Patent ID: 8590971

Claim:
A seat adjusting apparatus for a vehicle, comprising: a base member adapted to be provided at a vehicle floor; a supporting member pivotally supported at the base member by means of a first bearing for supporting a load applied to the supporting member; a pinion gear rotatably supported at either one of the base member and the supporting member by means of a second bearing, and driven and rotated by a driving device having a self-locking function; a sector gear integrally provided at the other one of the base member and the supporting member so as to be coaxial with the first bearing, the sector gear being formed with teeth engageable with the pinion gear at an engagement portion; and a restriction mechanism for restricting a relative rotation in at least one direction between the pinion gear and the sector gear, wherein the restriction mechanism is formed at the sector gear and includes a contact portion, the contact portion coming in contact with the pinion gear in a portion other than the engagement portion so that a component force of a reaction force acting on the pinion gear is reduced, the component force working in a direction in which the first bearing is separated away from the second bearing, and a thickness of a first tooth root of a tooth included in the teeth formed at the sector gear is larger than a thickness of a second tooth root of the other teeth formed at the sector gear, the tooth engaging with the pinion gear when the contact portion is in contact with the pinion gear.