Patent ID: 8235366

Claim:
A spring system comprising (i) a strut for arrangement between a dolly and a body of a rail vehicle, the strut comprising a non-resilient piston-in-cylinder unit with a cylinder and a piston displaceably received in the cylinder which bound a piston chamber, an abutment member, and a space arranged adjacent an end region of the abutment member remote from the piston chamber so that the space is fluidly separated from the piston chamber, wherein the piston or the cylinder is connectable to the dolly and the other of the components is connectable to the body and one or more resilient springs which cushion the body with respect to the dolly and which are connected in series to the non-resilient piston-in-cylinder unit, (ii) a hydraulic system which is in communication with the piston chamber, for varying an amount of a hydraulic medium in the piston chamber for adjusting a length of the strut, wherein the hydraulic system is non-resilient such that suspension of the rail vehicle is not ensured by the piston-in-cylinder unit and also is not ensured by the hydraulic system in communication with it, and (iii) a hydraulic accumulator connected to the space for hydraulically actuating the abutment member such that a hydraulic medium flows from the hydraulic accumulator into said space to change an end position of the piston in the cylinder in response to the piston chamber or the hydraulic system becoming pressure-less or a pressure in the piston chamber or in the hydraulic system falling below a value.