Light weight welded aluminum inflator

• US 4,547,342 A
• Filed: 04/02/1984
• Issued: 10/15/1985
• Est. Priority Date: 04/02/1984
• Status: Expired due to Term

• Current Assignee: Autoliv ASP Incorporated (Autoliv Incorporated)
• Original Assignee: Morton Thiokol, Inc.
• Inventors: Cunningham, Donald J., Adams, Gary V., Dahle, David P., Ahlf, Wilbur J.
• Primary Examiner(s): Lacey, David L.
• Application Number:
  US06/595,774
• Time in Patent Office: 561 Days
• Field of Search: 422/120, 422/165-167, 422/240, 422/305, 222/3, 280/736, 280/737, 280/740, 280/741, 137/68 A, 102/531
• US Class Current: 422/166
• CPC Class Codes: B01J 7/00 Apparatus for generating gases production of inert gas mixtures B01J19/14; for generating specific gases, see the relevant subclasses, e.g. C01B, C10J ; in "air bags" on vehicles B60R21/26; for starter gas F02C7/26; blasting cartridges for producing gas under pressure F42B3/04
• 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
• CPC Class Codes: Y10T 137/1647 Explosive actuation

Abstract

A gas generator or inflator particularly for the inflation of inflatable protective bags that are used in vehicle safety systems includes first and second aluminum structural components. The first component, a diffuser shell having outlet ports, includes integrally formed concentric cylinders which define chambers containing ignition materials, a solid gas generant composition and filters and provide ports for the passage of generated gases from chamber to chamber and then through the outlet ports. The second component, a base shell, has an attachment flange, includes an initiator, and is provided with three concentric surfaces that mate with the ends of the concentric cylinders of the first component. The three concentric cylinders of the first component are simultaneously joined with the concentric mating surfaces of the second component by a single inertia welding operation.

Claims

1. An inflator for the generation of gas to inflate vehicle inflatable crash protection bags comprising,

a solid gas generant composition which is operable upon ignition to produce gas and combustion products,

ignition means to ignite said gas generant composition,

initiator means to actuate said ignition means,

filter means to cool said gas and to trap said combustion products, and

first and second structural components,

said first structural component having three concentric cylinders which extend from a common wall means and define three concentric chambers with the inner chamber containing said ignition means, the intermediate chamber containing said gas generant composition, and the outer chamber containing said filter means, and with outlet ports in the outer one of said cylinders for the outflow of generated gas and with other ports in the inner cylinders for the passage of generated gas from chamber to chamber and then through the outlet ports in the outer cylinder,

said second structural component containing said initiator means, having an attachment flange, and providing concentric mating surfaces for the concentric cylinders of said first structural component, the concentric cylinders of said first structural component being welded to the concentric mating surfaces of said second structural component.

2. An inflator as defined in claim 1 wherein said first and second structural components are formed of aluminum.

3. An inflator as defined in claim 2 wherein the chambers defined by said concentric cylinders and said wall means of said first structural component comprise a central cylindrical chamber and surrounding concentric inner and outer toroidal chambers, said ignition means being contained in said central chamber, said gas generant composition in said inner toroidal chamber, and said filter means in said outer toroidal chamber, and

wherein said second structural component includes a hole at a central location thereof for mounting said initiator.

4. An inflator as defined in claim 3 including a closed container, said closed container containing said ignition means and having a recess formed in a portion thereof facing said second structural component, and

wherein said initiator means in said second structural component extends into the recess of said closed container.

5. An inflator as defined in claim 4 including cushion/spacer material, said closed container being positioned in spaced relation with said wall means of said first component by said cushion/spacer material.

6. An inflator as defined in claim 4 including an inner annular screen filter pack positioned in said inner toroidal chamber in surrounding relation with said gas generant composition therein, said inner screen pack being operative to remove particulate matter from the generated gas, and

further including an annular retaining disk for holding the said gas generant composition and said inner screen filter pack in said inner toroidal chamber away from the second structural component to facilitate the joining of said second structural component to said first structural component.

7. An inflator as defined in claim 6 wherein said annular retaining disk is made of aluminum.

8. An inflator as defined in claim 6 including an outer annular screen filter pack positioned in said outer toroidal chamber against the inner surface of the outer one of the three concentric cylinders, said outer screen filter pack being operative to remove particulate matter from and to cool the inflation gas.

9. An inflator as defined in claim 8 including an annular deflector ring positioned between said outer annular screen filter pack and the outer surface of the intermediate one of the three concentric cylinders, said deflector ring having a length that is at least as long as said intermediate concentric cylinder and being positioned at one end in contacting relation with said common wall means, the other end of said deflector ring having port holes therein for the passage of generated gas.

10. An inflator as defined in claim 9,

wherein said second structural component is welded to said first structural component with weld flash being formed adjacent the mating concentric surface of the intermediate one of said concentric cylinders and the associated mating surface of said second structural component during the welding operation,

wherein gases exiting the inner toroidal chamber are deflected by said deflector ring toward the end thereof having port holes therein and are caused to strike said weld flash, such weld flash serving to interrupt and break up the gas flow thereby to remove particulate matter from the inflation gas.

11. An inflator as defined in claim 1 wherein said first and second structural components are formed of aluminum,

wherein the chambers defined by said concentric cylinders and said wall means of said first structural component comprise a central cylindrical chamber and surrounding concentric inner and outer toroidal chambers, said ignition means being contained in said central chamber, said gas generant composition in said inner toroidal chamber, and said filter means in said outer toroidal chamber,

wherein said initiator means is positioned in said second structural component at a central location thereof,

including a closed container, said closed container containing said ignition means and having a recess formed in a portion thereof facing said second structural component,

wherein said initiator means in said second structural component extends into the recess of said closed container,

including an inner annular screen filter pack positioned in said inner toroidal chamber in surrounding relation with said gas generant composition therein, said inner screen pack being operative to remove particulate matter from the inflation gas,

including an annular retaining disk for holding said gas generant composition and said inner screen filter pack in said inner toroidal chamber away from said second structural component to facilitate joining of said second structural component to said first structural component,

including an outer annular screen filter pack positioned in said outer toroidal chamber against the inner surface of the outer one of said three concentric cylinders, said outer screen filter pack being operative to remove particulate matter from and to cool the inflation gas, and

including an annular deflector ring positioned between said outer annular screen filter pack and the outer surface of the intermediate one of the three concentric cylinders, said deflector ring having a length that is at least as long as said intermediate concentric cylinder and being positioned at one end in contacting relation with said common wall means, the other end of said deflector ring having port holes therein for the passage of inflation gas, said deflector ring being operative to deflect gases exiting the inner toroidal chamber toward the end thereof having port holes therein.