Air bag including variable tethers

An air bag assembly adapted for use in opposing relation to a vehicle occupant. The assembly includes one or more tethering elements which may be selectively released from a first restrained condition to a second restrained condition in a predefined manner so as to control the inflated profile of the air bag cushion based upon vehicle and/or occupant conditions while nonetheless maintaining tension within the tethering elements in both the first and second restrained conditions.

TECHNICAL FIELD

This invention relates to an air bag assembly, and more particularly to an air bag assembly including an inflatable air bag cushion having an arrangement of tethering elements within the air bag cushion to provide variable controlled shaping restraint within the air bag cushion. The tethers are releasable from a first restrained condition imparting a restrained tension to the air bag cushion to at least a second restrained condition so as to permit the air bag cushion to inflate to an enhanced profile while still providing a restrained tensioning arrangement.

BACKGROUND OF THE INVENTION

It is well known to provide an air bag assembly including an inflatable air bag cushion for protecting the occupant of a transportation vehicle. In an automotive vehicle such air bag assemblies are typically located in the hub of the steering wheel and in a recess in the vehicle instrument panel for protection of the vehicle occupants seated in opposing relation to such assemblies. Additional air bag assemblies may be located within the seats and/or door panels for protection of occupants during a side impact event. Air bag assemblies typically include an inflatable cushion, and a gas emitting inflator mounted in fluid communication with the inflatable cushion. In a driver side air bag module, a base plate typically supports the inflator at the interior of the steering wheel or other appropriate location opposing the occupant to be protected. The mouth of the air bag is disposed in surrounding relation to the inflator with a perimeter portion of the mouth being held between the base plate and an overlying retainer to effect a secure relation between the inflator and the cushion. In a passenger side assembly, the inflator is typically held within a trough-like housing with the air bag cushion being held along the walls of the housing such that inflation gas passes from the inflator into the cushion upon activation of the inflator. Both driver side air bag modules and passenger side air bag modules are well known. In the past it has been advocated to adjust the inflated profile of air bag cushions by selective release of tethering elements.

SUMMARY OF THE INVENTION

The present invention provides advantages and alternatives over the prior art by providing an air bag assembly adapted for use in opposing relation to a vehicle occupant which assembly includes one or more tethering elements which may be cooperatively released from a first restrained condition to a second restrained condition in a predefined manner so as to control the inflated profile of the air bag cushion based upon vehicle and/or occupant conditions while nonetheless maintaining tension in within the tethering elements in both the first and second restrained conditions.

While the invention has been illustrated and generally described above, it will hereinafter be described in connection with certain exemplary embodiments, constructions and procedures, it is to be understood that in no event is the invention to be limited to such illustrated and described embodiments, constructions and procedures. On the contrary, it is intended that the present invention shall extend to all alternatives and modifications as may embrace the principles of this invention within the true spirit and scope thereof.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Reference will now be made to the drawings wherein to the extent possible like reference numerals are utilized to designate like components throughout the various views. InFIG. 1, there is illustrated the interior of a vehicle10for transporting an operator12and a passenger14. As illustrated, the vehicle10may include a passenger side air bag system16mounted within the dash panel in substantially opposing relation to the vehicle passenger14. The vehicle10will also include a driver side air bag system17mounted within the steering wheel18for protection of the vehicle operator12. According to a potentially preferred practice, the air bag assembly mounted within the steering wheel18is stored in hidden relation below a cover20which opens along tear seams22upon activation of the air bag assembly in a manner as will be well known to those of skill in the art. Such activation typically takes place upon the occurrence and measurement of predetermined vehicle conditions such as deceleration at a rate exceeding a predetermined value.

