WO2013123371A1

WO2013123371A1 - Shockwave generating mechanism for automotive inflator deployment

Info

Publication number: WO2013123371A1
Application number: PCT/US2013/026405
Authority: WO
Inventors: Brian A. Laubacher; Bryce ROBINETTER; Darwin L. DINSDALE
Original assignee: Autoliv Asp, Inc.
Priority date: 2012-02-15
Filing date: 2013-02-15
Publication date: 2013-08-22

Abstract

Air bag cushion inflators include a hollow tube with an initiator assembly disposed at a first longitudinal end and a burst disk disposed at a second longitudinal end. An enclosure is disposed within the hollow tube, forming at least a portion of a combustion chamber in fluid communication with an initiator, and may include a pyrotechnic material. The enclosure includes at least one release mechanism adapted to release, in response to actuation of the initiator, at least a portion of the enclosure to be displaced within the hollow tube and generate a Shockwave of sufficient intensity to reliably rupture the burst disk and deploy the inflator. Methods of forming an airbag cushion inflator include obtaining a hollow tube and disposing an enclosure in the hollow tube to form at least a portion of a combustion compartment positioned to be in fluid communication with an initiator coupled to the hollow tube.

Description

SHOCKWAVE GENERATING MECHANISM FOR AUTOMOTIVE

INFLATOR DEPLOYMENT

TECHNICAL FIELD

[0001] The present disclosure relates generally to inflatable airbag cushions for motor vehicles. More specifically, various embodiments of the present disclosure relate to airbag inflators adapted for use in inflatable airbag modules for motor vehicles.

BACKGROUND

[0002] Modern motor vehicles typically employ various occupant protection systems that actuate from an undeployed to a deployed state without the need for intervention by the occupant. Such systems often include an inflatable occupant protection system in the form of a cushion or bag, commonly referred to as an "airbag cushion," which is now a legal requirement for new vehicles in numerous countries. Such airbag cushions are typically installed in various locations in a vehicle and may deploy into one or more locations within the vehicle between the occupant and certain parts of the vehicle interior, such as the doors, steering wheel, instrument panel, dashboard or the like, to prevent or cushion the occupant from forcibly striking such parts of the vehicle interior.

[0003] Various types or forms of occupant protection systems have been developed or tailored to provide desired vehicle occupant protection based on either or both the position or placement of the occupant within the vehicle and the direction or nature of the vehicle collision. For example, driver and passenger inflatable cushion installations have found wide usage for providing protection to drivers and front seat passengers, respectively, in the event of head-on type of collision. Other installations have found wide usage for providing protection to vehicle occupants in the event of a side impact (e.g., side collision, roll-over).

[0004] The airbag cushion is conventionally housed in an uninflated and folded condition to minimize space requirements. In the event of an accident, an accelerometer within the vehicle measures the abnormal vehicle movement and triggers the expulsion of rapidly expanding gases supplied and/or produced by a device commonly referred to as an "inflator." The expanding gases fill the airbag cushion, which inflates to provide protection to the driver and/or passenger from impact against a windshield, dashboard, or other surfaces of the vehicle interior. [0005] At least some conventional inflators depend on a Shockwave generated by an initiator in order for the inflator to operate properly. Accordingly, such inflators are dependent on initiator function. A sufficiently powerful Shockwave is typically produced when the initiator combusts a reactive charge at a sufficiently fast burn rate. However, if the initiator is slow at combusting the reactive charge for any reason, the intensity of a resulting Shockwave may be jeopardized, which may result in a failure of the inflator to deploy the airbag cushion. For example, an initiator employing too little of a reactive charge, that is wet, or with a reactive charge that does not burn quickly enough may generate a Shockwave with too little intensity to deploy the inflator, and consequently the airbag cushion.

