Multiple layered gas generating disk for use in gas generators

• US 5,507,890 A
• Filed: 05/17/1994
• Issued: 04/16/1996
• Est. Priority Date: 06/05/1992
• Status: Expired due to Fees

• Current Assignee: TRW Limited (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Original Assignee: TRW Limited (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Inventors: Swann, Timothy A., Boehmer, Eldron L.
• Primary Examiner(s): Walsh, Donald P.
• Assistant Examiner(s): CHI, ANTHONY
• Application Number:
  US08/243,988
• Time in Patent Office: 700 Days
• Field of Search: 149/14, 149/15, 149/16, 149/35
• US Class Current: 149/16
• CPC Class Codes: B01J 7/00 Apparatus for generating gases production of inert gas mixtures B01J19/14; for generating specific gases, see the relevant subclasses, e.g. C01B, C10J ; in "air bags" on vehicles B60R21/26; for starter gas F02C7/26; blasting cartridges for producing gas under pressure F42B3/04
• CPC Class Codes: B60R 21/2644 using only solid reacting substances, e.g. pellets, powder
• CPC Class Codes: C06B 35/00 Compositions containing a metal azide
• CPC Class Codes: C06B 45/16 the layer or zone containing at least one inorganic component from the group of azide, fulminate, phosphorus and phosphide
• CPC Class Codes: C06D 5/06 by reaction of two or more solids

Abstract

The present invention resides in a body of material which is ignitable to generate a gas for inflating an air bag. The body of material comprises at least two layers of ignitable gas generating material which are pressed together. One of the layers comprises a nitrogen generating composition which is easily ignited and burns rapidly. The other of the layers comprises a nitrogen generating composition which is less easily ignited and burns less rapidly than the one layer.

Claims

1. A body of material which is ignitable to generate a gas for inflating an air bag comprising:

three contiguous layers of particulate gas generating material, the intermediate layer of said layers comprising a particulate nitrogen generating composition which is easily ignited and burns rapidly; and

the outer two layers of said layers comprising a particulate nitrogen generating composition which is less easily ignited than said intermediate layer and burns more slowly than said intermediate layer wherein said body is cylindrical in configuration and said layers being pressed together, the layers extending transverse to the axis of said cylindrical configuration; and

wherein the thickness of one of said layers relative to any other layer is in the range of 20;

80 to 80;

20.

2. The body of claim 1 in which each of said layers of gas generating material comprises an azide and an oxidizer.

3. The body of claim 2 in which said azide is an alkali metal azide and the oxidizer in each of said layers is a metal oxide, the metal oxide of said intermediate layer being cupric oxide, and the metal oxide of said outer layers being iron oxide.

4. The body of claim 1 in the form of disks.

5. The body of claim 1 in the form of pellets.

6. A body of material which is ignitable to generate a gas for inflating an air bag comprising:

at least two contiguous layers of particulate gas generating material, each of said layers having opposed, distinct surfaces;

one of said layers comprising a particulate nitrogen generating composition which is easily ignited and burns rapidly; and

a second of said layers comprising a particulate nitrogen generating composition which is less easily ignited than said first layer and burns more slowly than said first layer,

said body being cylindrical in configuration and having a longitudinal axis which intersects each of said layers;

each of said layers having a thickness sufficient for the layer to contribute to the sustained burn of the body of material, the thickness of said one layer relative to the thickness of any other layer being in the range of 20;

80 to 80;

20.

7. The body of claim 6 in which each of said layers of gas generating material comprises an azide and an oxidizer, said layers being pressed together.

8. The body of claim 7 in which said azide is an alkali metal azide and said oxidizer of said one of said layers is a different oxidizer from the oxidizer in said second of said layers.

9. The body of claim 8 in which said azide is an alkali metal azide and the oxidizer in each of said layers is a metal oxide, the metal oxide of said one of said layers being cupric oxide, and the metal oxide of said second of said layers being iron oxide.

10. The body of claim 9 comprising three layers, wherein the intermediate layer is made of a faster burning material than the outer layers.

