A seatbelt device comprises a webbing, a bag body and an anchor member. The webbing is applied to the body of a vehicle occupant sitting on a seat. The bag body is provided along a length direction of the webbing, and the bag body is disposed at one side of the webbing and can be inflated by pressure of a fluid supplied from a length direction one side of the bag body. A deployment portion through which the fluid can pass is provided in the bag body, being disposed at width direction outer sides and a thickness direction another side of the webbing. An insertion hole is formed in the anchor member, through which the webbing and the bag body are inserted. The webbing is folded at the thickness direction one side when applied to the body of the sitting vehicle occupant, and the deployment portion of the bag body is disposed in the insertion hole.

Systems and methods described herein relate to adaptively adjusting the load limit of a seat belt load limiter. In one embodiment, an adaptive load-limit adjustment system estimates the weight of an occupant of a vehicle seat based on sensor data. The system also adjusts the load limit of the seat belt load limiter in accordance with the estimated weight of the occupant by causing one or more pins to protrude laterally a predetermined length from a torsional bar of the seat belt load limiter to change an effective diameter of the torsional bar and thereby adjust a shear force exerted during a vehicular crash on a STF that surrounds the torsional bar between the torsional bar and a housing of the seat belt load limiter.

Systems and methods described herein relate to adaptively adjusting the load limit of a seat belt load limiter. In one embodiment, an adaptive load-limit adjustment system estimates the weight of an occupant of a vehicle seat based on sensor data. The system also adjusts the load limit of the seat belt load limiter in accordance with the estimated weight of the occupant by causing one or more pins to protrude laterally a predetermined length from a torsional bar of the seat belt load limiter to change an effective diameter of the torsional bar and thereby adjust a shear force exerted during a vehicular crash on a STF that surrounds the torsional bar between the torsional bar and a housing of the seat belt load limiter.