[0006] As occupant protection systems can be a significant mechanism for reducing and/or avoiding injuries to occupants in the event of a collision, it is desirable that such occupant protection systems are deployed properly and reliably at the time of the collision. Accordingly, it is desirable to improve the reliability of one or more components of occupant protection systems.

BRIEF SUMMARY

[0007] Various embodiments of the present disclosure comprise airbag cushion inflators for use with an airbag module, where the inflator is adapted to generate a Shockwave sufficient to rupture a burst disk independent of at least some initiator operations. In one or more embodiments, such an inflator may include a hollow tube with an initiator assembly disposed at a first longitudinal end of the hollow tube. The initiator assembly includes an initiator. A burst disk may be disposed at a second longitudinal end of the hollow tube. An enclosure may be disposed within the hollow tube, and may form at least a part of a combustion compartment that is in fluid communication with the initiator. The enclosure includes at least one enclosure release mechanism. An enclosure release mechanism can be adapted to release at least a portion of the enclosure in response to deployment of the initiator, enabling the enclosure, or at least a portion thereof, to displace within the hollow tube in a direction generally toward the burst disk.

[0008] Additional embodiments of the present disclosure comprise inflatable airbag modules. According to one or more embodiments, such modules may include at least one inflatable cushion, and an inflator in fluid communication with the one or more inflatable cushions to provide a supply of inflation gas to the inflatable cushion during deployment. The inflator may comprise a hollow tube including a first longitudinal end and a second longitudinal end. A burst disk may be disposed at the second longitudinal end of the hollow tube. An enclosure may be disposed within the hollow tube, and may form at least a portion of a combustion compartment. The enclosure includes at least one enclosure release mechanism. An initiator assembly may be disposed at the first longitudinal end of the hollow tube, and may include an initiator positioned in fluid communication with the combustion compartment.

[0009] Other embodiments of the present disclosure comprise methods of forming an airbag cushion inflator. One or more embodiments of such methods may include obtaining a hollow tube including a first longitudinal end and an opposing second longitudinal end. The first longitudinal end may be adapted to receive an initiator coupled therewith and the second longitudinal end may be adapted to receive a burst disk disposed adjacent thereto. An enclosure may be disposed in the hollow tube to form at least a portion of a combustion compartment positioned to be in fluid communication with an initiator, when an initiator is coupled with the first longitudinal end of the hollow tube. The enclosure includes at least one enclosure release mechanism.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0010] Exemplary embodiments of the disclosure will become more fully apparent from the following description and appended claims, taken in conjunction with the accompanying drawings. Understanding that these drawings depict only exemplary embodiments and are, therefore, not to be considered limiting of the disclosure's scope, the exemplary embodiments of the disclosure will be described with additional specificity and detail through use of the accompanying drawings in which:

[0011] FIG. 1 shows a side view of the interior of a motor vehicle illustrating an inflatable airbag module according to at least one embodiment;

[0012] FIG. 2 is a cross-sectioned side view of an inflator according to at least one example;

[0013] FIG. 3 is a magnified view of an inflator showing an enclosure including a grooved or thinned enclosure release mechanism according to at least one example;

[0014] FIG. 4 is a magnified view of an inflator showing an enclosure including a shear pin enclosure release mechanism according to at least one example;

[0015] FIG. 5 is a cross-sectioned side view of illustrating two stages of deployment of an inflator according to at least one example; and [0016] FIG. 6 is a flow diagram illustrating at least one example of a method for forming an airbag cushion inflator adapted for use with an inflatable airbag module.

DETAILED DESCRIPTION

[0017] The illustrations presented herein are, in some instances, not actual views of any particular airbag cushion inflator or inflatable airbag module, but are merely idealized representations which are employed to describe the present disclosure. Additionally, elements common between figures may retain the same numerical reference designation.

