Patent ID: 6908521
Filing Date: 2005-06-21
Classification: B60R

Abstract:
1. A method of manufacturing a portion of a dashboard presenting an outside, an inside, and a wall including a cover for an air bag protection system placed behind the dashboard, as seen from the outside, the cover being invisible from the outside and being defined at its margin by a line of weakness in the wall of the dashboard, said line of weakness being visible from the inside and defining an opening for the air bag(s), the method comprising the following steps: a) injection molding a layer of hard plastics material; b) locally making a line of weakness in the layer of hard plastics material, from the inside; c) covering the layer of hard plastics material on the outside with a decorative covering; d) providing a tab having a hinge for hinging the cover relative to a reinforcing frame of hard plastics material adapted to be fastened to the inside of the dashboard and defining an ejection channel for the air bag(s), the tab being naturally sensitive to vibration generated by a device for welding plastics material by vibration and thus being naturally liable to transmit said vibration, said tab being adapted to be fastened to said layer of hard plastics material and to the reinforcing frame in the vicinity of the cover in areas that are situated on the inside of the dashboard; e) fastening the tab to the cover; f) in order to fasten the reinforcing frame to the dashboard, vibration welding it to the layer of hard plastics material in the immediate vicinity of the line of weakness, and prior to performing said welding, ensuring that a vibratory discontinuity exists between the reinforcing frame and the tab so that while the reinforcing frame is being welded, at least some of the vibration generated by the welding is absorbed away from the line of weakness defining the cover; and g) immediately before step f) or after said step, fastening the tab to the reinforcing frame.