The present invention relates generally to vehicle occupant protection systems, and more particularly to inflators employed in vehicle occupant protection systems incorporating inflatable protection devices.
It is well known to protect a vehicle occupant using an inflatable cushion, or airbag, which is inflated with gas when the vehicle encounters sudden deceleration, such as in a collision. In such systems, the airbag cushion is normally housed in an uninflated and folded condition to minimize space requirements. Upon actuation of the system, the airbag is inflated, in a matter of no more than a few milliseconds, with gas produced or supplied by a device commonly referred to as an inflator.
Many types of inflator devices have been disclosed in the art for the inflating of one or more inflatable restraint system airbag cushions. Prior art airbag systems utilize compressed stored gas inflators, pyrotechnic inflators and hybrid inflators. However, each of these types of inflators has been subject to certain disadvantages, such as greater than desired weight and space requirements, production of undesired or non-preferred combustion products in greater than desired amounts, and production or emission of gases at a greater than desired temperature. Thus, there is a continuing need and demand for further improvements in safety, simplicity, effectiveness, economy of size, and reliability in the apparatus and techniques used for inflating an inflatable device such as an airbag cushion.
The present invention provides an inflator comprising a housing having an interior and a plurality of gas exit orifices formed across its length. A liquid or thixotropic gas source material is positioned in the housing interior and is enclosed in a pliable, rupturable substantially gas-and-moisture-impermeable container. The gas source is a material (for example, hydrogen peroxide) adapted to undergo decomposition to form at least one gaseous decomposition product comprising an inflation gas. A reactant material is also positioned in the interior of the housing. The reactant material is a material (such as a catalyst) formulated to react with the gas source material to produce decomposition of the gas source material. An enclosure is positioned within the housing to form a cavity between an inner wall of the housing and the enclosure. The reactant material is positioned in the cavity. A plurality of orifices formed through the enclosure enables fluid communication between the interior of the enclosure and the cavity. The container is positioned in the enclosure. A resilient, expandable bladder is also positioned in the enclosure. A propellant is provided within the bladder for generation of combustion gases upon ignition of the propellant, to produce expansion of the bladder. An ignition source is provided for igniting the propellant. Upon ignition of the propellant, combustion gases expand the bladder which forces a portion of the container into the enclosure orifices, thereby stressing and rupturing the portions of the container in the orifices and releasing the hydrogen peroxide to flow through the orifice into the cavity, where it reacts with the catalyst to produce inflation gas. The inflator described herein provides a reliable, compact, inexpensively produced, and easily assembled source of non-toxic inflation gas for inflating elements of an inflatable vehicle occupant restraint system.
In the drawings illustrating embodiments of the present invention:
As shown in
An amount of a gas source material 20 is positioned in the interior of housing 12. Gas source material 20 is formulated to undergo decomposition to form decomposition products upon reaction with a reactant composition. The decomposition products include at least one gaseous decomposition product for use as an inflation gas. In the embodiment shown, gas source material 20 is an amount of liquid hydrogen peroxide in a molar quantity sufficient to generate effective amounts of water vapor and oxygen upon contact with a catalyst. Stated another way, the hydrogen peroxide is provided in amounts that will inflate an airbag at the desired rate of inflation upon contact with the catalyst. This may be determined on an iterative basis depending on the applicable protective system.
An amount of a reactant material 22 is also positioned in interior 13 of housing 12 in fluid isolation from gas source material 20. Reactant material 22 is adapted to react with the gas source material to produce decomposition of the gas source material, resulting in the generation of inflation gases. In the embodiment shown, reactant material 22 comprises a catalyst formulated to react with the hydrogen peroxide. The catalyst may be selected from Carulite® (Manganese dioxide and cupric oxide) made by Carus Chemical Co.; silver; manganate; potassium permanganate; potassium permanganate and alumina beads; and mixtures thereof, for example. Other useful known catalysts may also be employed whereby the catalyst is chosen to be reactive with the respective gas generating material housed within the container, thereby liberating gaseous products.
