Vehicle occupant protection apparatus with multiple stage inflator

摘要

An apparatus (10) comprises a pressure vessel (16) and an initiator assembly (18). The pressure vessel (16) defines first and second chambers (20, 22). A first combustible mixture in the first chamber (20) includes fuel gas at a first volume percentage. A second combustible mixture of gases in the second chamber (22) includes fuel gas at a second, greater volume percentage. The initiator assembly (18) includes a first igniter (26) which is actuatable to ignite the first combustible mixture. The initiator assembly (18) further includes a second igniter (28) which is actuatable to ignite the second combustible mixture. A controller (30) actuates the initiator assembly (18) in a selected one of a plurality of differing stages corresponding to a plurality of differing conditions. The differing stages of actuation include a stage in which the first igniter (26) is actuated and the second igniter (28) is not actuated.