Air bag inflator

• US 5,655,790 A
• Filed: 06/06/1995
• Issued: 08/12/1997
• Est. Priority Date: 06/06/1995
• Status: Expired due to Fees

• Current Assignee: TRW Vehicle Safety Systems Incorporated (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Original Assignee: TRW Vehicle Safety Systems Incorporated (Zeppelin - Stiftung der Stadt Friedrichshafen)
• Inventors: Thompson, Richard J., Faigle, Ernst M., Sparks, Tracy S.
• Primary Examiner(s): Ellis, Christopher P.
• Application Number:
  US08/471,406
• Time in Patent Office: 798 Days
• Field of Search: 280/736, 280/737, 280/741, 102/530, 102/531, 102/202, 102/202.14, 222/3, 222/5, 422/164, 422/167
• US Class Current: 280/737
• CPC Class Codes: B60R 2021/2633 with a plurality of inflation levels
• CPC Class Codes: B60R 21/264 using instantaneous generation of gas, e.g. pyrotechnic B60R21/268 takes precedence
• CPC Class Codes: B60R 21/272 with means for increasing the pressure of the gas just before or during liberation, e.g. hybrid inflators

Abstract

An air bag inflator (10) includes inflation fluid stored in a chamber (18). The inflator (10) includes a combustible sheet member (100) which comprises an oxidizable substrate, such as a polytetrafluoroethylene film, and a layer of a fuel material, such as magnesium, on the substrate. The combustible sheet member (100) is disposed in a perforated tube (90) in the chamber (18). The combustible sheet member (100), when ignited by an igniter (70), emits combustion products through openings (98) in the perforated tube (90) to warm and increase the pressure of the inflation fluid in the chamber (18). The inflation fluid includes 5% to 20% oxygen to support the combustion of the combustible sheet member (100).

Claims

1. An apparatus for inflating an inflatable vehicle occupant restraint, said apparatus comprising:

a container having a chamber;

a quantity of inflation fluid stored in said chamber;

combustible means for warming and increasing the pressure of said stored inflation fluid, said combustible means including a combustible sheet member disposed in said chamber;

said combustible sheet member comprising a substrate of oxidizing film and a layer of oxidizable fuel material on at least a portion of one surface of said film, said substrate and said fuel material being capable of reacting together exothermically on ignition;

first igniter means for igniting said combustible sheet member; and

directing means for directing said inflation fluid from said container to the inflatable restraint;

said inflation fluid comprising oxygen for supporting the combustion of said combustible sheet member.

2. An apparatus as set forth in claim 1 wherein said inflation fluid comprises from about 5% to about 20% by volume of said oxygen.

3. An apparatus as set forth in claim 2 wherein said inflation fluid comprises from about 80% to about 95% by volume of an inert gas, such as argon or nitrogen or a mixture of argon and nitrogen.

4. An apparatus as set forth in claim 1 wherein said inflation fluid comprises a combustible fuel gas, said oxygen in said inflation fluid comprising a first portion of said oxygen which is sufficient to support the combustion of said combustible fuel gas and a second portion of said oxygen for supporting the combustion of said combustible sheet member.

5. An apparatus as set forth in claim 4 comprising second igniter means for igniting said combustible fuel gas, said second igniter means being separately and independently actuatable from said first igniter means.

6. An apparatus for inflating an inflatable vehicle occupant restraint, said apparatus comprising:

a container having a chamber;

a quantity of inflation fluid stored in said chamber;

directing means for directing said inflation fluid from said container to the inflatable restraint;

a first perforated tube extending within said stored inflation fluid in said chamber;

a first combustible sheet member rolled up and disposed in said first perforated tube in said chamber;

a second perforated tube extending within said stored inflation fluid in said chamber;

a second combustible sheet member rolled up and disposed in said second perforated tube in said chamber;

first igniter means for selectively igniting said first combustible sheet member independently of said second combustible sheet member; and

second igniter means for selectively igniting said second combustible sheet member independently of said first combustible sheet member;

each one of said first and second combustible sheet members comprising a substrate of oxidizing film having a layer of oxidizable fuel material on at least a portion of one surface of said film, said substrate and said fuel material being capable of reacting together exothermically on ignition.

7. An apparatus as set forth in claim 6 wherein said inflation fluid comprises from about 5% to about 20% by volume of oxygen for supporting the combustion of said combustible sheet members.

8. An apparatus as set forth in claim 6 further comprising a pair of rapid deflagration members associated with said combustible sheet members, said rapid deflagration members being ignitable by said igniter means to help to ignite said combustible sheet members.

