Stamped metal toroidal hybrid gas generator

• US 5,588,676 A
• Filed: 03/14/1996
• Issued: 12/31/1996
• Est. Priority Date: 10/12/1994
• Status: Expired due to Fees

• Current Assignee: Autoliv ASP Incorporated (Autoliv Incorporated)
• Original Assignee: Morton International Incorporated (Autoliv Incorporated)
• Inventors: Smith, Bradley W., Rasmussen, Kirk H., Clark, Randall J., Kort, Leland B.
• Primary Examiner(s): Ellis, Christopher P.
• Application Number:
  US08/615,898
• Time in Patent Office: 292 Days
• Field of Search: 280/741, 280/736, 280/737, 280/740, 280/742, 222/3, 222/5, 102/530, 102/531, 422/164, 422/166
• US Class Current: 280/741
• 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 comprises a housing formed of welded-together metal stampings defining a toroidal gas chamber surrounding a center tie and storing pressurized gas therein. The center tie has a generally cylindrical sidewall and an outlet wall at an upper end thereof defines a rupturably sealed outlet orifice. An inverted stamped metal cup is matingly received in the center tie. The lip of the cup is welded to the lower end of the center tie, and the cup sidewall is circumferentially grooved for separating a sliding piston portion under pressure. A squib support wall and squib closes the lower end of the center tie and inverted cup to define a combustion chamber containing a pyrotechnic gas generant which, upon ignition, causes the inverted cup to separate at the groove and drive the sliding piston upwardly to an open position uncovering inlet openings from the combustion chamber to the gas storage chamber. Hot gasses from the combustion chamber flow into the gas storage chamber and the outlet orifice rupturably opens permitting stored gas and combustion products to exit the inflator. The sliding piston and center tie are tapered to control movement of the piston by friction and deformation, together with lanced limit stop tabs. The cup has a convex bottom, deformation portions and may carry a lance to open the orifice. A baffle provides a surface on which incomplete products of combustion are collected and captures debris. A deformable outlet diffuser provides compact packaging.

Claims

1. A hybrid inflator comprising a housing having:

A) an upper stamped metal housing part including a top wall and a cylindrical sidewall depending therefrom;

B) a lower stamped metal housing part including a bottom wall, a cylindrical sidewall extending upwardly therefrom and engaged with the cylindrical sidewall of the upper housing part and welded thereto, and a generally cylindrical center tie integrally formed in one piece with the bottom wall and extending from the bottom wall to the top wall and welded to the top wall;

C) an upper wall integrally formed in one piece with one of the upper or lower housing parts and extending across the upper end of the center tie;

D) the housing defining a gas storage chamber surrounding the center tie and the center tie defining at least one inlet opening to the gas storage chamber and the housing further defining a rupturably sealed outlet orifice from the gas storage chamber; and

E) an igniter assembly mounted in the center tie and including a pyrotechnic gas generant material for producing and delivering hot gasses to the gas storage chamber through the inlet opening thereto.

2. A hybrid inflator as defined in claim 1 wherein the upper wall defines the rupturably sealed exit orifice from the housing, and the upper wall, center tie and igniter assembly defines an outlet cavity adjacent the exit orifice,the outlet cavity communicating with the stored gas chamber through at least one outlet opening defined by the center tie.

3. A hybrid inflator as defined in claim 2 wherein the igniter assembly further comprises a stamped metal squib holder secured across the lower end of the center tie and a squib mounted therein, the igniter assembly including the squib holder and squib defining a combustion chamber for the pyrotechnic gas generant material.

4. A hybrid inflator as defined in claim 3 and further comprising a bottom plate secured to the bottom wall of the housing and extending acros the lower end of the center tie, the bottom plate defining an opening for ebracing and supporting a plug connter for providing an initiator signal to the squib.

5. A hybrid inflator as defined in claim 1 wherein the housing further comprises a mounting flange integral with one of the upper or lower stamped metal housing parts.

6. A hybrid inflator as defined in claim 1 and further comprising a stamped metal deformable diffuser including a top panel and a cylindrical diffuser sidewall, the cylindrical diffuser sidewall secured to the cylindrical sidewall of the upper housing part with the top panel lying closely adjacent the top wall and outlet orifice of the housing, and the top panel being deformable away from the top wall of the housing by inflation gasses from the exit orifice, the diffuser sidewall defining outlet openings for delivering the inflation gas to an airbag.

7. A hybrid inflator as defined in claim 1 wherein the igniter assembly further comprises a stamped metal squib holder secured across the open end of the center tie, and a squib mounted therein, the igniter assembly including the squib holder and together defining a combustion chamber for the pyrotechnic gas generant material.

8. A hybrid inflator as defined in claim 1 and further comprising a baffle secured to the housing within the gas storage chamber and positioned to receive incomplete combustion products and debris delivered to the gas storage chamber through the at least one inlet opening from the igniter assembly, said baffle angled to deflect debris away from the outlet orifice and the path of gas flow leading to the outlet orifice.

9. A hybrid inflator as defined in claim 8 wherein the center tie defines a plurality of inlet openings thereabout and the baffle is positioned surrounding the center tie.

10. A hybrid inflator as defined in claim 9 wherein the baffle is a stamped metal part welded to the lower housing part.