US Patent 7497463 Lining for the cover of an airbag

In order to realize the required weakening geometries in a lining material for the hinged cover of an airbag, punctures are produced on the inner side of a lining material by a puncturing needle, wherein the punctures are intermittently produced in the lining material from the inner side, the weakening geometry deviates from a straight line to ensure constant, reliable and defined tearing characteristics of the lining material, wherein for producing the lines of arbitrary weakening geometries by the punctures, the puncturing needle is oriented relative to the desired line direction in one preferred embodiment of the invention, i.e., the cutting edge of the puncturing needle is aligned with the weakening geometry to be produced.