PYROTECHNIC GAS GENERATOR WITH HOMOGENOUS SEPARATOR PHASE

• US 3,827,715 A
• Filed: 04/28/1972
• Issued: 08/06/1974
• Est. Priority Date: 04/28/1972
• Status: Expired due to Term

• Current Assignee: HBB Limited Partnership
• Original Assignee: Robert W. Lynch
• Inventors: Lynch, Robert W.
• Primary Examiner(s): Schonberg, David
• Assistant Examiner(s): Silverstrim, John P.
• Application Number:
  US05/248,738
• Time in Patent Office: 830 Days
• Field of Search: 280/15AB 60/254 102/102,39 149/2 23/281 220/24.2,24.3
• US Class Current: 280/731
• 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 21/203 in steering wheels or steering columns
• CPC Class Codes: B60R 21/217 Inflation fluid source retainers, e.g. reaction canisters; Connection of bags, covers, diffusers or inflation fluid sources therewith or together
• 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 pyrotechnic gas generator in an automobile passenger restraint bag system is described. The preferred arrangement in the automobile steering wheel inflates a driver restraint bag in about 25 milliseconds with a deflagration granular propellant of low net heat output. To raise the burn rate for the cool propellant an inert non-crushable solid separator phase such as steel balls is uniformly dispersed in the propellant and immobilized for inhibiting segregation of the propellant and separator phase. In one embodiment the gas generator cavity is completely filled with steel balls having the granular propellant dispersed therebetween. The separator phase also withdraws heat from the resultant gas and freezes out nongaseous reaction products.

Claims

1. An automobile driver restraint system comprising:

a generally cylindrical housing closed on one end and open on its other end;

means for mounting the housing in the hub of an automobile steering wheel for rotation therewith;

an axial shaft in the housing and integral therewith extending from the closed end towards the open end;

a plate member for closing the open end of the housing connected to the housing around its periphery, said member including gas passage means leading from the interior of the housing to the exterior thereof; and

means for interconnecting the axial shaft and the plate member.

2. An automobile driver restraint system comprising:

a cylindrical housing;

an axial shaft in the housing;

a plate enclosing one end of the housing;

means for mounting the housing in the hub of an automobile steering wheel;

a flexible inflatable bag connected to the housing;

a gas generating deflagration propellant in the housing;

means for igniting the propellant;

a plurality of gas passages comprising orifices through the plate leading from the housing into the interior of the bag;

a gas permeable diffuser adjacent the passages; and

a deflector plate mounted on the axial shaft opposite the passages for preventing straight line impingement of gas therefrom on the bag.

3. A driver restraint system as defined in claim 2 wherein the means for mounting comprises a spider connectible to an automobile steering wheel and including a central aperture;

and wherein the housing includes a peripheral nut ring for clamping against the spider.

4. A driver restraint system as defined in claim 3 wherein the gas passages through a plate comprise a distributor plate having a plurality of orifices therethrough and a nozzle plate spaced apart from the distributor plate and having a plurality of orifices therethrough and wherein the diffuser is between the distributor plate and the nozzle plate.

5. A driver restraint system as defined in claim 4 further comprising an inert noncrushable solid separator phase distributed in the propellant and immobilized for inhibiting segregation of the propellant and the separator phase.

6. An automobile driver restraint system comprising:

a cylindrical housing;

means for mounting the housing in the hub of an automobile steering wheel, a flexible inflatable bag connected to the housing;

a gas generating deflagration propellant in the housing;

an inert noncrushable solid separator phase distributed in the propellant and immobilized for inhibiting segregation of the propellant and the separator phase;

means for igniting the propellant;

a plurality of gas passages leading from the housing into the interior of the bag;

a gas permeable diffuser adjacent the passages; and

a deflector plate opposite the passages for preventing straight line impingement of gas therefrom on the bag.

7. A driver restraint system as defined in claim 6 wherein the gas passages each have an axis angulated relative to the axis of the housing.

8. A driver restraint system as defined in claim 7 wherein the housing includes an aperture plate dividing the housing into a propellant chamber and an igniter chamber, said deflagration propellant being in the propellant chamber and wherein the means for igniting the propellant comprises a high temperature gas generating propellant in the igniter chamber and an electric initiator adjacent the propellant.

9. A driver restraint system as defined in claim 8 wherein the diffuser comprises a screen adjacent the gas passages and a pack of metal machining chips adjacent the screen.

10. An automobile driver restraint system comprising:

a generally cylindrical housing closed on one end and open on its other end;

means for mounting the housing in the hub of an automobile steering wheel;

an axial shaft in the housing extending from the closed end towards the open end;

a plate member for closing the open end of the housing connected to the housing around its periphery, said member including gas passage means leading from the interior of the housing to the exterior thereof; and

means for interconnecting the axial shaft and the plate member comprising a deflector plate opposite the gas passage means, said deflector plate being removably connected to the axial shaft.

11. An automobile driver restraint system as defined in claim 10 further comprising:

a gas generating deflagration propellant in the housing;

means for igniting the propellant; and

a gas permeable diffuser between the propellant and the gas passage means.

12. An automobile driver restraint system as defined in claim 11 wherein the diffuser means comprises a screen adjacent the gas passage means and a layer of metal chips between the screen and the propellant.

13. A method for inflating an automobile passenger restraint bag comprising the steps of:

distributing a granular deflagration propellant in the interstices of an inert noncrushable solid separator phase;

igniting the propellant; and

passing the gas from the propellant into an inflatable bag.

14. A method for inflating an automobile passenger restraint bag as defined in claim 13 wherein the step of distributing comprises mixing the granular propellant with a plurality of individual separator elements.