Air bag inflator with mechanism for deactivation of second stage and autoignition

An inflator for an inflatable vehicle occupant protection device, said inflator comprising:

• a housing;
• an inflation fluid source in said housing for, when actuated, providing fluid for inflating the protection device;
• an electrically actuatable initiator connected with said housing for, when actuated, actuating said inflation fluid source;
• and
• an autoignition assembly actuatable in response to an increase in temperature in said housing above a predetermined temperature to cause actuation of said inflation fluid source, said autoignition assembly comprising an electrically energizable microelectromechanical system device (MEMS device);
• wherein said MEMS device is electrically energizable to produce combustion products including heat for actuating said inflation fluid source.

An inflator for an inflatable vehicle occupant protection device, said inflator comprising:

• a primary inflation fluid source and a secondary inflation fluid source actuatable independently of each other;
• vehicle electric circuitry for (i) sensing an occupant protection event for which inflation of the protection device by only said primary inflation fluid source is desired and (ii) actuating said primary inflation fluid source to inflate the protection device without actuating said secondary inflation fluid source;
• and
• a microelectromechanical system device (MEMS device) electrically energizable to actuate said secondary inflation fluid source a predetermined period of time after actuation of said primary inflation fluid source in response to sensing of said occupant protection event;
• wherein said MEMS device is electrically energizable to produce combustion products including heat for actuating said secondary inflation fluid source.

An apparatus for inflating an inflatable vehicle occupant protection device, said apparatus comprising:

• a housing;
• an inflation fluid source in said housing for, when actuated, providing inflation fluid for inflating the protection device;
• an electrically actuatable initiator connected with said housing for actuating said inflation fluid source;
• vehicle electric circuitry for actuating said initiator to actuate said inflation fluid source in response to sensing an occupant protection event for which inflation of the protection device is desired;
• a microelectromechanical system device (MEMS device) electrically energizable to cause actuation of said inflation fluid source;
• and
• means responsive to an event other than an occupant protection event for energizing said MEMS device to cause actuation of said inflation fluid source;
• wherein said means responsive to an event other than an occupant protection event comprises means responsive to an increase in temperature in said housing above a predetermined temperature;
• wherein said means responsive to an increase in temperature comprises a temperature transducer adjacent said inflation fluid source for sensing ambient temperature and for generating an electrical signal indicative of the ambient temperature.

An apparatus for inflating an inflatable vehicle occupant protection device, said apparatus comprising:

• a housing;
• an inflation fluid source in said housing for, when actuated, providing inflation fluid for inflating the protection device;
• an electrically actuatable initiator connected with said housing for actuating said inflation fluid source;
• vehicle electric circuitry for actuating said initiator to actuate said inflation fluid source in response to sensing an occupant protection event for which inflation of the protection device is desired;
• a microelectromechanical system device (MEMS device) electrically energizable to cause actuation of said inflation fluid source;
• and
• means responsive to an event other than an occupant protection event for energizing said MEMS device to cause actuation of said inflation fluid source;
• wherein said MEMS device is electrically energizable in response to an increase in ambient temperature to produce combustion products including heat for actuating said inflation fluid source.

An apparatus for inflating an inflatable vehicle occupant protection device, said apparatus comprising:

• a housing;
• an inflation fluid source in said housing for, when actuated, providing inflation fluid for inflating the protection device;
• an electrically actuatable initiator connected with said housing for actuating said inflation fluid source;
• vehicle electric circuitry for actuating said initiator to actuate said inflation fluid source in response to sensing an occupant protection event for which inflation of the protection device is desired;
• a microelectromechanical system device (MEMS device) electrically energizable to cause actuation of said inflation fluid source;
• and
• means responsive to an event other than an occupant protection event for energizing said MEMS device to cause actuation of said inflation fluid source;
• wherein said inflation fluid source comprises a primary inflation fluid source and a secondary inflation fluid source actuatable independently of each other;
• and
• said means responsive to an event other than an occupant protection event comprises second means for actuating said secondary inflation fluid source after actuation of only said primary inflation fluid source, said second means including said MEMS device.

An inflator for an inflatable vehicle occupant protection device, said inflator comprising:

• a housing;
• an inflation fluid source in said housing for, when actuated, providing fluid for inflating the protection device;
• an electrically actuatable initiator connected with said housing for, when actuated, actuating said inflation fluid source;
• and
• an autoignition assembly actuatable in response to an increase in temperature in said housing above a predetermined temperature to cause actuation of said inflation fluid source, said autoignition assembly comprising an electrically energizable microelectromechanical system device (MEMS device);
• wherein said autoignition assembly comprises a temperature transducer adjacent said inflation fluid source for sensing ambient temperature and for generating an electrical signal indicative of the ambient temperature.

An inflator for an inflatable vehicle occupant protection device, said inflator comprising:

• a housing;
• an inflation fluid source in said housing for, when actuated, providing fluid for inflating the protection device;
• an electrically actuatable initiator connected with said housing for, when actuated, actuating said inflation fluid source;
• and
• an autoignition assembly actuatable in response to an increase in temperature in said housing above a predetermined temperature to cause actuation of said inflation fluid source, said autoignition assembly comprising an electrically energizable microelectromechanical system device (MEMS device);
• wherein said MEMS device has a size in the range of from about one-quarter inch square to about one inch square land includes an array of at least three plenum chambers.

An inflator for an inflatable vehicle occupant protection device, said inflator comprising:

• a housing;
• an inflation fluid source in said housing for, when actuated, providing fluid for inflating the protection device;
• an electrically actuatable initiator connected with said housing for, when actuated, actuating said inflation fluid source;
• and
• an autoignition assembly actuatable in response to an increase in temperature in said housing above a predetermined temperature to cause actuation of said inflation fluid source, said autoignition assembly comprising an electrically energizable microelectromechanical system device (MEMS device);
• wherein said MEMS device comprises:
• an outer layer having a plurality of individually rupturable segments;
• a middle layer having a plurality of individual chambers associated in a one-to-one relationship with said rupturable segments of said outer layer and being closed by said rupturable segments, each one of said chambers having contents heatable to increase the pressure in said one chamber;
• and
• a base layer having a plurality of individually energizable electric heating elements associated in a one-to-one relationship with said chambers for, when energized, heating the contents of said chambers;
• each one of said rupturable segments being rupturable due to an increase in pressure in its associated chamber to enable flow of combustion products including heat out of said chamber.

An inflator for an inflatable vehicle occupant protection device, said inflator comprising:

• a primary inflation fluid source and a secondary inflation fluid source actuatable independently of each other;
• vehicle electric circuitry for (i) sensing an occupant protection event for which inflation of the protection device by only said primary inflation fluid source is desired and (ii) actuating said primary inflation fluid source to inflate the protection device without actuating said secondary inflation fluid source;
• and
• a microelectromechanical system device (MEMS device) electrically energizable to actuate said secondary inflation fluid source a predetermined period of time after actuation of said primary inflation fluid source in response to sensing of said occupant protection event;
• wherein said MEMS device is electrically energizable by vehicle electric circuitry at a predetermined time after actuation of said primary inflation fluid source upon sensing of said occupant protection event.