Inflator assembly

• US 5,390,954 A
• Filed: 11/02/1993
• Issued: 02/21/1995
• Est. Priority Date: 06/21/1991
• 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., Semchena, John H.
• Primary Examiner(s): Rice, Kenneth R.
• Application Number:
  US08/146,967
• Time in Patent Office: 476 Days
• Field of Search: 280/736, 280/740, 280/741, 280/742
• US Class Current: 280/736
• CPC Class Codes: B60R 2021/26076 characterised by casing
• CPC Class Codes: B60R 21/2171 specially adapted for elongated cylindrical or bottle-like inflators with a symmetry axis perpendicular to the main direction of bag deployment, e.g. extruded reaction canisters B60R21/2176 takes precedence
• CPC Class Codes: B60R 21/2644 using only solid reacting substances, e.g. pellets, powder
• CPC Class Codes: B60R 21/30 with means to draw ambient air into the flow line and mix such air with the inflation fluid

Abstract

A vehicle occupant restraint apparatus (10) includes an inflatable vehicle occupant restraint (12) and an inflator (14) for providing gas for inflating the restraint (12). The inflator (14) contains an ignitable gas generating material (70) which, when ignited, generates the gas. The inflator has a structure (72) which defines a combustion chamber (78) containing the gas generating material (70). The inflator (14) further has an axis (66), and directs the gas to flow from the combustion chamber (78) outward through the inflator (14) and outward from the inflator (14) in a direction transverse to the axis (66). The inflator (14) is free of a tubular body wall defining gas flow openings at a location outward of the structure (72) defining the combustion chamber (78).

Claims

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

an ignitable gas generating material which, when ignited, generates gas for inflating the restraint; and

a cylindrical inflator having a tubular part with a longitudinal central axis and axially opposite end portions, said tubular part of said inflator including means for defining a combustion chamber containing said gas generating material, said tubular part of said inflator further including cylindrical filter means for filtering said gas as said gas flows radially outward of said combustion chamber;

said inflator being free of a tubular body wall defining gas flow openings at a location radially outward of said means for defining said combustion chamber;

said inflator including constraining means for constraining said filter means from being deflected radially outward by the pressure of said gas, said constraining means extending over said filter means axially between said opposite end portions of said tubular part and circumferentially around said tubular part.

2. Apparatus as defined in claim 1 wherein said constraining means comprises a circumferentially endless support structure surrounding said filter means.

3. Apparatus as defined in claim 2 wherein said support structure comprises a braided sleeve of wire.

4. Apparatus as defined in claim 2 wherein said support structure comprises a wire wrapped helically around said filter means.

5. Apparatus as defined in claim 2 wherein said support structure has a surface means for defining a gap in said support structure which is open around the entire circumference of said support structure,, said gap comprising an unobstructed gas flow passage extending radially outward past said support structure around the entire circumference of said support structure.

6. Apparatus as defined in claim 5 wherein said support structure extends circumferentially around and axially along said filter means in a plurality of helical turns, said surface means including opposed helical surface portions of said support structure that are spaced from each other axially to define said gap axially between said opposed helical surface portions.

7. Apparatus as defined in claim 6 wherein said support structure includes a wire having a circular cross section, said plurality of helical turns being defined by successive sections of said wire which extend helically around filter means.

8. Apparatus comprising:

an inflatable vehicle occupant restraint; and

an inflator for providing gas for inflating said restraint, said inflator containing an ignitable gas generating material which, when ignited, generates said gas;

said inflator having means for defining a combustion chamber containing said gas generating material, said inflator further having an axis and means for directing said gas to flow from said combustion chamber outward through said inflator and outward from said inflator in a direction transverse to said axis;

said inflator being free of a tubular body wall defining gas flow openings at a location outward of said means for defining said combustion chamber;

said inflator including a pressurizing means for increasing the pressure of said gas flowing outward through said inflator by blocking said gas from flowing past said pressurizing means until said pressure reaches a predetermined elevated level, said inflator having a generally cylindrical shape and further including means for constraining said inflator from deflecting out of said generally cylindrical shape under the influence of said pressure, said constraining means comprising a circumferentially endless wire structure located radially outward of said pressurizing means;

said pressurizing means including a rupturable pressure controlling structure which bursts radially outward when said pressure reaches said predetermined elevated level, said wire structure providing clearance for said pressure controlling structure to burst radially outward at any number of locations spaced from each other around the circumference of said wire structure.