Refining again to
In accordance with the present invention, a mechanism is provided for producing rupture of container 24 to enable fluid communication between gas source material 20 and reactant material 22, thereby enabling reaction between the gas source material and the reactant to generate inflation gas. In the embodiment of the invention shown in
As seen in
A bladder 42 is positioned in the interior of enclosure 28 and is substantially coextensive with housing 12. Bladder 42 may be in contact with container 24, or the bladder 42 may be partially or completely spaced apart from the container 24 prior to activation of the inflator 10. However, bladder 42 is positioned in communication with container 24 such that, upon expansion, the bladder 42 contacts the container 24 to force a portion of the container 24 into at least one (but preferably more than one) of enclosure orifices 34. Forcing of a portion of the container into orifices 34 causes stressing and rupturing of the portion of the container in the orifice, thereby releasing the contents of container 24 to flow through the rupture into cavity 30. Bladder 42 may be extruded from a rubber compound or some other suitably elastic material.
To produce expansion of bladder 42, a propellant 44 is extruded or otherwise provided within the bladder for generation of combustion gases upon ignition of the propellant. Propellant 44 generally extends along a length of bladder 42. In one embodiment, propellant 44 comprises silicone as a fuel at about 10-25% by weight, and a perchlorate oxidizer such as ammonium, lithium, or potassium perchlorate making up the remainder. The silicone may be purchased, for example, from General Electric or other well-known suppliers. Silicone provides the additional benefit of acting as a binder, facilitating the extrusion of propellant strips or ribbons, as described herein. The other propellant constituents may be provided by suppliers or by manufacturing methods well known in the art. Exemplary suitable compositions are disclosed in co-owned U.S. Pat. No. 6,805,377, herein incorporated by reference. In a preferred embodiment, bladder 42 may be coated with the propellant composition on an inner wall along the length thereof.
An ignition source 46 is also provided for igniting propellant 44. Ignition source 46 ignitably communicates with propellant 44 and may be activated by a crash sensor upon a crash event, for example. Ignition source may comprise, for example, an electric match pyrotechnic product, such as manufactured by Daveyfire Inc. of Sacramento, Calif. USA and as is well known in the art. While such electric matches provide a relatively inexpensive means of ignition, it will be understood that numerous other ignition systems could be used with the same effectiveness. Other typical igniters known in the art are also contemplated.
Other methods may be used to produce expansion of bladder 42. For example, expansion of bladder 42 may be produced by a flow of a fluid, such as a compressed gas, from a compressed fluid source (not shown) into bladder 42. The compressed gas source provides an expandable fluid to bladder 42 to expand the bladder upon activation of the inflator.
Referring to
Referring to
In one particular embodiment (shown in
In another particular embodiment (not shown), layer 27 is formed from a different material (having a different strength) than layer 29. Ultimate load F1 of layer 27 is such that, when bladder 42 is inflated, the pressure generated inside container 24 is sufficient to cause the load in layer 27 in orifices 42 to exceed ultimate load F1, thereby rupturing film layer 27 at orifices 34. Ultimate load F2 of film layer 29 is such that, when bladder 42 is inflated, the pressure generated against film layer 29 is insufficient to cause the forces in layer 29 in orifices 34 to meet or exceed ultimate load F2. Thus, layer 29 will not rupture when bladder 42 forces layer 29 into orifices 42.
In the manner described above, layer 29 is provided with a strength sufficient to prevent rupture of the layer if bladder 42 forces layer 29 against orifices 34. Thus, a film layer 29 that is not rupturable due to inflation of bladder 42 is interposed between the bladder and orifices 24. This helps prevent rupture of bladder 42 at orifices 34 after rupture of film layer 27.
Referring to
A linear inflator as described herein may be incorporated into an airbag system 200.
Referring again to
Safety belt system 150 may be in communication with a crash event sensor 158 (for example, an inertia sensor or an accelerometer) including a known crash sensor algorithm that signals actuation of belt pretensioner 156 via, for example, activation of a pyrotechnic igniter (not shown) incorporated into the pretensioner. U.S. Pat. Nos. 6,505,790 and 6,419,177, previously incorporated herein by reference, provide illustrative examples of pretensioners actuated in such a manner.
