Patent ID: 8210507

Claim:
A spring element in which stiffness is adjusted by hydraulically produced pressure, the spring element comprising: (I) at least two elastomer layers ( 1 ), (ii) at least one non-elastic intermediate layer ( 2 ), and (iii) at least one hydraulic device ( 4 , 7 , 9 , 11 , 12 ), the elastomer layers being separated from one another by the non-elastic intermediate layer, and the non-elastic intermediate layer having a centrally arranged opening so that the spring element has, at least in an interior thereof, a continuous elastomer core region to which the individual elastomer layers are connected, and the hydraulic device being mounted at at least one of an upper and a lower end of the spring element and, by introduction of a hydraulic fluid into the spring element, hydraulic pressure causing compression of the elastomer layers ( 1 ) in a vertical direction with respect to the elastomer layers and the non-elastic intermediate layer of the spring element, and thus at least one of resulting in and increasing a hydraulic fluid-containing displacement space in the elastomer core region of the spring element; and an elastic correspondingly shaped pressure membrane ( 5 , 25 ) being arranged between the elastomer layers ( 1 ) of the spring element and the displacement space, the pressure membrane ( 5 , 25 ) being connected at its edge to the hydraulic device, resulting in a hydraulic fluid-containing membrane space ( 12 ) which, in a case of a hydraulic pressure, corresponds to the displacement space, and the hydraulic device being connected to the membrane space, via a hydraulic line ( 4 ), and comprising at least one sealing element ( 10 , 10 a , 6 , 21 , 22 , 24 ) which is prestressed and is arranged such that an increased pressure is generated on the pressure membrane in a region of the connection of the pressure membrane to the hydraulic device, compared with pressure in the membrane space, so that the membrane space is closed off in a pressure-tight manner from the elastomer layers and the non-elastic intermediate layer of the spring element and the hydraulic device.