PYROTECHNIC GAS GENERATOR

• US 3,711,115 A
• Filed: 11/24/1970
• Issued: 01/16/1973
• Est. Priority Date: 11/24/1970
• Status: Expired due to Term

• Current Assignee: Thomas E. Lohr
• Original Assignee: Thomas E. Lohr
• Inventors: Lohr, Thomas E.
• Primary Examiner(s): Betts, Kenneth H.
• Assistant Examiner(s): Silverstrim, John P.
• Application Number:
  US05/092,368
• Time in Patent Office: 784 Days
• Field of Search: 280/15AB 23/281 102/34.5,37.7,39,40,58 9/321
• US Class Current: 280/736
• 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 gas generation method and apparatus for use in inflation of vehicle gas bags. A purely pyrotechnic gas generator is provided for inflation of vehicle gas bags in which the sequential ignition of two or more combustion stages provides combustion gases which are directed to a conduit disposed within the generator. A compartment disposed in the generator to remove water contributes additional gas in the form of water vapor to the conduit. A gas bag, in communication with the conduit, is inflated by the gas generated during combustion.

Claims

1. An apparatus for inflation of a gas bag disposed in a vehicle comprising:

a. a container means provided within with conduit means;

b. a first combustion stage disposed in the upstream end of said container means and in gas flow communication with said conduit means;

c. an ignition means connected to the upstream end of said first combustion stage to ignite said first stage upon impact of said vehicle;

d. a second combustion stage disposed adjacent to and downstream of said first combustion stage and in gas flow communication with said conduit means;

e. an ignition delay means disposed within said first combustion stage in communication with said second combustion stage, for ignition of said second stage after combustion and generation of gas in said first stage is completed;

f. a moisture absorbing means disposed downstream of said second combustion stage, means for liberating water vapor from said moisture absorbing means, into said conduit means during combustion g. said conduit means having an outlet means disposed downstream of said moisture absorbing means, in gas flow communication with said gas bag, whereby combustion gases generated in said combustion stages and water vapor liberated from said moisture absorbing means flow into said gas bag through said conduit means.

2. An apparatus in accordance with claim 1 including vortex generator means disposed between the downstream end of said conduit means and said outlet means whereby a cool gas stream generated in said vortex generator means is directed into said outlet means.

3. An apparatus in accordance with claim 1 wherein said first and said second combustion stages are disposed in the peripheral section of said container means in communication with said conduit means for communication of the gas generated in said stages with said gas bag.

4. An apparatus in accordance with claim 1 wherein said conduit means comprises a cylindrical opening in said container means provided with a venturi nozzle, defined by said inner boundry of said moisture absorbing means.

5. An apparatus in accordance with claim 1 wherein said container means comprises a cylindrical shell.

6. An apparatus in accordance with claim 1 wherein said moisture absorbing means comprises a multiplicity of hydrate forming, water sorbing crystals encased in a compartment whereby said combustion stages are maintained free of moisture prior to the ignition of said generator.

7. A gas generator in accordance with claim 1 wherein said ignition means comprises a squib.

8. A gas generator in accordance with claim 1 wherein said ignition delay means comprises an enclosed solid mixture of gun powder and decelerators.

9. A gas generator in accordance with claim 1 wherein said first and second combustion stages each comprise a solid combustible material disposed in a single enclosed compartment in communication with said conduit means.

10. A gas generator in accordance with claim 9 wherein said combustible material is a solid mixture of rubber and ammonium nitrate.

11. A gas generator in accordance with claim 9 wherein said combustible material is a solid mixture of polyvinyl chloride and ammonium oxylate.

12. A gas generator for inflation of a gas bag disposed in a vehicle comprising:

a. a container means provided within with conduit means in gas flow communication with said gas bag;

b. a first combustion stage for generating gas in said container including separated first and second compartments in gas flow communication with said conduit means;

c. an ignition means connected to said first compartment of said first combustion to ignite said first combustion stage upon impact of said vehicle;

d. a second combustion stage for generating gas in gas flow communication with said conduit means, comprising separated first and second compartments disposed adjacent to and downstream of said first combustion stage;

e. an ignition delay means disposed within said second compartment of said first combustion stage for ignition of said first compartment of said second combustion stage after combustion of said first combustion stage is completed;

f. a water removal means through which at least a portion of said generated gas flows disposed downstream of And adjacent to said second combustion stage, said water removal means in gas flow communication with said conduit means through aperture means in said conduit means and characterized by an inner boundry defining a nozzle means in said conduit means; and

g. an outlet means adjacent to and connected to said conduit means and said gas bag, whereby combustion gases generated in said first and second combustion stages and water vapor liberated from said water removal means during ignition of said combustion stages flow into said gas bag.

13. A gas generator in accordance with claim 7 including vortex generator means disposed between the downstream end of said conduit means and said outlet means, whereby a cool gas stream generated in said vortex generator means is directed into said outlet means.

14. A gas generator in accordance with claim 12 wherein said second compartment of said first and second compartments comprises a solid combustible material contained within wall means in communication with said conduit means and said first compartment.

15. A gas generator in accordance with claim 14 wherein said combustible material is a solid mixture of ammonium nitrate and carbon.

16. A gas generator in accordance with claim 12 wherein said first compartment of said first and second combustion stages comprises a solid combustible material provided with cylindrical air tubes, contained within wall means separating said first compartment from said conduit means and said second compartment, said wall means, separating said first and second compartments, provided with a plurality of openings for communication between said first and said second compartments.

17. A gas generator in accordance with claim 16 wherein said combustible material is black powder.

18. A gas generator in accordance with claim 16 wherein said combustible material is a mixture of rubber and aluminum nitrate.

19. A method for generation of gas for inflation of a gas bag in a vehicle comprising the steps of:

a. igniting a first combustion stage of a gas generator upon impact of said vehicle whereby combustion gases are generated into a conduit in communication with said gas bag;

b. igniting a second combustion stage after combustion and generation of gases in said first combustion stages is completed, whereby combustion gases continue to flow into said conduit;

c. liberating water vapor stored in said generator downstream of said second stage said water vapor being liberated by passing at least a portion of said generated gas through a hydrated material and by decreasing the equilibrium pressure of said hydrated material; and

d. inflating a gas bag in communication with said conduit by a combined stream comprising said combustion gases and said water vapor.

20. A method in accordance with claim 19 including the step of separating said combined stream into a hot and a cool stream upstream of said gas bag whereby only the cool stream is used to inflate said gas bag.