Airbag inflator

• US 6,752,421 B2
• Filed: 01/02/2003
• Issued: 06/22/2004
• Est. Priority Date: 01/03/2002
• Status: Expired due to Fees

• Current Assignee: Automotive Systems Laboratory, Incorporated (Ningbo Junsheng Investment Group Co., Ltd.)
• Original Assignee: Automotive Systems Laboratory, Incorporated (Ningbo Junsheng Investment Group Co., Ltd.)
• Inventors: Krupp, Robert M., Patterson, Donald B., Khandhadia, Paresh S.
• Primary Examiner(s): Ilan, Ruth
• Application Number:
  US10/335,786
• Publication Number:
  US 20030122355A1
• Time in Patent Office: 537 Days
• Field of Search: 102/530, 102/531, 280/736, 280/737, 280/741, 280/742, 287/35
• US Class Current: 280/741
• CPC Class Codes: B60R 2021/2633 with a plurality of inflation levels
• CPC Class Codes: B60R 2021/2648 comprising a plurality of combustion chambers or sub-chambers
• CPC Class Codes: B60R 21/2644 using only solid reacting substances, e.g. pellets, powder

Abstract

The present invention provides an inflator 10 for an inflatable restraint system in an automobile. The inflator includes an elongate inflator body 11 having a plurality of inflation apertures 40 and defining a first combustion chamber 25 wherein a first propellant charge 28 is positioned. A partitioning assembly 26 is nested within the inflator body 11, and positioned proximate the second end 17. The partitioning assembly 26 defines a second combustion chamber 35 wherein a second propellant charge 38 is positioned. First and second initiators 12 and 9 are provided, and are selectively operable to ignite the propellant charges 28 and 38 respectively, thereby supplying an inflation gas via the first chamber 25 to an inflatable restraint cushion.

Claims

1. An inflator for an inflatable restraint system in an automobile, the inflator comprising:

an elongate inflator body having a first end and a second end and a plurality of inflation apertures, said inflator body defining a first chamber wherein a first propellant charge is positioned;

a partitioning assembly within said inflator body, and positioned proximate said second end, said partitioning assembly defining a second chamber operatively independent of said first chamber wherein a second propellant charge is positioned within said second chamber;

a filter radially spaced about said first chamber but not said second chamber whereby all gases produced by said inflator are filtered exclusively therethrough;

a first and a second initiator operably associated with said first and said second propellant charges, respectively;

wherein said initiators are selectively operable to ignite said propellant charges, thereby supplying an inflation gas via said first chamber to an inflatable restraint cushion.

2. The inflator of claim 1 wherein said partitioning assembly comprises an end closure member and a cap.

3. The inflator of claim 1 wherein said inflator body is substantially cylindrical, and said partitioning assembly comprises a substantially cylindrical base coaxial with said inflator body.

4. The inflator of claim 1 further comprising:

a plenum formed within said inflator body and positioned between said first and second chambers, said plenum fluidly communicating with said first chamber upon activation thereof and said plenum communicating with said second chamber upon activation thereof;

a plurality of adjacent gas generant wafers in said plenum; and

a spring member disposed between said partitioning assembly and said wafers,

wherein said spring member biases said wafers toward said first end of said inflator body, thereby securing at least a portion of said first propellant charge.

5. The gas generator of claim 2 wherein said closure member is nested within said inflator body.

6. The gas generator of claim further comprising:

a first end closure member having a substantially cylindrical extension; and

a perforated disk positioned in said extension, said disk separating said first end closure member into a first and second sub-chamber, wherein a booster propellant is positioned in said first sub-chamber.

7. An inflator for an inflatable restraint cushion comprising:

an elongate inflator body having a first end and a second end, said inflator body defining a plenum and a plurality of gas discharge orifices;

a first propellant charge disposed in a first chamber;

a first initiator operably associated with said first propellant charge;

a second propellant charge in a second chamber proximate said second end of said inflator body;

a second initiator operably associated with said second propellant charge;

a partitioning member at least partially encasing said second propellant charge, and at least partially defining said second chamber; and

a filter radially spaced about said first chamber but not said second chamber whereby all gases produced by said inflator are filtered exclusively therethrough,

wherein ignition of said second propellant charge produces an inflation gas that displaces said partitioning member, thereby establishing fluid communications between said second chamber and said plenum.

8. The inflator of claim 7 wherein said partitioning member comprises a substantially cylindrical first portion having a first diameter, and a substantially cylindrical second portion having a second diameter smaller than said first diameter, said partitioning member substantially coaxial with said inflator housing.

9. An inflator for an inflatable restraint system in an automobile, the inflator comprising:

an elongate inflator body having a first end and a second end and a plurality of inflation apertures, said inflator body defining a first chamber wherein a first propellant charge is positioned;

a partitioning assembly within said inflator body, and positioned proximate said second end, said partitioning assembly defining a second chamber wherein a second propellant charge is positioned;

a first and a second initiator operably associated with said first and said second propellant charges, respectively;

a plenum formed within said inflator body and positioned between said first and second chambers, said plenum fluidly communicating with said first chamber upon activation thereof and said plenum communicating with said second chamber upon activation thereof;

a plurality of adjacent gas generant wafers in said plenum; and

a spring member disposed between said partitioning assembly and said wafers,

wherein said spring member biases said wafers toward said first end of said inflator body, thereby securing at least a portion of said first propellant charge and said initiators are selectively operable to ignite said propellant charges, thereby supplying an inflation gas via said first chamber to an inflatable restraint cushion.

10. An inflator for an inflatable restraint cushion comprising:

an elongate inflator body having a first end and a second end, said inflator body defining a plenum and a plurality of gas discharge orifices;

a first propellant charge disposed in a first chamber;

a first initiator operably associated with said first propellant charge;

a second propellant charge in a second chamber proximate said second end of said inflator body;

a second initiator operably associated with said second propellant charge;

a partitioning member at least partially encasing said second propellant charge, and at least partially defining said second chamber;

wherein ignition of said second propellant charge produces an inflation gas that displaces said partitioning member, thereby establishing fluid communications between said second chamber and said plenum, and, said partitioning member comprises a substantially cylindrical first portion having a first diameter, and a substantially cylindrical second portion having a second diameter smaller than said first diameter, said partitioning member substantially coaxial with said inflator housing.