Patent ID: 7866753

Claim:
A vehicle seat reclining device comprising: a first arm adapted to be fixed to one of a seat cushion side and a seat back side of a vehicle seat; a second arm adapted to be fixed to the other of the seat cushion side and the seat back side of the vehicle seat and relatively rotatably supported by the first arm; an internal toothed portion provided in an inner space formed between the first arm and the second arm, the internal toothed portion being formed at the second arm; a plurality of pawls including at least one main pawl and a sub pawl provided in the inner space and movably supported by the first arm, each of the plurality of pawls having an external toothed portion engaging with or disengaging from the internal toothed portion in response to the movement of the respective pawl; a cam rotatably provided in the inner space for pushing the respective pawl to engage the external toothed portion of the respective pawl with the internal toothed portion and moving the respective pawl to disengage the external toothed portion from the internal toothed portion; a spring provided between the first arm and the cam for rotatably urging the cam in a direction in which the respective pawl is pushed by the cam; a transmitting structure provided between the plurality of pawls and the cam for transmitting and converting the rotation of the cam to the movement of the pawls; a first restricting structure disposed between the at least one main pawl and the second arm for holding the at least one main pawl in a disengagement state between the external toothed portion of the at least one main pawl and the internal toothed portion; and a second restricting structure disposed between the sub pawl, which does not include the first restricting structure, and the cam for holding the sub pawl in a disengagement state between the external toothed portion of the sub pawl and the internal toothed portion.