A drive system with a signal transmitter (2) which can be actuated by physical effort and utilises hydraulic, pneumatic or electric auxiliary power is proposed for a device which influences the movement of one or more drives in intermediate positions. So that an operator deliberately has the opportunity of working efficiently, the signal transmitter (2) and/or an actuating member (1) connected to it can be acted upon by a restoring force, is effective in the opposite direction during actuation by physical effort and can be controlled by load-dependent signals of the drive system. <IMAGE>
