Multi-chamber gas generating system

• US 20060017270A1
• Filed: 07/25/2005
• Published: 01/26/2006
• Est. Priority Date: 07/23/2004
• Status: Active Grant

• 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: Khandhadia, Paresh S., Quioc, Eduardo L.
• Granted Patent: US 7,275,760 B2
• Time in Patent Office: Days
• US Class Current: 280/741
• 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

A multi-chamber gas generating system (10) has a housing (12) with openings (24) formed in a wall thereof. A gas-tight internal divider (42) separates the housing into two chambers (80, 80′). A gas generating sub-assembly (100) incorporating a baffle system is positioned in the first chamber (100). The sub-assembly (100) includes a first tubular member (44) and a second tubular member (52) positioned within the first member. The first and second members have openings (49, 54) formed therein to enable fluid communication between an interior of the second member (52) and the housing openings (24). The housing openings (24) are axially displaced from the first member opening (49) such that combustion products flow in a first axial direction between the first member opening and the housing opening. The first member opening (49) is axially displaced from the second member openings (54) such that combustion products flow in a second axial direction between the second member openings (54) and the first member opening (49). The second axial direction is substantially opposite from the first axial direction. A second sub-assembly (100′) in second housing chamber (80′) includes third and fourth tubular members (44′, 52′) similar to the first and second members and having openings therein axially displaced relative to each other such that combustion products flow in the second axial direction between the third member opening (49′) and the housing openings (24), and in the first axial direction between the fourth member openings (54′) and the third member opening (49′).

Claims

1. A multi-chamber gas generating system comprising:

an elongated housing including a housing wall having at least one opening formed therein to enable fluid communication between an interior of the housing and an exterior of the housing;

a divider secured within the interior of the housing to separate the interior of the housing into a first chamber and a second chamber, the divider forming a gas-tight barrier between the chambers;

a first tubular member positioned within the first housing chamber, the first tubular member having at least one opening formed therein to enable fluid communication between an interior of the first tubular member and the at least one opening formed in the housing wall;

a second tubular member positioned within the first tubular member, the second tubular member including at least one opening formed therein to enable fluid communication between an interior of the second tubular member and the at least one opening formed in the first tubular member,

the at least one housing wall opening being axially displaced from the at least one opening in the first tubular member such that combustion products flow in a first axial direction between the at least one opening in the first tubular member and the at least one housing wall opening, the at least one opening in the first tubular member being axially displaced from the at least one opening in the second tubular member such that combustion products flow in a second axial direction between the at least one opening in the second tubular member and the at least one opening in the first tubular member, the second axial direction being substantially opposite from the first axial direction;

a third tubular member positioned within the second housing chamber, the third tubular member having at least one opening formed therein to enable fluid communication between an interior of the third tubular member and the at least one opening formed in the housing wall;

a fourth tubular member positioned within the third tubular member, the fourth tubular member including at least one opening formed therein to enable fluid communication between an interior of the fourth tubular member and the at least one opening formed in the third tubular member,

the at least one housing wall opening being axially displaced from the at least one opening in the third tubular member such that combustion products flow in the second axial direction between the at least one opening in the third tubular member and the at least one housing wall opening, the at least one opening in the third tubular member being axially displaced from the at least one opening in the fourth tubular member such that combustion products flow in the first axial direction between the at least one opening in the fourth tubular member and the at least one opening in the third tubular member,

the first and second tubular members being positioned within the first chamber, and the third and fourth tubular members being positioned within the second chamber.

2. The gas generating system of claim 1 wherein the first tubular member includes a base portion positioned proximate the divider, the at least one second tubular member opening is formed in an end portion of the second tubular member, and wherein the end portion of the second tubular member is positioned adjacent the first tubular member base portion.

3. The gas generating system of claim 1 further comprising a cooling element positioned between the at least one second tubular member opening and the at least one first tubular member opening for cooling combustion products flowing therebetween.

4. The gas generating system of claim of claim 3 wherein the cooling element comprises a metallic mesh filter.

5. The gas generating system of claim 1 further comprising a tubular inner member positioned within the second tubular member, the tubular inner member including at least one opening formed therein to enable fluid communication between an interior of the tubular inner member and the at least one opening formed in the second tubular member.

6. The gas generating system of claim 5 further comprising a gas generant composition positioned between the second tubular member and the tubular inner member.

7. The gas generating system of claim 5 further comprising an ignition compound positioned within the tubular inner member.

8. A multi-chamber gas generating system comprising:

an elongated housing including a housing wall having at least one opening formed therein to enable fluid communication between an interior of the housing and an exterior of the housing;

a divider secured within the interior of the housing to separate the interior of the housing into a first chamber and a second chamber, the divider forming a gas-tight barrier between the chambers;

a first sub-assembly positionable within the first chamber, the second sub-assembly including

a first tubular member having at least one opening formed therein to enable fluid communication between an interior of the first tubular member and the at least one opening formed in the housing wall;

a second tubular member positioned within the first tubular member, the second tubular member including at least one opening formed therein to enable fluid communication between an interior of the second tubular member and the at least one opening formed in the first tubular member,

an tubular inner member positioned within the second tubular member, the inner tubular member including at least one opening formed therein to enable fluid communication between an interior of the inner tubular member and the at least one opening formed in the second tubular member;

