Abstract: A seat back or a seat base of an automobile seat with a frame includes a spring system extending between two opposing cross braces consisting of meander-shaped shaped spring wires and upholstery in a seat surface. The level determined by the supporting surface of the shaped wire springs may be so changed by tension belts passing through the shaped wire springs at different tensions that it is more strongly arched when the belts are in relaxed condition than when they are tightened.

Abstract: A car seat having a seat part and a central spring system for the seat part. The central spring system can be adjusted to vary the hardness of the seat part. Additionally, the car seat is provided with side reinforcements on the seat part that extend in the traveling direction, whose position or the position of their upper edge regions is adjustable in accordance with the hardness of the spring system of the seat. The adjustment of the spring system is such that a greater degree of hardness corresponds to a higher position of the upper edge regions of the side reinforcements.

Abstract: An adjustable backrest of a motor vehicle seat is provided. The backrest includes two vertical, laterally undivided stationary supportive areas, and a central supportive area arranged between them. The central supportive area includes an upper section, as a guided headrest, the height of which may be adjusted. The central supportive area, that is provided beneath the headrest, is embodied in such a way as to be divided horizontally into a lower and a central section. The lower section is arranged to be stationary and the central section is arranged such that its height may be adjusted.

Abstract: A motor vehicle seat with a belt that can be stretched across the lower back portion of the seat. The belt can be tightened to varying degrees, and serves as a lordotic support. One end of the belt winds onto a belt drum that can be activated by a hand-operated wheel.

Abstract: A seat back or a seat base of an automobile seat with a frame includes a spring system extending between two opposing cross braces consisting of meander-shaped shaped spring wires and upholstery in a seat surface. The level determined by the supporting surface of the shaped wire springs may be so changed by tension belts passing through the shaped wire springs at different tensions that it is more strongly arched when the belts are in relaxed condition than when they are tightened.