Lumbar support unit, for vehicle seat backrest, has fluid-filled chambers with variable volumes and pump chambers with walls moved by mechanical devices to vary volume and change backrest contour

摘要

The unit has fluid-filled chambers (3), each with a variable volume, arranged inside the backrest to change its contour. Each chamber is connected to a pump chamber (5) with variable volume. The total volume of the pump chambers and the variable-volume chambers is not variable, but contains the same overall fluid volume. The pump chamber walls are moved by mechanical operating devices (6) to vary the individual volumes of the pump chambers. An Independent claim is included for a unit to vary the pump chamber volume of a lumbar support unit mechanically.