9. Apparatus comprising:

an inflatable vehicle occupant restraint; and

an inflator for providing gas for inflating said restraint, said inflator containing an ignitable gas generating material which, when ignited, generates said gas;

said inflator having means for defining a combustion chamber containing said gas generating material, said inflator further having an axis and means for directing said gas to flow from said combustion chamber outward through said inflator and outward from said inflator in a direction transverse to said axis;

said inflator being free of a tubular body wall defining gas flow openings at a location outward of said means for defining said combustion chamber;

said inflator including a pressurizing means for increasing the pressure of said gas flowing outward through said inflator by blocking said gas from flowing past said pressurizing means until said pressure reaches a predetermined elevated level, said inflator having a generally cylindrical shape and further including means for constraining said inflator from deflecting out of said generally cylindrical shape under the influence of said pressure, said constraining means comprising a circumferentially endless wire structure located radially outward of said pressurizing means;

said constraining means defining a gap in said wire structure, said gap being open around the entire circumference of said wire structure, said gap comprising a passage through which said gas can flow radially outward past said wire structure around the entire circumference of said wire structure.

10. Apparatus comprising:

an inflatable vehicle occupant restraint; and

an inflator for providing gas for inflating said restraint, said inflator containing an ignitable gas generating material which, when ignited, generates said gas;

said inflator having means for defining a combustion chamber containing said gas generating material, said inflator further having an axis and means for directing said gas to flow from said combustion chamber outward through said inflator and outward from said inflator in a direction transverse to said axis;

said inflator being free of a tubular body wall defining gas flow openings at a location outward of said means for defining said combustion chamber;

said inflator including a pressurizing means for increasing the pressure of said gas flowing outward through said inflator by blocking said gas from flowing past said pressurizing means until said pressure reaches a predetermined elevated level, said inflator having a generally cylindrical shape and further including means for constraining said inflator from deflecting out of said generally cylindrical shape under the influence of said pressure, said constraining means comprising a circumferentially endless wire structure located radially outward of said pressurizing means;

said wire structure comprises a braided sleeve of wire.

11. Apparatus comprising:

an inflatable vehicle occupant restraint; and

a generally cylindrical inflator for providing gas for inflating said restraint, said inflator containing an ignitable gas generating material which, when ignited, generates said gas;

said inflator including a tubular filter extending circumferentially around said gas generating material, said filter including means for filtering said gas as said gas flows radially outward through said filter;

said inflator further including a pressurizing means for increasing the pressure of said gas flowing through said filter by blocking said gas from flowing past said pressurizing means until said pressure reaches a predetermined elevated level, said pressurizing means including a rupturable pressure controlling structure extending circumferentially around said filter;

said inflator being free of a tubular body wall having gas flow openings at a location radially outward of said rupturable pressure controlling structure.

12. Apparatus as defined in claim 11 further comprising housing means for containing said restraint and said inflator, said housing means defining an enclosed space which comprises a gas flow path extending from said inflator to said restraint, said inflator having a generally cylindrical peripheral surface exposed to said gas flow path circumferentially entirely around said axis.

13. Apparatus as defined in claim 12 wherein said rupturable pressure controlling structure is exposed to said gas flow path circumferentially entirely around said axis.

14. Apparatus as defined in claim 12 wherein said housing means defines an inner compartment containing said inflator and an outer compartment containing said restraint, said housing means including a barrier means for maintaining a desired spacing between said inflator and said restraint, said barrier means including a retainer member which is located between said inner and outer compartments, said gas flow path extending through openings in said retainer member.

15. Apparatus as defined in claim 14 further comprising sealing means for hermetically sealing said inner compartment from said outer compartment, said sealing means including a rupturable sheet of hermetic sealing material extending over said openings in said retainer member.

