Roll bar device with a case fixed on the vehicle

Rollover protection systems of this kind typically have a rollover bar that can be extended in the event of danger and is guided in a cassette that is fixed to the vehicle and can be extended and retracted. A number of constructions have become known for the structure of this cassette, whose manufacturing costs and weight are relatively high. According to the invention, a relatively lightweight cassette can be produced by simple means through a structure of the cassette consisting of two sheet metal shells, a large-area, tall cassette front part (1) and a lower cassette closing plate (2), which both each have two half shells (1a, 2a) for accommodating support tubes (3), the length of which is preferably determined according to the height of the cassette closing plate (2), and which are fastened in the mutually opposite half shells (1a, 2a) of the cassette front part (1) and the cassette closing plate (2) in a dimensionally accurate manner corresponding to the distance between the two legs of the rollover bar (13).