Venting device for an airbag inflator

• US 7,658,406 B2
• Filed: 07/22/2007
• Issued: 02/09/2010
• Est. Priority Date: 07/22/2007
• Status: Expired due to Fees

• Current Assignee: Key Safety Systems, Inc. (Ningbo Junsheng Investment Group Co., Ltd.)
• Original Assignee: Key Safety Systems, Inc. (Ningbo Junsheng Investment Group Co., Ltd.)
• Inventors: Townsend, Richard, Deych, Alexander
• Primary Examiner(s): Culbreth; Eric
• Application Number:
  US11/781,254
• Publication Number:
  US 20090020990A1
• Time in Patent Office: 933 Days
• Field of Search: 280/736, 280/739, 280/737
• US Class Current: 280/737
• CPC Class Codes: B60R 2021/26029 Ignitors
• CPC Class Codes: B60R 21/264 using instantaneous generation of gas, e.g. pyrotechnic B60R21/268 takes precedence
• CPC Class Codes: B60R 21/274 characterised by means to rupture or open the fluid source

Abstract

A device for supporting a rupturable closure member of a pressure vessel, such as an airbag inflator has a hollow support with a tapered portion and an adjoining cylindrical portion. An exterior surface of the tapered portion has longitudinally extending grooves therein. An igniter is located adjacent the cylindrical portion of the support and a pyrotechnic substance is located in the cylindrical portion of the support between the igniter and the tapered portion of the support. A rupturable closure member being forced against an open first end of the tapered portion of the support by the gas in the pressure vessel such that a chamber is formed within the support. The igniter when activated ignites the pyrotechnic substance and the burning pyrotechnic substance generates gas under pressure that causes the tapered portion of the support to break along the longitudinally extending grooves and no longer support the rupturable closure member allowing the gas in the pressure vessel to rupture the unsupported rupturable closure member.

Claims

1. A device for supporting a rupturable closure member of a pressure vessel, the device comprising:

a hollow support having a tapered portion and an adjoining cylindrical portion, both an inside diameter and an outside diameter of the tapered portion having minimum sizes at an open first end of the support, both the inside and outside diameters of the tapered portion of the support increasing to maximum sizes at a second end of the tapered portion that is adjacent to a first end of the cylindrical portion, and the cylindrical portion extending to an open second end of the support, an exterior surface of the tapered portion having longitudinally extending grooves therein;

an igniter located adjacent the cylindrical portion of the support;

a pyrotechnic substance located in the cylindrical portion of the support.

2. The device for supporting a rupturable closure member of a pressure vessel according to claim 1 further comprising a hollow support housing, the cylindrical portion of the support being fixed to an interior of the support housing such that the tapered portion of the support extends beyond the support housing.

3. The device for supporting a rupturable closure member of a pressure vessel according to claim 2 further comprising a hollow vent housing fixed to the support housing such that the tapered portion of the support is located inside the vent housing, the vent housing having passageways therethrough that are oriented radially with respect to a longitudinal axis of the vent housing.

4. The device for supporting a rupturable closure member of a pressure vessel according to claim 3 further comprising a rupturable closure member fixed to the vent housing axially aligned with the first end of the tapered portion of the support such that the first end of the tapered portion of the support contacts the rupturable closure member when the rupturable closure member is deformed in a direction towards the support.

5. An airbag inflator containing gas under pressure, said airbag inflator comprising:

an inflator housing with an outlet passage through which the gas flows from the inflator housing;

a rupturable closure member blocking flow of the gas from the inflator housing;

a device for supporting the rupturable closure member, the device comprising a hollow support having a tapered portion and an adjoining cylindrical portion, both an inside diameter and an outside diameter of the tapered portion having minimum sizes at an open smaller end of the tapered portion, both the inside and outside diameters of the tapered portion increasing to maximum sizes at a larger end of the tapered portion that is adjacent to the cylindrical portion, and the cylindrical portion extending to an open second end of the support, an exterior surface of the tapered portion having longitudinally extending grooves therein;

an igniter located adjacent the cylindrical portion of the support;

a pyrotechnic substance located in the cylindrical portion of the support;

the rupturable closure member being forced against the open first end of the tapered portion of the support by the gas in the inflator housing such that a chamber is formed within the support, the igniter when activated ignites the pyrotechnic substance and the burning pyrotechnic substance generates gas under pressure that causes the tapered portion of the support to break along the longitudinally extending grooves and no longer support the rupturable closure member allowing the gas in the inflator housing to rupture the unsupported rupturable closure member.

6. The airbag inflator according to claim 5 wherein the device for supporting the rupturable closure member further comprises a hollow support housing, the cylindrical portion of the support being fixed to an interior of the support housing such that the tapered portion of the support extends beyond the support housing;

and a hollow vent housing fixed to the support housing such that the tapered portion of the support is located inside the vent housing, the vent housing having passageways therethrough that are oriented radially with respect to a longitudinal axis of the vent housing, the vent housing being fixed to the inflator housing.