As shown, the vehicle10may incorporate one or more sensors24such as optical sensors for measuring the dimensions of the vehicle occupants12,14. Likewise, mass and/or position sensors (not shown) may be incorporated within the seaming structure and/or at other suitable locations to provide further information on the characteristics of the vehicle occupants. A sensor may also be provided to register whether or not the occupants are utilizing recommended seat belts. Data from the various sensors measuring occupant parameters as well as data from sensors measuring vehicle conditions may be translated to an onboard computer which in turn relays deployment activation signals to the driver side air bag system17and the passenger side air bag system16during a collision event. Referring toFIGS. 2-4, a first arrangement for a vehicle air bag assembly is shown schematically. As shown, the air bag assembly28includes an inflatable air bag cushion30having a gas inlet opening32in fluid communication with a gas emitting inflator34which may be housed at a support member35such as a base plate or the like.

As will be appreciated by those of skill in the art, the air bag cushion30may be formed by seaming together panels of pliable material such as fabric and the like to achieve a desired configuration. In the illustrated assembly, the air bag cushion30may be formed by seaming together two substantially disk shaped pieces of material by a seam36to form the construction substantially as illustrated in FIG.2. Of course, it is to be understood that this simplified construction is exemplary only and that any other construction including multiple panel constructions may likewise be utilized if desired.

In the illustrated embodiment, the air bag assembly28includes an arrangement of shape restraining elongate tethering elements38such as elongate straps or the like. As illustrated, the tethering elements38preferably extend from positions of attachment40on a body portion of the air bag cushion30to a collection region42at the interior of an impact face44of the air bag cushion30.

As best illustrated inFIG. 4wherein the air bag cushion30is shown turned inside out from its normal operative condition, the collection region42may include a threaded guide element46in the form of a panel of material seamed around its perimeter to the underside of the impact face44. According to the illustrated construction, the guide element46includes a plurality of perimeter acceptance openings48for acceptance of the tethering elements. The guide element46also preferably includes a central outlet opening50through which the joined together tethering elements38may be pulled in a manner to be described further hereinafter.

As best illustrated through simultaneous reference toFIGS. 2 and 4, the tethering elements38may be joined together at the position of convergence below the guide element46such as by a seam52which connects the tethering elements38together and in affixed relation to an anchoring line54such as a strap or the like. Thus, by pulling the anchoring line54away from the impact face44, the effective operative depth of the tethering elements38may be shortened (FIG.2). As illustrated, the shortened operative depth of the tethering elements38may be maintained by holding the anchoring line54at an anchoring assembly56which is adapted to selectively disengage from the anchoring line54under conditions where expanded depth is desired in the air bag cushion30.

By way of example only, and not limitation, according to one contemplated arrangement the anchoring assembly56may include a displaceable locking pin element60which mateably engages a portion of the anchoring line54so as to hold the anchoring line54in place with the tethering elements38in the shortened operative condition illustrated in FIG.2. The locking pin element60may be operatively connected to a solenoid62which strokes open or closed upon the receipt of an activation signal through lead lines64such that upon activation, the locking pin element60is moved out of locking relation to the anchoring line54(FIG.3). By way of example only, such activation may take place in instances such as use of the system by a large occupant and/or an occupant seated a substantial distance away from the air bag cushion and/or an impact event of extreme severity in which enhanced cushion depth may be desirable.

Of course, the disengagement of a locking pin element is to be understood as being merely an exemplary method of releasing the anchoring line54and that any other suitable method may likewise be used. By way of example only, and not limitation, it is contemplated that the solenoid62may be replaced with a pressure generating squib which moves the locking pin element60out of engagement with the anchoring line54. It is also contemplated that the anchoring line54may be held in place by a frangible explosive-type bolt release which is activated by an initiator. It is also contemplated that the anchoring line54may be cut or burned through such as by the use of an actuated knife blade or detonation cord or the like.

Regardless of the actual structure of the anchoring assembly, it is contemplated that the anchoring assembly56will be adapted to selectively retain or release the anchoring line54so as to adjust the operative depth of the tethering elements38. In operation, it is contemplated that the anchoring line54will be normally held at the anchoring assembly56so as to shorten the operative depth of the tethering elements38and thereby restrain the depth of the air bag cushion30(FIG.2). However, upon the occurrence of vehicle and/or occupant conditions which necessitate a deeper air bag profile, the solenoid62or other release mechanism is activated thereby releasing the anchoring line54and allowing the air bag cushion30to expand to a deeper profile (FIG.3). As will be appreciated, in the extended depth arrangement illustrated inFIG. 3, the tethering elements38preferably remain in affixed relation to one another even after the release of the anchoring line54. Thus, even in the expanded depth arrangement, the tethering elements38are held in tension and cannot be withdrawn completely from the guide element46. A degree of profile restraint is thereby maintained by the tethering elements38even in the released condition.

