US Patent 7621596 Lumbar support

The invention relates to a lumbar support comprising a plurality of pneumatically operated chambers (11-14) for adjusting the curvature of a seat back, wherein the lumbar support comprises two outer chambers (11, 12) and two central chambers (13, 14) in the longitudinal direction of the seat back, wherein the two central chambers (13, 14) are arranged over one another perpendicularly to the longitudinal direction of the seat back between the two outer chambers, wherein each outer chamber has an air connection to one of the two central chambers.