[0018] Various aspects of the present disclosure include inflators adapted for use with inflatable airbag modules. Such inflatable airbag modules may be employed in various locations within a motor vehicle. For example, FIG. 1 shows a side view of the interior of a motor vehicle illustrating an inflatable airbag module 100 according to at least one example. The inflatable airbag module 100 includes an inflator 102 and an inflatable airbag cushion 104, illustrated as a deployed inflatable curtain. The inflatable airbag module 100 and the airbag cushion 104 are positioned and configured to provide protection for a person 106 sitting in a seat 108 in the vehicle. In an accident in which the vehicle is decelerated, the person 106 may tend to move forwardly towards the steering wheel 1 10, but may be restrained by a conventional seat belt and/or airbag. In the case of a side impact (e.g., side collision, roll-over), the person 106 may strike the window 1 12 in the door beside the person 106, the vehicle B-pillar 1 14, or both. There is also the risk that if the glass in the window 1 12 breaks, the head of the person 106 may be thrown out of the window opening.

[0019] The inflatable airbag cushion 104, which may also be referred to as an inflatable cushion and is shown in the operative (or deployed) state in FIG. 1 , is initially retained in a recess provided in the door frame 1 16 located above the door of the vehicle. The recess may extend over more than simply a linear portion of the door frame so that the two ends of the recess may not be in alignment with the main part of the recess. The inflator 102 is adapted to provide an inflation fluid to the airbag cushion 104 for its inflation.

[0020] The inflator 102 may be associated with a sensor (not shown) which senses a side impact situation and activates the inflator 102 at the appropriate instant. The inflator 102 can be connected by a hose 1 18 to a duct 120, which duct 120 forms a part of the inflatable airbag cushion 104. The airbag cushion 104 may include a plurality of cells 122 extending at least substantially parallel. [0021] When an accident occurs, such as a side impact, the inflator 102 produces, forms or otherwise supplies an inflation fluid, which is passed into the hose 1 18 and then the duct 120 and inflates the cells 122. The inflatable airbag cushion 104 thus moves from its initial stored position within the recess in the door frame 1 16 to the operative position shown in FIG. 1. That is, the airbag cushion 104 extends downwardly from the top of the door frame 1 16 to form a generally flat structure located between at least a portion of the person 106 and a portion of the motor vehicle (e.g., between the head of the person 106 and the adjacent window 1 12 or B-pillar 1 14).

[0022] It is noteworthy, that while the example described with reference to FIG. 1 involves an airbag cushion 104 adapted for use as an inflatable curtain, other examples of inflatable airbag modules of the present disclosure may be employed for a number of other types of airbag cushions, including, but not limited to other side impact (e.g., head, thorax, combined) airbag cushions, knee airbag cushions, as well as other airbag cushions for use in a motor vehicle.

[0023] According to at least one feature, the inflator 102 of the inflatable airbag module 100 is adapted to improve the performance and reliability of the inflator 102 when deployed. FIG. 2 is a cross-sectioned side view of an inflator 102 according to at least one example. The inflator 102 generally includes an elongated hollow tube 202 defining a chamber 204 for enclosing a quantity of fluid therein, designated by the reference numeral 206. In the example shown in FIG. 2, the fluid 206 may comprise a stored fluid, such as a pressurized expandable fluid. However, other examples of the inflator 102 may be adapted to enclose a quantity of gas generant adapted to be converted into a supply of inflation fluid during deployment, as well as a combination of stored fluid and gas generant, commonly referred to as a "hybrid". In examples in which the inflator 102 encloses a quantity of gas generant, either alone or in combination with a stored fluid, the gas generant can be disposed within the chamber 204 in a manner to provide an opening adapted to enable a Shockwave, described below, to pass through at least substantially unimpeded. For example, in some examples, a gas generant may be disposed as a grain comprising a centrally located bore through which a Shockwave may travel, while still enabling the gas generant to be ignited. In other examples, a plurality of grains may be disposed around a perforated conduit to enable a Shockwave to pass through the perforated conduit, while still enabling the gas generant to be ignited by means of the perforations in the conduit. [0024] The hollow tube 202 may be composed of a metal or metal alloy, such as steel, magnesium alloy, etc., and can be formed by any suitable method, such as stamping, machining, casting, extrusion, etc. The hollow tube 202 includes opposing first and second longitudinal ends, 208 and 210, respectively. An initiator 212 may be coupled to the first longitudinal end 208, for instance as part of an initiator assembly 214. Such an initiator assembly 214 may be coupled to the first longitudinal end 208 using, for example, an inertial weld 216. In other examples, at least a portion of the initiator assembly 214 may be formed integral to the hollow tube 202. The initiator 212 is adapted to inflate (e.g., ignite) and/or release the stored fluid 206 upon receipt of an electrical signal, such as may be generated by a sensor (not shown) upon the sensing of a collision. More particularly, the initiator 212 may include a squib in communication with a reactive charge, such as the reactive charge 231. The squib can produce an ignition charge on receipt of an electrical signal to ignite the reactive charge 231. The reactive charge 231 , in at least some examples, may comprise a gas generant material.

