Trw Occupant Restraint Systems Gmbh & Co. Kg

Ralf Strobel

Hermann-Karl Weller

A belt retractor for a vehicle safety belt comprises a belt spool () rotatably mounted in a frame () and a coupling disc () rotatably mounted relative to the belt spool. With a rotation relative to the belt spool, the coupling disc can bring about a locking of the rotation of the belt spool in unwinding direction of the safety belt. The belt spool has a first friction element () and the coupling disc has a second friction element (). The first and second friction elements are positioned such that they are able to connect the belt spool and the coupling disc with each other with a friction fit.

Belt retractor

A belt retractor comprises a belt spool rotatably mounted in a frame, a locking mechanism for the belt spool with at least one locking disc connected to the belt spool, and a torque limiting member arranged in a force flow path between the belt spool and the locking disc. The torque limiting member is constructed as a friction clutch comprising two clutch faces lying opposite each other and a friction member arranged between the clutch faces. The friction member is constructed as a flat spring part having shaped sections. The shaped sections lie at least partially against at least one of the clutch faces.

Friction clutch and belt retractor with friction clutch

In a belt retractor the absolute angle of rotation of the belt reel is sensed by an incremental counter. The incremental counter is calibrated by sensing the angle of rotation of a control disc coupled to the belt reel by a reduction gear unit. The count of the incremental counter represents the absolute angle of rotation of the belt reel with high accuracy. Various components of a restraint system are controlled as a function of the thus measured absolute angle of rotation of the belt reel.

Belt retractor and method of controlling operation of an occupant restraint system

A belt retractor has a frame (,), a belt reel rotatably mounted about an axis in the frame, a control disc (,) coaxial with the belt reel and a reduction gear unit (,) which translates rotation the belt reel into a reduced rotation of the control disc. The control disc has a cutout window (,) between a pair of detector elements. The first (,) of these detector elements is connected to the belt reel for joint rotation and the second (,) is arranged as fixed relative to the frame. The window is located on the same radius as said detector elements relative to the axis. The arrangement provides a precise measurement of the absolute angle of rotation of the belt reel.

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Schwäbisch Gmünd, Germany

Ralf Strobel