Operation

The Punto 97 range has a new type of pre-tensioner with a "BILEVEL" mechanical sensor; the differences compared with the previous versions are outlined below.

OPERATION

Sensor in rest position

The "BILEVEL" mechanical sensor comprises 2 masses, m1 and m2 and opposing springs. Mass m1 is very much bigger than mass m2.

In the case of an event which does not involve activation, the acceleration value creates a speed (of around 0.2 m/sec) at mass m1 which, after having travelled distance S1, is not sufficient to move the second mass m2 by distance S2 required to release the grille (1) and the striker (2) and thereby cause the activation of the pre-tensioner. The 2 masses m1 and m2 return to their original positions.

Sensor during operation

In the case of an event which involves activation, the acceleration value creates a speed (around 1.3 m/sec) at mass m1 sufficient to complete travel S1 and consequently thrust the second mass m2 to produce the movement S2. At the end of the movement S2 the second mass releases the grille (1) which frees the striker (2) which activates the pyrotechnic charge (3).