Hybrid inflator

• US 7,320,479 B2
• Filed: 10/03/2005
• Issued: 01/22/2008
• Est. Priority Date: 10/03/2005
• Status: Active Grant

• 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: Adams, John H., Stembler, Edward R., Mulville, Michael F., Kelley, Michael E., Burroughs, Carter L., Trevillyan, Dennis A.
• Primary Examiner(s): Dickson; Paul N.
• Assistant Examiner(s): Brown; Drew J.
• Application Number:
  US11/241,222
• Publication Number:
  US 20070075535A1
• Time in Patent Office: 841 Days
• Field of Search: 280/741, 280/737, 280/736, 280/742
• US Class Current: 280/736
• CPC Class Codes: B60R 2021/2685 comprising a plurality of pressure chambers
• 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

A hybrid inflator for inflating an airbag system has one or more heater assemblies with an enhancer charge contained in the heater with bypass ports or openings in direct communication with the inert gas. Upon ignition a portion of the enhancer charge bypasses the heater gas generant charge to pre-heat the inert gas prior to or simultaneously with a remaining portion of the enhancer charge igniting the heater gas generant charge.

Claims

1. A hybrid inflator for inflating an airbag system of a vehicle, comprising:

an inflator housing having a pair of opposite ends, the inflator housing being filled with a pressurized medium containing an inert gas;

one or more gas heaters inside the inflator housing and one gas heater being connected at an end of at least one of the pair of opposite ends of the inflator housing, at least one of the one or more gas heaters including;

an outer shell formed by a heater housing having a plurality of heater holes and a plurality of bypass openings;

a gas generating chamber in which a gas generant charge is stored, the gas generating chamber and the inflator housing being in communication with each other through the plurality of heater holes and the plurality of bypass openings;

an ignition means connected to at least one of the one or more gas heaters connected at an end of the inflator housing and being located at an end of the inflator housing;

an enhancer chamber in which an enhancer charge is stored, the enhancer chamber being located between the gas generating chamber in which the gas generant charge is stored and the ignition means, and separated from the gas generating chamber by a bulkhead, the bulkhead having one or more first openings to the gas generator chamber, and being located in close proximity to the plurality of bypass openings; and

a rupture disk attached to and covering the one or more first openings in the bulkhead;

wherein the enhancer charge when ignited by the ignition means increases the pressure in the enhancer chamber causing the rupture disk to burst after a predetermined pressure is reached within the enhancer chamber, passes ignited gases through the one or more first openings in the bulkhead and passes a portion of the ignited gases of the enhancer charge through the bypass openings in proximity to the bulkhead pre-heating the inert gas in the inflator and a remaining portion of the ignited enhancer charge ignites the gas generant charge stored in the gas generating chamber.

2. The hybrid inflator of claim 1 wherein the inflator housing has a second end and the inflator has two gas heaters with one gas heater at each end of the inflator housing.

3. The hybrid inflator of claim 2 wherein the inflator housing is tubular shaped having a reduced diameter central portion.

4. The hybrid inflator of claim 3 wherein the central portion has a gas outlet opening, the outlet opening being sealed by an outlet burst disk.

5. The hybrid inflator of claim 3 wherein the central portion has a gas fill port, the gas fill port being sealed.

6. The hybrid inflator of claim 3 wherein the reduced diameter central portion is covered by a cylindrical gas distribution manifold to form a manifold area, the distribution manifold includes a plurality of holes.

7. A hybrid inflator for inflating an airbag system of a vehicle, comprising:

an inflator housing having a pair of opposite ends, the inflator housing being filled with a pressurized medium containing an inert gas;

one or more gas heaters internal of the heater housing and one gas heater being connected at an end of at least one of the pair of opposite ends of the inflator housing, at least one of the one or more gas heaters including;

an outer shell formed by a heater housing having a plurality of heater holes;

a gas generating chamber in which a gas generant charge is stored, the gas generating chamber and the inflator housing being in communication with each other through the plurality of heater holes;

an ignition means connected to the at least one of the one or more gas heaters connected at an end of the inflator housing and being located at an end of the inflator housing;

an enhancer chamber in which an enhancer charge is stored, the enhancer chamber being located between the gas generating chamber in which the gas generant charge is stored and the ignition means, and separated from the gas generating chamber by a bulkhead, the bulkhead having one or more first openings to the gas generator chamber, and the enhancer chamber having one or more bypass openings to the inflator housing; and

a rupture disk attached to and covering the one or more first openings in the bulkhead;

wherein the enhancer charge when ignited by the ignition means passes ignited gases of the enhancer charge through the enhancer chamber bypass openings to the inflator housing thereby pre-heating the inert gas in the inflator housing, after a predetermined pressure is reached within the enhancer chamber upon ignition of the enhancer charge, the rupture disk bursts and the enhancer chamber passes ignited enhancer charge gases through the one or more first openings in the bulkhead and ignites the gas generant charge stored in the gas generating chamber.

8. The hybrid inflator of claim 7 wherein the inflator housing has a second end and the inflator has two gas heaters with one gas heater at each end of the inflator housing.

9. The hybrid inflator of claim 8 wherein the inflator housing is tubular shaped having a reduced diameter central portion.

10. The hybrid inflator of claim 9 wherein the central portion has a gas outlet opening, the outlet opening being sealed by an outlet burst disk.

11. The hybrid inflator of claim 9 wherein the central portion has a gas fill port, the gas fill port being sealed.

12. The hybrid inflator of claim 9 wherein the reduced diameter central portion to provide a manifold area that is covered by a cylindrical gas distribution manifold to form a manifold area, the distribution manifold includes a plurality of holes around the circumference.