The present description is for illustrative purposes only, and should not be construed to narrow the breadth of the present invention in any fashion. Thus, the various structural and operational features herein disclosed are susceptible to a number of modifications, none of which departs from the scope of the present invention as defined in the appended claims. For example: the bladder inflation rate may be controlled by propellant characteristics and amount; the pressure within the inner tube may be controlled by propellant characteristics and amount; the size and quantity of the inner tube perforations may be adjusted to tailor the hydrogen peroxide flow rate over the catalyst; and catalyst characteristics such as material, particle size, and particle surface characteristics including porosity may be used to control the decomposition of the hydrogen peroxide. Other aspects, features and advantages will be apparent upon an examination of the attached drawing figures.
This application is entitled to and claims the benefit of Provisional Patent Application Ser. No. 60/520,956 filed on Nov. 18, 2003.
Number | Name | Date | Kind |
---|---|---|---|
3397639 | Alderfer | Aug 1968 | A |
3606377 | Martin | Sep 1971 | A |
3721456 | McDonald | Mar 1973 | A |
3733088 | Stephenson | May 1973 | A |
3785674 | Poole et al. | Jan 1974 | A |
3799573 | Olsson et al. | Mar 1974 | A |
3897961 | Leising et al. | Aug 1975 | A |
3904221 | Shiki et al. | Sep 1975 | A |
3929074 | San Miguel | Dec 1975 | A |
3986808 | Keith | Oct 1976 | A |
4005876 | Jorgensen et al. | Feb 1977 | A |
4012211 | Goetz | Mar 1977 | A |
4200615 | Hamilton et al. | Apr 1980 | A |
4322385 | Goetz et al. | Mar 1982 | A |
4358998 | Schneiter et al. | Nov 1982 | A |
4561675 | Adams et al. | Dec 1985 | A |
4781645 | Kato | Nov 1988 | A |
4846368 | Goetz | Jul 1989 | A |
4878690 | Cunningham | Nov 1989 | A |
4890860 | Schneiter | Jan 1990 | A |
4950458 | Cunningham | Aug 1990 | A |
5060973 | Giovanetti | Oct 1991 | A |
5094475 | Olsson et al. | Mar 1992 | A |
5101730 | Bender et al. | Apr 1992 | A |
5109772 | Cunningham et al. | May 1992 | A |
5139588 | Poole | Aug 1992 | A |
5211224 | Bouldin | May 1993 | A |
5308370 | Kraft et al. | May 1994 | A |
5322322 | Bark et al. | Jun 1994 | A |
5324071 | Gotomyo et al. | Jun 1994 | A |
5345873 | Lauritzen et al. | Sep 1994 | A |
5368329 | Hock | Nov 1994 | A |
5409259 | Cunningham et al. | Apr 1995 | A |
5439250 | Kokeguchi et al. | Aug 1995 | A |
5443286 | Cunningham et al. | Aug 1995 | A |
5462308 | Seki et al. | Oct 1995 | A |
5464249 | Lauritzen et al. | Nov 1995 | A |
5482315 | Chandler et al. | Jan 1996 | A |
5503079 | Kishi et al. | Apr 1996 | A |
5503428 | Awotwi et al. | Apr 1996 | A |
5503806 | Fulmer et al. | Apr 1996 | A |
5540154 | Wilcox et al. | Jul 1996 | A |
5540459 | Daniel | Jul 1996 | A |
5542704 | Hamilton et al. | Aug 1996 | A |
5547638 | Rink et al. | Aug 1996 | A |
5551343 | Hock et al. | Sep 1996 | A |
5562303 | Schleicher et al. | Oct 1996 | A |
5573271 | Headly | Nov 1996 | A |
