Fluid fuel-containing initiator device for an air bag inflator

• US 5,531,473 A
• Filed: 11/15/1994
• Issued: 07/02/1996
• Est. Priority Date: 05/31/1994
• Status: Expired due to Fees

• Current Assignee: Autoliv ASP Incorporated (Autoliv Incorporated)
• Original Assignee: Morton International Incorporated (Autoliv Incorporated)
• Inventors: Rink, Karl K., Monk, David B., Johnson, Kelly B., Beus, Glen S.
• Primary Examiner(s): Dickson, Paul N.
• Application Number:
  US08/339,603
• Time in Patent Office: 595 Days
• Field of Search: 280/737, 280/741, 280/742, 280/736, 422/164, 422/165, 422/166, 102/530, 102/531, 149/87, 149/83
• US Class Current: 280/737
• CPC Class Codes: B60R 2021/26064 characterised by auto-ignition means
• CPC Class Codes: B60R 2021/2633 with a plurality of inflation levels
• CPC Class Codes: B60R 2021/2725 using a fluid fuel gas generator
• CPC Class Codes: B60R 21/272 with means for increasing the pressure of the gas just before or during liberation, e.g. hybrid inflators
• CPC Class Codes: C06D 5/00 Generation of pressure gas, e.g. for blasting cartridges, starting cartridges, rockets explosive compositions containing an oxidizer, fuels for rocket engines intended for reaction with an oxidant other than air C06B

Abstract

An initiator device for an air bag inflator contains fluid fuel which, upon reaction, produces gas used in the inflation of an inflatable safety device for an occupant of a motor vehicle.

Claims

1. An apparatus for inflating an inflatable device, said apparatus comprising:

a first chamber wherein a fuel is burned to produce combustion products and

an air bag inflator initiator device comprising;

container means defining a fluid fuel storage volume storing at least one fuel in the form of a fluid and an igniter charge storage volume adjacent said fluid fuel storage volume storing a charge of an igniter material; and

means for initiating the charge of igniter material to at least produce sufficient combustion products including heat to heat the fuel within said container means and non-mechanically increase the pressure of the fuel within the container means to rupture said container means to release the fuel therefrom into said first chamber.

2. The apparatus of claim 1 wherein said fluid fuel storage volume is contained within a sealed storage chamber.

3. The apparatus of claim 2 wherein a rupturable separation means separates said fluid fuel storage volume from said igniter charge storage volume.

4. The apparatus of claim 3 wherein the igniter material is in the form of a shaped charge to concentrate and direct forces along an axis against said rupturable separation means to facilitate rupture of said rupturable separation means upon ignition of the igniter material.

5. The apparatus of claim 2 wherein said sealed storage chamber comprises at least one wall pre-weakened to facilitate rupture upon initiation of the igniter material charge.

6. The apparatus of claim 1 wherein said means for initiating the igniter material upon ignition thereof additionally produces sufficient combustion products to result in combustion of at least a portion of the fuel released therefrom.

7. The apparatus of claim 1 wherein the igniter material comprises a pyrotechnic material.

8. The apparatus of claim 1 wherein said initiation means additionally comprises means for electrostatic discharge protection.

9. The apparatus of claim 1 wherein said fluid fuel comprises a gaseous form.

10. The apparatus of claim 1 wherein said fluid fuel comprises a liquid form.

11. The apparatus of claim 1 wherein said fluid fuel comprises a finely divided solid form.

12. The apparatus of claim 1 wherein said fluid fuel comprises a multi-phase combination of fluid fuel in at least two forms selected from the group consisting of gas, liquid, and finely divided solid.

13. The apparatus of claim 1 wherein said means for initiating the charge of igniter material comprises an exploding bridgewire squib.

14. The apparatus of claim 1 wherein said means for initiating the charge of igniter material comprises an exploding foil initiator.

15. The apparatus of claim 1 wherein in said first chamber said at least one fuel in the form of a fluid and at least one oxidant are burned to produce fuel combustion products including hot combustion gas, said first chamber including at least one gas exit opening and having sealing means normally closing said gas exit opening, the combustion of said fuel and said oxidant increasing the temperature and pressure within said first chamber, said first chamber sealing means adapted to open when a predetermined increase in pressure within said first chamber is realized whereby at least a portion of said hot combustion gas is expelled from said first chamber;

and with said apparatus additionally comprising a second chamber containing a supply of pressurized stored gas, said second chamber in fluid communication with said first chamber upon the opening of said gas exit opening sealing means, said hot combustion gas expelled from said first chamber mixing with said pressurized stored gas to produce inflation gas, said second chamber including at least one gas exit port and having sealing means normally closing said gas exit port, the mixing of said hot combustion gas with said pressurized stored gas increasing the temperature and pressure within said second chamber, said second chamber sealing means adapted to open when a predetermined increase in pressure within said second chamber is realized after said hot combustion gas expelled from said first chamber mixes with said pressurized stored gas to produce said inflation gas,

whereby at least a portion of said inflation gas is expelled from said second chamber to inflate the inflatable device.

