Abstract: To limit the power output of a hydraulic assembly consisting of plural driven hydraulic motors, hydraulic pumps driving said motors, a single pump driving motor and control means for controlling the hydraulic flow to said drive hydraulic motors, a controller is provided which is supplied with an input signal from a subtractor which in turn is supplied with signals from a reference value setting device and an actual value setting device, the actual value setting device sensing the speed of the driving motor. An output signal of the controller is applied to all of the control means and is multiplied in each control means by a signal proportional to the setting of said control means, in order to obtain the flow control signal.

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.