9. An apparatus for inflating an inflatable vehicle occupant restraint, said apparatus comprising:

a container having a chamber;

a quantity of inflation fluid stored in said chamber;

combustible means for warming and increasing the pressure of said stored inflation fluid, said combustible means including a combustible sheet member disposed in said chamber;

said combustible sheet member comprising a substrate of oxidizing film and a layer of oxidizable fuel material on at least a portion of one surface of said film, said substrate and said fuel material being capable of reacting together exothermically on ignition;

first igniter means for igniting said combustible sheet member;

directing means for directing said inflation fluid from said container to the inflatable restraint;

said inflation fluid comprising oxygen for supporting the combustion of said combustible sheet member; and

a rapid deflagration member associated with said combustible sheet member, said rapid deflagration member being ignitable by said first igniter means to help to ignite said combustible sheet member;

said combustible sheet member having a central passage, said rapid deflagration member comprising a cord which extends through at least a portion of said central passage of said combustible sheet member.

10. An apparatus as set forth in claim 9 wherein said rapid deflagration member comprises a pyrotechnic material sheathed in tin.

11. An apparatus for inflating an inflatable vehicle occupant restraint, said apparatus comprising:

a container having a chamber;

a quantity of inflation fluid stored in said chamber;

combustible means for warming and increasing the pressure of said stored inflation fluid, said combustible means including a combustible sheet member disposed in said chamber;

said combustible sheet member comprising a substrate of oxidizing film and a layer of oxidizable fuel material on at least a portion of one surface of said film, said substrate and said fuel material being capable of reacting together exothermically on ignition;

first igniter means for igniting said combustible sheet member;

directing means for directing said inflation fluid from said container to the inflatable restraint;

said inflation fluid comprising oxygen for supporting the combustion of said combustible sheet member;

said inflation fluid comprising a combustible fuel gas, said oxygen in said inflation fluid comprising a first portion of said oxygen which is sufficient to support the combustion of said combustible fuel gas and a second portion of said oxygen for supporting the combustion of said combustible sheet member; and

a rapid deflagration member associated with said combustible sheet member, said rapid deflagration member comprising a pyrotechnic material sheathed in tin and being ignitable by said first igniter means to help to ignite said combustible sheet member.

12. An apparatus for inflating an inflatable vehicle occupant restraint, said apparatus comprising:

a container having a chamber;

a quantity of inflation fluid stored in said chamber;

directing means for directing said inflation fluid from said container to the inflatable restraint;

a first perforated tube extending within said stored inflation fluid in said chamber;

a first combustible sheet member rolled up and disposed in said first perforated tube in said chamber;

a second perforated tube extending within said stored inflation fluid in said chamber;

a second combustible sheet member rolled up and disposed in said second perforated tube in said chamber;

first igniter means for selectively igniting said first combustible sheet member independently of said second combustible sheet member; and

second igniter means for selectively igniting said second combustible sheet member independently of said first combustible sheet member;

each one of said first and second combustible sheet members comprising a substrate of oxidizing film having a layer of oxidizable fuel material on at least a portion of one surface of said film, said substrate and said fuel material being capable of reacting together exothermically on ignition;

each one of said first and second combustible sheet members having a first end portion disposed adjacent to said igniter means and a second end portion disposed farther from said igniter means than said first end portion, each one of said first and second combustible sheet members comprising a strip of sheet material rolled up in a series of turns into a conical configuration and having a central passage which has a generally conical configuration, said central passages having relatively large diameters at said first end portions of said combustible sheet members and relatively small diameters at said second end portions of said combustible sheet members, each one of said strips of sheet material having an edge surface extending along the entire length of said strip of sheet material between said first end portion and said second end portion, each one of said edge surfaces of said strips of sheet material being exposed to said igniter means along substantially the entire length of said combustible sheet members.

13. An apparatus for inflating an inflatable vehicle occupant restraint, said apparatus comprising:

a container having a chamber;

a quantity of inflation fluid stored in said chamber;

combustible means for warming and increasing the pressure of said stored inflation fluid, said combustible means including a combustible sheet member;

a perforated tube extending within said inflation fluid in said chamber and having a plurality of radial openings, said combustible member being disposed in said perforated tube;

said combustible sheet member comprising a substrate of oxidizing film and a layer of oxidizable fuel material on at least a portion of one surface of said film, said substrate and said fuel material being capable of reacting together exothermically inside said perforated tube on ignition to produce hot combustion products which flow outward through said plurality of radial openings in said perforated tube into said chamber;

first igniter means for igniting said combustible sheet member; and

directing means for directing said inflation fluid from said container to the inflatable restraint;

said inflation fluid comprising oxygen for supporting the combustion of said combustible sheet member.

14. An apparatus as set forth in claim 13 wherein said inflation fluid comprises from about 5% to about 20% by volume of said oxygen.

15. An apparatus as set forth in claim 14 wherein said inflation fluid comprises from about 80% to about 95% by volume of an inert gas, such as argon or nitrogen or a mixture of argon and nitrogen.

16. An apparatus as set forth in claim 13 wherein said inflation fluid comprises a combustible fuel gas, said oxygen in said inflation fluid comprising a first portion of said oxygen which is sufficient to support the combustion of said combustible fuel gas in said chamber and a second portion of said oxygen for supporting the combustion of said combustible sheet member inside said perforated tube in said chamber.