16. An apparatus for inflating an inflatable device, said apparatus comprising:

a first chamber wherein a fuel is burned to produce combustion products and

an air bag inflator initator device comprising;

container means defining a sealed fluid fuel storage chamber storing at least one fuel in the form of a fluid and an igniter charge storage chamber adjacent said fluid fuel storage chamber storing a charge of a pyrotechnic igniter material, with said sealed fluid fuel storage chamber and said igniter charge storage chamber separated by means of at least one rupturable wall contact barrier; and

means for initiating the charge of pyrotechnic igniter material to produce sufficient combustion products to rupture both said rupturable wall contact barrier and said fluid fuel storage chamber to release the fuel therefrom into said first chamber, as well as to ignite at least a portion of the released fuel.

17. The apparatus of claim 16 wherein the igniter material is in the form of a shaped charge to concentrate and direct forces along an axis against said rupturable wall contact barrier to facilitate rupture thereof upon ignition of the igniter material.

18. The apparatus of claim 16 wherein said sealed storage chamber comprises at least one wall pre-weakened to facilitate rupture upon initiation of the igniter material charge.

19. The apparatus of claim 16 wherein said initiation means additionally comprises means for electrostatic discharge protection.

20. The apparatus of claim 16 wherein said fluid fuel comprises a form selected from the group of gas, liquid, finely divided solid and a multi-phase combination of fluid fuel in at least two forms selected from the group consisting of gas, liquid, and finely divided solid.

21. The apparatus of claim 16 wherein said means for initiating the charge of igniter material comprises an exploding bridgewire squib.

22. The apparatus of claim 16 wherein said means for initiating the charge of igniter material comprises an exploding foil initiator.

23. The apparatus of claim 16 wherein in said first chamber said at least one fuel in the form of a fluid and at least one oxidant are burned to produce fuel combustion products including hot combustion gas, said first chamber including at least one gas exit opening and having sealing means normally closing said gas exit opening, the combustion of said fuel and said oxidant increasing the temperature and pressure within said first chamber, said first chamber sealing means adapted to open when a predetermined increase in pressure within said first chamber is realized whereby at least a portion of said hot combustion gas is expelled from said first chamber;

a second chamber containing a supply of pressurized stored gas, said second chamber in fluid communication with said first chamber upon the opening of said gas exit opening sealing means, said hot combustion gas expelled from said first chamber mixing with said pressurized stored gas to produce inflation gas, said second chamber including at least one gas exit port and having sealing means normally closing said gas exit port, the mixing of said hot combustion gas with said pressurized stored gas increasing the temperature and pressure within said second chamber, said second chamber sealing means adapted to open when a predetermined increase in pressure within said second chamber is realized after said hot combustion gas expelled from said first chamber mixes with said pressurized stored gas to produce said inflation gas,

whereby at least a portion of said inflation gas is expelled from said second chamber to inflate the inflatable device.

24. An apparatus for inflating an inflatable device, said apparatus comprising:

a fuel in the form of a finely divided solid fluid free of combustion oxidant,

at least one oxidant,

a first chamber wherein said fuel in the form of a finely divided solid fluid free of combustion oxidant and said at least one oxidant are burned to produce combustion products including hot combustion gas, said first chamber including at least one gas exit opening and having sealing means normally closing said gas exit opening, the combustion of the fuel and said oxidant increasing the temperature and pressure within said first chamber, said first chamber sealing means adapted to open when a predetermined increase in pressure within said first chamber is realized whereby at least a portion of said hot combustion gas is expelled from said first chamber,

a second chamber containing a supply of pressurized stored gas, said second chamber in fluid communication with said first chamber upon the opening of said gas exit opening sealing means, said hot combustion gas expelled from said first chamber mixing with said pressurized stored gas to produce inflation gas, said second chamber including at least one gas exit port and having sealing means normally closing said gas exit port, the mixing of said hot combustion gas with said pressurized stored gas increasing the temperature and pressure within said second chamber, said second chamber sealing means adapted to open when a predetermined increase in pressure within said second chamber is realized after said hot combustion gas expelled from said first chamber mixes with said pressurized stored gas to produce said inflation gas, whereby at least a portion of said inflation gas is expelled from said second chamber to inflate said device, and

initiator means for initiating burning of the fuel and said at least one oxidant.

25. The apparatus of claim 24 wherein the fuel in the form of a finely divided solid fluid comprises a carbonaceous material.

