Airbag fabric diffuser

[0001] The present invention relates generally to safety restraint systems using airbags and particularly to an airbag containing a perforated cloth diffuser and a perforated cushion deflector. A preferred configuration facilitates even deployment of a head side airbag for protection of vehicle occupants from side impact.

[0002] As the automobile has developed, so have methods of ensuring passenger safety. Several methods of safety restraint systems have emerged during this development, including the airbag. Since the introduction of the airbag various degrees of implementing it have emerged including use in protecting passengers from side impact scenarios. To achieve this, vehicle designers have placed airbag systems in a number of locations including passenger seats, vehicle doors and vehicle roof frames. Various methods of improving airbag performance have also been developed. One example, pertinent to the present invention, is the use of a cylindrical metal diffuser that facilitates even deployment or inflation of the airbag.

[0003] It is an object of the present invention to make a significant improvement over side impact airbag systems through implementation of an improved diffuser system. Although effective, traditional metal diffusing systems often tend to be relatively expensive and may require an increased amount of packaging space. This has an overall effect of limiting the areas wherein diffused airbag systems can be implemented. The present invention replaces the traditional metal diffuser systems with a fabric diffuser. The fabric diffuser offers the same performance as the traditional diffusers, however, it boasts distinct advantages. Initially, a fabric diffuser is both lightweight and cost effective. Manufacture of a fabric diffuser is also less complicated than that of a metal diffuser. A more significant advantage is that fabric diffuser systems in accordance with the present invention have improved packaging characteristics over traditional metal diffusers and can disperse gas rearwardly into the cushion. A fabric diffuser, in contrast to a metal diffuser, can be tightly folded with the overall airbag in its initial packaging. As a result, more options are open to designers in locating airbag systems.

[0004] An airbag of the present invention comprises a sewn outer shell, and a diffuser system, to include a perforated fabric diffuser and a perforated cushion deflector, disposed within the sewn outer shell. As a result of the advantages described above, the airbag can be inconspicuously packaged in the upper trim running a distance along the front and rear passenger windows. The sewn outer shell is preferably sewn in such a way as to form individual cell areas. In a preferred embodiment, the diffuser incorporates a series of openings along its edge that are located at an area generally above each of the individual cells. Upon deployment of the airbag, the inflation gas initially inflates the diffuser system. The diffuser system then channels the gas to the individual cells, causing the airbag to be evenly inflated. Such a system offers a significant degree of protection for both front and rear passengers. The present airbag is particularly useful as a head side airbag, but not however thereby limited.

[0005] Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood however that the detailed description and specific examples, while indicating preferred embodiments of the invention, are intended for purposes of illustration only, since various changes and modifications within the scope of the invention will become apparent to those skilled in the art from the following detailed description.

[0011] The present invention is primarily directed at airbag or vehicle occupant protection systems and more specifically to improving the adaptability and performance of such systems through the use of a diffuser system.

[0012] With reference to FIG. 1, the side view of a head side airbag 10 (also referred to as a cushion) is displayed. An outer shell 12 is sewn in such a manner as to form an interior 14 and two portions, 16 and 18, each having a plurality of individual cells 20, and an inlet 22. Internal to the sewn outer shell is a fabric or cloth diffuser 24. The fabric or cloth diffuser 24 has a series of openings 26 along its edges and in a preferred embodiment, may also include an inlet or gas entry orifice 22′ in lieu of an inlet on the airbag. The outer shell 12 is constructed in such a manner as to form a first plurality of tab portions 28 which are used to attach the airbag 10 to a vehicle (best shown in FIGS. 4 and 5). Additionally, a strap 30 is sewn to a corner of the airbag 10 and attached to the vehicle structure thereby stabilizing the forward portion of the airbag 10 during operation.

[0013] The fabric or cloth diffuser 24 is formed from first unsewn pattern 32, shown in FIG. 2. The first unsewn pattern 32 includes a plurality of round holes or perforations that upon the folding of the first unsewn pattern 32 form the openings 26 extending across a portion of the length of the airbag 10, a second plurality of tab portions 36, and a first set of inlet halves 38. The cushion deflector 40 is formed from a second unsewn pattern 42. The second unsewn pattern 42 preferably includes a cloth wall 44 defining at least one gas flow attenuating orifice 46 used to balance the amount of gas dispersed between the forward and rearward portions of the airbag 10. Additionally, upon airbag assembly, orifices 47 of the cushion deflector 40 are aligned with openings 26 and thereby provide fluid communication between the fabric or cloth diffuser 24 and the cushion deflector 40. A third plurality of tab portions 48 extend from opposing sides of the second unsewn pattern 42 for reinforcement of the first plurality of tab portions 28. If desired, a second set of inlet halves 50 are provided at opposite ends of the cushion deflector 40 and upon airbag assembly also preferably define a gas entry orifice 22″.