a permeable gas cooling element positionable between the at least one second tubular member opening and the at least one first tubular member opening;

a gas generant composition positioned between the second tubular member and the inner tubular member;

an ignition compound positioned within the inner tubular member;

a second sub-assembly positionable within the second chamber, the second sub-assembly including

a third tubular member positioned within the interior of the housing, the third tubular member having at least one opening formed therein to enable fluid communication between an interior of the third tubular member and the at least one opening formed in the housing wall;

a fourth tubular member positioned within the third tubular member, the fourth tubular member including at least one opening formed therein to enable fluid communication between an interior of the fourth tubular member and the at least one opening formed in the third tubular member,

another tubular inner member positioned within the fourth tubular member, the other inner tubular member including at least one opening formed therein to enable fluid communication between an interior of the other inner tubular member and the at least one opening formed in the fourth tubular member;

a permeable gas cooling element positionable between the at least one fourth tubular member opening and the at least one third tubular member opening;

a gas generant composition positioned between the fourth tubular member and the other inner tubular member;

an ignition compound positioned within the other inner tubular member;

the first sub-assembly having a first orientation with respect to the divider,

the second sub-assembly having a second orientation with respect to the divider,

the second orientation being inverted, with respect to the divider, from the first orientation.

9. The gas generating system of claim 8 wherein the at least one housing wall opening is axially displaced from the at least one opening in the first tubular member such that combustion products flow in a first axial direction between the at least one opening in the first tubular member and the at least one housing wall opening;

the at least one opening in the first tubular member is axially displaced from the at least one opening in the second tubular member such that combustion products flow in a second axial direction between the at least one opening in the second tubular member and the at least one opening in the first tubular member;

the at least one housing wall opening is axially displaced from the at least one opening in the third tubular member such that combustion products flow in the second axial direction between the at least one opening in the third tubular member and the at least one housing wall opening; and

the at least one opening in the third tubular member is axially displaced from the at least one opening in the fourth tubular member such that combustion products flow in the first axial direction between the at least one opening in the fourth tubular member and the at least one opening in the third tubular member, the second axial direction being substantially opposite from the first axial direction.

10. A vehicle occupant protection system comprising:

an airbag system including an airbag and a gas generating system coupled to the airbag so as to enable fluid communication with the airbag upon activation of the airbag system, the gas generating system including;

an elongated housing including a housing wall having at least one opening formed therein to enable fluid communication between an interior of the housing and an exterior of the housing;

a divider secured within the interior of the housing to separate the interior of the housing into a first chamber and a second chamber, the divider forming a gas-tight barrier between the chambers;

a first tubular member positioned within the first housing chamber, the first tubular member having at least one opening formed therein to enable fluid communication between an interior of the first tubular member and the at least one opening formed in the housing wall;

a second tubular member positioned within the first tubular member, the second tubular member including at least one opening formed therein to enable fluid communication between an interior of the second tubular member and the at least one opening formed in the first tubular member,

the at least one housing wall opening being axially displaced from the at least one opening in the first tubular member such that combustion products flow in a first axial direction between the at least one opening in the first tubular member and the at least one housing wall opening, the at least one opening in the first tubular member being axially displaced from the at least one opening in the second tubular member such that combustion products flow in a second axial direction between the at least one opening in the second tubular member and the at least one opening in the first tubular member, the second axial direction being substantially opposite from the first axial direction;

a third tubular member positioned within the second housing chamber, the third tubular member having at least one opening formed therein to enable fluid communication between an interior of the third tubular member and the at least one opening formed in the housing wall;

a fourth tubular member positioned within the third tubular member, the fourth tubular member including at least one opening formed therein to enable fluid communication between an interior of the fourth tubular member and the at least one opening formed in the third tubular member,

the at least one housing wall opening being axially displaced from the at least one opening in the third tubular member such that combustion products flow in the second axial direction between the at least one opening in the third tubular member and the at least one housing wall opening, the at least one opening in the third tubular member being axially displaced from the at least one opening in the fourth tubular member such that combustion products flow in the first axial direction between the at least one opening in the fourth tubular member and the at least one opening in the third tubular member,

the first and second tubular members being positioned within the first chamber, and the third and fourth tubular members being positioned within the second chamber.

11. The vehicle occupant protection system of claim 10 further comprising a crash event sensor in communication with a known crash sensor algorithm for signaling activation of the airbag system.

12. The vehicle occupant protection system of claim 10 further comprising a safety belt assembly including at least one safety belt.

13. A multiple chamber gas generating system comprising:

a first subassembly containing a first perforate housing, a first propellant chamber inwardly radially spaced within said housing, a first initiator assembly in operable communication with said first propellant chamber for activation of said first propellant chamber, and a first cooling element located radially outwardly of said first propellant chamber; and

a second subassembly containing a second perforate housing, a second propellant chamber inwardly radially spaced within said second housing, a second initiator assembly in operable communication with said second propellant chamber for activation of said second propellant chamber, and a second cooling element located radially outwardly of said second propellant chamber,

wherein said first and second cooling elements produce axial flow of gases produced upon activation of said gas generating system, and said first and second subassemblies are substantially identical in design and are coaxially positioned within said gas generating system.

14. The multiple gas generating system of claim 13 wherein said first and second cooling elements are baffle assemblies formed by a plurality of concentric tubular members.