Patent ID: 8251430

Claim:
A vehicle seat reclining device configured to be attached to a vehicle body and to cooperate with a locking device affixed to a tiltable backrest of a vehicle seat, the vehicle seat reclining device comprising: a rail linearly extending along a central axial line, the rail being affixable to the vehicle body so as to be at least substantially tangent to an arched path traced in space by the locking device as the backrest tilts; a slider slidably supported on the rail; a striker immovably affixed to the slider and configured to engage with the locking device; and a latch mechanism configured to selectively permit or prevent sliding of the slider along the central axial line relative to the rail, the latch mechanism including: at least one engaging portion coupled to the slider and configured to be retracted from the rail during a tilting operation and to advance toward the rail to lock the backrest in a tilted position, and a plurality of engagable portions provided on the rail and configured to engage with the advanced engaging portion to prevent the slider from sliding relative to the rail along the central axial line, wherein clearances are provided between the rail and each side of the slider in a width direction, the width direction being orthogonal to a rotational axis serving as an axis of the engaging portion when it is in engagement with the engagable portion and also being orthogonal to the central axial line, and rotatable portions project from each side of the slider in the width direction and at least narrow the clearances so as to guide rotation of the slider relative to the rail around the rotational axis.