7. The airbag inflator according to claim 6 wherein the rupturable closure member is fixed to the vent housing axially aligned with the first end of the tapered portion of the support.

8. An airbag inflator comprising:

a tubular inflator housing containing gas under pressure, the inflator housing having two ends with an outlet passage at one end of the inflator housing sealed by a rupturable closure member blocking the flow of gas from the inflator housing, wherein gas can flow from the inflator housing upon the rupturing of the rupturable closure member;

a device fixed to said one end of the inflator housing for supporting the rupturable closure member, the device comprising a hollow support having a tapered portion and an adjoining cylindrical portion, both an inside diameter and an outside diameter of the tapered portion having minimum sizes at an open smaller end of the tapered portion of the support, both the inside and outside diameters of the tapered portion increasing to maximum sizes at a larger end of the tapered portion that is adjacent to the cylindrical portion, and the cylindrical portion extending to an open end of the support, an exterior surface of the tapered portion having longitudinally extending grooves therein;

an igniter located adjacent the cylindrical portion of the support;

a pyrotechnic substance located in the cylindrical portion of the support;

the rupturable closure member being forced against the open first end of the tapered portion of the support by the gas in the inflator housing such that a chamber is formed within the support, the igniter when activated ignites the pyrotechnic substance and the burning pyrotechnic substance generates gas under pressure that causes the tapered portion of the support to break along the longitudinally extending grooves and no longer support the rupturable closure member allowing the gas in the inflator housing to rupture the unsupported rupturable closure member.

9. The airbag inflator according to claim 8 wherein the device for supporting the rupturable closure member further comprises a hollow support housing, the cylindrical portion of the support being fixed to at least one interior surface of the support housing such that the tapered portion of the support extends beyond the support housing;

and a hollow vent housing fixed to the support housing such that the tapered portion of the support is located inside the vent housing, the vent housing having at least one gas escape passageway therethrough that is oriented radially with respect to a longitudinal axis of the vent housing, the vent housing being fixed to said one end of the inflator housing with the outlet passage being located in the vent housing, the rupturable closure member being fixed to the vent housing axially aligned with the first end of the tapered portion of the support.

10. The airbag inflator according to claim 8 further comprising a vent port assembly affixed to the tubular inflator housing and spaced apart from and between the ends of the tubular inflator housing.

11. An airbag inflator comprising:

a tubular inflator housing containing gas under pressure, the tubular inflator housing having two ends and a longitudinal axis;

a hollow vent housing having an end wall fixed to one end of the tubular inflator housing, the vent housing having a longitudinal axis that is coaxial with the longitudinal axis of the tubular inflator housing, the end wall of the vent housing having a gas outlet passage therethrough such that an interior chamber of the vent housing communicates with an interior chamber of the inflator housing via the gas outlet passage;

a rupturable closure member fixed to the vent housing blocking the flow of gas through the outlet passage from inside the inflator housing through the outlet passage to inside the vent housing, and the vent housing having at least one gas escape opening therethrough oriented radially with respect to the longitudinal axis of the vent housing to allow gas to pass from inside the vent housing to outside the vent housing;

a hollow support housing fixed to the vent housing, the hollow support housing having a longitudinal axis that is coaxial with the longitudinal axes of both the vent housing and the inflator housing;

a hollow support for supporting the rupturable closure member, the support having a tapered portion and an adjoining cylindrical portion, both an inside diameter and an outside diameter of the tapered portion having minimum sizes at an open smaller end of the tapered portion, both the inside and outside diameters of the tapered portion increasing to maximum sizes at a larger end of the tapered portion that is adjacent to the cylindrical portion, and the cylindrical portion extending to an open end of the support, an exterior surface of the tapered portion having longitudinally extending grooves therein, the cylindrical portion of the support being fixed to at least one interior surface of the support housing such that the tapered portion of the support extends beyond the support housing into the vent housing;

an igniter is located adjacent of the cylindrical portion of the support;

a pyrotechnic substance located in the cylindrical portion of the support;

the rupturable closure member being forced against the open first end of the tapered portion of the support by the gas in the inflator housing such that a chamber is formed within the support, the igniter when activated ignites the pyrotechnic substance and the burning pyrotechnic substance generates gas under pressure that causes the tapered portion of the support to break along the longitudinally extending grooves and no longer support the rupturable closure member allowing the gas in the inflator housing to rupture the unsupported rupturable closure member.

12. The airbag inflator according to claim 11 further comprising a vent port assembly affixed to the tubular inflator housing and spaced apart from and between the ends of the tubular inflator housing.