Adjustable vehicle seat

The seat has a lifting device (7) provided with a bead (8) made of soft and deformable material, and an arm (9) supporting the positioning bead. The arm is located in a plane beam (3) and adjustable in height for emergence of the bead. The lifting device is covered by a lining. An upper part (11) of the bead is made of foam, where the bead includes a lower base plate (10). The lifting device is controlled by a motor. The upper part of the bead is partially covered by a film.