5578787 | Kobari et al. | Nov 1996 | A |
5588670 | Storey et al. | Dec 1996 | A |
5588672 | Karlow et al. | Dec 1996 | A |
5607181 | Richardson et al. | Mar 1997 | A |
5615914 | Galbraith et al. | Apr 1997 | A |
5623115 | Lauritzen et al. | Apr 1997 | A |
5626360 | Lauritzen et al. | May 1997 | A |
5635665 | Kishi et al. | Jun 1997 | A |
5735572 | Clark et al. | Apr 1998 | A |
5743556 | Lindsay et al. | Apr 1998 | A |
5752715 | Pripps et al. | May 1998 | A |
5779263 | Lane et al. | Jul 1998 | A |
5826904 | Ellis et al. | Oct 1998 | A |
5827996 | Yoshida et al. | Oct 1998 | A |
5845933 | Walker et al. | Dec 1998 | A |
5868424 | Hamilton et al. | Feb 1999 | A |
5871228 | Lindsay et al. | Feb 1999 | A |
5908204 | Smith | Jun 1999 | A |
5941563 | Schoenborn | Aug 1999 | A |
5941752 | Liebermann | Aug 1999 | A |
5967550 | Shirk et al. | Oct 1999 | A |
6019861 | Canterberry et al. | Feb 2000 | A |
6029994 | Perotto et al. | Feb 2000 | A |
6032979 | Mossi et al. | Mar 2000 | A |
6039820 | Hinshaw et al. | Mar 2000 | A |
6051158 | Taylor et al. | Apr 2000 | A |
6053110 | Marchant et al. | Apr 2000 | A |
6056319 | Ruckdeschel et al. | May 2000 | A |
6062143 | Grace et al. | May 2000 | A |
6077371 | Lundstrom et al. | Jun 2000 | A |
6129023 | Marsaud et al. | Oct 2000 | A |
6142518 | Butt et al. | Nov 2000 | A |
6145876 | Hamilton | Nov 2000 | A |
6170867 | Rink et al. | Jan 2001 | B1 |
6176517 | Hamilton et al. | Jan 2001 | B1 |
6177028 | Kanda et al. | Jan 2001 | B1 |
6315847 | Lee et al. | Nov 2001 | B1 |
6336651 | Mramor et al. | Jan 2002 | B1 |
6347566 | Rabotinsky et al. | Feb 2002 | B1 |
6382661 | Sutherland | May 2002 | B1 |
6412816 | Gast et al. | Jul 2002 | B1 |
6416599 | Yoshikawa et al. | Jul 2002 | B1 |
6425601 | Lewis | Jul 2002 | B1 |
6497429 | Matsumoto | Dec 2002 | B2 |
6502513 | Barnes et al. | Jan 2003 | B1 |
6595546 | Smith | Jul 2003 | B2 |
6595547 | Smith | Jul 2003 | B2 |
6601871 | Fischer | Aug 2003 | B2 |
6688231 | Herrmann | Feb 2004 | B1 |
6752421 | Khandhadia et al. | Jun 2004 | B2 |
6755438 | Rink et al. | Jun 2004 | B2 |
6805377 | Krupp et al. | Oct 2004 | B2 |
6846013 | Smith | Jan 2005 | B2 |
6846014 | Rink et al. | Jan 2005 | B2 |
6942261 | Larsen et al. | Sep 2005 | B2 |
7025164 | Takimoto | Apr 2006 | B2 |
7052041 | McCormick | May 2006 | B2 |
20020038948 | Yamamori et al. | Apr 2002 | A1 |
20030173761 | Rink et al. | Sep 2003 | A1 |
20030178828 | Rink et al. | Sep 2003 | A1 |
20030197354 | Beland et al. | Oct 2003 | A1 |
20040061316 | Elgadah et al. | Apr 2004 | A1 |
20040084885 | Burns et al. | May 2004 | A1 |
20050116454 | Stevens | Jun 2005 | A1 |
20050151358 | Burns | Jul 2005 | A1 |
20050200103 | Burns et al. | Sep 2005 | A1 |
20050218637 | Burns | Oct 2005 | A1 |
20050218638 | Burns et al. | Oct 2005 | A1 |
20060022444 | Khandhadia | Feb 2006 | A1 |
20060138763 | Brady | Jun 2006 | A1 |
Number | Date | Country | |
---|---|---|---|
20050104349 A1 | May 2005 | US |
Number | Date | Country | |
---|---|---|---|
60520956 | Nov 2003 | US |