Igniter assembly with retractable piston

1. An igniter assembly ( 20 ) for releasing gas flow when assembled to an inflator ( 10 ), the igniter assembly ( 20 ) comprising:

an igniter housing ( 22 ), a squib ( 60 ) electrically actuated and fitted in an end of the igniter housing ( 22 ) and a retractable piston ( 50 ) affixed to the igniter housing ( 22 ) wherein the igniter housing ( 22 ) extends inwardly forming a chamber to hold a portion of the squib ( 60 ) and the retractable piston ( 50 ) is held in the chamber of the igniter housing ( 22 ) at an end opposite the squib ( 60 ), the retractable piston ( 50 ) having a sleeve ( 52 ) portion sized to fit inside the chamber portion, the sleeve ( 52 ) portion having one or more vent holes ( 54 ); and

wherein upon actuation of the squib ( 60 ) the retractable piston ( 50 ) propels impacting breaking a frangible closure ( 40 ) releasing gases pushing the piston ( 50 ) retractably back into or over the igniter housing ( 22 ).

2. The igniter assembly ( 20 ) of claim 1 wherein the igniter assembly ( 20 ) has the squib ( 60 ) in the igniter end extending through an opening for access to electrical connectors of the squib ( 60 ).

3. The igniter assembly ( 20 ) of claim 1 wherein the retractable piston ( 50 ) has an impact end ( 55 ) spaced a distance (d) from a rupture portion ( 48 ) of the frangible closure ( 40 ), and the sleeve ( 52 ) has a length (e) exceeding the distance the retractable piston ( 50 ) moves to break the rupture portion ( 48 ) on activation of the squib ( 60 ).

4. The igniter assembly ( 20 ) of claim 3 wherein the retractable piston ( 50 ) has a base portion ( 58 ) positioned between the sleeve ( 52 ) and the impact end ( 55 ).

5. The igniter assembly ( 20 ) of claim 4 wherein the impact end ( 55 ) has a diameter smaller than the rupture portion ( 48 ) of the frangible closure ( 40 ).

6. The igniter assembly ( 20 ) of claim 5 wherein the diameter from the impact end ( 55 ) to the base ( 58 ) of the retractable piston ( 50 ) is constantly increasing in diameter to the base ( 58 ).

7. The igniter assembly ( 20 ) of claim 6 wherein the sleeve ( 52 ) has a projecting ring ( 59 ) adjacent the base ( 58 ) to press fit into the chamber of the igniter housing ( 22 ).

8. An igniter assembly ( 20 ) for releasing gas flow when assembled to an inflator ( 10 ), the igniter assembly ( 20 ) comprising:

an igniter housing ( 22 ), a squib ( 60 ) electrically actuated and fitted onto an end of the igniter housing ( 22 ) and a retractable piston ( 50 ) affixed to the igniter housing ( 22 ) wherein the igniter housing ( 22 ) extends inwardly forming a chamber to hold a portion of the squib ( 60 ) and the retractable piston ( 50 ) is held in the chamber of the igniter housing ( 22 ) at an end opposite the squib ( 60 ) wherein the retractable piston ( 50 ) has a sleeve portion sized to fit over the igniter housing ( 22 ) at an end opposite the squib ( 60 ), the sleeve ( 52 ) portion having one or more vent holes ( 54 ); and

wherein upon actuation of the squib ( 60 ) the retractable piston ( 50 ) propels impacting breaking a frangible closure ( 40 ) releasing gases pushing the piston ( 50 ) retractably back onto or over the igniter housing ( 22 ).

9. The igniter assembly ( 20 ) of claim 8 wherein the igniter assembly ( 20 ) has the squib ( 60 ) in the igniter end extending through an opening for access to electrical connectors of the squib ( 60 ).

10. The igniter assembly ( 20 ) of claim 8 wherein the retractable piston ( 50 ) has an impact end ( 55 ) spaced a distance (d) from a rupture portion ( 48 ) of the frangible closure ( 40 ), and the sleeve ( 52 ) has a length (e) exceeding the distance the retractable piston ( 50 ) moves to break the rupture portion ( 48 ) on activation of the squib ( 60 ).

11. The igniter assembly ( 20 ) of claim 10 wherein the retractable piston ( 50 ) has a base portion ( 58 ) positioned between the sleeve ( 52 ) and the impact end ( 55 ).

12. The igniter assembly ( 20 ) of claim 11 wherein the impact end ( 55 ) has a diameter smaller than the rupture portion ( 48 ) of the frangible closure ( 40 ).

13. The igniter assembly ( 20 ) of claim 12 wherein the diameter from the impact end ( 55 ) to the base ( 58 ) of the retractable piston ( 50 ) is constantly increasing in diameter to the base ( 58 ).

