Dual inflator apparatus including pyrotechnic inflator

• US 6,142,518 A
• Filed: 12/05/1997
• Issued: 11/07/2000
• Est. Priority Date: 12/05/1997
• Status: Expired due to Fees

• Current Assignee: Autoliv ASP Incorporated (Autoliv Incorporated)
• Original Assignee: OEA Incorporated (Autoliv Incorporated)
• Inventors: Strickland, Royce M. Jr., Butt, Ron J., Kafadar, Charles B.
• Primary Examiner(s): CULBRETH, ERIC D
• Application Number:
  US08/986,255
• Time in Patent Office: 1,068 Days
• Field of Search: 280/741, 280/736, 280/742, 280/735
• US Class Current: 280/741
• CPC Class Codes: B60R 2021/26058 using a combination of inflators
• CPC Class Codes: B60R 2021/2633 with a plurality of inflation levels
• CPC Class Codes: B60R 2021/2725 using a fluid fuel gas generator
• 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
• CPC Class Codes: B60R 21/264 using instantaneous generation of gas, e.g. pyrotechnic B60R21/268 takes precedence
• CPC Class Codes: B60R 21/2644 using only solid reacting substances, e.g. pellets, powder
• 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 inflation apparatus that includes at least two inflators for selected use in inflating an air bag is disclosed. In one embodiment, the two inflators include a micro hybrid inflator and a pyrotechnic inflator. The micro hybrid inflator includes a pressurized medium having oxygen that contributes to the inflation gases that fill the inflatable. The pyrotechnic inflator is essentially free of any such stored gas. Both inflators include a fuel-rich gas generating material. In another embodiment, instead of a micro hybrid inflator, another pyrotechnic inflator is utilized that includes an oxygen-rich gas generating material. In still another embodiment, a fluid fuel acts as a source of oxygen for the fuel-rich gas generating material of the pyrotechnic inflator. When both inflators of the dual inflation apparatus are activated, the oxygen gas that is present is used in further combusting products of combustion from the pyrotechnic inflator having the fuel-rich gas generating material. Preferably, activation of each inflator depends upon whether the vehicle collision that results in air bag activation is low impact or high impact. In at least one embodiment, the two inflators can be affixed to a support assembly with a desired arrangement of the inflators to provide a low profile and reduced space usage by the inflation apparatus.

Claims

1. An apparatus for use in inflating an inflatable in a vehicle, comprising:

a first inflator including oxygen gas that is at least present after activation of said first inflator; and

a second inflator including a pyrotechnic inflator having a pyrotechnic gas generating material and being substantially free of a pressurized medium, said pyrotechnic gas generating material being fuel-rich and generating insufficient oxygen gas such that, in the absence of oxygen gas from said first inflator, after activation of said first and second inflators, an amount of toxic gas is present

and, when oxygen gas from said first inflator is present, said amount of toxic gas is reduced.

2. An apparatus, as claimed in claim 1, wherein:

said first inflator includes a hybrid inflator having a hybrid gas generating material and an activation assembly for use in activating said first gas generating material and in which said hybrid inflator activation assembly is activated during each of a high impact collision and a low impact collision of the vehicle.

3. An apparatus, as claimed in claim 1, wherein:

said pyrotechnic inflator includes an activation assembly for use in activating said pyrotechnic gas generating material when the vehicle is subject to a high impact collision and said pyrotechnic gas generating material is not used to generate inflation gases when the vehicle is subject to a low impact collision.

4. An apparatus, as claimed in claim 1, further including:

a support assembly that includes a flange assembly having a chamber and in which products of combustion including inflation gases from each of said first and second inflators are combined such that further combustion of said products of combustion of said pyrotechnic gas generating material occurs.

5. An apparatus, as claimed in claim 1, wherein:

said pyrotechnic inflator includes an outlet from which inflation gases exit to the inflatable and also includes a central longitudinal axis, with said outlet being spaced from said central longitudinal axis.

6. An apparatus, as claimed in claim 1, wherein:

said first inflator includes a inflator housing and a diffuser assembly adjacent one end of said inflator housing and in which each of said first and second inflators generate products of combustion including inflation gases when said first and second inflators are activated and in which the products of combustion including the inflation gases from said first and second inflators are combined in said diffuser assembly.

7. An apparatus, as claimed in claim 1, wherein:

said first inflator includes a hybrid inflator that provides a substantially greater pressure increase in the inflatable than said pyrotechnic inflator when said hybrid inflator and said pyrotechnic inflator are activated during filing of the inflatable.

8. An apparatus, as claimed in claim 1, wherein:

said pyrotechnic inflator develops less pressure than is developed by said first inflator.

9. An apparatus, as claimed in claim 1, further including:

a support assembly having a flange with a substantially planar outer surface and concave section, with said pyrotechnic inflator being disposed at an oblique angle relative to said outer surface.

10. An apparatus, as claimed in claim 1, wherein:

each of said first and second inflators, when activated, outputs products of combustion including inflation gases and in which the products of combustion from said second inflator are further combusted using the products of combustion of said first inflator in the inflatable.

11. An apparatus, as claimed in claim 1, wherein:

the oxygen gas of said first inflator after activation thereof has a concentration of at least 2% of the gas of said first inflator.

12. An apparatus, as claimed in claim 1, wherein:

concentration of the oxygen gas after activation of said first inflator is in the range of about 2%-30% of the gas in said first inflator.

13. An apparatus, as claimed in claim 1, wherein:

said first inflator includes a fluid fuel.

14. An apparatus, as claimed in claim 1, wherein:

said first inflator includes at least one inert gas and oxygen for use in combining with products of combustion from said pyrotechnic inflator.

15. An apparatus, as claimed in claim 1, wherein:

said first inflator includes a pyrotechnic inflator and said oxygen gas is present only after activation of said pyrotechnic inflator.

16. A method for inflating an inflatable located in a vehicle, comprising:

generating first products of combustion including inflation gases that are oxygen-rich when a first inflator is activated;

generating second products of combustion including inflation gases that are fuel-rich when a second inflator is activated and wherein, in the absence of said products of combustion from said first inflator, an amount of toxic gas is present;

combining said first products of combustion and said second products of combustion wherein, after said combining step, an acceptable amount of toxic gas is present.

17. A method, as claimed in claim 16, wherein:

said step of generating said first products of combustion includes initiating activation of said first inflator when each of a low impact signal and high impact signal is received by said first inflator.

18. A method, as claimed in claim 16, wherein:

said step of generating said second products of combustion includes initiating activation of said second inflator only when a high impact signal is received by said second inflator.

19. A method, as claimed in claim 16, wherein:

said step of generating said first products of combustion includes using an oxygen-rich gas generating material contained in said first inflator.

20. A method, as claimed in claim 16, wherein:

said step of generating said second products of combustion includes using a fuel-rich propellant contained in said second inflator.

21. A method, as claimed in claim 16, wherein;

said step of generating said first products of combustion includes providing an oxygen concentration of at least 2% of said inflation gases using said first inflator.

22. A method, as claimed in claim 16, wherein:

said combining step includes supporting said first and second inflators using a flange assembly and receiving said inflation gases from each of said first and second inflators in a chamber of said flange assembly.

23. A method, as claimed in claim 16, wherein:

said first inflator includes an inflator housing and a diffuser assembly disposed adjacent an end of said inflator housing and in which said combining step includes receiving said inflation gases from each of said first and second inflators in said diffuser assembly.

24. A method, as claimed in claim 16, wherein:

said combining step includes mixing said first products of combustion and said second products of combustion in the inflatable to produce further products of combustion.