To improve restraining performance of a four-point seat belt.
Right and left lap belts 3 of the four-point seat belt are taken up with a lap side retractor 2 provided in an lower part of a seat cushion 1, and right and left shoulder belts 6 joined with respective lap belts are taken up with a shoulder side retractor 8 provided in a rear part of a seat back 4. Take-up force Mr of the lap side retractor is set larger than take-up force Ms of the shoulder side retractor (Mr>Ms). Accordingly as the lap belts are prevented from being pulled up to a side of the shoulder belts according to the take-up force of the sholder belts, a position of the lap belt with respect to a waist part of an occupant is prevented from being displaced according to the lap belts to restrict a moving amount of a waist at the time of collision, and the restraining performance can be improved in the four-point seat belt with an improved fitting property using the retractor.
MIYAMOTO KAZUAKI
TERAUCHI TATSUYA
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