Pyrotechnic linear inflator
First Claim
1. An inflator for use in an inflatable vehicle occupant protection system, the inflator comprising:
- a longitudinal inflator housing including a perforated section to enable fluid communication between an interior of the housing and an exterior of the housing;
an enclosure extending along at least a portion of the housing interior, the enclosure having a substantially uniform cross-sectional area along at least a portion of the enclosure, the enclosure including at least first and second perforated sections to enable fluid communication between the enclosure and an exterior of the enclosure, the first perforated section having a first total gas exit aperture area and the second perforated section having a second total gas exit aperture area, the second total gas exit aperture area being greater than the first total gas exit aperture area;
a first gas generant composition positioned within the at least a portion of the enclosure to extend along a first length, the first gas generant composition being distributed substantially uniformly along the at least a portion of the enclosure so as to provide a quantity of first gas generant composition having a first mass of gas generant per unit length of the first length; and
a second gas generant composition positioned within a second portion of said enclosure so as to enable combustion of the second gas generant composition in response to combustion of the first gas generant composition, the second gas generant composition extending along a second length so as to provide a quantity of second gas generant composition having a second mass of gas generant per unit length of the second length, the second mass of gas generant per unit length being greater than the first mass of gas generant per unit length.
1 Assignment
0 Petitions
Accused Products
Abstract
An inflator (10) for use in an inflatable vehicle occupant protection system. The inflator (10) includes a longitudinal enclosure (22) and a first gas generant (24) positioned along the enclosure (22). Enclosure gas exit apertures (40) are arranged along the enclosure (22) to enable fluid communication between the enclosure (22) and an exterior of the enclosure. and to provide controlled venting of combustion gases from the enclosure (22) as the first gas generant composition (24) burns, thereby controlling the speed and direction of combustion propagation of the first gas generant. Combustion of the first gas generant (24) results in an inflator housing internal pressure of at least a first predetermined minimum internal pressure. The second gas generant composition (91) is also configured to combust to generate inflation gas providing at least a second predetermined minimum internal pressure in the housing, the second predetermined minimum internal pressure being higher than the first predetermined minimum internal pressure. As combustion of first gas generant (24) nears completion, flame from combustion of the first gas generant composition (24) reaches the end (22b) of the enclosure (22) and contacts the second gas generant composition (91), igniting the second gas generant (91) and producing a burst of gas and a resulting in an increase in inflator housing internal pressure. Gas exit apertures (20) along the housing (12) are sized such that the housing internal pressure is maintained at at least the first predetermined minimum level after passage of a predetermined time period after inflator activation.
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Citations
20 Claims
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1. An inflator for use in an inflatable vehicle occupant protection system, the inflator comprising:
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a longitudinal inflator housing including a perforated section to enable fluid communication between an interior of the housing and an exterior of the housing;
an enclosure extending along at least a portion of the housing interior, the enclosure having a substantially uniform cross-sectional area along at least a portion of the enclosure, the enclosure including at least first and second perforated sections to enable fluid communication between the enclosure and an exterior of the enclosure, the first perforated section having a first total gas exit aperture area and the second perforated section having a second total gas exit aperture area, the second total gas exit aperture area being greater than the first total gas exit aperture area;
a first gas generant composition positioned within the at least a portion of the enclosure to extend along a first length, the first gas generant composition being distributed substantially uniformly along the at least a portion of the enclosure so as to provide a quantity of first gas generant composition having a first mass of gas generant per unit length of the first length; and
a second gas generant composition positioned within a second portion of said enclosure so as to enable combustion of the second gas generant composition in response to combustion of the first gas generant composition, the second gas generant composition extending along a second length so as to provide a quantity of second gas generant composition having a second mass of gas generant per unit length of the second length, the second mass of gas generant per unit length being greater than the first mass of gas generant per unit length. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17)
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18. A method for maintaining internal pressure in an inflator housing at least a final predetermined minimum level for at least a minimum predetermined time period, comprising the steps of:
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providing an inflator housing including a plurality of gas exit apertures spaced therealong to enable fluid communication between an interior of the housing and an exterior of the housing, the gas exit apertures having a total area defining a total housing gas exit aperture area;
arranging a quantity of a first gas generant composition within the housing to combust within a first predetermined time period to generate inflation gas providing at least a first predetermined minimum internal pressure in the housing;
arranging a quantity of a second gas generant composition so as to enable combustion of the second gas generant composition in response to combustion of the first gas generant composition, the second gas generant composition being configured to combust within a second predetermined time period to generate inflation gas providing at least a second predetermined minimum internal pressure in the housing, the second predetermined minimum internal pressure being higher than the first predetermined minimum internal pressure; and
sizing the total housing gas exit aperture area such that the housing internal pressure is at least the first predetermined minimum level after passage of the minimum predetermined time period. - View Dependent Claims (19)
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20. A vehicle occupant restraint system comprising:
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an airbag system having at least one airbag and an inflator coupled to the airbag so as to enable fluid communication with an interior of the airbag upon activation of the inflator, the inflator including;
a longitudinal inflator housing including a perforated section to enable fluid communication between an interior of the housing and an exterior of the housing;
a longitudinal enclosure extending along at least a portion of the housing interior, the longitudinal enclosure having a substantially uniform cross-sectional area along at least a portion of the longitudinal enclosure, the longitudinal enclosure including at least first and second perforated sections to enable fluid communication between the longitudinal enclosure and an exterior of the longitudinal enclosure, the first perforated section having a first total gas exit aperture area and the second perforated section having a second total gas exit aperture area, the second total gas exit aperture area being greater than the first total gas exit aperture area;
a first gas generant composition positioned within a first portion of the longitudinal enclosure to extend along a first length, the first gas generant composition being distributed substantially uniformly along the at least a portion of the longitudinal enclosure so as to provide a quantity of first gas generant composition having a first mass of gas generant per unit length of the first length; and
a second gas generant composition positioned within a second portion of the longitudinal enclosure so as to enable combustion of the second gas generant composition in response to combustion of the first gas generant composition, the second gas generant composition extending along a second length so as to provide a quantity of second gas generant composition having a second mass of gas generant per unit length of the second length, the second mass of gas generant per unit length being greater than the first mass of gas generant per unit length.
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Specification