Patent ID: 7309108
Filing Date: 2007-12-18
Classification: B60N

Abstract:
1. A headrest device of a vertically movable type in combination with a seat having a seat back, which comprises: a headrest body; a stay means for supporting said headrest body upon said seat back, said means having a surface which extends rectilinearly along the longitudinal direction thereof; a lock mechanism provided on said seat back, said lock mechanism including: at least one first lock notch ( at least one second lock notch ( a lock plate movably disposed in the lock mechanism; and a biasing means for normally biasing said lock plate to contact with said surface of said stay means, so that said lock plate may be lockingly engaged in one of said at least one first lock notch ( said stay means being slidably connected with said lock mechanism so as to be movable vertically, thereby allowing said headrest body to be adjusted in height via said stay means respect to said seat back through selective engagement of said lock plate in one of said at least one first lock notch and said at lease one second lock notch; and said stay means having a plurality of recessed portions formed in the surface thereof at a region between said at least one first lock notch and said at least one second lock notch, said plurality of recessed portions being minute or small in depth so as to preclude locking engagement between said lock plate and any of said plurality of recessed portions and to only cause a change in friction between said lock plate and said plurality of recessed portions to avoid constant friction therebetween and prevent generation of friction noise when said lock plate is in sliding contact with the surface of said stay means.