Variable inflation force airbag inflator

• US 20030184067A1
• Filed: 07/10/2002
• Published: 10/02/2003
• Est. Priority Date: 03/26/2002
• Status: Active Grant

• Current Assignee: Appy Risk Technologies Limited (Trak Global Group Ltd.)
• Original Assignee: Intelligent Mechatronic Systems Inc. (Trak Global Group Ltd.)
• Inventors: Axakov, Dmitri, Basir, Otman, Karray, Fakhri, Haramina, Viktor
• Granted Patent: US 6,796,581 B2
• Time in Patent Office: Days
• US Class Current: 280/741
• CPC Class Codes: B60R 2021/26029 Ignitors
• CPC Class Codes: B60R 2021/2633 with a plurality of inflation levels
• CPC Class Codes: B60R 2021/2685 comprising a plurality of pressure chambers
• CPC Class Codes: B60R 21/26 characterised by the inflation fluid source or means to control inflation fluid flow arrangement or mounting thereof to the vehicle B60R21/20; blasting cartridges for producing gas under pressure in general F42B3/04; initiators or igniters therefor F42B3/10

Abstract

An inflator for an airbag includes a container defining and outer surface and an inner compartment. A plurality of igniters are disposed within the inner compartment and are operably associated with a gas-generating unit. Each gas-generating unit is formed by a pair of matched stamped housings. Bushing separate and secure the gas-generating units in place along the outer surface of the container. Each gas-generating unit defines an annular chamber filled with gas generating material. Each of the igniters within the container are independently ignitable and are mechanically isolated from each other to prevent actuation of one igniter in response to the actuation of an adjacent igniter. The igniters are independently actuated to control the magnitude of inflation force of the airbag.

Claims

1. An airbag assembly comprising;

a container defining an inner chamber and an outer surface having a plurality of igniter openings;

a plurality of independently actuated igniters disposed within said inner chamber;

a plurality of separable gas generating units supported about said container and containing a gas-producing material associated with at least one of said igniters

said plurality of igniters substantially isolated from each other such that actuation of one of said plurality of igniters does not cause actuation of any other of said plurality of igniters.

2. The assembly of claim 1, wherein said plurality of gas generating units are mounted to said outer surface of said container and include an inlet in communication with at least one of said plurality of igniter openings and a plurality of gas output openings on an end distal from said inlets.

3. The assembly of claim 2, wherein said gas generating units define an annular compartment including a gas filter covering said gas output openings.

4. The assembly of claim 3, wherein said annular compartment of said gas generating unit is disposed about an axis of rotation centered within said container and includes a width generally transverse to said axis of rotation and a length generally perpendicular to said axis of rotation, said width decreasing with increasing perpendicular distance from said axis of rotation.

5. The assembly of claim 1, wherein said gas generating units are secured in place along said container by a plurality of bushings disposed therebetween.

6. The assembly of claim 5, wherein said bushings and said gas generating units are trapped in position along said container between a flange on one end of the container and a fastener secured to a second end.

7. The assembly of claim 5, wherein said container includes a plurality of diameters defining a plurality of shoulders and each of said gas generating units trapped between one of said shoulders and a fastener installed on an opposite side of said gas generating unit.

8. The assembly of claim 1, wherein each of said gas generating units included first and second metal housings placed adjacent to each other.

9. The assembly of claim 8, wherein said inlets are formed by corresponding notches defined by each of said first and second metal housings.

10. The assembly of claim 7, wherein each of said metal housings includes a first portion transverse to said axis of rotation, and a second portion substantially parallel to said axis of rotation.

11. The assembly of claim 1, wherein said igniters are mechanically isolated by a self hardening compound filling said interval between igniters within said container, such that one of said igniters is not actuated by actuation of an adjacent igniter.

12. The assembly of claim 1, wherein said igniters are mechanically isolated by inner walls disposed within said container to prevent actuation of one igniter in response to actuation of an adjacent igniter.

13. The assembly of claim 1, wherein each of said igniters is disposed within an igniter housing mounted within said container.

14. The assembly of claim 17, wherein said igniter housing is replaceably mounted within said container

15. The assembly of claim 1, further including a thermal screen disposed about said outer surface of said container and between said gas generating units to prevent ignition of said gas producing material by heat generated from an adjacent gas generating unit.

16. The assembly of claim 1, wherein said igniter includes at least one flange portion for mounting within a motor vehicle.

17. The assembly of claim 1, wherein each of said gas generating units includes a specific gas generating ability relative to the other gas generating units according to a predetermine relationship.

18. The assembly of claim 17, wherein there are three gas generating units and said predetermined relationship is 1:

2;

4.

19. The assembly of claim 1, wherein said each of said gas generating units forms a generally parabolic shape about said axis of rotation.

20. The assembly of claim 1, wherein each of said gas generating units forms a generally hyperbolic shape about said axis of rotation.

21. The assembly of claim 7, wherein each of said gas generating units forms a generally conical shape about said axis of rotation.

22. A method of fabricating a gas generator for an airbag assembly comprising the steps of:

a. installing a first bushing over an outer surface of a container;

b. installing a first pair of mated sections forming a first gas generating unit onto said outer surface adjacent said first bushing;

c. alternating installation of a bushing and a gas generating unit onto the outer surface of the container;

d. securing the bushings and gas generating units onto said container with a fastener secured on one end of the container.

23. The method of claim 22, further including the step of forming the mated sections from flat metal sheet.

24. The method of claim 22, further including the step of installing and mechanically isolating a plurality of igniters within an inner compartment defined by the container such that at least one of the igniters is operably associated with one of the gas generating units

25. The method of claim 22, further defined by installing three gas generators to the outer diameter of said igniter holder.

26. The method of claim 25, further including the step of defining a relationship of gas generating capacity between said three gas-generators.

27. The method of claim 26, wherein said defining a relationship step is further defined by defining a relationship of 1:

2;

4 between said gas generators.