A filter for use in safety air bags as employed in vehicles and the like comprises one or more compressed grooved wires, wherein the wire or wires have an outer diameter of about 0.010 to 0.050 inches and the grooves have a depth in the range of 0.001 to about 0.005 inches. A plurality of grooves, preferable about 10-14, of about 0.018 diameter stainless steel wire, having a depth of about 0.001 inches to about 0.0025 inches, are equally spaced about the periphery of the wire, which is cylindrical. The pitch of the groove spacing may differ for different implementations. The wire outer surface between grooves may have a radius, preferably about 0.0025 inches in a wire of about 0.018 inches diameter. A stainless steel wire is preferred, but other wire metals may be used according to a given implementation.

A filter for gas generator has an outer geometry substantially of a hollow cylinder and it is formed by a wound body of a metal wire. The metal wire is made of an elongated member having a V-shaped cross-section orthogonal to a direction of extension thereof. A V-shaped groove defined in the metal wire faces a hollow portion in the filter for gas generator and an angle of the V-shaped groove is not smaller than 130[] and not greater than 140[].

The invention relates to a gas generator (10) for a vehicle occupant safety system comprising an outer casing (20) and a filter structure (30) for purifying and/or cooling gas released inside the outer casing (20), wherein the filter structure (30) is integrated in the outer casing (20). The invention further relates to an airbag module and a vehicle occupant safety system comprising said gas generator as well as to a manufacturing method.

The present invention provides a gas generator in which short-passing of combustion gas is prevented. A cylindrical filter 30 including a first annular end surface 32 abutted against a top plate 12 and a second annular end surface 33 abutted against a bottom plate 21 is disposed inside a housing 10. A corner portion 75 formed by a bottom surface 71 and an outer circumferential wall 74 of a support member 70 is abutted against an abutting portion between the second annular end surface 33 and the bottom plate 21 to prevent the short-passing of the combustion gas from this portion.

A filter unit for a gas generator includes a filter and a filter housing coaxially positioning and fixing the filter in a filter accommodating space. The filter housing includes a first restraining end part disposed as a closing surface at one end of the filter housing and restraining a one axial end surface of the filter, a second restraining end part disposed at an other end of the filter housing, surrounding a gas inflow port, and restraining an other axial end surface of the filter, and a peripheral wall part connecting the first restraining end part and the second restraining end part and including a gas discharge port. The peripheral wall part includes a restraining peripheral wall part restraining a peripheral surface of the filter, and a non-restraining peripheral wall part in which the gas discharge port is disposed.

Expanded metal sheets are used to produce tubular filters. The expanded metal sheet has a multiplicity of rows of openings arranged to reduce nesting when the sheet is rolled on itself. In particular, the pitch between the rows of openings, the sizes of the openings, or both the pitch between the rows of openings and the sizes of the openings are varied to reduce nesting when the expanded metal sheet is rolled on itself. The filters can include external circumferential grooves, rounded corners produced by a point loading process, textured surfaces between openings, and/or torturous internal paths produced by non-perforated areas of an expanded metal sheet. The expanded metal sheet can be composed of carbon steel coated with a material having a higher heat conductivity, e.g., tin. Among other things, the filters can be used in automobile airbag inflators to capture slag and absorb heat produced by the inflator's explosive charge.

An airbag assembly may include an airbag and an inflator that provides inflation gas to inflate the airbag. A filter module may be positioned such that inflation gas exiting the inflator must first pass through the filter module. The filter module may be formed of a sheet of metal that is wrapped into a generally spiraling tubular shape. The filter module may have an inner layer, an intermediate layer, and an outer layer. The intermediate layer generally encircles the inner layer, and the outer layer generally encircles the inner layer and the intermediate layer in a spiraling fashion. The inner layer, the intermediate layer, and the outer layer each may have a pattern of holes and dimples that are separate from and/or displaced from each other. The dimples may protrude toward an adjacent layer to maintain spacing to enable relatively unrestricted gas flow from the holes of the inner layer through unaligned holes of the intermediate layer and the outer layer. The resulting tortuous gas flow path may help to slow, cool, and/or purify the gas before it exits the inflator.

The present invention provides a gas generator in which short-passing of combustion gas is prevented.

A cylindrical filter 30 including a first annular end surface 32 abutted against a top plate 12 and a second annular end surface 33 abutted against a bottom plate 21 is disposed inside a housing 10. A corner portion 75 formed by a bottom surface 71 and an outer circumferential wall 74 of a support member 70 is abutted against an abutting portion between the second annular end surface 33 and the bottom plate 21 to prevent the short-passing of the combustion gas from this portion.

A filter for an inflator includes a rolled sheet centered on an axis or three dimensionally printed as a whole and including a plurality of openings. A deflector is associated with each opening for directing inflation fluid in a non-radial direction relative to the axis.

A filter for use in safety air bags as employed in vehicles and the like comprises one or more compressed grooved wires, wherein the wire or wires have an outer diameter of about 0.010 to 0.050 inches and the grooves have a depth in the range of 0.001 to about 0.005 inches. A plurality of grooves, preferable about 10-14, of about 0.018 diameter stainless steel wire, having a depth of about 0.001 inches to about 0.0025 inches, are equally spaced about the periphery of the wire, which is cylindrical. The pitch of the groove spacing may differ for different implementations. The wire outer surface between grooves may have a radius, preferably about 0.0025 inches in a wire of about 0.018 inches diameter. A stainless steel wire is preferred, but other wire metals may be used according to a given implementation.