Multi-stage regulator for variable displacement pumps

Multi-stage regulator for a variable displacement volume pump with a pressure regulating piston to which a pressure (P) derived from the output side of a said variable displacement volume pump can be applied, and which upon increasing pressure can be displaced counter to the force of a flexible restoring element, said regulator comprising a regulating piston having a plurality of part pistons, including at least a first part piston and a second part piston, to which pressure can be simultaneously supplied, said part pistons being engagable with each other such that they can be moved simultaneously over a limited regulating distance in a parallel manner, wherein for at least said second part piston of said plurality of part pistons a stop is provided which limits the regulating distance of said second part piston in opposition to the direction of force of said restoring element as the pressure increases, wherein said first part piston of said plurality of part pistons still remains movable counter to the force of the restoring element, wherein said first and second part pistons have transferring means therebetween such that the force acting on said second part piston when being in engagement with said first part piston is transferred to said first piston via said second part piston.