US Patent 7549700 Mechanism for thin seat lumbar

A a lumbar support has a flexible seat suspension and a supporting mechanism. The lumbar support device is capable of providing an infinite number of vertical adjustment points. The supporting mechanism is connected to the flexible seat suspension by slide elements and travels up and down the side rails of the flexible seat suspension to the seat occupant's desired position. The movement of the supporting mechanism is accomplished both vertically along the flexible seat suspersion and horizonally relative to the seat by using wire cables, tractions cables, and a series of pulleys. The pulley system reduces the load of the actuators used in the lumbar device making it possible to use smaller, less expensive actuators.