[0025] The second longitudinal end 210 of the hollow tube 202 may be enclosed with a burst disk 218. The burst disk 218 may comprise any rupturable device or other temporary closure device that can be positioned over an outlet at the second longitudinal end 210 of the hollow tube 202. In some instances, the burst disk 218 may include one or more scored seams to facilitate the rupturing of the burst disk 218. The burst disk 218 can generally be rupturable to open and enable a compressed gas to exit the chamber 204 and inflate an inflatable airbag cushion, such as the inflatable cushion 104 in FIG. 1.

[0026] Referring still to FIG. 2, a diffuser assembly 220 may be formed integral with or appropriately coupled to the second longitudinal end 210 of the hollow tube 202. For example, the diffuser assembly 220 may be coupled to the second longitudinal end 210 with an inertial weld 222, or the diffuser assembly 220 may be formed integral with the hollow tube 202. The diffuser assembly 220 may include a boss 224 to which is joined or connected a diffuser element 226.

[0027] The inflator 102 may further include a combustion compartment 228 within the hollow tube 202 and positioned in fluid communication with the initiator 212. The combustion compartment 228 may include an area in which fluid pressure produced during deployment of the initiator 212 is at least initially contained. The combustion compartment 228 can be formed at least in part by an enclosure 230, which can be disposed within the hollow tube 202 to at least partially enclose the initiator 212. In some examples, the enclosure 230 may include a reactive charge comprising a pyrotechnic material 231 disposed therein such that the pyrotechnic material 231 is in sufficient communication with the initiator 212 to be ignited by the initiator 212 on deployment of the inflator 102. The enclosure 230 generally includes at least one enclosure release mechanism adapted to release at least a portion of the enclosure 230 to displace within the hollow tube 202 in a direction generally toward the burst disk 218 in response to deployment of the initiator 212.

[0028] Turning to FIG. 3, a magnified view of an inflator showing at least one example of an enclosure. The enclosure 300 may include a generally cylindrical shape formed by sidewalls 302 and including an open end 304 and a closed end 306. The sidewalls 302 at the open end 304 may be disposed adjacent to a portion of the initiator assembly 214 and/or the hollow tube 202. The open end 304 can be disposed in relation to the initiator 212 so that the initiator 212 is in fluid communication with the combustion compartment 228.

[0029] In at least some examples, the enclosure 300 may include a surface 308 disposed at the closed end 306, and sized and shaped to extend laterally for at least substantially filling the hollow tube 202. For instance, the surface 308 may laterally extend to a diameter "D" that is at least slightly smaller than an inner diameter "ID" of a cylindrically-shaped hollow tube 202. The surface 308 may be integrally formed as part of the sidewall 302 at the closed end 306, or the surface 308 can be a separate component coupled to the sidewall 302 at the closed end 306. The surface 308 can be generally configured to not block gas flow from exiting the hollow tube 202. That is, the surface 308 can be configured so that it does not cause plugging within the hollow tube 202.