26. The apparatus of claim 24 wherein the fuel in the form of a finely divided solid fluid comprises a cellulosic material.

27. The apparatus of claim 26 wherein the cellulosic material is selected from the group consisting of cellulose acetate, cellulose methyl ether, and cellulose nitrate.

28. The apparatus of claim 24 wherein said initiator means comprises a pyrotechnic initiator device.

29. The apparatus of claim 24 wherein at least one of said first chamber sealing means and said second chamber sealing means is pressure sensitive,

wherein when the first chamber sealing means is pressure sensitive, the increase in pressure within said first chamber upon the combustion of the finely divided solid fuel and said oxidant effects the opening of said first chamber sealing means and

wherein when the second chamber sealing means is pressure sensitive, the increase in pressure within said second chamber upon the mixing of said hot combustion gas with said pressurized stored gas effects the opening of said second chamber sealing means.

30. The apparatus of claim 24 wherein at least one of said first chamber sealing means and said second chamber sealing means is adapted to open by mechanical means.

31. The apparatus of claim 24 wherein said first chamber is pressurized.

32. The apparatus of claim 24 wherein the at least one fuel in the form of a finely divided solid fluid free of combustion oxidant is selected from the group consisting of carbonaceous materials;

cottons, woods, and peat;

food feed flours, starches and grain dusts;

plastics, rubbers, and polymer resins;

metal and metal alloy materials; and

mixtures thereof.

33. A method for inflating an inflatable safety device in a vehicle, said method comprising the steps of:

burning at least one fuel in the form of a finely divided solid fluid free of combustion oxidant with at least one oxidant in a first sealed chamber to produce combustion products including hot combustion gas, wherein the first sealed chamber includes at least one gas exit opening normally closed by a sealing means, said burning increasing the temperature and pressure within the first chamber,

opening the first chamber sealing means when a predetermined increase in pressure within said first chamber is realized to expel the hot combustion gas from the first chamber into a second chamber containing a supply of pressurized stored gas,

mixing the expelled hot combustion gas with the pressurized stored gas in the second chamber to produce inflation gas, wherein the second chamber includes at least one gas exit port normally closed by a sealing means, said mixing increasing the temperature and pressure within the second chamber, and

opening the second chamber port sealing means, after said hot combustion gas expelled from said first chamber has mixed with said pressurized stored gas to produce the inflation gas and when a predetermined increase in pressure within said second chamber is realized, to expel the inflation gas from the second chamber to inflate the inflatable safety device.

34. The method of claim 33 wherein the fuel in the form of a finely divided solid fluid comprises a carbonaceous material.

35. The apparatus of claim 33 wherein the fuel in the form of a finely divided solid fluid comprises a cellulosic material.

36. The method of claim 33 wherein said burning is initiated by means of a pyrotechnic initiator device.

37. The method of claim 33 wherein at least one of the first and second chamber sealing means is pressure sensitive,

wherein when the first chamber sealing means is pressure sensitive, the increase in pressure within the first chamber upon said burning of the finely divided solid fluid fuel and the oxidant effects the opening of said first chamber sealing means and

wherein when the second chamber sealing means is pressure sensitive, the increase in pressure within the second chamber upon the mixing of the hot combustion gas with the pressurized stored gas effects the opening of the second chamber sealing means.

38. The method of claim 33 wherein at least one of the first and second chamber sealing means is opened by mechanical means.

39. The method of claim 33 wherein said first chamber for said burning is pressurized.

40. The method of claim 33 wherein the at least one fuel in the form of a finely divided solid fluid free of combustion oxidant is selected from the group consisting of carbonaceous materials;

cottons, woods, and peat;

food feed flours, starches and grain dusts;

plastics, rubbers, and polymer resins;

metal and metal alloy materials; and

mixtures thereof.

41. An apparatus for inflating an inflatable device, said apparatus comprising:

a first chamber wherein a fuel in the form of a finely divided solid fluid and at least one oxidant are burned to produce combustion products including hot combustion gas, said first chamber including at least one gas exit opening and having sealing means normally closing said gas exit opening, the combustion of the fuel and the oxidant increasing the temperature and pressure within said first chamber, said first chamber sealing means adapted to open when a predetermined increase in pressure within said first chamber is realized whereby at least a portion of said hot combustion gas is expelled from said first chamber,

a second chamber containing a supply of pressurized stored gas, said second chamber in fluid communication with said first chamber upon the opening of said gas exit opening sealing means, said hot combustion gas expelled from said first chamber mixing with said pressurized stored gas to produce inflation gas, said second chamber including at least one gas exit port and having sealing means normally closing said gas exit port, the mixing of said hot combustion gas with said pressurized stored gas increasing the temperature and pressure within said second chamber, said second chamber sealing means adapted to open when a predetermined increase in pressure within said second chamber is realized after said hot combustion gas expelled from said first chamber mixes with said pressurized stored gas to produce said inflation gas, whereby at least a portion of said inflation gas is expelled from said second chamber to inflate said device, and

