HEADREST FOR A MOTOR VEHICLE SEAT

The invention relates to a headrest (1) comprising a secondary body (4) mounted in longitudinal sliding fashion on a main body (3) via a locking device comprising a latch (5) mounted in vertical sliding fashion on said main body between a locking position - unlocking position - where it cooperates with - moves away from - a rack (6) presenting a plurality of grooves (22) presenting an inclined rear face (23) and a substantially vertical front face (24), said latch presenting a locking part of complementary shape to that of said grooves, so that said latch placed in the locking position fits snugly into the groove (22) in which it is engaged, as well as another locking part and an additional part (25) arranged so as to insert into a rear end groove (30) of the rack (6) when said secondary body is arranged at the end of travel toward the front.