Motor vehicle seat head-rest, has locking unit with unlocking drive mechanism having electromagnet or piezoelectric drive, and retaining unit connected to movable unlocking unit through balls, where mechanism moves unlocking unit

摘要

The head-rest has a locking unit, controlled by a collision sensor (38), with an unlocking drive mechanism having an electromagnet or a piezoelectric drive (40). The unit has retaining unit (42) connected to an assembly, and a movable unlocking unit (44) connected to another assembly. The units (42, 44) are in contact with each other through balls. The mechanism is associated to the unit (44) to move the unit (44). The former assembly includes fixation units for a fixation on a backrest (22) of a motor vehicle seat. The latter assembly includes a support pad (24) and is displaced with respect to the former assembly.