Control valve device for an indirect acting rail vehicle pneumatic brake

The control valve unit (1) for an indirectly acting pneumatic brake of a rail vehicle has an adjusting valve (6) which in a first selected position creates a flow connection between an adjusting volume (8) and a control chamber (10), and in a second selected position creates a flow connection between the adjusting volume and a vent (18). The adjusting valve is operated by a piston (20) which in the first selected position is loaded by the main air line pressure (pHL) and a spring unit (22), and in the second position by the pressure (pA) in the control chamber.