Filter with stiffening ribs

Abstract

Annular wire mesh filters for airbag assemblies for passenger vehicles are provided with a series of ribs extending parallel with the axis of the annulus and along the outer wall. The ribs provide added strength to the filter. Also provided is a method of manufacturing the compressed mesh filter with a uniform density, and a molding tool (mold, mandrel, and plunger) for making the compressed mesh articles of this invention.

1. A wire mesh filter for use in an airbag inflator assembly including a gas generator and an airbag; the wire mesh filter including a knitted wire mesh having an annular geometry defined by an axis with two ends and an outer cylindrical wall and a plurality of at least four ribs directed along the axis and extending at least partially along the outer cylindrical wall, the ribs comprising the mesh filter; wherein gases that are explosively generated by the gas generator pass into and through the wire mesh filter in order to inflate the airbag. 
     
     
       2. The improved filter of  claim 1 , wherein the ribs extend fully along the outer wall between the two ends. 
     
     
       3. The improved filter of  claim 1  wherein the wire comprises 304 or 309 stainless steel. 
     
     
       4. An improved airbag assembly comprising a gas generator, an inflatable bag, and a filter through which gas explosively generated passes into and inflates the bag, wherein the improvement comprises a knitted wire mesh filter having an annular geometry defining an axis and an outer circumferential wall, said outer circumferential wall being deformed into ribs parallel with said axis, and said mesh filter having an annular geometry defined by an axis with two ends and an outer cylindrical circumferential wall, and a plurality of at least four ribs directed along said axis and extending along the outer cylindrical wall, the ribs comprising said mesh filter. 
     
     
       5. A passanger  passenger vehicle having an airbag, wherein the improvement comprises an airbag assembly comprising a gas generator, an inflatable bag, and a filter through which gas explosively generated passes into and inflates the bag, said filter being a knitted wire mesh filter having an annular geometry defining an axis and an outer circumferential wall, said outer circumferential wall being deformed into ribs parallel with said axis, and said mesh filter having an annular geometry defined by an axis with two ends and an outer cylindrical circumferential wall, and a plurality of at least four ribs directed along said axis and extending along the outer cylindrical wall, the ribs comprising said mesh filter. 
     
     
       6. The improved filter of  claim 4 , wherein said ribs extend only partially along the length of said axis. 
     
     
       7. The improved filter of  claim 1 , wherein the distance between adjacent ribs along said outer cylindrical wall approximates the width of each such rib. 
     
     
       8. The improved airbag assembly of  claim 4 , wherein the distance between adjacent ribs along said outer cylindrical wall approximates the width of each such rib. 
     
     
       9. The improved airbag assembly of  claim 4 , wherein said ribs extend only partially along the length of said axis. 
     
     
       10. The improved airbag assembly of  claim 4 , wherein the distance between adjacent ribs along said outer cylindrical wall approximates the width of each such rib. 
     
     
       11. The improved airbag assembly of  claim 9 , wherein the distance between adjacent ribs along said outer cylindrical wall approximates the width of each such rib. 
     
     
       12. A passenger vehicle having an airbag, wherein the improvement comprises an airbag assembly comprising a gas generator, an inflatable bag, and a filter through which gas explosively generated passes into and inflates the bag, said filter being a knitted wire mesh filter having an annular geometry defining an axis and an outer circumferential wall, said outer circumferential wall being deformed into ribs parallel with said axis, and said mesh filter having an annular geometry defined by an axis with two ends and an outer cylindrical circumferential wall, and a plurality of at least three ribs directed along said axis and extending only partly along the outer cylindrical wall, the ribs comprising said mesh filter.