HYBRID AIRBAG INFLATOR

• US 20190322239A1
• Filed: 04/19/2018
• Published: 10/24/2019
• Est. Priority Date: 04/19/2018
• 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: Norman, III, Kent, McLeod, William F.
• Granted Patent: US 10,875,490 B2
• Time in Patent Office: Days
• CPC Class Codes: B60R 2021/26029 Ignitors
• CPC Class Codes: B60R 2021/26064 characterised by auto-ignition means
• CPC Class Codes: B60R 2021/2642 comprising a plurality of combustion chambers or sub-chambers
• CPC Class Codes: B60R 21/017 including arrangements for providing electric power to safety arrangements or their actuating means, e.g. to pyrotechnic fuses or electro-mechanic valves
• CPC Class Codes: B60R 21/264 using instantaneous generation of gas, e.g. pyrotechnic B60R21/268 takes precedence
• CPC Class Codes: B60R 21/2644 using only solid reacting substances, e.g. pellets, powder
• 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 airbag inflator (100, 200) has a disk-shaped pressure vessel having a central axis with a domed upper housing portion (20) with a sealed exhaust port (22) for releasing inflation gases and a domed lower body portion (10) welded to the domed upper housing portion (20). The domed lower body portion (10) has one or more protrusions (12) extending from an outer or exterior surface positioned offset from the center axis. At least one of the protrusions (12) houses an igniter assembly (60) with accessible electrical connections (61, 63). The disk-shaped pressure vessel inflator (100, 200) contains gas generant pellets (2) and a quantity of pressurized inert gas (1) for inflating an airbag. The combination of the protrusions (12) and domed lower body portion (10) has a unique profile of a petaloid shape. Optionally, the domed upper housing portion (20) can also have the petaloid shape.

Claims

1. A hybrid airbag inflator comprises:

a disk-shaped pressure vessel having a central axis with a domed upper housing portion with a sealed exhaust port for releasing inflation gases and a domed lower body portion welded to the domed upper housing portion, the domed lower body portion having one or more protrusions extending from an outer or exterior surface positioned offset from the center axis, at least one of the protrusions housing an igniter assembly with accessible electrical connections; and

wherein the disk-shaped pressure vessel contains gas generant pellets and a quantity of pressurized inert gas for inflating an airbag.

2. The hybrid airbag inflator of claim 1 further comprises:

a diffuser cap for receiving and encircling the domed upper housing portion, the diffuser cap being fixed to the pressure vessel and having a perforated circular wall, a closed top and a mounting flange for attaching the pressure vessel to a vehicle structure.

3. The hybrid airbag inflator of claim 1 wherein the domed lower body portion has three protrusions equally spaced apart at 120 degrees around and offset from the axis, each protrusion extending vertically from the outer or exterior surface by a vertical distance equal to the other protrusions forming a petaloid.

4. The hybrid airbag inflator of claim 3 wherein the domed upper housing portion has three protrusions equally spaced apart at 120 degrees around and offset from the axis, each protrusion extending vertically from the outer or exterior surface by a vertical distance equal to the other protrusions forming a petaloid.

5. The hybrid airbag inflator of claim 1 further comprises a fill ball, the fill ball is used to seal a fill opening or port on the domed lower body portion.

6. The hybrid airbag inflator of claim 5 wherein the fill ball is made of a metal material that is resistance welded to the domed lower body portion after inert gas is placed into the inflator under high pressure

7. The hybrid airbag inflator of claim 1 wherein the inert gas is typically a mixture of Argon and Helium.

8. The hybrid airbag inflator of claim 1 further comprises a generant chamber with an open tube for receiving an igniter assembly, the open tube being aligned with an opening of one of the protrusions extending from the exterior surface of the lower housing.

9. The hybrid airbag inflator of claim 1 wherein the igniter assembly has several components, an igniter holder for receiving an igniter, an igniter cap, an enhancer chamber and enhancer tablets.

10. The hybrid airbag inflator of claim 9 wherein the igniter holder is laser welded or otherwise affixed to the generant chamber.

11. The hybrid airbag inflator of claim 10 wherein the igniter has a pair of electrical connectors which are provided to connect to an electrical wiring connection to receive an electrical current when the device is activated causing the igniter to fire a small propellant charge stowed in the igniter.

12. The hybrid airbag inflator of claim 11 wherein the igniter cap encircles and holds the igniter and is resistance welded or otherwise affixed along flanged surfaces to the igniter holder securely fixing the igniter.

13. The hybrid airbag inflator of claim 12 wherein the enhancer tablets are stowed inside the enhancer chamber above the igniter cap, the enhancer tablets are small charges of combustible material used to ignite gas generant tablets stored inside the generant chamber.

14. The hybrid airbag inflator of claim 13 wherein for sound dampening and noise suppression, a lower cushion of material is provided that sits in the bottom of the gas generant chamber.

15. The hybrid airbag inflator of claim 14 further comprises an upper cushion of material, the gas generant being compactly packed between the cushioning materials to minimize rattling.

16. The hybrid airbag inflator of claim 15 further comprises an autoignition tablet that is also placed in the generant chamber, the autoignition tablet is a safety feature that will ignite when the device is exposed to a high temperature such as a fire, when the autoignition tablet ignites, it sets off the gas generant tablets and the enhancer tablets to prevent a premature explosion.

17. The hybrid airbag inflator of claim 15 wherein above the upper cushion is a generant cap with a plurality of holes sealed by a rupturable disk of cap foil, the cap foil seals the holes of the cap and the gas generant chamber when the generant cap is pressed onto the generant chamber.

18. The hybrid airbag inflator of claim 17 wherein above the generant cap is a baffle, the baffle has an elevated ring with a plurality of openings or holes.

19. The hybrid airbag inflator of claim 18 wherein in a depression formed by the elevated ring is placed a perforated ring with a cylindrical wall with a large number of holes, the center opening of the perforated ring being set over a small centering protrusion of the baffle.

20. The hybrid airbag inflator of claim 1 is a dual stage inflator having two igniter assemblies, one being in a primary gas generant chamber and the other igniter assembly being in a second stage generant chamber, both chambers fitting into the lower body portion.

21. The hybrid airbag inflator of claim 20 the primary generant chamber occupies approximately 270 degrees with the secondary chamber occupying about 90 degrees of circumference.

22. The hybrid airbag inflator of claim 21 wherein an enlarged secondary generant chamber occupies approximately 120 degrees and a reduced primary chamber occupies 240 degrees of circumference.

23. The hybrid airbag inflator of claim 22 wherein the primary and secondary generant chambers being equally sized.

24. The hybrid airbag inflator of claim 23 wherein the protrusions extending from the dome shaped top of the inflator provide a stable platform upon which the inflator can sit during assembly of the various components.

25. The hybrid airbag inflator of claim 1 wherein the protrusions on the inflator act as legs having a flat horizontal surface that can be used for vertically supporting the lower body portion or domed upper housing portion during the assembly operation.