[0030] In the example illustrated in FIG. 3, an enclosure release mechanism 310 is included as a groove or thinned region formed in the sidewall 302 of the enclosure 300. In the example illustrated, the enclosure release mechanism 310 is formed in an outer surface of the sidewall 302 of the enclosure 300. In other examples, however, an enclosure release mechanism 310 can be formed in an inner surface of the sidewall 302 of the enclosure 300 and/or a combination of the inner and outer surfaces. The enclosure release mechanism 310 can be configured to fail when the pressure within the combustion compartment 228 reaches a predetermined threshold value. For example, the groove or thinned region forming the enclosure release mechanism 310 can be sized and shaped so that the remaining portion of the sidewall 302 in the area of the enclosure release mechanism 310 is adapted to fail (i.e., break or rupture) when a predetermined force is exerted on the sidewalls 302, enabling a portion of the enclosure 300 to move within the hollow tube 202 in a direction generally toward the burst disk 218.

[0031] Turning to FIG. 4, a magnified view of an inflator showing at least another example of an enclosure. The enclosure 400 may include a generally cylindrical shape formed by sidewalls 402 and including an open end 404 and a closed end 406. The sidewalls 402 at the open end 404 may be disposed adjacent to a portion of the initiator assembly 214 and/or the hollow tube 202. The open end 404 can be disposed in relation to the initiator 212 so that the initiator 212 is in fluid communication with the combustion compartment 228.

[0032] Similar to the enclosure 300 of FIG. 3, the enclosure 400 of FIG. 4 may include a surface 408 disposed at the closed end 406, and sized and shaped to at least substantially fill the hollow tube 202. For instance, the surface 408 may laterally extend to a diameter "D" that is at least slightly smaller than an inner diameter "ID" of a cylindrically-shaped hollow tube 202. The surface 408 may be integrally formed as part of the sidewall 402 at the closed end 406, or the surface 408 can be a separate component coupled to the sidewall 402 at the closed end 406. The surface 408 can be generally configured so that the surface 408 will not block gas flow from exiting the hollow tube 202. That is, the surface 408 can be configured so that it does not cause plugging within the hollow tube 202.

[0033] In the example illustrated in FIG. 4, an enclosure release mechanism 410 is included as a shear pin disposed through a portion of the enclosure 400 and through a portion of the hollow tube 202 and/or the initiator assembly 214. In the example shown, the shear pin enclosure release mechanism 410 extends through two sidewalls 402 of the enclosure 400. In other examples, however, a shear pin enclosure release mechanism 410 can be configured to extend through only one sidewall 402 of the enclosure 400. The enclosure release mechanism 410 can be configured to fail when the pressure within the combustion compartment 228 reaches a predetermined threshold value. For example, the shear pin forming the enclosure release mechanism 410 can be sized and shaped so that the shear pin is adapted to fail when a predetermined shear force is exerted on the shear pin by the sidewall 402 of the enclosure 400, enabling the enclosure 400, or at least a portion thereof, to move within the hollow tube 202 in a direction generally toward the burst disk 218.

[0034] The examples illustrated and described with reference to FIGS. 3 and 4 are intended to provide non-limiting examples of enclosure release mechanisms that may be employed with an enclosure. Referring to FIG. 2, those of ordinary skill in the art will understand that combinations of the foregoing and/or other enclosure release mechanisms may be employed that are suitable to release at least a portion of the enclosure 230 such that the released enclosure 230, or a released portion of the enclosure 230, can displace within the hollow tube 202 in a direction generally toward the burst disk 218 in response to deployment of the initiator 212. With continued reference to FIG. 2 and by way of additional non- limiting examples, the enclosure release mechanism may include an adhesive bond coupling the enclosure 230 to the initiator assembly 214 and/or to the hollow tube 202, an adhesive bond coupling two portions of the enclosure 230 together, a weld coupling the enclosure 230 to the initiator assembly 214 and/or to the hollow tube 202, and a weld coupling two portions of the enclosure 230 together, etc., as well as combinations thereof.

