| 摘要 |
<p>An energy absorbing seat belt retractor (20) has a frame (22); and a torsion bar (70, 70') having first and second sides, rotationally supported relative to the frame. The torsion bar is either pre-torqued to create a permanent deformation therein or has an annular cross section to reduce a transition zone betweeen the torsion bar's elastic and plastic deformation regions. The retractor also includes a locking device (200) which is activated during a vehicle crash and is operative on the first side (76) of the torsion bar to stop the torsion bar from rotating. A spool (30) is connected to the second side of the torsion bar. The spool has a seat belt (36) wound thereon. When the locking device is activated to prevent the first side of the torsion bar from rotating and with a predetermined load communicated to the seat belt, the spool and the torsion bar rotate in a direction of belt protraction opposed by a reaction force generated by the pre-torqued torsion bar.</p> |
