Active venting inflator device

• US 20070267855A1
• Filed: 05/19/2006
• Published: 11/22/2007
• Est. Priority Date: 05/19/2006
• Status: Active Grant

• Current Assignee: Autoliv ASP Incorporated (Autoliv Incorporated)
• Original Assignee: Autoliv ASP Incorporated (Autoliv Incorporated)
• Inventors: Enders, Mark L., Lang, Gregory J., Lewis, Robert E.
• Granted Patent: US 7,469,926 B2
• Time in Patent Office: Days
• US Class Current: 280/739
• CPC Class Codes: B60R 2021/23384 having ends which are movable or detachable during deployment
• CPC Class Codes: B60R 2021/23388 having ends which are movable or detachable during deployment
• CPC Class Codes: B60R 2021/2765 comprising means to control the venting
• CPC Class Codes: B60R 21/2338 Tethers
• 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 21/276 with means to vent the inflation fluid source, e.g. in case of overpressure B60R21/30 takes precedence; venting means on inflatable member walls B60R21/239

Abstract

An inflator device for inflating an inflatable cushion of an inflatable cushion restraint system. The inflator device includes a supply of gas generant material disposed within a sealed chamber, and an initiator device in reaction initiation combination with the supply of gas generant material. A venting orifice connects the chamber to the surrounding ambient environment, and a rupturable seal seals the venting orifice. Upon reaction initiation of the gas generant material to produce inflation gas, the rupturable seal ruptures to vent the chamber to the ambient environment. A valve assembly can be disposed adjacent the venting orifice. A moveable valve piston, in combination with an actuator device, can block the venting orifice as needed to close the venting orifice and stop inflation gas venting. An optional tether release mechanism can be used in combination with the valve assembly to release a cushion tether upon closing of the venting orifice.

Claims

1. In an inflator device for inflating an inflatable cushion of an inflatable cushion restraint system, the inflator device including a supply of gas generant material disposed within a sealed chamber and an initiator device in reaction initiation combination with the supply of gas generant material, the improvement comprising:

a venting orifice connecting the chamber to an ambient environment; and

a rupturable seal sealing the venting orifice, wherein upon reaction initiation of the gas generant material, the rupturable seal ruptures to vent the chamber to the ambient environment.

2. The inflator device according to claim 1 additionally comprising a valve in combination with the venting orifice, wherein the valve is closable to block venting through the venting orifice upon rupture of the rupturable seal.

3. The inflator device according to claim 2 wherein the valve comprises a valve assembly disposed adjacent the venting orifice, the valve assembly comprising:

a valve passageway aligned with the venting orifice;

a valve piston moveable within the valve passageway; and

a valve actuator device for moving the valve piston within the valve passageway, wherein upon actuation of the valve actuator, the valve piston moves to at least partially block venting through the venting orifice.

4. The inflator device according to claim 3 additionally comprising a plurality of radial vent passageways radially extending from the valve passageway and connecting the valve passageway to the ambient environment.

5. The inflator device according to claim 3 wherein the valve actuator device comprises a valve initiator device disposed at an end of the valve passageway opposite the venting orifice.

6. The inflator device according to claim 5 additionally comprising a pressure release opening connecting the valve passageway to the ambient environment, wherein in an open position before actuation of the valve initiator device, the valve piston is disposed over the pressure release opening and upon actuation of the valve initiator device, the valve piston moves within the valve passageway, whereby the pressure release opening is disposed between the valve piston and the valve initiator device.

7. The inflator device according to claim 3 wherein the valve assembly additionally comprises a piston locking element disposed partially within an aperture in a wall of the valve passageway, wherein a portion of the piston locking element extending from the aperture is disposed adjacent the valve piston to secure the valve piston in an open position adjacent the valve actuator.

8. The inflator device according to claim 7 wherein upon actuation of the valve actuator, the piston locking element is moveable to allow the valve piston to move within the valve passageway and the piston locking element then secures the valve piston in a closed position adjacent the venting orifice.

9. The inflator device according to claim 8 wherein the piston locking element comprises a snap ring.

10. The inflator device according to claim 3 additionally comprising a tether release mechanism in combination with the valve assembly, wherein the valve actuator device is in actuating combination with the tether release mechanism.

