Operation (page 3 of 3)

The action of the main spring (9) for the power unit tensions the bowden cable (6) connected to the locking cable, which, in turn, activates the retraction of the seat belt webbing.

On account of the tension induced by the passenger on the webbing and the counter-force of the main spring (9), once the device is activated, the belt tends to be released. For this purpose a locking system has been introduced, incorporating a locking ellipse (15) in the anchorage cable which, at the end of the tensioning, is driven by the splining in the outer casing (14) and is kept there by the safety spring (13). This prevents the release of the belt.

The diagram illustrates the webbing locking system. In detail A the locking ellipse (15) is driven by the splining in the outer casing (14) by the action of the safety spring (13) when the belt is retracted by the bowden cable. In detail B the ellipse (15) is locked when the webbing retraction cable tends to return to the original position.