Land vehicles – Wheeled – Attachment
Reexamination Certificate
2000-03-31
2001-06-19
Dickson, Paul N. (Department: 3618)
Land vehicles
Wheeled
Attachment
C280S731000
Reexamination Certificate
active
06247722
ABSTRACT:
TECHNICAL FIELD
The present invention relates to a cover for a vehicle air bag, and more particularly to a cover having one or more hidden tear seams which separate upon application of force by an inflating air bag thereby permitting the air bag to exit through the cover at the location of the separated tear seams.
BACKGROUND OF THE INVENTION
It is well known in motor vehicles to provide an air bag module for protecting a vehicle occupant. It is also generally known to provide an air bag module including an inflatable restraint cushion and an inflator for discharging gas to inflate the cushion upon sensing predetermined vehicle conditions. It is also known to provide air bag modules including cover elements overlying an inflatable restraint cushion and inflator in a stored position within the module wherein the cover elements include tear seams which open upon application of pressure by the inflatable restraint cushion during inflation such that the inflatable restraint cushion exits the module through the torn cover element.
Tear seams within prior cover elements have taken the form of: (i) scored grooves on the inner or outer surface of the cover; (ii) rows of spaced grooves on the inner surface of the cover with the grooves being closer together near the center of the cover and further apart at locations removed from the center of the cover; (iii) a continuous groove on the inner surface of the cover with the groove being deeper in portions near the center of the cover and shallower at locations removed from the center; and (iv) interconnected grooves consisting of spaced deeper grooves of substantially uniform size and shape with shallower grooves in the spaces between the deeper grooves with the deeper grooves being closer together near the center of the cover and spaced further apart at locations removed from the center.
As will be appreciated, the presence of scored grooves on the exterior of the cover may be aesthetically displeasing. When the tear seams are formed on the inner surface of the cover so as to reduce their visibility, the prior art has advocated the preferential concentration of grooves either in terms of numbers or height at the center of the cover with such concentration diminishing at locations removed from the center. Such preferential concentration of groove elements at the center of the cover may give rise to a substantial thinning of the overall cover thickness at the center which may make the cover subject to damage by externally applied forces thereby requiring premature replacement of the cover. Moreover, the high concentration of groove elements at the center of the cover may give rise to a shadowing affect which may cause the lines of fracture to be made visible to the vehicle occupants.
SUMMARY OF THE INVENTION
This invention provides advantages and alternatives over the prior art by providing a frangible cover for a vehicle air bag assembly which cover includes at least one tear seam across the inner surface of the cover which tear seam is substantially invisible at the exterior surface. The tear seam is comprised of a multiplicity of spaced apart depressions of substantially uniform depth extending from the inner surface of the cover towards the outer surface of the cover thereby reducing the thickness of the cover to a substantially uniform level at the locations of the depressions. The depressions are preferably spaced at substantially regular intervals along the length of the tear seam substantially without preferential concentration of the depressions at any one location along the tear seam. That is, the average number of depressions per unit length along the length of the tear seam will be substantially the same at the center of the seam and at locations removed from the center of the seam. The width of the depressions in the direction substantially transverse to the tear seam may vary along the length of the tear seam. Depressions of greater width may be located at the center of the tear seam.
Due to the substantially regular intervals of the depressions and their substantially uniform depth, no one area of the tear seam is thinned preferentially in comparison to other areas. Thus, incidents of damage from external forces may be reduced. Moreover, the absence of highly concentrated thinned areas may reduce the visibility of the underlying tear seam and thereby improve the aesthetic character of the final part. Controlled tearing of the seam may be effected through adjustment of the width dimension of the depressions transverse to the seam line so as to promote the initiation of seam separation at predetermined locations without the need for weakening the overall seam. Wider depressions may be disposed at the center of the seam. The depressions may be either discrete or interconnected by a shallower groove running between the individual depressions.
Thus, according to one aspect of the present invention a frangible cover is provided for disposition within a vehicle in covering relation to an inflatable air bag when the air bag is in an uninflated stored position. The cover opens by surface fracture upon application of force by the air bag as the air bag is inflated thereby permitting egress of the air bag through the cover into the vehicle interior. The cover includes an invisible tear seam disposed across the interior surface of the cover without a concentrated thinning of the cover element at any given location across the tear seam due to the substantially regular arrangement of depressions of substantially uniform height along the tear seam.
According to a further potentially preferred aspect of the present invention, a frangible cover is provided for disposition within a vehicle in covering relation to an inflatable air bag when the air bag is in an uninflated stored position. The cover opens by surface fracture upon application of force by the air bag as the air bag is inflated thereby permitting egress of the air bag through the cover into the vehicle interior. The cover includes an invisible tear seam disposed across the interior surface of the cover without a concentrated thinning of the cover element at any given location across the tear seam due to the substantially regular arrangement of depressions of substantially uniform height along the tear seam. The width of the depressions in the direction substantially transverse to the tear seam may be varied along the length of the tear seam. The width of the depressions at the center of the tear seam may be greater than the width of the depressions at the ends of the tear seam. The cover may be constructed of one or more than one layer. In the event that the cover has more than one layer, different materials may be used to form the different layers.
REFERENCES:
patent: 4148503 (1979-04-01), Shiratori et al.
patent: 4903986 (1990-02-01), Cok et al.
patent: 5060971 (1991-10-01), Nambu et al.
patent: 5248532 (1993-09-01), Sawada et al.
patent: 5292150 (1994-03-01), Watanabe et al.
patent: 5320380 (1994-06-01), Hamada et al.
patent: 5335935 (1994-08-01), Proos et al.
patent: 5730460 (1998-03-01), Niederman
patent: 5913534 (1999-06-01), Klingauf
patent: 6050594 (2000-04-01), Budnick
Brodi, Jr. James Joseph
Visconti Carl Henry
Delphi Technologies Inc.
Dickson Paul N.
Marra Kathryn A.
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