Air bag module and steering wheel assembly

• US 6,029,992 A
• Filed: 11/24/1997
• Issued: 02/29/2000
• Est. Priority Date: 10/02/1996
• Status: Expired due to Term

• Current Assignee: Autoliv Development AB (Autoliv Incorporated)
• Original Assignee: General Motors Corporation (General Motors Company)
• Inventors: Weckesser, David Scott, Finnigan, Brian Thomas, Holmes, Francis Joseph, Niederman, Robert Raymond, Vendely, Michael Joseph
• Primary Examiner(s): Rice, Kenneth R.
• Application Number:
  US08/976,784
• Time in Patent Office: 827 Days
• Field of Search: 280/728.2, 280/731, 280/732
• US Class Current: 280/728.2
• CPC Class Codes: B60R 21/2035 using modules containing inflator, bag and cover attachable to the steering wheel as a complete sub-unit steering wheel covers with tear lines B60R21/21656; assembling of modules B60R21/217
• CPC Class Codes: B60R 21/217 Inflation fluid source retainers, e.g. reaction canisters; Connection of bags, covers, diffusers or inflation fluid sources therewith or together

Abstract

An air bag module and steering wheel assembly includes an air bag module and a steering wheel. The air bag module includes a base plate and an air bag. At least one mounting member extends from the base plate and through the air bag to attach the air bag to the base plate. A cover has at least one vertically extending side wall including at least one cover slot in which the air bag and base plate are loosely seated therein while leaving the cover free for manual removal from the base plate. The air bag is trapped in the cover slot between side wall and the base plate. The steering wheel has a receiving area for receiving the module therein for attachment to the steering wheel. An upstanding capture plate forms a vertically extending wall generally surrounding the receiving area. The capture plate engages the side wall of the cover when the module is inserted into the receiving area and captures the side wall of the cover and the air bag between the base plate and the capture plate such that the cover and the air bag are anchored to the base plate for withstanding the forces of air bag inflation.

Claims

1. An air bag module and steering wheel assembly comprising:

an air bag module including

a base plate,

an air bag,

at least one mounting member extending from the base plate and extending through the air bag to attach the air bag to the base plate; and

a cover having at least one vertically extending side wall including at least one cover slot in which the air bag and base plate are loosely seated while leaving the cover free for manual removal from the base plate, the air bag being trapped in the cover slot between side wall and the base plate; and

a steering wheel having

a receiving area for receiving the module therein for attachment to the steering wheel, and

an upstanding capture plate forming a vertically extending wall surrounding the receiving area, the capture plate engaging the side wall of the cover when the module is inserted into the receiving area and capturing the side wall of the cover and the air bag between the base plate and the capture plate such that the cover and the air bag are anchored to the base plate for withstanding the forces of air bag inflation.

2. The assembly of claim 1 further including an inflator having a radially outwardly extending inflator flange, and wherein the base plate is separate from the inflator flange, the mounting member extending through the inflator flange to connect the inflator flange to the base plate and wherein the air bag is captured between the inflator flange and the base plate.

3. The assembly of claim 1 wherein the cover slot is defined by an upper boss and a lower boss and wherein the air bag and base plate are captured between the upper and lower bosses.

4. The assembly of claim 1 wherein the cover slot is defined by an upper boss and a lower boss, the lower boss being spaced apart directly beneath the upper boss, and wherein the air bag and base plate are captured between the upper and lower bosses.

5. The assembly of claim 1 wherein the side wall of the cover includes a plurality of upper bosses and a plurality of lower bosses thereon, and wherein the lower bosses are spaced vertically beneath the upper bosses, the upper bosses being positioned above the base plate and the lower bosses being positioned below the base plate when the cover is connected to the base plate, the air bag being wrapped around the base plate for engaging both the upper and lower bosses, whereby upon insertion of the module into the receiving area of the steering wheel, the capture plate traps the air bag between the side wall and the capture plate and also traps the upper and lower bosses above and below the base plate, respectively, to anchor the cover to the base plate during air bag deployment.

6. The assembly of claim 5 wherein the upper and lower bosses are generally planar and extend generally perpendicular to and radially inward from the side wall of the cover.

