Spring return seat belt winder - has two reels connected with S-shaped spiral spring and inertial blocking inside spring housing

摘要

The seat belt take up mechanism uses a spiral spring wound in S-shape onto two reels for controlled return feed action and has a ball and socket inertia blocking. The spiral spring (3) is coiled onto a working reel (1) with one end and on a feed reel (2). The connecting length of the spring forms with the two reels an S-shape. When the webbing is pulled out from the initial wound-up condition, one reel (1) rotates accordingly and the spring (3) uncoils from the reel and is taken up by the other reel where it becomes pre-stressed and provides the force which tends to return the webbing into the initial position. The housing of the reel contains an inertia blocking mechanism consisting of a ball fitted in a concave holder carrying an arm pivot on a fulcrum. The free end of the arm has a spring catch with the free end pointing towards the inner surface of a cylinder fitted with a number of teeth.