14. An inflator ( 10 ) comprising:

an inflator housing ( 12 ) for storing inflation gases under pressure;

a frangible closure ( 40 ) sealing the inflation gas inside the inflator housing ( 12 );

a diffuser ( 30 ) attached to an end of the inflator housing ( 12 ), the diffuser ( 30 ) having a plurality of holes ( 32 ) for directing gas flow;

an igniter assembly ( 20 ) for releasing gas flow, the igniter assembly ( 20 ) having an igniter housing ( 22 ), a squib ( 60 ) electrically actuated and fitted in an end of the igniter housing ( 22 ) and a retractable piston ( 50 ) affixed to the igniter housing ( 22 ) wherein the igniter housing ( 22 ) extends inwardly relative to the diffuser ( 30 ) forming a chamber to hold a portion of the squib ( 60 ), the retractable piston ( 50 ) is held in the chamber of the igniter housing ( 22 ) at an end opposite the squib ( 60 ) and the retractable piston ( 50 ) having a sleeve ( 52 ) portion sized to fit inside the chamber portion, the sleeve ( 52 ) portion having one or more vent holes ( 54 ); and

wherein upon actuation of the squib ( 60 ) the retractable piston ( 50 ) propels impacting breaking the frangible closure ( 40 ) releasing gases pushing the piston ( 50 ) retractably back into or over the igniter housing ( 22 ).

15. The inflator ( 10 ) of claim 14 wherein the diffuser ( 30 ) has the igniter assembly ( 20 ) held in place with the squib ( 60 ) and the igniter end extending through an opening in the diffuser ( 30 ) for access to electrical connectors of the squib ( 60 ).

16. The inflator ( 10 ) of claim 14 wherein the frangible closure ( 40 ) is affixed to an end of the diffuser ( 30 ).

17. The inflator ( 10 ) of claim 16 wherein the diffuser ( 30 ) is affixed to the inflator housing ( 12 ).

18. The inflator ( 10 ) of claim 14 wherein the retractable piston ( 50 ) has an impact end ( 55 ) spaced a distance (d) from a rupture portion ( 48 ) of the frangible closure ( 40 ), and the sleeve ( 52 ) has a length (e) exceeding the distance the retractable piston ( 50 ) moves to break the rupture portion ( 48 ) on activation of the squib ( 60 ).

19. The inflator ( 10 ) of claim 15 wherein the retractable piston ( 50 ) has a base portion positioned between the sleeve ( 52 ) and the impact end ( 55 ).

20. The inflator ( 10 ) of claim 19 wherein the impact end ( 55 ) has a diameter smaller than the rupture portion ( 48 ) of the frangible closure ( 40 ).

21. The inflator ( 10 ) of claim 20 wherein the diameter from the impact end ( 55 ) to the base ( 58 ) of the retractable piston ( 50 ) is constantly increasing in diameter to the base ( 58 ).

22. The inflator ( 10 ) of claim 21 wherein the sleeve ( 52 ) has a projecting ring ( 59 ) adjacent the base ( 58 ) to press fit into the chamber of the igniter housing ( 22 ).

23. An inflator ( 10 ) comprising:

an inflator housing ( 12 ) for storing inflation gases under pressure;

a frangible closure ( 40 ) sealing the inflation gas inside the inflator housing ( 12 );

a diffuser ( 30 ) attached to an end of the inflator housing ( 12 ), the diffuser ( 30 ) having a plurality of holes ( 32 ) for directing gas flow;

an igniter assembly ( 20 ) for releasing gas flow, the igniter assembly ( 20 ) having an igniter housing ( 22 ), a squib ( 60 ) electrically actuated and fitted onto an end of the igniter housing ( 22 ) and a retractable piston ( 50 ) affixed to the igniter housing ( 22 ) wherein the igniter housing ( 22 ) extends inwardly relative to the diffuser ( 30 ) forming a chamber to hold a portion of the squib ( 60 ), the retractable piston ( 50 ) is held in the chamber of the igniter housing ( 22 ) at an end opposite the squib ( 60 ) wherein the retractable piston ( 50 ) has a sleeve portion sized to fit over the igniter housing ( 22 ) at an end opposite the squib ( 60 ), the sleeve ( 52 ) portion having one or more vent holes ( 54 ); and

wherein upon actuation of the squib ( 60 ) the retractable piston ( 50 ) propels impacting breaking the frangible closure ( 40 ) releasing gases pushing the piston ( 50 ) retractably back into or over the igniter housing ( 22 ).

24. The inflator ( 10 ) of claim 23 wherein the diffuser ( 30 ) has the igniter assembly ( 20 ) held in place with the squib ( 60 ) and the igniter end extending through an opening in the diffuser ( 30 ) for access to electrical connectors of the squib ( 60 ).

25. The inflator ( 10 ) of claim 23 wherein the frangible closure ( 40 ) is affixed to an end of the diffuser ( 30 ).

26. The inflator ( 10 ) of claim 25 wherein the diffuser ( 30 ) is affixed to the inflator housing ( 12 ).

27. The inflator ( 10 ) of claim 23 wherein the retractable piston ( 50 ) has an impact end ( 55 ) spaced a distance (d) from a rupture portion ( 48 ) of the frangible closure ( 40 ), and the sleeve ( 52 ) has a length (e) exceeding the distance the retractable piston ( 50 ) moves to break the rupture portion ( 48 ) on activation of the squib ( 60 ).