Patent ID: 7669933

Claim:
A headrest mechanism, comprising: a headrest stay provided in a headrest; a headrest support, the headrest support comprising a locking portion, wherein the headrest stay is inserted into, and pulled out of the headrest support, a height of the headrest is adjusted by moving the headrest stay, and an adjustment operation and a pullout operation are performed in the headrest support; an engagement member, provided in the headrest support; a plurality of adjustment portions provided in the headrest stay, wherein movement of the headrest stay is prevented by engagement of the engagement member with one of the plurality of adjustment portions, and the engagement member disengages from the one of the plurality of adjustment portions when the adjustment operation is performed in the headrest support to allow the headrest stay to move; and a pullout prevention portion provided in the headrest stay, wherein the headrest stay is prevented from being pulled out by engagement of the engagement member with the pullout prevention portion, and the engagement of the engagement member is prohibited only when the pullout operation is performed in the headrest support to allow the headrest stay to be pulled out, wherein: the pullout operation includes a first operation and a second operation; the engagement member further comprises a first engagement portion and a second engagement portion; movement of the headrest stay is prevented by engagement of the first engagement portion with one of the plurality of adjustment portions provided in the headrest stay; the headrest stay is prevented from being pulled out by engagement of the second engagement portion with the pullout prevention portion provided in the headrest stay; when the adjustment operation is performed in the headrest support, the first engagement portion disengages from the one of the plurality of adjustment portions to allow the headrest stay to move; when the first operation of the pullout operation is performed in the headrest support, the second engagement portion disengages from the pullout prevention portion, and the first engagement portion engages with the pullout prevention portion; when the second operation of the pullout operation is performed in the headrest support, the first engagement portion disengages from the pullout prevention portion to allow the headrest stay to be pulled out; and the first operation of the pullout operation comprises rotating the locking portion of the headrest support from a first position to a second position.