[0035] With reference to FIG. 5, operation of an inflator 102 will be described according to at least one example. In the event of a deployment event, such as a collision, an accelerometer (not shown) may transmit an electrical signal to the initiator 212. On receipt of the electrical signal, the initiator 212 may ignite its reactive charge and/or a reactive charge within the combustion compartment 228 (e.g., pyrotechnic material 231 in FIG. 2), as depicted by the ignition event 502 in the top image of FIG. 5. As a result of igniting the reactive charge of the initiator and/or the reactive charge in the combustion compartment 228, the pressure within the combustion compartment 228 may increase. When the pressure within the combustion compartment 228 is at or near a predefined threshold, the enclosure release mechanism of the enclosure 230 may fail, releasing at least a portion of the enclosure 230. If the inflator 102 includes a stored fluid, then the predefined threshold may be determined such that it will overcome a pressure on the enclosure 230 from the stored fluid. By way of example and not limitation, if the hollow tube 202 is filled with a stored fluid at about 7,600 psi (about 52.4 MPa), and the threshold for causing the enclosure release mechanism to fail is about 9,500 psi (about 65.5 MPa), then the pressure within the combustion compartment 228 may need to be about 17, 100 psi (about 1 17.9 MPa) or greater in order to cause the enclosure release mechanism to fail (i.e., 9,500 psi greater than the pressure of the stored fluid). Accordingly, the initiator 212, alone or in combination with the reactive charge in the combustion compartment 228, may be adapted to generate a target pressure at or above the predetermine pressure threshold within the combustion compartment 228 to cause the enclosure release mechanism to fail.

[0036] When at least a portion of the enclosure 230 is released, the enclosure 230, or at least a portion thereof, may displace within the hollow tube 202 in a direction generally toward the burst disk 218, as shown in the bottom image of FIG. 5. As the enclosure 230, or at least a portion thereof, is released and displaced, a Shockwave 504 can be generated in a direction generally toward the burst disk 218. Because at least a portion of the enclosure 230 is released when the pressure within the combustion compartment 228 is about at the predefined threshold, the magnitude or strength of the Shockwave 504 is independent of the rate at which the initiator 212 ignites and is more consistent between two or more different inflators 102. In other words, since the forces on the enclosure 230 are about the same between two or more inflators 102 incorporating similar enclosures 230 when the enclosure release mechanism fails, the force at which the enclosure 230 displaces will be about the same for each of the similarly configured inflators 102. Consequently, the magnitude or strength of the Shockwave 504 generated by such displacement of the enclosure 230 will be about the same as well. Furthermore, because the enclosure 230 contains the pressure up to about the designated failure point, resulting in a Shockwave of at least substantially similar intensity, operation of the inflator 102 becomes at least partially independent of the speed of combustion of the initiator 212.

[0037] The Shockwave 504 generated by the displaced portion of the enclosure 230 is adapted to rupture the burst disk 218. Because the magnitude or strength of the Shockwave 504 is at least substantially repeatable and configurable as discussed above, the burst disk 218 can be ruptured reliably and consistently among similarly configured inflators 202. With the burst disk 218 ruptured, compressed gas within the hollow tube 202 can flow out from the inflator 102 into an inflatable airbag cushion coupled with the inflator 102 (e.g., the inflatable airbag cushion 104 of FIG. 1).

