FIELD

The present disclosure generally concerns an inflator for providing inflation gases for an inflatable vehicle safety device, such as an inflatable airbag. More particularly, the present disclosure concerns a dual stage inflator for an inflatable vehicle airbag.

BACKGROUND

This section provides background information related to the present disclosure which is not necessarily prior art.

Inflatable occupant restraints or airbags are commonly included on motor vehicles to provide impact protection for occupants of the motor vehicle. In the event of an accident, one or more sensor within the vehicle measure abnormal deceleration, for example, and triggers inflation of the airbag within a few milliseconds with gas produced by a device commonly referred to as an “inflator”. The inflated airbag cushions and protects the motor vehicle occupant from impact forces.

Various types of inflators have been disclosed in the art for the inflation of airbags. One known inflator devices is shown and described in commonly assigned U.S. Pat. No. 6,189,927 (the '927 patent). The inflator of the '927 patent is an adaptive pyrotechnic inflator, or dual stage inflator, having gas generant materials in two chambers. The gas generant materials are independently activated by two ignition devices. The gas generant material-containing chambers of such ignitors may be referred to as “combustion chambers” as the gas generant material therein is combusted or otherwise reacted to produce gas used to inflate an associated occupant restraint. U.S. Pat. No. 6,189,927 is hereby incorporated by reference as if fully set forth herein.

While known inflators for inflatable occupant restraints, including the inflator of U.S. Pat. No. 6,189,927, have generally proven to be suitable for their intended uses, a continuous need for improvement in the relevant art remains.

SUMMARY

This section provides a general summary of the disclosure, and is not a comprehensive disclosure of its full scope or all of its features.

It is a general object of the present teachings to provide a dual stage inflator with a combustion cup including a lid and having an increased volume for gas generant loading.

In accordance with one particular embodiment, the present teachings provide a dual stage inflator for an inflatable vehicle safety device including a housing defining a first chamber containing a first gas generant material. An ignitor cup is disposed in the first chamber and defines an interior containing an ignitor material. A first ignitor device extends into the interior of the ignitor cup. A combustion cup and a lid are disposed in the first chamber and cooperate to define a second chamber containing a second gas generant material. The combustion cup includes a cup sidewall extending between a first axial end and a second axial end. The first axial end is an open end. The lid is normally in a closed position relative to the combustion cup to close the open end of the combustion cup and is moveable away from the combustion cup in response to an increase of pressure within the combustion cup for venting combustion gas out of the combustion cup. A second ignitor device extends into the combustion cup and closes the second axial end of the combustion cup. The combustion cup includes a first axially extending portion adjacent the first axial end having a first outer diameter and a second axially extending portion adjacent the second axial end having a second outer diameter greater than the first outer diameter. The lid includes a lid sidewall extending in an axial direction and radially overlapping at least a portion of the combustion cup including the first outer diameter.

In accordance with another particular embodiment, the present teachings provide an inflator for an inflatable vehicle safety device including a cup having a cup sidewall and an open end. The cup sidewall extends between a first axial end and a second axial end. A lid cooperates with the cup sidewall to define a combustion chamber. The lid normally closes the combustion chamber and is movable away from the cup sidewall to vent combustion gas from the combustion chamber. A gas generant is disposed in the combustion chamber. An ignition device extends into the combustion chamber. The cup includes a first axially extending portion adjacent the first axial end having a first outer diameter and a second axially extending portion adjacent the second axial end having a greater second outer diameter. The lid includes an axially extending lid sidewall extending in an axial direction and radially overlapping at least a portion of the cup including the first outer diameter.

Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.

