Abstract: To reduce the piston velocity in a cylinder as the piston approaches the end positions, a signal transmitter is provided for sensing the position of a part driven by means of the piston and cylinder assembly, and thus of the piston in the cylinder. The signal of the signal transmitter is applied to a control unit in which it is compared with a signal from an actuator means. The signal from the actuator means controls the extension and shortening of the piston and cylinder assembly and the velocity at which this occurs, and may be positive or negative. The comparison of signals is so exploited that if it is established by this comparison that the piston is not in the areas of the end positions or, alternatively is in these areas but is activated by the actuator means to move away therefrom, the signal from the actuator means is not acted upon, whereas if the piston is in these areas and approaches the end positions, the hydraulic fluid supply to the piston and cylinder assembly is continuously reduced.