Load-bearing shaped parts can be used in various fields of engineering. As an example, various applications in the field of vehicle occupant restraint systems are explained hereinbelow. However, it is expressly pointed out that the invention can be applied to all fields of engineering.
A shaped part to which the invention can be applied is, for example, a locking catch which can be used to connect a belt tensioner drive with the belt spool of a belt winder. The locking catch is part of a coupling which in normal state separates the belt winder from the belt tensioner drive, so that the belt spool of the belt winder is freely rotatable. If, however, the belt tensioner drive is activated, for example by a sensor arranged on the vehicle, which establishes that given thresholds of the vehicle deceleration have been exceeded, the belt tensioner drive must be coupled with the belt spool within the shortest period of time, in order to provide a rotation of the belt spool in the belt webbing winding direction. Owing to the required short response time and also the moment of rotation which is to be transferred, the locking catch is exposed here to high stresses.
In order to reliably reach the desired strength, the locking catch is usually produced as a sintered piece. In this way, in addition to the necessary strength, also the required accuracy of shape can be obtained. Alternatively, such a shaped part can also be produced by machine working of a blank made of steel. In each case, high manufacturing costs are incurred. In addition, cold impact pressings of steel are known. A disadvantage here is the high expenditure of energy on forming. Furthermore, in shaped parts of steel, the comparatively high weight is a disadvantage.