initiator means for initiating burning of the fuel and said at least one oxidant,

said apparatus additionally comprising a fluid fuel storage element storing the fuel in the form of a finely divided solid fluid free of combustion oxidant, said fluid fuel storage element comprising a rupturable flexible wall bladder comprised of material impervious to the fuel and wherein the fuel is stored free of combustion oxidant, said bladder housed within said first chamber and with said initiator means first rupturing said rupturable wall bladder and then initiating the burning of the fuel and said at least one oxidant in said first chamber.

42. An apparatus for inflating an inflatable device, said apparatus comprising:

a first chamber wherein a fuel in the form of a finely divided solid fluid and at least one oxidant are burned to produce combustion products including hot combustion gas, said first chamber including at least one gas exit opening and having sealing means normally closing said gas exit opening, the combustion of the fuel and said oxidant increasing the temperature and pressure within said first chamber, said first chamber sealing means adapted to open when a predetermined increase in pressure within said first chamber is realized whereby at least a portion of said hot combustion gas is expelled from said first chamber,

a second chamber containing a supply of pressurized stored gas, said second chamber in fluid communication with said first chamber upon the opening of said gas exit opening sealing means, said hot combustion gas expelled from said first chamber mixing with said pressurized stored gas to produce inflation gas, said second chamber including at least one gas exit port and having sealing means normally closing said gas exit port, the mixing of said hot combustion gas with said pressurized stored gas increasing the temperature and pressure within said second chamber, said second chamber sealing means adapted to open when a predetermined increase in pressure within said second chamber is realized after said hot combustion gas expelled from said first chamber mixes with said pressurized stored gas to produce said inflation gas, whereby at least a portion of said inflation gas is expelled from said second chamber to inflate said device, and

initiator means for initiating burning of the fuel and said at least one oxidant,

said apparatus additionally comprising a fluid fuel storage element storing the fuel in the form of a finely divided solid fluid free of combustion oxidant, said fluid fuel storage element comprising a sealed storage chamber wherein the fuel is stored free of combustion oxidant, said sealed storage chamber including at least one fuel exit opening, sealing means normally closing said fluid exit opening, and opening means to open said fuel exit opening sealing means, said storage chamber in fluid communication with said first chamber upon the opening of said at least one fuel exit opening.

43. A method for inflating an inflatable safety device in a vehicle, said method comprising the steps of:

burning at least one fuel in the form of a finely divided solid fluid with at least one oxidant in a first sealed chamber to produce combustion products including hot combustion gas, wherein the first sealed chamber includes at least one gas exit opening normally closed by a sealing means, said burning increasing the temperature and pressure within the first chamber,

opening the first chamber sealing means to expel the hot combustion gas from the first chamber into a second chamber containing a supply of pressurized stored gas,

mixing the expelled hot combustion gas with the pressurized stored gas in the second chamber to produce inflation gas, wherein the second chamber includes at least one gas exit port normally closed by a sealing means, said mixing increasing the temperature and pressure within the second chamber, and

opening the second chamber port sealing means to expel the inflation gas from the second chamber to inflate the inflatable safety device,

wherein the fuel in the form of a finely divided solid fluid is stored free of combustion oxidant in a rupturable flexible wall bladder comprised of material impervious to the fuel, with the bladder housed within the first chamber, the method additionally comprising the step of rupturing the bladder to release the fuel to contact the oxidant prior to said burning.

44. A method for inflating an inflatable safety device in a vehicle, said method comprising the steps of:

burning at least fuel in the form of a finely divided solid fluid with at least one oxidant in a first sealed chamber to produce combustion products including hot combustion gas, wherein the first sealed chamber includes at least one gas exit opening normally closed by a sealing means, said burning increasing the temperature and pressure within the first chamber,

opening the first chamber sealing means to expel the hot combustion gas from the first chamber into a second chamber containing a supply of pressurized stored gas,

mixing the expelled hot combustion gas with the pressurized stored gas in the second chamber to produce inflation gas, wherein the second chamber includes at least one gas exit port normally closed by a sealing means, said mixing increasing the temperature and pressure within the second chamber, and

opening the second chamber port sealing means to expel the inflation gas from the second chamber to inflate the inflatable safety device,

wherein the fuel in the form of a finely divided solid fluid is stored free of combustion oxidant in a sealed storage chamber including at least one fuel exit opening having sealing means normally closing the fuel exit opening, the method additionally comprising the step, prior to said burning, of opening the sealing means to permit the fuel to be in communication with the oxidant in the first chamber.