamber, said regulator valve including a valve closure member selectively connecting said other of the chambers with said branch line, said valve closure member being operatively coupled to said displaceable member by a lost motion connection, said regulator valve being in open state when the volume of the storage chamber is relatively large and in closed state when the volume of the storage chamber is relatively small, said open and closed states of said regulator valve corresponding to a relatively large change in volume of said storage chamber, said regulator valve remaining in closed state as said storage chamber undergoes change in volume between said relatively small volume and said relatively large volume.