Patent EP0694447A2 successfully refreshed from Google Patents.
EP0694447A2
Expired / Lapsed
EP
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Varying permeability filter for airbag inflator
Assignee: Morton International LLC
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Filing: 1995-07-20
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Granted: —
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Expires: 2015-07-20
Abstract
Abstract An airbag inflator (30) includes a housing (32) for holding gas generating materials (62) and has an outer diffuser wall (36) with a ring of discharge or diffuser ports (36a) arranged to direct the gas into an airbag for rapid inflation. The ports are generally closer to one of the top and bottom end walls (34, 42) of the container than they are to the opposite end wall. A gas filter (90) of varying permeability is mounted in the housing inside the periphery of the outer diffuser wall adjacent to the ring of ports, and has a gas permeability characteristic that varies between a maximum permeability rating in a first region (96) farthest away from the ring of ports to a minimum permeability rating adjacent a second region (92) closer to the ports. The varying permeability areas (92, 94, 96) tend to even out the gas flow over the entire available flow cross-section of the filter so that blow-through or burn holes do not develop, resulting in a maximum of filtering and entrapment of contaminants as well as excellent cooling of the hot gases with the least flow resistance overall.
Inventors
- 👤 Brian H. Fulmer
- 👤 Todd S. Parker
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-27 22:13
CPC Classifications
B; B60; B60R; B60R21/00; B60R21/02; B60R21/16; B60R21/26; B60R21/264; B60R21/2644; B01; B01D; B01D46/00; B01D46/0039; B01D46/0041; B01D46/0043; B01D46/24; B01D2273/00; B01D2273/20; B01D2275/00; B01D2275/30; B01D2279/00; B01D2279/10
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
192 words
An airbag inflator (30) comprising: a container (32) holding gas generating means (62) having an outer side wall (36) formed with a plurality of ports (36a) for discharging gas at spaced apart positions around said wall; said container including spaced apart opposite end walls (34, 42) joined to opposite edges of said outer side wall (36) defining a filter space adjacent the interior of said outer side wall (36) and outwardly of said gas generating means (62), said ports (36a) being spaced closer to one of said end walls than the other; and a gas filter (90) in said container for entrapping contaminants from the gas generated by said gas generating means (62), said filter having an outer edge adjacent said ports for discharging filtered and cooled gas into said ports and an inner edge adjacent said gas generating means for receiving gas therefrom, said gas filter having regions extending from said inner edge to said outer edge, said regions having different gas permeabilities that vary between a maximum at a first region (96) farthest from said plurality of ports and a minimum at a second region (92) closest to said ports.
Claim 2
Dependent Claim
33 words
An airbag inflator according to claim 1 wherein the shortest direct flow path extending between said gas generating means (62) and said ports (36a) extends across said region (92) of minimum gas permeability.
Claim 3
Dependent Claim
31 words
An airbag inflator according to claim 2 wherein said filter (90) includes at least one other region (94) having a gas permeability greater than said filter region (92) of minimum permeability.
Claim 4
Dependent Claim
34 words
An airbag inflator according to claim 3 wherein said filter (90) includes yet another region of gas permeability greater than said one other region (94) and adjacent the other (42) of said end walls.
Claim 5
Dependent Claim
37 words
An airbag inflator according to any one of claims 2 to 4, wherein said filter (90) has a plurality of levels of different gas permeability (92, 94, 96) spaced from said level of said direct flow path.
Claim 6
Dependent Claim
160 words
A filter (90) for use in an inflator (30) of a vehicle airbag system (10), said inflator having a gas generation zone (60) containing gas generation means (62) and a gas discharge region defined by a plurality of gas discharge ports (36a) spaced around the outer side wall (36) of the inflator, wherein said filter comprises: an annulus of porous filtering material having an inner filter wall capable of fitting around said gas generation zone (60), and an outer filter wall which is capable of fitting within said outer side wall (36), said annulus of porous filtering material having at least two zones of differing gas permeability at different levels along its axial length, the first zone (92) of porous filtering material being located at the level of the porous filtering material corresponding to said gas discharge region having a smaller gas permeability than a second zone (94, 96) at a level removed from that of said gas discharge region.
Claim 7
Dependent Claim
60 words
A filter according to claim 6, wherein: at least three zones (92, 94, 96) of differing gas permeability are defined at different levels along the axial length of said annulus of porous filtering material, the zone (96) of filtering material which is furthest from said first zone having a gas permeability greater than that of the other zones (92, 94).
Claim 8
Dependent Claim
48 words
A filter according to claim 7, wherein the zones (92, 94, 96) of differing gas permeability are provided at levels along said axial length such that each zone has a greater gas permeability than any of the other zones which are located closer to said first zone (92).
Claim 9
Dependent Claim
48 words
A filter according to any one of claims 6 to 8 wherein said zones (92, 94, 96) of differing gas permeability are located along said axial length to provide an even rate of flow through said filter (90) from said inner filter wall to said gas discharge region.
Claim 10
Dependent Claim
37 words
A filter (90) for use in the inflator of a vehicle airbag system (10) comprising an annulus of porous filtering material having at least two zones of different gas permeabilities at different positions along its axial length.
Claim 11
Dependent Claim
30 words
A filter according to claim 10 wherein at least three zones (92, 94, 96) of different gas permeabilities are provided at different positions along the axial length of said annulus.
Claim 12
Dependent Claim
57 words
A filter according to claim 11 wherein: one zone (92) has a lower gas permeability than any of the other zones (94, 96), and the remaining zones are located along said axial length such that each such remaining zone (94, 96) has a greater gas permeability than any other remaining zone located closer to said one zone.
Claim 13
Dependent Claim
42 words
A filter according to any one of claims 10 to 12 wherein said annulus of porous filtering material is formed from an elongated strip of filter medium (100, 110, 120) having a plurality of sections (92, 94, 96) having different gas permeabilities.
Claim 14
Dependent Claim
38 words
A filter according to claim 13 wherein said annulus of porous filtering material is formed of metal wound in successive convolutions (102) and said zones of different gas permeabilities are formed by groups of perforations of different size.
Claim 15
Dependent Claim
20 words
A filter according to claim 14 wherein said perforations are formed by expanded metal (100) having differing degrees of expansion.
Claim 16
Dependent Claim
18 words
A filter according to claim 14 wherein said perforations are formed by pushing openings in said strip (110).
Claim 17
Dependent Claim
30 words
A filter according to claim 13 wherein said sections (92, 94, 96) having different gas permeabilities are formed by establishing different densities of stranded materials across said elongated strip (120).
References Cited (Backward Citations)
No citation records indexed.
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