Motor vehicle air bag cover having a skin with a virtually invisible tear seam formed by miniature holes

Abstract

A cover for covering an air bag in a motor vehicle has a thin elastic plastic skin, a rigid substrate and an intermediate layer of soft plastic foam. The skin has a tear seam and the substrate includes a door that is impacted by the inflating air bag and presses outward against the foam layer and the skin to tear the foam layer and the tear seam and then swing outward with a torn section of the foam layer and skin to form an opening in the cover for deployment of the air bag into the passenger space in the vehicle. The tear seam in the skin is formed with extremely small laser machined holes that are not observable to a person of normal vision when viewed from a normal viewing distance in the passenger compartment by having a maximum hole size dimension at the outer side of the skin that does not exceed about 0.0005 inches. The array of holes are arranged in a prescribed tear seam pattern and relative to each other so as to reduce the tensile strength of the skin along the tear seam by not more than about 50 percent whereby the structural integrity of the skin is maintained prior to air bag inflation but then on the occurrence of the latter, the tear seam will assuredly tear from the force of the inflating air bag to form an opening therefor in the skin.

Dependencies are inferred from the claim text.