[0038] Further aspects of the present disclosure relate to methods of making an airbag cushion inflator adapted for use with an inflatable airbag module. FIG. 6 is a flow diagram illustrating at least one example of a method for forming an airbag cushion inflator, such as one or more of the inflators described above with reference to FIGS. 1 -5. Referring to FIGS. 2 and 6, the method 600 includes obtaining a hollow tube 202 at step 602. Obtaining the hollow tube 202 may include forming the hollow tube 202 by, for example, stamping, machining, casting, extrusion etc. In other implementations, the hollow tube 202 may be obtained as a preformed component.

[0039] At step 604, an enclosure 230 may be disposed in the hollow tube 202. The enclosure 230 includes at least one enclosure release mechanism, such as any of the enclosure release mechanisms described herein above. The enclosure 230 is disposed to form at least a portion of a combustion compartment 228. The enclosure 230 may be disposed in the hollow tube 202 by coupling an open end of the enclosure 230 to the hollow tube 202 and/or the initiator assembly 214.

[0040] At step 606, an initiator assembly 214 may be disposed adjacent to a first longitudinal end 208 of the hollow tube 202. In at least some implementations, the initiator assembly 214 may be coupled to the hollow tube 202. In one or more other implementations, the initiator assembly 214, or at least a portion thereof, may be formed integral to the hollow tube 202. The initiator assembly 214 includes an initiator 212 therewith. In some implementations, the enclosure 230 may be first coupled with the initiator assembly 214, and the enclosure 230 can be disposed in the hollow tube 202 when the initiator assembly 214 is disposed adjacent to the first longitudinal end 208 of the hollow tube 202.

[0041] At step 608, a burst disk 218 may be disposed adjacent to a second longitudinal end 210 of the hollow tube 202. In some implementations, the burst disk 218 may be disposed to cover an outlet formed in the second longitudinal end 210 or the burst disk 218 may be disposed adjacent to the second longitudinal end 210 as part of a diffuser assembly 220 to cover an outlet at the second longitudinal end 210.

[0042] It is noted, that although the forgoing method 600 is depicted as a flow diagram showing the various steps as a sequential process, many of the forgoing acts can be performed in another sequence, in parallel, or substantially concurrently. In addition, the order of the acts may be re-arranged.

[0043] The present features may be embodied in other specific forms without departing from its structures, methods, or other essential characteristics as broadly described herein and claimed hereinafter. The described embodiments and implementations are to be considered in all respects only as illustrative, and not restrictive. The scope of the disclosure is, therefore, indicated by the appended claims, rather than by the foregoing description. All changes that come within the meaning and range of equivalency of the claims are to be embraced within their scope.

Claims

CLAIMS What is claimed is:

1. An airbag cushion inflator, comprising:

a hollow tube;

an initiator assembly disposed at a first longitudinal end of the hollow tube, the initiator assembly including an initiator;

a burst disk disposed at a second longitudinal end of the hollow tube; and

an enclosure disposed within the hollow tube and forming at least a part of a combustion compartment in fluid communication with the initiator, wherein the enclosure includes an enclosure release mechanism.

2. The airbag cushion inflator of claim 1, wherein the enclosure release mechanism is adapted to release at least a portion of the enclosure to displace within the hollow tube in a direction generally toward the burst disk in response to actuation of the initiator.

3. The airbag cushion inflator of claim 2, wherein when at least a portion of the enclosure is released and displaced within the hollow tube, a shockwave adapted to open the burst disk is generated with at least substantially consistent magnitude to ensure consistent opening behavior of the burst disk.

4. The airbag cushion inflator of claim 1, wherein the enclosure release mechanism comprises a groove formed in a sidewall of the enclosure.

5. The airbag cushion inflator of claim 1, wherein the enclosure release mechanism comprises a shear pin disposed through a portion of the enclosure and through a portion of at least one of the hollow tube or the initiator assembly.

6. The airbag cushion inflator of claim 1, wherein the enclosure release mechanism comprises an adhesive coupling together at least one of the enclosure and the hollow tube, the enclosure and the initiator assembly, or two portions of the enclosure.