16. Apparatus as defined in claim 11 wherein said filter has a generally cylindrical tubular shape, said inflator further including means for constraining said filter from deflecting out of said generally cylindrical tubular shape under the influence of said pressure, said constraining means comprising a circumferentially endless wire structure located radially outward of said rupturable pressure controlling structure.

17. Apparatus as defined in claim 16 wherein said wire structure comprises a braided sleeve of wire.

18. Apparatus as defined in claim 16 wherein said wire structure has a surface means for defining a gap in said wire structure which is open around the entire circumference of said wire structure, said gap comprising an unobstructed gas flow passage extending radially outward past said wire structure around the entire circumference of said wire structure.

19. Apparatus as defined in claim 18 wherein said wire structure extends circumferentially around and axially along said filter in a plurality of helical turns, said surface means including opposed helical surface portions of said wire structure that are spaced from each other axially to define said gap axially between said opposed helical surface portions.

20. Apparatus as defined in claim 19 wherein said wire structure includes a wire having a circular cross section, said plurality of helical turns being defined by successive sections of said wire which extend helically around said filter.

21. Apparatus as defined in claim 20 wherein said successive sections of said wire are wrapped in tension around said filter so as to apply a radially directed compressive force to said filter, said force constraining said filter to maintain a radial thickness which extends uniformly along the length of said filter.

22. Apparatus comprising:

an inflatable vehicle occupant restraint;

an ignitable gas generating material which, when ignited, generates gas for inflating said restraint;

a tubular structure having a longitudinal central axis and means for defining a combustion chamber containing said gas generating material; and

first and second end caps, each of said end caps being located at a respective axial end of said tubular structure, said end caps blocking said gas from flowing axially outward from said combustion chamber;

said tubular structure having a peripheral surface portion between said end caps, said peripheral surface portion of said tubular structure being defined at least in part by wire extending circumferentially around said axis;

said peripheral surface portion of said tubular structure being defined by helical sections of wire which extend circumferentially entirely around said axis;

said helical sections of wire having axially opposed helical surface portions defining a helical gap extending circumferentially entirely around said axis, said gap comprising an unobstructed gas flow passage extending radially outward past said helical sections of wire around the entire circumference of said helical sections of wire.

23. Apparatus comprising:

an inflatable vehicle occupant restraint;

an ignitable gas generating material which, when ignited, generates gas for inflating said restraint;

a tubular structure having a longitudinal central axis and means for defining a combustion chamber containing said gas generating material; and

first and second end caps, each of said end caps being located at a respective axial end of said tubular structure, said end caps blocking said gas from flowing axially outward from said combustion chamber;

said tubular structure having a peripheral surface portion between said end caps, said peripheral surface portion of said tubular structure being defined at least in part by wire extending circumferentially around said axis;

said peripheral surface portion of said tubular structure being defined by helical sections of wire which extend circumferentially entirely around said axis;

said helical sections of wire being defined by first and second wire strands, said first wire strand having a plurality of first helical sections which extend from one axial end of said tubular structure toward the other axial end of said tubular structure in a first circumferential direction, said second wire strand having a plurality of second helical sections which extend from said one axial end toward said other axial end in a second circumferential direction opposite to said first circumferential direction, said second wire strand defining a plurality of intersections with said first wire strand and crossing over said first wire strand at each intersection of said wire strands.

24. Apparatus comprising:

an inflatable vehicle occupant restraint;

an ignitable gas generating material which, when ignited, generates gas for inflating said restraint;

a tubular structure having a longitudinal central axis and means for defining a combustion chamber containing said gas generating material; and

first and second end caps, each of said end caps being located at a respective axial end of said tubular structure, said end caps blocking said gas from flowing axially outward from said combustion chamber;

said tubular structure having a peripheral surface portion between said end caps, said peripheral surface portion of said tubular structure being defined at least in part by wire extending circumferentially around said axis;

said peripheral surface portion of said tubular structure being defined by a braided wire sleeve structure.

25. Apparatus as defined in claim 24 wherein said braided wire sleeve structure has opposite axial end portions which extend over said end caps, said end portions of said braided wire sleeve structure comprising means for securing said end caps to said ends of said tubular structure.