Patent ID: 7478998

Claim:
A supply device configured to supply pressure fluid into at least one vehicle brake, said supply device comprising: a pressure fluid inlet, a pressure fluid outlet, a piston is movably arranged in a bore of an accommodating member and has at least two hydraulically active diameters to supply pressure fluid in a direction of the pressure fluid outlet, at least one non-return valve is used for ventilation of a working chamber into which the piston is immersed, wherein the piston has a multi-part design and comprises at least two synchronously movable partial pistons, with a first partial piston exhibiting a first hydraulically active diameter, and a second partial piston exhibiting a second hydraulically active diameter, the first hydraulically active diameter of the first partial piston defining a pre-charging mechanism, wherein the first partial piston is defined by a cylindrical body of substantially constant diameter and the second partial piston includes a sealing seat for a valve member of the at least one non-return valve.