Pre tension device tension controller of magnetic damper safety belt tightening device Pre tensioner belt tensioner for a load limiter, so that when the vehicle is in abnormal situations to take at least two safety precautions, the pre tension device comprises a clutch, clutch some and load limiters, the clutch comprises an annular groove, if some dry second connection protrusion, a convergence of the three groove at least some. The clutch includes at least some three second connection protrusion, the second protrusion inclined surface composed of cohesion on one side, and forms a right angled surface on the other side, so that some cohesion and collaboration with grooves, and promised the clutch to rotate reversely, and the upper and lower guide in the second chamber, the upper and lower internal diameter line separation and all forming, in order to guide the clutch to rotate in the winding direction;, the load limiter comprises a plurality of third connecting device, groove and a load controller, the load controller includes a torsion bar and the reel disc and cooperation. Magnetic damper For details please visit our official website: http://www.www.swlawyer.org.cn Source: http://www.www.swlawyer.org.cn? (reproduced please specify the reproduced source)