Ultrasonic Blade Design for Scoring Double Angle Groove And Products Therefrom

Abstract

The present invention relates to the formation of a double angle V-groove in the backside of plastic shells to provide a preweakened section for a vehicle application. The double angle V-groove may be located at the airbag deployment opening of a vehicle.

1 . A method for providing a weakening groove in the underside of a plastic skin to be used as the covering layer for an instrument panel which overlies an inflatable air bag device in the interior of a vehicle, comprising the steps of: 
 molding a plastic skin,    providing an ultrasonic knife having a double angle blade,    contacting the underside of the plastic skin with said double angle knife blade,    scoring the underside of said plastic skin with said knife blade, wherein said double angle blade comprises the following general shape:                          wherein angle A is less than angle B.