Patent ID: 7469853

Claim:
A seatbelt retractor comprising: a spool formed into a hollow cylindrical shape and is capable of winding a seatbelt onto a spool outer periphery or unwinding the seatbelt from the spool outer periphery, wherein the seatbelt is adapted to be worn by a vehicle occupant seated in a seat; a seatbelt retractor housing in which at least the spool is accommodated; a motor configured to rotate the spool in the belt winding direction or the belt unwinding direction; a motor speed-reduction mechanism configured to reduce the rotational speed of the motor via a plurality of gears between the driving shaft of the motor and the spool; and a control mechanism configured to control the operation of the motor, wherein the correlation among the volume V 1 of a motor housing of the motor, the volume V 2 of a cylinder portion of the spool, and a storage volume V 3 within the seatbelt retractor housing is V 3 <V 1 +V 2 , wherein the storage volume V 3 is a volume of the inner space of a roll formed by the seatbelt in the wound-up state, wherein the motor is accommodated in the cylinder portion of the spool, and wherein the length of the spool is substantially the same as the length of the motor housing.