Filters for vehicle occupant restraint system fluid supplies

Claim 2

A filter for filtration of contaminants produced in the gas flow of a gas generator of the type used for inflation in vehicle occupant restraint systems, said filter comprising: (a) a plurality of layers comprising plenum zones for dispersing and filtering contaminants contained in said gas flow throughout said plenum zone, each of said layers being formed of a first filter material comprising a metallic wool material, each of said layers of first filter material defining a plenum zone; and (b) a plurality of layers of a second filter material, said second filter material being fibrous and having a porosity substantially less than said first filter material, wherein said plurality second filter material layers and said layers of plenum zones are disposed in alternating arrangement such that each layer of said second filter material is bounded on opposite sides thereof by a plenum zone layer; (c) first porous support means located adjacent the upstream side of said plurality of plenum zones; and (d) second porous support means located adjacent the downstream side of said plurality of plenum zones, said second support means permitting a gas flow therethrough, said first and second filter materials disposed between said first and second support means.

Claim 3

The filter as defined in claim 1, wherein, (a) said first material comprises fibers having diameters in the range of about 50 to about 150 microns; and (b) said second filter material comprises fibers having diameters in the range of about 1 to about 20 microns.

Claim 4

The filter as defined in claim 1 wherein said first filter material comprises steel wool and said second material comprises glass fibers.

Claim 5

The filter as defined in claim 1 wherein each layer of said first material is of substantially equal porosity.

Claim 6

The filter as defined in claim 1 wherein each layer of said second filter material is of substantially equal porosity.

Claim 7

The filter as defined in claim 1, wherein said plurality of layers of said second filter material are arranged to effect progressively finer filtration of contaminants in a downstream direction.

Claim 8

The filter as defined in claim 1 wherein said second filter material is a metallic material and said plurality of layers of said second filter material are arranged to effect progressively finer filtration of contaminants in a downstream direction.

Claim 9

The filter as defined in claim 1, wherein each of said second filter material layers is progressively less porous in the direction of flow.

Claim 10

A fluid generator for inflating an expandable confinement of a vehicle occupant restraint system, said fluid generator comprising: (a) housing means defining fluid discharge means for discharging fluid flow from said housing means; (b) fluid generating means disposed within said housing and including ignitable material which, upon ignition, burns to generate inflation gas and products of combustion for producing a flow of inflation gas; (c) filter means disposed within said housing means intermediate said fluid discharge means and said fluid generating means, said filter means including (i) a plurality of layers of a first filter material, said first filter material being formed of a metallic wool material, each of said layers of first filter material defining a plenum zone for dispersing and filtering contaminants contained in said fluid flow throughout said plenum zone, (ii) a plurality of layers of a second filter material, said second filter material being fibrous and having a porosity substantially less than said first filter material, said plurality of first and second filter material layers being disposed in alternating arrangement such that each layer of said second filter material is bounded on opposite sides thereof by one of said plenum zones, said second filter material chosen from the group consisting of non-woven metallic material or glass fibers; (d) first porous support means located adjacent the upstream side of said plurality of plenum zones; and (e) second porous support means located adjacent the downstream side of said plurality of plenum zones, said second support means permitting a gas flow therethrough, said first and second filter materials disposed between said first and second support means; and (f) means operable upon activation to ignite said ignitable material means.

Claim 11

A fluid generator for inflating an expandable confinement of a vehicle occupant restraint system, said fluid generator comprising: (a) housing means defining fluid discharge means for discharging fluid flow from said housing means; (b) fluid generating means disposed within said housing and including ignitable material which, upon ignition, burns to generate inflation gas and products of combustion for producing a flow of inflation gas; (c) filter means disposed within said housing means intermediate said fluid discharge means and said fluid generating means, said filter means including (i) a plurality of layers of a first filter material, said first filter material being formed of a metallic wool material, each of said layers of first filter material defining a plenum zone for dispersing and filtering contaminants contained in said fluid flow throughout said plenum zone, (ii) a plurality of layers of a second filter material, said second filter material being fibrous and having a porosity substantially less than said first filter material, said plurality of first and second filter material layers being disposed in alternating arrangement such that each layer of said second filter material is bounded on opposite sides thereof by one of said plenum zones, said second filter material chosen from the group consisting of non-woven metallic material or glass fibers; (d) first porous support means located adjacent the upstream side of said plurality of plenum zones; and (e) second porous support means located adjacent the downstream side of said plurality of plenum zones, said second support means permitting a gas flow therethrough, said first and second filter materials disposed between said first and second support means; and (f) means operable upon activation to ignite said ignitable material means.

Claim 12

The fluid generator defined in claim 9 wherein: (a) said first material comprises fibers having diameters in the range of about 50 to about 150 microns; and (b) said second filter material comprises fibers having diameters in the range of about 1 to about 20 microns.

Claim 13

The fluid generator as defined in claim 9 wherein said first filter comprises steel wool and said second filter material comprises glass fibers.

Claim 14

The fluid generator as defined in claim 9 wherein each layer of said first material is of substantially equal porosity.

Claim 15

The filter as defined in claim 9 wherein each layer of said second filter material is of substantially equal porosity.

Claim 16

The fluid generator as defined in claim 9 wherein said plurality of layers of said second filter material are arranged to effect progressively finer filtration of contaminants in a downstream direction.

Claim 17

A fluid generator as defined in claim 9, wherein said second filter material is metallic, said plurality of layers of said second filter material are arranged to effect progressively finer filtration of contaminants in a downstream direction.

Claim 18

The fluid generator as defined in claim 9, wherein each of said second filter material layers is progressively less porous in the direction of flow.