Patent ID: 7988233

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 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 cam having a cam surface to be in contact with a cam portion formed on the pawls and pressing the pawls in a direction in which the pawls are to be engaged with the inner toothed portion by rotation of the cam; a spiral spring for rotationally biasing the cam in one direction having an inner end portion engaged with the cam, an outer end portion engaged with the lower arm and a wound portion formed by winding and provided between the inner end portion and the outer end portion, and the outer end portion having a straight line portion extending consecutively from the wound portion in a tangential direction of the wound portion; and an accommodating portion provided at the lower arm and having a guide recessed portion for accommodating the straight line portion of the spiral spring and being in contact with an inner peripheral side surface of the straight line portion and at the same time being in contact with an outer peripheral side surface of the straight line portion at a portion farther toward an outer end side than a contact point with the inner peripheral side surface.