RPM Regulator for fuel injection pumps

In an rpm regulator for use with a fuel injection pump associated with an internal combustion engine, said regulator including a housing within which a suction chamber is defined, a control lever, a regulating spring assembly including at least one spring connected to the control lever, a device for generating an rpm signal and applying a corresponding force to the control lever in opposition to a force exerted by the regulating spring assembly, and an adjustment lever connected to the regulating spring assembly for adjusting the preload exerted by the regulating spring assembly, the improvement in the regulating spring assembly comprising:

• a. two holding members;
• b. two compression springs mounted within the holding members;
• c. a cylinder having a closed bottom portion and serving as one of the holding members;
• and
• d. a piston sealingly displaceable within said cylinder, said piston including a throttle aperture therein and defining an enclosed volume with said cylinder between said piston and the bottom portion of said cylinder, said enclosed volume being filled with fuel and being in communication with the suction chamber through said aperture, wherein said piston serves to separate the two compression springs from each other, and wherein relative outward movement of said holding members results in compression of said springs.