Ignition orifice in fluid fueled inflator

• US 5,806,885 A
• Filed: 04/24/1997
• Issued: 09/15/1998
• Est. Priority Date: 04/24/1997
• Status: Expired due to Fees

• Current Assignee: Morton International Incorporated (Autoliv Incorporated)
• Original Assignee: Autoliv ASP Incorporated (Autoliv Incorporated)
• Inventors: Hock, Christopher
• Primary Examiner(s): Dickson, Paul N.
• Application Number:
  US08/840,061
• Time in Patent Office: 509 Days
• Field of Search: 280/737, 280/741, 280/736, 280/742, 102/530, 102/531
• US Class Current: 280/737
• CPC Class Codes: B60R 21/264 using instantaneous generation of gas, e.g. pyrotechnic B60R21/268 takes precedence

Abstract

An improved inflator wherein a flowing combustible fluid is combusted in a combustion zone defined by diverging walls is disclosed. The improved inflator provides enhanced consistency of operation thereby permitting the use of lighter components while avoiding deployments which produce excessive "bag slap".

Claims

1. An inflator comprising:

(a) a storage chamber containing a combustible fluid;

(b) a combustion chamber;

(c) an initiator capable of igniting said combustible fluid in said combustion chamber;

(d) a fluid flow path extending between said storage chamber and said combustion chamber, said fluid flow path including;

(i) a throttling zone containing the smallest cross sectional area of said fluid flow path, and

(ii) a diverging zone located between said throttling zone and said combustion chamber, said diverging zone providing an increasing cross sectional area as said diverging zone extends away from said throttling zone; and

(e) an openable structure sealing said fluid flow path, said openable structure being capable of opening said fluid flow path when said initiator is activated.

2. The inflator of claim 1, wherein:

at least a portion of said diverging zone is defined by continuously diverging walls defining said fluid flow path.

3. The inflator of claim 2, wherein:

at least a portion of said diverging zone is shaped like a segment of a cone.

4. The inflator of claim 1, further comprising:

a nucleating structure located in said diverging zone.

5. The inflator of claim 4, wherein:

said nucleating structure comprises metal wire.

6. The inflator of claim 1, further comprising:

a dividing wall located between said storage chamber and said combustion chamber, and wherein

said fluid flow path extends through said dividing wall.

7. The inflator of claim 6, wherein:

said diverging zone comprises a conical cavity extending into said dividing wall from said combustion chamber.

8. The inflator of claim 6, wherein:

said throttling zone comprises the entrance to said fluid flow path from said storage chamber.

9. The inflator of claim 6, wherein:

said storage chamber also comprises a side wall, and

said dividing wall is adapted to be displaced along said side wall as said combustible fluid is discharged from said storage chamber through said fluid flow path.

10. The inflator of claim 9, further comprising:

a spring arranged to provide a biased force capable of causing said dividing wall to be displaced when said combustible fluid is discharged.

11. The inflator of claim 6, wherein:

said openable structure comprises a weakened section of said dividing wall.

12. The inflator of claim 11, wherein:

said weakened section comprises a portion of said wall which is not as thick as the remainder of the wall.

13. The inflator of claim 1, wherein said combustible fluid is a liquid.

14. The inflator of claim 1 wherein said combustible fluid is a liquified gas.

15. The inflator of claim 1 wherein said combustible fluid is a gas.

16. An inflator comprising:

(a) a storage chamber containing a combustible fluid;

(b) a fluid flow path extending from said storage chamber, said fluid flow path including;

(i) a throttling zone containing the smallest cross sectional area of said fluid flow path, and

(ii) a combustion zone, said combustion zone including a section of increasing cross sectional area as said combustion zone extends away from said throttling zone;

(c) a nucleating structure located in said combustion zone

(d) an initiator capable of igniting said combustible fluid in said combustion zone;

(e) an openable structure sealing said fluid flow path, said openable structure being capable of opening said fluid flow path when said initiator is activated.

17. The inflator of claim 16, wherein:

at least a portion of said section of increasing cross sectional area is defined by continuously diverging fluid flow path walls.

18. The inflator of claim 17, wherein:

said continuously diverging fluid flow path walls define the shape of said portion as a segment of a cone.