11. The body of claim 6 in the form of disks.

12. The body of claim 6 in the form of pellets.

13. A body of material which is ignitable to generate a gas for inflating an air bag comprising:

at least two contiguous layers of particulate gas generating material, each of said layers having opposed, distinct surfaces;

one of said layers comprising a particulate nitrogen generating composition which is easily ignited and burns rapidly; and

a second of said layers comprising a particulate nitrogen generating composition which is less easily ignited than said first layer and burns more slowly than said first layer;

in which the slower burning composition forms a sinter on burning, and the faster burning composition forms a molten metal on burning, the molten metal plating on the sinter of the slower burning composition on burning.

14. The body of claim 13 in which each of said layers of gas generating material comprises an azide and a metal oxide, the metal oxide of the faster burning layer being cupric oxide, and the metal oxide of the slower burning layer being iron oxide.

15. The body of claim 14 comprising three layers, wherein the intermediate layer is a layer of faster burning composition than the outer layers.

16. The body of claim 15 being cylindrical in configuration and comprising a plurality of layers pressed together, the layers extending transverse to the axis of said cylindrical configuration.

17. The body of claim 16 in the form of disks.

18. The body of claim 16 in the form of pellets.

19. An apparatus for protecting a vehicle occupant during a collision comprising:

an air bag;

means for inflating said air bag including at least one body of gas generating material which is ignitable to generate a gas for inflating said air bag, said body comprising;

three contiguous layers of particulate gas generating material, the intermediate layer of said layers comprising a particulate nitrogen generating composition which is easily ignited and burns rapidly; and

the outer two layers of said layers comprising a particulate nitrogen generating composition which is less easily ignited than said intermediate layer and burns more slowly than said intermediate layer wherein said body is cylindrical in configuration and said layers being pressed together, the layers extending transverse to the axis of said cylindrical configuration; and

wherein the thickness of one of said layers relative to any other layer is in the range of 20;

80 to 80;

20.

20. An apparatus for protecting a vehicle occupant during a collision, said apparatus comprising:

an air bag;

means for inflating said air bag including at least one body of gas generating material which is ignitable to generate a gas for inflating said air bag, said body comprising;

at least two contiguous layers of particulate gas generating material, each of said layers having opposed, distinct surfaces,

one of said layers comprising a particulate nitrogen generating composition which is easily ignited and burns rapidly, and

a second of said layers comprising a particulate nitrogen generating composition which is less easily ignited than said first layer and burns more slowly than said first layer,

said body being cylindrical in configuration and having a longitudinal axis which intersects each of said layers,

each of said layers having a thickness sufficient for the layer to contribute to the sustained burn of the body of material, the thickness of said one layer relative to the thickness of any other layer being in the range of 20;

80 to 80;

20.

21. An apparatus for protecting a vehicle occupant during a collision, said apparatus comprising:

an air bag;

means for inflating said air bag including at least one body of gas generating material which is ignitable to generate a gas for inflating said air bag, said body comprising;

at least two contiguous layers of particulate gas generating material, each of said layers having opposed, distinct surfaces,

one of said layers comprising a particulate nitrogen generating composition which is easily ignited and burns rapidly, and

a second of said layers comprising a particulate nitrogen generating composition which is less easily ignited than said first layer and burns more slowly than said first layer,

in which the slower burning composition forms a sinter on burning, and the faster burning composition forms a molten metal on burning, the molten metal plating on the sinter of the slower burning composition on burning.

22. A body of material which is ignitable to generate a gas for inflating an air bag comprising:

at least two contiguous layers of particulate gas generating material, each of said layers having opposed, distinct surfaces;

one of said layers comprising a particulate nitrogen generating composition which is easily ignited and burns rapidly; and

a second of said layers comprising a particulate nitrogen generating composition which is less easily ignited than said first layer and burns more slowly than said first layer,

said body being cylindrical in configuration and having a longitudinal axis which intersects each of said layers;

each of said layers having a thickness sufficient for the layer to contribute to the sustained burn of the body of material and effective to generate an S-shaped tank pressure curve and wherein the thickness of one of said layers relative to any other layer is in the range or 20;

80 to 80;

20.