7. The airbag cushion inflator of claim 1 , wherein the enclosure release mechanism comprises a weld coupling together at least one of the enclosure and the hollow tube, the enclosure and the initiator assembly, or two portions of the enclosure.

8. The airbag cushion inflator of claim 1 , further comprising a surface disposed at a closed end of the enclosure, the surface being sized and shaped to extend laterally to at least substantially fill the hollow tube.

9. The airbag cushion inflator of claim 8, wherein the surface is configured to not block gas flow within the hollow tube.

10. The airbag cushion inflator of claim 1 , further comprising a pyrotechnic material disposed within the enclosure.

1 1. An inflatable airbag module, comprising:

an inflatable cushion; and

an inflator in fluid communication with the inflatable cushion, the inflator comprising: a hollow tube including a first longitudinal end and a second longitudinal end; a burst disk disposed at the second longitudinal end of the hollow tube;

an enclosure disposed within the hollow tube and forming at least a portion of a combustion compartment, wherein the enclosure includes an enclosure release mechanism; and

an initiator assembly disposed at the first longitudinal end of the hollow tube and including an initiator positioned in fluid communication with the combustion compartment.

12. The inflatable airbag module of claim 1 1 , wherein the enclosure release mechanism is adapted to release at least a portion of the enclosure and enable the enclosure or at least a portion thereof to be displaced within the hollow tube in a direction generally toward the burst disk in response to deployment of the initiator.

13. The inflatable airbag module of claim 1 1, wherein the enclosure release mechanism comprises at least one mechanism selected from a group of mechanisms comprising: a groove formed in a sidewall of the enclosure;

a shear pin disposed through a portion of the enclosure and through a portion of at least one of the hollow tube or the initiator assembly;

an adhesive coupling together at least one of the enclosure and the hollow tube, the enclosure and the initiator assembly, or two portions of the enclosure; and

a weld coupling together at least one of the enclosure and the hollow tube, the enclosure and the initiator assembly, or two portions of the enclosure.

14. The inflatable airbag module of claim 11, further comprising:

a surface disposed at a closed end of the enclosure, the surface being sized and shaped to extend latterly for at least substantially filling the hollow tube without causing plugging within the hollow tube.

15. A method of forming an airbag cushion inflator, the method comprising:

obtaining a hollow tube including a first longitudinal end and an opposing second longitudinal end, wherein the first longitudinal end is adapted to receive an initiator coupled therewith and the second longitudinal end is adapted to receive a burst disk disposed adjacent thereto; and

disposing an enclosure in the hollow tube to form at least a portion of a combustion compartment positioned to be in fluid communication with an initiator when an initiator is coupled with the first longitudinal end of the hollow tube, wherein the enclosure includes an enclosure release mechanism.

16. The method of claim 15, wherein the enclosure release mechanism is adapted to release at least a portion of the enclosure to displace within the hollow tube to generate a Shockwave adapted to open a burst disk disposed adjacent to the second longitudinal end of the hollow tube, wherein the Shockwave is generated with at least substantially consistent strength to ensure consistent opening behavior of the burst disk..

17. The method of claim 15, wherein disposing an enclosure in the hollow tube to form at least a portion of a combustion compartment comprises coupling an open end of the enclosure to at least one of the hollow tube or an initiator assembly disposed adjacent to the first longitudinal end of the hollow tube.

18. The method of claim 15, wherein the enclosure release mechanism comprises a groove formed in a sidewall of the enclosure.

19. The method of claim 15, wherein the enclosure release mechanism comprises a shear pin disposed through a portion of the enclosure and through a portion of at least one of the hollow tube or the initiator assembly.

20. The method of claim 15, wherein the enclosure release mechanism comprises at least one of an adhesive or a weld coupling together at least one of the enclosure and the hollow tube, the enclosure and the initiator assembly, or two portions of the enclosure.

21. The method of claim 15, further comprising:

disposing a pyrotechnic material within the enclosure.