DEVICE FOR SECURELY ADJUSTING THE HEIGHT OF A HEADREST, IN PARTICULAR FOR A MOTOR VEHICLE SEAT

摘要

The invention concerns a device for securely adjusting the height of a headrest, in particular for a motor vehicle seat, said headrest comprising at least a spindle engaged inside a sleeve (1; 30) integral with the structure (2) of said seat. The invention is characterised in that it comprises at least a ring (3; 32) provided in a housing (12) of said sleeve and arranged for receiving and clamping said spindle, said ring and said housing having cam surfaces (15, 17, 18, 19) co-operating so that the ring selectively tightens or loosens said spindle when said ring is subjected, by means of said spindle, to predetermined direction stresses.