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.

Description

[0001] 1. The Field of the Invention[0002] This invention relates to filters, and especially filter elements useful for filtering hot gases used in the deployment of passenger airbags, and to methods for making and using such filters, and to airbags and vehicles containing the same.[0003] 2. The State of the Art[0004] Relatively recent concerns with passenger safety in land vehicles has led to the development of "alrbag" technology, a passive restraint and protection system comprising a bag or pillow-like bladder that is inflated in an extremely short period of time using compressed or chemically-generated gas to fill the bag. The inflated bag is disposed or deployed between the front or side of the passenger and an interior portion of the vehicle's passenger compartment.[0005] The first generation of pyrotechnic airbag vehicle occupant restraint systems used azide compositions (typically sodium azide, NaN.sub.3, mixed a heavy metal oxide) to generate the gas used to inflate the air...

AI Technical Summary

Benefits of technology

0011] One object of this invention to provide a relatively inexpensive a...

Problems solved by technology

Much of this matter is not only extremely hot but also of a caustic composition, and the particulate matter, travelling a high velocity, is potentially dangerous to the integrity of the bag and the occupant to be protected thereby.

If no measures are taken to ameliorate the degradative effects of this mixed phase reaction mixture, the gases and/or particulates would penetrate the bag, likely causing its failure and, in the most serious situations, causing injuries to the passenger.

There are other trade-offs, as particulate deflection devices are typically expensive machined parts which are fabricated from heavy steel plate (because they are not amenable to fabrication by stamping, their cost of manufacturing is increased).

According to the above-referenced '323 patent, there is also a problem with quali...

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