Inflator with Flow Wash Strainer

Patent metadata

Field	Value
Publication number	US-2016229372-A1
Application number	US-201415022700-A
Country	US
Kind code	A1
Filing date	Sep 17, 2014
Priority date	Sep 19, 2013
Publication date	Aug 11, 2016
Grant date	—

Abstract

An airbag inflator ( 10 ) has an inflator housing ( 20 ) with an internal chamber ( 11 ); a pyrotechnic gas generant ( 8 ) stored in the internal chamber inside the housing ( 20 ) for generating inflation gases upon ignition; a strainer ( 50 ) with openings through which the inflation gases pass prior to inflating the airbag; a primary nozzle wall ( 40 ) positioned between the strainer and the gas generator; a plenum chamber ( 12 ) between the primary nozzle wall ( 40 ) and the strainer ( 50 ). The primary nozzle wall ( 40 ) has a plurality of nozzles ( 40 a, 40 b ) with nozzle openings ( 42, 44 ) oriented radially about the wall which directs gas flow tangentially spiraling laterally onto the strainer while preventing the inflation gas from flowing radially. The tangentially flowing gases impinge an internal face of the strainer laterally causing gas generant particles to recirculate and burn internally and residual debris of a size greater than the openings of the strainer ( 50 ) to be swept and settle in the plenum chamber ( 12 ) of the housing.

First claim

What is claimed is:

1 . An airbag inflator ( 10 ) comprises:
an inflator housing ( 20 ) with an internal chamber ( 11 ); a pyrotechnic gas generant ( 8 ) stored in the internal chamber ( 11 ) inside the housing ( 20 ) for generating inflation gases upon ignition; a strainer ( 50 ) with openings through which the inflation gases pass prior to inflating the airbag; a primary nozzle wall ( 40 ) positioned between the strainer ( 50 ) and the gas generator; a plenum chamber ( 12 ) between the primary nozzle wall ( 40 ) and the strainer ( 50 ); and wherein the primary nozzle wall ( 40 ) has a plurality of nozzles ( 40 a, 40 b ) with nozzle openings ( 42 , 44 ) oriented radially about the wall which directs gas flow tangentially spiraling laterally onto the strainer ( 50 ) while preventing the inflation gas from flowing radially, the tangentially flowing gases impinge an internal face of the strainer laterally causing gas generant particles to recirculate and burn internally and residual debris of a size greater than the openings of the strainer ( 50 ) to be swept and settle in the plenum chamber ( 12 ) of the housing ( 20 ).

2 . The airbag inflator ( 10 ) of claim 1 wherein the inflator housing ( 20 ) is a circular short cylindrical pancake shaped structure with a plurality of openings ( 21 ) for inflation gases to exit.

3 . The airbag inflator ( 10 ) of claim 2 wherein the strainer ( 50 ) is a short circular hollow cylinder with an inside diameter encircling the primary nozzle wall ( 40 ) and the gas generant and extending internally of the housing ( 20 ) to a height equal to the distance between upper and lower surfaces of the housing wherein inflation gases must pass through the strainer ( 50 ) prior to exiting the housing openings ( 21 ).

4 . The airbag inflator ( 10 ) of claim 1 wherein the primary nozzle wall ( 40 ) is in the form of an annular ring spaced from the strainer ( 50 ), the space between the primary wall and the strainer defines the plenum chamber ( 12 ).

5 . The airbag inflator ( 10 ) of claim 4 wherein the primary nozzle wall ( 40 ) is made of sheet metal or a hollow cylindrical tube.

6 . The airbag inflator ( 10 ) of claim 5 wherein the nozzle openings ( 42 , 44 ) are formed by stamping the sheet metal or hollow cylindrical tube to create the nozzles ( 42 , 44 ) by cutting and forming scoop shaped depressions or bulges each having an opening transverse or perpendicular to the wall.

7 . The airbag inflator ( 10 ) of claim 6 wherein the primary nozzle wall ( 40 ) has ends joined to form a tubular ring for encircling the gas generant.

8 . The airbag inflator ( 10 ) of claim 7 wherein the ends are welded, riveted or otherwise fastened together.

9 . The airbag inflator ( 10 ) of claim 7 wherein the openings of scoop shaped nozzles are oriented parallel to radial lines extending from an axis of the primary nozzle wall ( 40 ) when formed as a ring.

10 . The airbag inflator ( 10 ) of claim 1 wherein the primary nozzle wall ( 40 ) has a height extending to an upper and a lower surface of the housing ( 20 ) thereby sealing the gas generant in the internal chamber wherein the inflation gas must pass through the nozzle openings ( 42 , 44 ) into the plenum chamber ( 12 ).

11 . The airbag inflator ( 10 ) of claim 1 wherein the plurality of nozzle openings ( 42 , 44 ) are arranged in one or more rows around the circumference of the primary nozzle wall ( 40 ) to create a cyclonic flow vortex.

12 . The airbag inflator ( 10 ) of claim 1 wherein the plurality of nozzle openings ( 42 , 44 ) are arranged in at least two rows of equally spaced nozzle openings, an upper row and a lower row, each row having at least four nozzle openings.

13 . The airbag inflator ( 10 ) of claim 11 wherein the one or more rows extends about the circumference surface of the primary nozzle wall ( 12 ).

14 . The airbag inflator ( 10 ) of claim 12 wherein the nozzle openings ( 42 , 44 ) of each row are equal in number and equally spaced between openings.

15 . The airbag inflator ( 10 ) of claim 14 wherein the openings within one row are aligned with openings in each adjacent row.

16 . The airbag inflator ( 10 ) of claim 14 wherein the openings within each row are staggered relative to an adjacent row.

17 . The airbag inflator ( 10 ) of claim 11 wherein the primary nozzle wall ( 12 ) has one or more upper rows of nozzle openings ( 42 , 44 ) facing in a first direction for receiving inflation gases and one or more lower rows facing in a second opposite direction for receiving gas flows, wherein the gas flows tangentially into an upper portion of the strainer ( 50 ) in the first direction and tangentially in a second opposite direction into a lower portion of the strainer ( 50 ) thereby creating two oppositely directed cyclonic flow vortexes.

18 . The airbag inflator ( 10 ) of claim 1 wherein the strainer ( 50 ) is made of one or more layers of wire mesh ( 52 ).

19 . The airbag inflator ( 10 ) of claim 18 wherein the wire mesh ( 52 ) of the strainer ( 50 ) has openings sized to 20 microns.

20 . The airbag inflator ( 10 ) of claim 19 wherein the strainer ( 50 ) is a single layer of wire mesh ( 52 ) formed into an annular ring.

Assignees

• Key Safety Systems Inc
• Key Safety Systems Inc

Inventors

• Spencer Byron

Classifications

• B60R2021/26011

  using a filter through which the inflation gas passes · CPC title

• B60R21/264 Primary

  using instantaneous generation of gas, e.g. pyrotechnic (B60R21/268 takes precedence) · CPC title