The invention relates to a hydraulic device comprising at least two cylinder-piston assemblies (8, 10) which are each of the double-action type with a front chamber (17, 20) and a rear chamber (18, 19) on either side of a piston (16, 21) and wherein the chambers of the cylinder-piston assemblies (8, 10) are connected in series in a hydraulic control circuit such that the front chamber (20) of a first assembly has a direct connection to a rear chamber (18) of a second assembly. At least one of the cylinder-piston assemblies (8, 10) is provided herein with valve means (31, 32) which open a bypass bypassing the piston of the assembly when the piston is situated close to the direct connection at the end of its stroke and the effective piston surfaces are the same in the chambers mutually connected by the direct connection.