As will be appreciated, the present invention is adaptable to a large number of alternatives and variations. By way of example only, and not limitation, a variation on the embodiment as described above is illustrated inFIGS. 5-8wherein elements corresponding to those previously illustrated and described are designated by like reference numerals increased by100. As shown, the air bag cushion130is substantially similar to the configuration previously described with the exception that the perimeter includes a peripheral selvage portion170located outboard of the perimeter seam136. As shown, a multiplicity of openings172is disposed around the selvage portion170. As will be appreciated by those of skill in the art, the air bag cushion is typically formed with the attached tethers sewn around the exterior and is thereafter turned inside out for subsequent use. Thus, in the operative condition the selvage170defines an interior ring with the openings172inboard of the perimeter seam136(FIG.8). As best seen inFIG. 7, in order to provide radial profiling restraint, each of the openings172may thereafter be pulled to the center of the air bag cushion130in a gathered relationship. This gathering at the center transforms the previously circular air bag cushion130to a substantially square orientation. As best illustrated inFIG. 6, the gathered arrangement yielding the relatively low profile square orientation may be maintained by passing the anchoring line154through the aligned openings172and securing the anchoring line154in place at the anchoring assembly156as previously described. Thus, prior to the activation of the anchoring assembly156to release the anchoring line154, the tethering elements138are held in a state of shortened operative depth with the sides of the air bag cushion130being simultaneously restrained against radial expansion. Upon the release of the anchoring line154, the outward projection of the impact face144pulls the anchoring line154out of engagement with the openings172thereby allowing the air bag cushion130to expand radially outwardly to provide enhanced lateral coverage. At the same time, the tethering elements138are permitted to extend to their full normal operative depth between the positions of attachment140on the air bag cushion body and the guide element146at the collection region142. However, as with the previously described construction, the tethering elements138remain attached to one another and thus maintain a degree of shape forming tethering tension even in the released stated illustrated in FIG.8.

Still another exemplary embodiment of the present invention is illustrated inFIGS. 9-11wherein elements corresponding to those previously described are designated by like reference numerals within a200series. In the illustrated embodiment, the tethering elements238extend away from positions of attachment240along the air bag cushion body to a collection region242at the impact face244. At the collection region242, the tethering elements238are affixed by a seam252to both the impact face244as well as to an anchoring line254. Thus, as illustrated inFIG. 10, the impact face244is restrained directly by the anchoring line254. As shown, such an arrangement provides an enhanced degree of restraint at the impact face244. In the illustrated arrangement, the air bag cushion230also includes a selvage portion270with acceptance openings272as previously described in relation to the embodiment ofFIGS. 5-8. Thus, as shown inFIG. 10, substantial restraint may be achieved in both the lateral and vertical expansion of the air bag cushion230when the anchoring line254is held in an anchored position. However, upon release of the anchoring line254, both vertical and lateral expansion is permitted (FIG.11). Of course, as with previous embodiments, the tethering elements238retain an effective operative depth between the positions of attachment240and the collection region242such that a degree of shape defining tensioning restraint is maintained even in the released condition. Of course, if desired, the perimeter openings272may be eliminated or not used so as to provide greater radial expansion even in the initial restrained condition.

It is to be understood that while the present invention has been illustrated and described in relation to various exemplary embodiments, constructions and practices that such embodiments, constructions and practices are intended to be illustrative only and that the present invention is in no event to be limited thereto. Rather, it is contemplated that modifications and variations embodying the principles of the present invention will no doubt occur to those of skill in the art and it is therefore contemplated and intended that the present invention shall extend to all such modifications and variations as may incorporate the broad principles of the invention within the full spirit and scope thereof.