Gas generating system for the inflation of a protective bag

• US 3,904,221 A
• Filed: 05/10/1973
• Issued: 09/09/1975
• Est. Priority Date: 05/19/1972
• Status: Expired due to Term

• Current Assignee: Ikuo Harada, Masaaki Shiga, Tadamasa Harada, Takehiko Shiki
• Original Assignee: Ikuo Harada, Masaaki Shiga, Tadamasa Harada, Takehiko Shiki
• Inventors: Shiki, Takehiko, Harada, Tadamasa, Harada, Ikuo, Shiga, Masaaki
• Primary Examiner(s): Schonberg, David
• Assistant Examiner(s): Silverstrim, John P.
• Application Number:
  US05/358,931
• Time in Patent Office: 852 Days
• Field of Search: 280/15AB 102/39R 23/281
• US Class Current: 280/736
• CPC Class Codes: B60R 2021/2633 with a plurality of inflation levels
• CPC Class Codes: B60R 2021/2648 comprising a plurality of combustion chambers or sub-chambers
• CPC Class Codes: B60R 21/2644 using only solid reacting substances, e.g. pellets, powder
• CPC Class Codes: F42B 3/04 for producing gas under pressure generators of inflation fluid especially adapted for vehicle air bags B60R21/26

Abstract

A light compact gas generating system is provided for the inflation of a protective bag to cushion a passenger (including a driver) from impact within a high speed vehicle such as an automobile the system can generate a low temperature, non-toxic and dustless gas with such a velocity as to inflate the bag in an extremely short time (in the order of 20-60 milliseconds). The system comprises a chamber surrounded by a wall composed at least in part of a layer comprising a plurality of metal wire gauzes which provide the passageway of the generated gas, a gas generating chemical composition enclosed in the chamber and at least one ignition tube enclosed in the chamber. The gas generating chemical composition consists essentially of at least one member selected from the group consisting of alkali metal azides, alkaline earth metal azides and hydroxy metal azides having the general formula M(OH)m(N3)n, wherein M represents a metal, said member being preferably strontium azide or barium azide. The composition generates non-toxic molecular nitrogen gas, which can be breathed by the passenger without ill effect.

Claims

1. A gas generating system for the inflation of a protective bag to cushion a passenger from impact with the structure of a high speed vehicle comprising (1) a chamber surrounded by a layer of metal wire gauzes wherein said layer hAs a heat capacity above 5 calories/*C per 1 mol of the generated nitrogen gas, having a ratio of total surface area of the wires to the total volume of the wires in the range of 150-400 cm 1, having a fractional void in the range of 60-90%, and having a thickness of 0.3-3 cm, (2) a gas generating chemical composition enclosed in the chamber, wherein said chemical composition is composed of (a) at least one metal azide selected from the group of alkali metal azides, alkali earth metal azides and hydroxy metal azides having the general formula M(OH)m(N3)n, wherein M represents Mg, Ca, Mn, Co and Ni, N represents nitrogen atoms, and m,n represent a positive number respectively where m plus n means atomic valency of M, and (b) at least one oxidizing agent, (3) at least one ignition tube for igniting said chemical composition in the chamber.

2. A gas generating system according to claim 1, wherein said gas generating chemical composition further contains a reductive metal powder as a third component.

3. A gas generating system according to claim 1, wherein a part of the chamber wall which does not form the passageway of the generated gas is substantially covered with a thick sheet of silicon resin to prevent the passenger and the bag completely from burning.