Instrument panel with integral hidden door cover and method of manufacture thereof

• US 6,533,314 B2
• Filed: 12/30/1999
• Issued: 03/18/2003
• Est. Priority Date: 12/30/1999
• Status: Expired due to Term

• Current Assignee: Inteva Products LLC (Renco Group Incorporated)
• Original Assignee: Delphi Technologies, Inc. (BorgWarner Incorporated)
• Inventors: Merrifield, Richard Allen, Sommer, James John
• Primary Examiner(s): Dickson, Paul N.
• Assistant Examiner(s): DRAPER, DEANN L
• Application Number:
  US09/476,743
• Publication Number:
  US 20020063417A1
• Time in Patent Office: 1,174 Days
• Field of Search: 280/732, 280/728.3, 280/728.1, 264/138, 264/139, 264/163
• US Class Current: 280/728.3
• CPC Class Codes: B60R 21/2165 characterised by a tear line for defining a deployment opening

Abstract

According to the present invention, an instrument panel having an instrument panel cover including a hidden deployment region integrally formed within an inner surface thereof by an ultrasonic embossing process is provided. More specifically, the deployment region comprises at least one and preferably a plurality of scores or cuts formed in the inner surface according to a predetermined pattern. The scores represent weakened portions of the instrument panel cover designed so that the force of an inflating air bag cushion causes the instrument panel cover to separate along the scores to thereby provide an opening for the inflating air bag cushion to deploy therethrough and be directed into the passenger compartment of a vehicle. The deployment region may be defined by any number of scores and therefore may have a variety of patterns, including but not limited to “H” pattern, “U” pattern, and “I” pattern.

Claims

1. A method of forming a hidden, integral passenger air bag door in an instrument panel cover, comprising:

forming a deployment region in an inner surface of said instrument panel cover by simultaneously ultrasonically embossing a plurality of scores in said inner surface such that said plurality of scores do not pass completely through said instrument panel cover to an outer surface, said plurality of scores defining said deployment region and providing a weakened tear pattern in said inner surface so that deployment of an air bag cushion causes said deployment region to open along said at least one score;

adhering a first surface of a foam layer to said inner surface; and

adhering a substrate to a second surface of said foam layer, said substrate surface having an air bag opening disposed therein.

2. The method as in claim 1, wherein said plurality of scores are formed simultaneously by a blade of an ultrasonic device having an ultrasonic transducer.

3. The method as in claim 2, wherein said ultrasonic device includes three ultrasonic blades.

4. The method as in claim 1, wherein said blade vibrates at a predetermined ultrasonic frequency to melt said inner surface.

5. The method as in claim 1, wherein said deployment region has a shape selected from the group consisting of U-shaped, H-shaped and I-shaped.

6. A method for forming an instrument panel cover for use in a vehicle having an air bag, comprising,

a) forming an instrument panel cover of a thermoplastic material, said instrument panel cover having an exterior surface and an inner surface;

b) placing said instrument panel cover on a fixture having a vacuum system providing a vacuum environment for nesting said instrument panel cover; and

c) simultaneously and ultrasonically scoring said inner surface of said instrument panel cover by an ultrasonic device to a predetermined depth, said predetermined depth defining a remaining thickness between said predetermined depth and said exterior surface.

7. The method as in claim 6, wherein said ultrasonic device has a blade configured to define a deployment region in said instrument panel cover, said blade being vibrated by said ultrasonic device.

8. The method as in claim 7, wherein said blade melts said inner surface of said instrument panel cover.

9. The method as in claim 6, further comprising:

adhering a first surface of a foam layer to said inner surface;

adhering a substrate to said foam layer said substrate having an opening configured and dimensioned to allow an inflatable air bag to pass therethrough; and

providing a detachable door member to said substrate, said door member being configured and dimensioned to cover said opening when said door member is attached to said substrate.

10. A method of forming an air bag door in an instrument panel cover, comprising:

positioning an outer surface of said instrument panel cover on a fixture so that an inner surface of said instrument panel cover faces away from said fixture;

positioning a scoring device relative to said fixture so that said inner surface faces said scoring device;

vibrating said scoring device at a selected frequency;

extending said scoring device into contact with said inner surface, said selected frequency being sufficient to cause said scoring device to simultaneously and ultrasonically form a plurality of scores to form a score line in said inner surface without forming surface, score line comprising a plurality of simultaneously formed scores, said score line defining a deployment region of said instrument panel cover; and

withdrawing said scoring device from said inner surface and removing said instrument panel cover from said fixture.

11. The method as in claim 10, further comprising:

adhering a first surface of a foam layer to said inner surface after withdrawing said scoring device from said inner surface and removing said instrument panel cover from said fixture; and

adhering a substrate to a second surface of said foam layer, said substrate surface having an air bag opening disposed therein.

12. The method as in claim 10, wherein said fixture comprises a vacuum system for securing an outer surface of said instrument panel cover to said fixture.

13. The method as in claim 10, wherein said scoring device comprises at least one blade.

14. The method as in claim 13, further comprising:

activating a pneumatic drive system to extend and withdraw said at least one blade.

15. The method as in claim 13, wherein the number of blades in, said at least one blade depends upon a configuration of said deployment region.

16. The method as in claim 15, wherein said configuration of said deployment region has a shape selected from the group consisting of U-shaped, H-shaped and I-shaped.

17. The method as in claim 10, wherein said instrument panel cover is formed of a thermoplastic material.

18. The method as in claim 17, wherein said thermoplastic material is selected from the group consisting of a polyethylene based polyolefin elastomer and a polypropylene based thermoplastic elastomer.