[0014] When assembling the airbag 10, the perforated cushion deflector 40 or the second unsewn pattern 42 is folded in half along a lateral axis “A” such that the third plurality of tab portions 48 on opposing sides of the second unsewn pattern 42 align with one another and the second set of inlet halves 50 align with one another. The folded second unsewn pattern 42 is sewn in between the folded fabric or cloth diffuser 24 thereby orienting the wall 44 generally transverse to the length of the airbag 10 or diffuser 24 (or to the gas flow), as shown in FIG 1. The first unsewn pattern 32 is folded in half along a longitudinal axis “B” such that the second plurality of tab portions 36 on opposing sides of the first unsewn pattern 32 align with one another and the first set of inlet halves 38 align with one another. As shown in FIG. 1, the folded first unsewn pattern 32, with the folded second unsewn pattern 42 positioned within first unsewn pattern 32, is sewn in between first and second panels 52 and 54 of the outer shell 12 so that the upper edge 33 of the folded first unsewn pattern 32 is sewn coincident with the upper edge 11 of the outer shell 12. The airbag 10 is preferably supported by a plastic cartridge or plastic interior molding (not shown), that is in turn supported by the roof frame 56. A protective cover (not shown) preferably envelopes the airbag 10. The first and second panels 52 and 54, respectively, of the outer shell 12 actually include the first plurality of tab portions 28 which overlap the second plurality of tab portions 36 of the fabric or cloth diffuser 24 and the third plurality of tab portions 48 of the cushion deflector 40 thereby reinforcing the mounting tabs 28 for attachment to the vehicle.

[0015] FIG. 4 depicts the head side airbag 10 mounted in a vehicle passenger compartment 64 with the airbag 10 in its uninflated state. The airbag 10 is mounted to a roof frame 56 opposite a vehicle floor 60. As shown in FIG. 5, a vehicle 62 has a passenger compartment 64 including a forward boundary 66, a rearward boundary 68, sides 70, wherein each respective side 70 contains a door 72, a side window 74, a plurality of pillars 76, and a roof frame 56. Additionally, the strap 30 is attached to both the airbag 10 and a first pillar 78. An inflating mechanism or airbag inflator 80, manufactured as known in the art, is also attached to the airbag 10 in fluid communication with inlet 22, and mounted to the roof frame 56. Upon a crash event, the inflating mechanism or airbag inflator 80 activates and the airbag 10 is thus deployed, as shown in FIG. 5. Stated another way, when triggered, the inflating mechanism or airbag inflator 80 releases gas into inlet 22 thereby inflating the airbag 10. The fabric or cloth diffuser 24 and the cushion deflector 40 taken together form a diffuser system 82. The diffuser system 82 is initially inflated and directs the gas flow via the openings 26 into the individual cells 20 of the airbag 10. Importantly, gas flow entering inlet 22 and traversing through the fabric or cloth diffuser 24 is attenuated as it encounters the wall 44 and the attenuating orifice 46, thereby dispersing the gas flow across the airbag 10 in a substantially uniform fashion. As shown FIGS. 1, 3 and 5, the wall 44 is at least partially laterally transverse to the gas flow entering inlet 22, or transverse to the lengths of the fabric or cloth diffuser 24 and the airbag 10. The strap 30 functions to limit forward inward movement of the airbag 10 during the deployment process. Upon deployment, the airbag 10 aids in protecting the occupants by substantially covering the side windows 74 of the passenger compartment 64.

[0016] A stitch 86 is best shown in FIG. 1 and runs along the periphery of the airbag 10 to integrate the airbag components and to also define the sides of the cells 20. As shown in FIG. 1, the fabric or cloth diffuser 24 and the cushion deflector 40 are sewn in between the first and second panels 52 and 54 of the outer shell 12 such that stitch 86 integrates the fabric or cloth diffuser 24 and the cushion deflector 40 within the sewn outer shell 12. As described above, inlet or gas entry orifice 22′, 22″ is formed by sewing the first set of inlet halves 38 of the fabric or cloth diffuser 24 together, and/or, by sewing the second set of inlet halves 50 of cushion deflector 40 together. When both the first set of inlet halves 38 and the second set of inlet halves 50 are employed, for improved strength for example, the second set of inlet halves 50 are placed in an aligned and overlying relationship to the first set of inlet halves 38 prior to sewing within the first and second panels 52 and 54 of the outer shell 12. The airbag 10, and therefore the outer shell 12, the fabric or cloth diffuser 24, and, for example, the cushion deflector 40 are formed from nylon or other materials known for their use in airbags.

[0017] The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not regarded as a departure from the scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.