The present disclosure relates to a pneumatic adjusting device for adjusting a side wing of a vehicle seat from a default position to an actuation position, the adjusting device comprising: a two-armed lever having an outer lever arm for adjusting the side wing and an inner lever arm, an inflatable balloon device, e.g. balloon, for adjusting the inner for adjusting the arm, and mechanical spring means for adjusting the inner for adjusting the arm.
Hereby, it is provided that, in the default position of the adjusting device, the balloon device is inflated, in the default position, the spring means is tensioned and biases the inner lever arm into the actuation position, and in the actuation position, the spring means compresses the balloon.