Operation

OPERATION

The operation of the device is based on the action of the inertial force, resulting from the vehicle’s deceleration, on the mass of the cylinder-piston assembly.

The lever E is hinged on F to the cylinder-piston assembly. In the rest condition, this lever is subjected to the tension of the spring I and is locked by the lug G.

When, following a crash, the inertial force acting on the mass of the assembly A overcomes the force I, the assembly rotates slightly and releases the lever E from the lug G.

Pulled by the spring I, the lever acts as a striker on the trigger of the charge D.

The gas released from the combustion (mainly nitrogen, and so harmless) pushes the piston B along the tube A. The piston pulls with it the steel cable C, attached at the other end to the belt winding reel, so winding the belt by an amount which varies depending on the type and speed of impact of the car. After intervention, the belt remains locked, so indicating that the device has intervened.