Inflator having a variable gas flow throttle

• US 20070138775A1
• Filed: 02/21/2006
• Published: 06/21/2007
• Est. Priority Date: 12/20/2005
• Status: Active Grant

• Current Assignee: Kay Safety Systems, Inc.
• Original Assignee: Key Safety Systems, Inc. (Ningbo Junsheng Investment Group Co., Ltd.)
• Inventors: Rademacher, Manfred, Klettenheimer, Guido, Rossbach, Thomas, Verheugen, Joachim
• Granted Patent: US 7,347,449 B2
• Time in Patent Office: Days
• US Class Current: 280/736
• CPC Class Codes: B60R 2021/26094 characterised by fluid flow controlling valves
• CPC Class Codes: B60R 21/26 characterised by the inflation fluid source or means to control inflation fluid flow arrangement or mounting thereof to the vehicle B60R21/20; blasting cartridges for producing gas under pressure in general F42B3/04; initiators or igniters therefor F42B3/10
• CPC Class Codes: B60R 21/268 using instantaneous release of stored pressurised gas B60R21/26005 takes precedence

Abstract

An airbag inflator has a variable gas flow throttle disposed in a gas flow path. The throttle has at least one gas passageway through a base portion thereof. A tab extends from the base portion and is bendable towards the base portion by a selected amount of gas pressure to closes or at least partially close the gas passageway. The tab may have another gas passageway therethrough.

Claims

1. An inflator comprising a gas storage container and a gas flow path through which inflation gas can pass to exit the inflator when the inflator is activated, characterized by the gas flow path includes a variable gas flow throttle member having at least one gas flow passageway therethrough, the gas flow passageway in the variable gas flow throttle member having a gas flow area A₁ that is varied by a tab being bent towards the gas flow passageway by a predetermined minimum gas pressure inside the gas storage container to at least partially block the gas flow passageway and reduce the gas flow area through the variable gas flow throttle member.

2. The inflator according to claim 1 further comprising at least one second passageway on the variable gas flow throttle member, the second passageway having a constant fluid flow area A₂ wherein the initial fluid flow area is the sum of A₁ and A₂ and after exposure to the predetermined pressure or greater the sum of the fluid flow equals A₂.

3. The inflator according to claim 1 further comprising at least one second passageway on the variable gas flow throttle member, the second passageway having a constant fluid flow area A₂ wherein the second passageway is on the tab.

4. The inflator according to claim 1 further comprising a positive thrust stop, the positive thrust stop preventing the tab form bending beyond a fully closed position.

5. The inflator according to claim 4 wherein the positive thrust stop being formed by complimentary inclined edges or chamfers in the tab and the variable gas flow throttle member.

6. The inflator according to claim 1 wherein the inflator has a disk shaped housing and the variable gas flow throttle member is adjacent to or an integral part of the housing structure and includes one or more tabs and a space between the one or more tabs and the variable gas flow throttle member defines the fluid flow area A₁.

7. The inflator according to claim 1 wherein the inflator has a longitudinally cylindrical housing and the variable gas flow throttle member is disposed between an inflation gas generating source and an exhaust port.

8. The inflator according to claim 1 wherein the tab is inclined 60°

or less relative to the variable gas flow member to form the passageway.

9. A variable gas flow throttle for an inflator comprising a variable gas flow throttle member having at least one gas flow passageway therethrough, the gas flow passageway in the variable gas flow throttle member having a gas flow area A₁ that is defined by a space between a tab on the variable gas flow member and the variable gas flow member and the area A₁ can be varied when installed in an inflator by the tab on the variable gas flow member being bent towards the gas flow passageway by a predetermined minimum force or gas pressure to at least partially close the space and at least partially block the gas flow passageway and reduce the gas flow area through the variable gas flow throttle member.

10. The variable gas flow throttle for an inflator according to claim 9 wherein the tab is inclined 60°

or less relative to the variable gas flow member to form the passageway.

11. The variable gas flow throttle for an inflator according to claim 9 further comprising at least one second passageway through the variable gas flow throttle member, the second passageway having a constant fluid flow area A₂ wherein the initial fluid flow area is the sum of A₁ and A₂ and after exposure to the predetermined force or pressure or greater the sum of the fluid flow equals A₂.

12. The variable gas flow throttle for an inflator according to claim 9 further comprising at least one second passageway through the variable gas flow throttle member, the second passageway having a constant fluid flow area A₂ wherein the second passageway is on the tab.

13. The variable gas flow throttle for an inflator according to claim 9 further comprising a positive thrust stop, the positive thrust stop preventing the tab form bending beyond a fully closed position.

14. The variable gas flow throttle for an inflator according to claim 13 wherein the positive thrust stop is formed by complimentary inclined edges or chamfers in the tab and the variable gas flow throttle member.