Abstract: The seat belt system includes a locking device for locking the retractor having a sensor-weight type acceleration sensor for activating the locking device, a posture controller for controlling a posture of a sensor weight of the sensor-weight type acceleration sensor, an angle detection device for detecting a rotation angle of a backrest, and an interlocking member for allowing the angle detection device to interlock with the posture controller. The angle detection device allows the interlocking member to rotate in accordance with the reclining angle of the backrest. The posture controller F is controlled by means of the rotation of the interlocking member 11 so as to keep the sensor-weight type acceleration sensor horizontal when the reclining angle is within a range where a passenger wears the seat belt and not to interlock with the angle detection device K when the reclining angle is outside of the range.

Abstract: The seat belt system includes a locking device for locking the retractor having a sensor-weight type acceleration sensor for activating the locking device, a posture controller for controlling a posture of a sensor weight of the sensor-weight type acceleration sensor, an angle detection device for detecting a rotation angle of a backrest, and an interlocking member for allowing the angle detection device to interlock with the posture controller. The angle detection device allows the interlocking member to rotate in accordance with the reclining angle of the backrest. The posture controller F is controlled by means of the rotation of the interlocking member 11 so as to keep the sensor-weight type acceleration sensor horizontal when the reclining angle is within a range where a passenger wears the seat belt and not to interlock with the angle detection device K when the reclining angle is outside of the range.