Seat structure for motor vehicle, has backrest structure including mobile structure elastically returned to safety position when force exerted on support body exceeds preset value and starts to displace mobile structure to safety position

摘要

The structure has a backrest structure including a mobile structure that carries a headrest (3). The mobile structure is mounted movably on a fixed structure (2c) between a normal usage position (38a) and a safety position (38b) in which the headrest is moved forward. The mobile structure is maintained in the position (38a) until a force (F) exerted rearwards on a support body of the mobile structure remains below a preset value. The mobile structure is elastically returned to the position (38b) when the force exceeds the value and starts to displace the mobile structure to the position (38b).