7. The assembly of claim 1 wherein the side wall of the cover includes a plurality of downwardly extending tab portions each having upper and lower inwardly projecting bosses thereon, and wherein the lower bosses are spaced vertically beneath the upper bosses, the upper bosses being positioned above the base plate and the lower bosses being positioned below the base plate when the cover is connected to the base plate, the air bag being wrapped around the base plate and being positioned between the upper and lower bosses and the base plate, whereby upon insertion of the module into the receiving area of the steering wheel, the tab portions are trapped between the base plate and the vertically extending wall of the capture plate and wherein the tab portions are prevented from outward movement and wherein the respective bosses are trapped above and below the base plate to anchor the cover and the air bag to the base plate during air bag deployment.

8. The assembly of claim 7 wherein the upper and lower bosses are generally planar and extend generally perpendicular to and radially outward from the side walls of the cover.

9. The assembly of claim 1 wherein the capture plate is a single continuous plate surrounding the receiving area of the steering wheel.

10. The assembly of claim 1 wherein the steering wheel includes a mounting portion to which the module is mounted and wherein the capture plate is integrally formed with the mounting portion of the steering wheel.

11. The assembly of claim 10 wherein the vertically extending wall of the capture plate extends generally perpendicular to the mounting portion.

12. The assembly of claim 1 wherein the module is unidirectionally inserted into the receiving area of the steering wheel and wherein the vertically extending wall of the capture plate is parallel to the insertion direction of the module into the receiving area of the steering wheel.

13. The assembly of claim 1 wherein the steering wheel includes spaced apart spoke portions extending radially outward from the capture plate and wherein the cover includes a downwardly extending outer cover flange spaced radially outward from the side wall of the cover and wherein the outer cover flange extends between the spoke portions and covers the capture plate when the module is mounted in the receiving area of the steering wheel.

14. A method of assembling an air bag module and steering wheel assembly, the method comprising the steps of:

providing an air bag module including a base plate having mounting members extending downwardly therefrom and an air bag having a mouth portion including apertures therein;

inserting the mounting members through respective air bag apertures and wrapping the mouth portion of the air bag around an outer edge of the base plate to loosely connect the air bag to the base plate;

providing a cover of the module having a vertically extending side wall including a plurality of inwardly projecting upper and lower bosses thereon;

pulling the cover over the base plate and inserting the base plate and air bag between the upper and lower bosses to loosely connect the cover to the base plate for transport and storage while leaving the cover free for removal from the base plate;

providing a steering wheel including a receiving area for receiving the module therein and the steering wheel having a capture plate including an upstanding vertical wall surrounding the receiving area; and

inserting the module into the receiving area such that the vertical wall engages the side wall of the cover and simultaneously capturing the side wall of the cover and the air bag between the base plate and the vertical wall of the steering wheel such that the cover is anchored to the base plate for withstanding the forces of air bag inflation and such that the base plate and air bag are securely trapped between the upper and lower bosses.

15. The method of claim 14 further including the steps of providing an inflator having a radially outwardly extending inflator flange that is separate from the base plate and capturing the air bag between the inflator flange and the base plate.

16. A method of assembling an air bag module and steering wheel assembly, the method comprising the steps of:

providing an air bag module including a base plate having mounting members extending downwardly therefrom and an air bag having a mouth portion including apertures therein;

inserting the mounting members through respective air bag apertures and wrapping the mouth portion of the air bag around an outer edge of the base plate to loosely connect the air bag to the base plate;

providing a cover of the module having a vertically extending side wall including at least one circumferentially extending cover slot thereon;

pulling the cover over the base plate and inserting the base plate and air bag within the cover slot to loosely connect the cover to the base plate for transport and storage while leaving the cover free for removal from the base plate;

providing a steering wheel including a receiving area for receiving the module therein and the steering wheel having a capture plate including an upstanding vertical wall surrounding the receiving area; and

inserting the module into the receiving area such that the vertical wall engages the side wall of the cover and simultaneously capturing the side wall of the cover and the air bag between the base plate and the vertical wall of the steering wheel such that the cover is anchored to the base plate for withstanding the forces of air bag inflation and such that the base plate and air bag are securely trapped in the cover slot.

17. The method of claim 16 further including the steps of providing an inflator having a radially outwardly extending inflator flange that is separate from the base plate and capturing the air bag between the inflator flange and the base plate.