Gas generator

• US 20020145275A1
• Filed: 04/10/2001
• Published: 10/10/2002
• Est. Priority Date: 04/10/2001
• Status: Active Grant

• Current Assignee: Key Safety Systems, Inc. (Ningbo Junsheng Investment Group Co., Ltd.)
• Original Assignee: Breed Automotive Technology, Inc. (Ningbo Junsheng Investment Group Co., Ltd.)
• Inventors: Hosey, Edward Otis, Lam, Keith Hing, Canterberry, J. B.
• Granted Patent: US 6,553,914 B2
• Time in Patent Office: Days
• US Class Current: 280/741
• CPC Class Codes: B60R 2021/26029 Ignitors
• CPC Class Codes: B60R 21/272 with means for increasing the pressure of the gas just before or during liberation, e.g. hybrid inflators
• CPC Class Codes: B60R 22/4628 characterised by fluid actuators, e.g. pyrotechnic gas generators actuating a cable B60R22/4619
• CPC Class Codes: F42B 3/04 for producing gas under pressure generators of inflation fluid especially adapted for vehicle air bags B60R21/26
• CPC Class Codes: F42B 3/103 Mounting initiator heads in initiators; Sealing-plugs
• CPC Class Codes: F42B 3/182 having shunting means F42B3/185 takes precedence; details of shunting devices H01R13/7032
• CPC Class Codes: H01R 13/7032 making use of a separate bridging element directly cooperating with the terminals

Abstract

A gas generator according has a polymeric closure and an igniter subassembly comprising an igniter and a polymeric gas generator body. The gas generator body and the polymeric closure define a hermetically sealed combustion chamber for receiving a gas generant. The igniter receives an electrical current and ignites the gas generant. The generated gas can be used in vehicle occupant safety devices including seat belt pretensioners, airbags, compressed gas vessel openers, and other devices requiring a rapid pulse of high-pressure gas.

Claims

1. A gas generator comprising:

an igniter subassembly comprising an igniter for receiving an electrical current and igniting a gas generant inset molded in a polymeric gas generator body having a combustion chamber wall;

a polymeric closure attached to said polymeric gas generator body;

a combustion chamber for receiving a gas generant, said combustion chamber defined by said igniter, said polymeric closure and said polymeric combustion chamber wall; and

a gas generant disposed in said combustion chamber.

2. The gas generator of claim 1, wherein said igniter subassembly further comprises a polymeric flange integrally formed with said polymeric gas generator body and extending radially therefrom;

and a polymeric interior annular portion extending into said combustion chamber, said polymeric annular portion forming an annular recess with an interior wall of said combustion chamber wall, said annular recess forming a part of said combustion chamber.

3. The gas generator of claim 1 wherein said combustion chamber is hermetically sealed.

4. The gas generator of claim 2 wherein said combustion chamber is hermetically sealed.

5. The gas generator of claim 1 wherein said polymeric closure is hermetically sealed to the exterior of said combustion chamber wall.

6. The gas generator of claim 1 wherein said closure is hermetically sealed to the interior of said polymeric combustion chamber wall.

7. The gas generator of claim 1 wherein said polymeric closure and polymeric gas generator body comprise nylon 6/6.

8. A gas generator, comprising:

a logitudinal axis;

an igniter subassembly comprising an igniter for receiving an electrical current and igniting a gas generant molded in a polymeric material;

a polymeric closure hermetically sealed to said igniter subassembly;

a combustion chamber defined by said igniter, said polymeric closure and said igniter subassembly.

9. The gas generator of claim 8, wherein said igniter subassembly further comprises:

a combustion chamber wall that partially defines said combustion chamber, said combustion chamber consisting essentially of a polymer;

a polymeric flange integrally formed with said polymeric gas generator body and extending radially outward therefrom; and

a polymeric interior annular portion extending into said combustion chamber, said annular portion forming an annular recess with said interior wall, said annular recess forming a part of said combustion chamber.

10. The gas generator of claim 9, wherein said igniter is integrally formed with said igniter subassembly, said igniter comprising:

a charge cavity defined by said polymeric annular portion; and

an electrical connector communicating with said charge cavity, such that said electrical connector is capable of receiving an electrical current and transmitting said electrical current to said charge cavity to ignite a primary pyrotechnic material.

11. An assembly comprising a vessel containing compressed gas and a gas generator adapted to open said vessel by rupturing a closure of said vessel, said gas generator, comprising:

an igniter subassembly comprising an igniter for receiving an electrical current and igniting a gas generant inset molded in a polymeric gas generator body having a combustion chamber wall;

a closure comprising a polymer;

a combustion chamber for receiving a gas generant, said combustion chamber defined by said igniter, said polymeric closure and said polymeric combustion chamber wall; and

a gas generant disposed in said combustion chamber.

15. The gas generator of claim 14, wherein said combustion chamber has a volume that will accommodate not greater than about five grams of a gas generant.

17. The method of claim 16, wherein a polymeric annular portion that is integrally formed with said igniter subassembly surrounds said first end of said igniter, said polymeric annular portion extending into said combustion chamber and forming an annular recess with said interior wall.

18. The method of claim 16, wherein an igniter is integrally formed with said igniter subassembly, said igniter being a charge cavity operatively connected to said electrical connector, said electrical connector adapted to receive an electrical current and to transmit said electrical current to said charge cavity, said charge cavity being defined by a polymeric annular portion that extends into said combustion chamber, said annular portion forming an annular recess with said interior wall.

12. A gas generator having a logitudinal axis for use with a vehicle occupant restraint system, said gas generator comprising:

a polymeric igniter subassembly having a combustion chamber wall with an interior wall, said combustion chamber wall comprising a polymer, a polymeric flange integrally formed with said polymeric gas generator body and extending radially outward therefrom, said igniter subassembly further comprising a polymeric interior annular portion extending into a combustion chamber, said combustion chamber having a volume formed by said polymeric igniter subassembly and a polymeric closure, said polymeric closure being hermetically sealed to said polymeric combustion wall;

said annular portion forming an annular recess with said interior wall and defining a charge cavity, said polymeric material being nylon 6/6; and

an electrical connector communicating with said charge cavity, such that said electrical connector is adapted to receive an electrical current and to transmit said electrical current to said charge cavity to ignite a pyrotechnic material, which ignites a gas generant.

13. A gas generator comprising:

an igniter subassembly comprising an igniter for receiving an electrical current and igniting a gas generant inset molded in a polymeric gas generator body having a combustion chamber wall;

a polymeric closure attached to said polymeric gas generator body, the polymeric gas generator body and closure comprising at least one material selected from the group consisting essentially of glass fiber reinforced nylon 6/6, acrylo nitrile butadyene, polyetheramides, polyphenyline oxide, and polyarylamide;

a combustion chamber for receiving a gas generant, said combustion chamber defined by said igniter, said polymeric closure and said polymeric combustion chamber wall; and

a gas generant disposed in said combustion chamber.

14. A gas generator comprising:

an igniter subassembly comprising an igniter for receiving an electrical current and igniting a gas generant inset molded in a polymeric gas generator body having a combustion chamber wall;

a polymeric closure attached to said polymeric gas generator body;

a combustion chamber for receiving a gas generant, said combustion chamber defined by said igniter, said polymeric closure and said polymeric combustion chamber wall.

16. A method for manufacturing a gas generator, comprising the steps of:

providing a mold;

inserting an igniter or an igniter header assembly into said mold;

injecting a flowable polymeric material into said mold such that an igniter subassembly is formed that surrounds said electrical connector, said igniter subassembly forming a combustion chamber such that a gas generant may be disposed therein.