Inflator and method of assembly

• US 20050161925A1
• Filed: 01/26/2005
• Published: 07/28/2005
• Est. Priority Date: 01/27/2004
• 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: Blackburn, Jeffery S.
• Granted Patent: US 7,178,829 B2
• Time in Patent Office: Days
• US Class Current: 280/741
• CPC Class Codes: B60R 21/2171 specially adapted for elongated cylindrical or bottle-like inflators with a symmetry axis perpendicular to the main direction of bag deployment, e.g. extruded reaction canisters B60R21/2176 takes precedence
• CPC Class Codes: B60R 21/261 with means other than bag structure to diffuse or guide inflation fluid
• CPC Class Codes: B60R 21/2644 using only solid reacting substances, e.g. pellets, powder

Abstract

An inflator (10) for use in inflatable restraint systems. The inflator includes an inner body portion (12) defining a combustion chamber (20) and including one or more apertures (13) formed therealong to enable fluid communication between the combustion chamber (20) and an exterior of the combustion chamber. A filter material (14) is positioned along an exterior of the inner body portion (12), for filtering and cooling combustion products emanating from the apertures (13) of the inner body portion (12). An outer body wrap (16) is provided having a pair of opposed longitudinal edges (16a, 16b). The outer body wrap (16) is formed from a foldable sheet material and has a dimension between the opposed edges (16a, 16b) sufficient to enable the wrap (16) to substantially enclose the predetermined thickness of filter material (14) when the wrap (16) is folded about the filter material (14). One or more apertures (23) are provided along the outer body wrap (16) to enable fluid communication between the filter (14) and an exterior of the inflator (10). In one embodiment, the apertures (23) are formed along a seam extending between the opposed edges (16a, 16b) of the folded outer body wrap (16). Alternatively, the outer body wrap (16) may be pierced or punched to provide apertures therealong prior to folding of the wrap (16) about the filter material (14). The wrap (16) is folded about the filter material (14) to substantially enclose the filter material such that a predetermined thickness of the filter material is positioned intermediate the one or more inner body portion apertures (13) and the one or more outer body wrap apertures (23). The wrap (16) is then secured in the folded configuration using welding or other suitable means.

Claims

1. An inflator comprising:

an inner body portion defining a combustion chamber, the inner body portion including at least one aperture formed therealong to enable fluid communication between the combustion chamber and an exterior of the combustion chamber;

a filter material positioned along an exterior of the inner body portion; and

an outer body wrap having at least a pair of opposed longitudinal edges and at least one aperture formed therealong to enable fluid communication between the filter material and an exterior of the inflator,

the outer body wrap being folded about the filter material to substantially enclose the filter material such that a predetermined thickness of the filter material is positioned intermediate the at least one inner body portion aperture and the at least one outer body wrap aperture.

2. The inflator of claim 1 wherein the filter material is attached to the inner body portion.

3. The inflator of claim 2 wherein the filter material is attached to the inner body portion by welding.

4. The inflator of claim 1 wherein the outer body wrap is attached to the filter material.

5. The inflator of claim 4 wherein the outer body wrap is attached to the filter material along a first edge of the wrap.

6. The inflator of claim 5 wherein a second edge of the outer body wrap is attached to the filter material.

7. The inflator of claim 3 wherein the filter material is attached to the inner body portion.

8. The inflator of claim 1 wherein a first portion of the outer body wrap is attached to a second portion of the wrap to form a seam between the portions of the wrap.

9. The inflator of claim 8 wherein the first portion of the outer body wrap is attached to the second portion of the wrap at a plurality of points to define at least one unwelded seam extending between the plurality of points, the unwelded seam defining the at least one aperture formed along the outer body wrap to enable fluid communication between the filter material and the exterior of the inflator.

10. The inflator of claim 1 wherein multiple layers of the filter material are positioned between the at least one inner body portion aperture and the at least one outer body wrap aperture.

11. The inflator of claim 10 wherein the filter material is folded over upon itself to provide multiple layers of filter material extending between the at least one inner body portion aperture and the at least one outer body wrap aperture.

12. The inflator of claim 1 wherein the outer body wrap is attached to the inner body portion to form at least one junction therebetween.

13. The inflator of claim 12 wherein the at least one aperture formed along the outer body wrap is formed along the at least one junction between the inner body portion and the outer body wrap.

14. The inflator of claim 1 further comprising:

a quantity of a gas generant composition positioned in the combustion chamber; and

an igniter positioned so as to enable fluid communication between the igniter and the gas generant composition upon activation of the igniter.

15. A method for manufacturing an inflator, the method comprising the steps of:

providing an inner body portion defining a combustion chamber, the inner body portion including at least one aperture formed therealong to enable fluid communication between the combustion chamber and an exterior of the combustion chamber;

providing a sheet of a filter material;

folding the sheet of filter material over the at least one inner body aperture to provide a multi-layered arrangement of filter material having a predetermined thickness and covering the at least one inner body aperture;

providing an outer body wrap having a pair of opposed longitudinal edges, the outer body wrap being formed from a foldable sheet material, the outer body wrap having a dimension between the opposed edges sufficient to enable the wrap to substantially enclose the filter material when the wrap is folded about the filter material;

folding the outer body wrap to substantially enclose the filter material; and

securing the outer body wrap in a folded configuration.

16. The inflator body of claim 15 wherein the step of folding the sheet of filter material comprises the steps of folding the filter material into a multi-layered structure, and securing the filter material in a folded configuration prior to positioning the filter material over the at least one inner body portion aperture.

17. The method of claim 15 wherein the step of folding the outer body wrap comprises folding the outer body wrap so as to define at least one aperture along the wrap to enable fluid communication between the filter and an exterior of the inflator.

18. The method of claim 15 wherein the step of securing the outer body wrap in the folded position comprises connecting a portion of the outer body wrap to another portion of the outer body wrap.

19. An inflator manufactured in accordance with the method set forth in claim 15.

20. A vehicle occupant restraint system comprising:

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;

an inner body portion defining a combustion chamber, the inner body portion including at least one aperture formed therealong to enable fluid communication between the combustion chamber and an exterior of the combustion chamber;

a filter material positioned along an exterior of the inner body portion; and

an outer body wrap having at least a pair of opposed longitudinal edges and at least one aperture formed therealong to enable fluid communication between the filter material and an exterior of the inflator,

the outer body wrap being folded about the filter material to substantially enclose the filter material such that a predetermined thickness of the filter material is positioned intermediate the at least one inner body portion aperture and the at least one outer body wrap aperture.