11. The inflator device according to claim 10 wherein the valve actuator device comprises a valve initiator device disposed at an end of the valve passageway opposite the venting orifice, the valve assembly additionally comprises a valve venting channel connecting the valve passageway to the tether release mechanism, and the piston includes an opening therethrough, wherein upon actuation of the valve initiator device, the valve initiator device moves the piston and reaction products pass through the valve venting channel to actuate the tether release mechanism.

12. A method of using the inflator device of claim 3 upon a collision, the method comprising:

initiating reaction of the supply of gas generant material to produce inflation gas;

actuating the valve actuator to move the valve piston within the valve passageway; and

blocking the venting orifice with the valve piston to direct the inflation gas only to the inflatable cushion.

13. An inflator device for inflating an inflatable cushion of an inflatable cushion restraint system, the inflator device comprising:

a housing at least in part defining a chamber;

a supply of gas generant material disposed at least partially within the chamber;

an initiator device in reaction initiation combination with the supply of gas generant material;

the housing including an outlet orifice in inflation combination with the inflatable cushion;

the housing including a venting orifice connecting the chamber to an ambient environment; and

a rupturable seal sealing each of the outlet orifice and the venting orifice.

14. The inflator device according to claim 13 additionally comprising a valve assembly disposed adjacent the venting orifice, the valve assembly comprising:

a valve passageway defined by the valve assembly and aligned with the venting orifice, the valve passageway including a plurality of vent passageways radially extending from the valve passageway and connecting the valve passageway to the ambient environment;

a valve piston moveable within the valve passageway; and

a valve initiator device disposed at an end of the valve passageway opposite the venting orifice, wherein upon actuation of the valve initiator device, the valve piston moves and at least partially blocks the venting orifice.

15. The inflator device according to claim 14 wherein the valve assembly additionally comprises a snap ring disposed partially within an aperture in a wall of the valve passageway, wherein a portion of the snap ring extending from the aperture is disposed adjacent the valve piston to secure the valve piston in an open position adjacent the valve actuator.

16. The inflator device according to claim 14 additionally comprising a tether release mechanism in combination with the valve assembly, wherein the valve initiator device is in actuating combination with the tether release mechanism.

17. The inflator device according to claim 16 wherein the valve assembly additionally comprises a valve venting channel connecting the valve passageway to the tether release mechanism and the tether release mechanism comprises:

a tether release chamber including an inlet opening in a first chamber side wall and a piston opening in a chamber end wall, the inlet opening in discharge alignment with a valve venting channel of the valve assembly;

a tether piston moveable within the chamber and including a piston rod extending through the piston opening and for retaining a tether connected to the inflatable cushion;

wherein upon actuation of the valve initiator device, reaction products in the valve passageway enter the tether release chamber through the valve venting channel and move the piston toward a second chamber end wall opposite the first chamber end wall, thereby sliding the piston rod to release the tether.

18. The inflator device according to claim 17 additionally comprising a compressible member disposed between the piston and a second chamber end wall opposite the first chamber end wall.

19. The inflator device according to claim 18 additionally comprising a tether release mechanism mount for attaching the tether release mechanism to the valve assembly, the tether release mechanism mount including a passageway extending between the valve venting channel and the inlet opening.

20. An inflator device for inflating an inflatable cushion of an inflatable cushion restraint system, the inflator device comprising:

a housing including a first housing wall and a second housing wall and at least in part defining a chamber;

a supply of gas generant material disposed at least partially within the chamber;

an initiator device in reaction initiation combination with the supply of gas generant material;

an outlet orifice in the first housing wall and in inflation combination with the inflatable cushion;

a venting orifice in the second housing wall connecting the chamber to an ambient environment;

a rupturable seal sealing each of the outlet orifice and the venting orifice;

a valve assembly disposed adjacent the venting orifice, the valve assembly including a valve passageway aligned with the venting orifice, a valve piston moveable within the valve passageway, a valve initiator device disposed at an end of the valve passageway opposite the venting, and a valve venting channel, wherein upon actuation, the valve initiator device produces a reaction product that moves the valve piston to at least partially block the venting orifice; and

a tether release mechanism comprising a tether release chamber and a tether piston moveable within the tether release chamber, the tether release chamber including a chamber side wall including an inlet opening in discharge alignment with the valve venting channel and a piston opening in a chamber end wall adjacent the chamber side wall, the tether piston including a piston rod extending through the piston opening for retaining a tether connected to the inflatable cushion.