Patent ID: 8002352

Claim:
A seat reclining device comprising: a lower arm adapted to be fixed to a seat cushion side; an upper arm relatively rotatably supported by the lower arm and adapted to be fixed to a seat back side; a plurality of pawls disposed within the lower arm and movable in a radial direction guided by guide walls, and respectively having an outer toothed portion engageable with or disengageable from an inner toothed portion provided at an inner periphery of the upper arm; a wedge member provided between at least one of the plurality of pawls and the guide wall; a cam having a cam surface to be in contact with cam portions formed on the plurality of pawls and pressing the pawls in a direction in which the pawls are to be engaged with the inner toothed portion by a rotation of the cam, and having a wedge pressing cam portion for pressing the wedge member outwardly in a radial direction thereby rotating the upper arm relative to the lower arm; and a biasing member for rotationally biasing the cam in one direction.