A park brake system for vehicles

A park brake system for vehicles is provided that has an actuator (10) with an electric drive motor and an electronic control unit provided with an interface. A reduction gear has an input connected to the output of the electric motor and an output member for connection to mechanical brakes of the vehicle. A command unit (22) has a transducer connected to the electronic control unit. The transducer converts position indication signals into appropriate digital signals to enable the control unit to generate corresponding brake control commands. With appropriate control signals from the electronic control unit, the mechanical brake system can thus reflect positional brake commands from the command unit (22) within an operating range from OFF to ON, including partial activation conditions of the park brake.