Abstract:
A volume-filling mechanical structure for modifying a crash including: a bolster system defined by an outer bolster and an inner bolster; a honeycomb celled material expandable from a dormant state to a deployed state, the honeycomb celled material disposed intermediate the outer and inner bolsters cooperatively positioned with the honeycomb celled material to cover surfaces defining the honeycomb celled material in the deployed and dormant states; a means for deploying the honeycomb celled material from the dormant state to the deployed state causing the outer bolster to translate away from the inner bolster; and a tether operably connecting one end of the honeycomb celled material to the means for deploying the honeycomb celled material from the dormant state to the deployed state.

Description:
TECHNICAL FIELD 
     The present invention relates to structures used for crash protection and/or crash energy management at around the time of a vehicle crash, and more particularly to means for deploying mechanical structures, which are volumetrically reconfigurable such as to occupy a small volume when in a dormant state and then rapidly expand to a larger volume in a deployed state when needed for providing crash protection and/or crash energy management. 
     BACKGROUND OF THE INVENTION 
     A vehicle, in addition to the inherent crush characteristics of its structure, may have dedicated crash energy management structures. Their function is exclusively to dissipate energy in the event of a crash. Such dedicated structures have predetermined crush characteristics which contribute to the resulting deceleration pulse to which the occupants are subjected. 
     In the vehicular arts there are two known types of such dedicated crash energy management structures: those which are passive, and those which are active. 
     An example of a passive dedicated crash energy management structure is an expanded honeycomb celled material, which has been used to a limited degree in certain vehicles.  FIG. 1  exemplifies the process of fabrication of a honeycomb-celled material. A roll  10  of sheet material having a preselected width W is cut to provide a number of substrate sheets  12 , each sheet having a number of closely spaced adhesive strips  14 . The sheets  12  are stacked and the adhesive cured to thereby form a block, referred to as a HOBE® (registered trademark of Hexcel Corporation) block  16  having a thickness T. The HOBE block is then cut into appropriate lengths L to thereby provide HOBE bricks  18 . The HOBE brick is then expanded by the upper and lower faces  20 ,  22  thereof being separated away from each other, where during the adhesive strips serve as nodes whereat touching sheets are attached to each other. A fully expanded HOBE brick is composed of a honeycomb celled material  24  having clearly apparent hexagonal cells  26 . The ratio of the original thickness T to the expanded thickness T′ is between 1 to 20 to 1 to 60. An expanded honeycomb celled material provides crash energy management parallel to the cellular axis at the expense of vehicular space that is permanently occupied by this dedicated energy management structure. 
     Typically, crash energy management structures have a static configuration in which their starting volume is their fixed, operative volume, i.e. they dissipate energy and modify the timing characteristics of the deceleration pulse by being compressed (i.e., crushing or stroking of a piston in a cylinder) from a larger to a smaller volume. Since these passive crash energy management structures occupy a maximum volume in the uncrushed/unstroked, initial state, they inherently occupy vehicular space that must be dedicated for crash energy management—the contraction space being otherwise unstable. Expressed another way, passive crash energy management structures use valuable vehicular space equal to their initial volume which is dedicated exclusively to crash energy management throughout the life of the vehicle even though a crash may never occur, or may occur but once during that time span. This occupied contraction space is not available for other uses, including functions such as enabling a more spacious vehicle interior and styling flexibility. 
     The fixed fore-aft location of a knee bolster may constrain how far the lower portion of the instrument panel can be placed forward and away from the knees of an occupant. This constraint can limit comfort for the occupant. The position of current fixed-in place knee bolster systems is also a constraint on interior spaciousness. It is known that utilization of inflatable knee bolster systems brings the location of the lower portion of the instrument panel rearward when preferred. However, such crash triggered inflatable knee bolster systems do not typically retract automatically, and could require complete replacement after actuation. Such replacement is expensive, a cost borne by the consumer. 
     Active crash energy management structures have a predetermined size which expands at the time of a crash so as to increase their contribution to crash energy management. 
     One type of dedicated active crash energy management structure is a stroking device, basically in the form of a piston and cylinder arrangement. Stroking devices have low forces in extension and significantly higher forces in compression (such as an extendable/retractable bumper system) which is, for example, installed at either the fore or aft end of the vehicle and oriented in the anticipated direction of crash induced crush. The rods of such devices would be extended to span the previously empty spaces upon the detection of an imminent crash or an occurring crash (if located ahead of the crush front). This extension could be triggered alternatively by signals from a pre-crash warning system or from crash sensors or be a mechanical response to the crash itself. An example would be a forward extension of the rod due to its inertia under a high G crash pulse. Downsides of such an approach include high mass and limited expansion ratio (1 to 2 rather than the 1 to 20 to 1 to 60 possible with a compressed honeycomb celled material). 
     Another type of active dedicated crash energy management structure includes inflatable airbags or pyrotechnic air cans. Downsides of such systems, in addition to those discussed above, include low force levels and low ratios of crush force to added mass due to the lack of mechanical rigidity of these systems. 
     Accordingly, what remains needed in the vehicular arts is a dedicated vehicular crash energy management structure which provides at times other than a crash event open spaces for other uses than crash pulse management, a high level of compression ratio, high crush force, and a low crush force to mass ratio. 
     Examples of some such active and passive devices are detailed in U.S. Pat. No. 6,702,366 the contents of which are incorporated by reference herein. U.S. Pat. No. 6,702,366 provides for both active and passive crash energy management structures. Specifically, U.S. Pat. No. 6,702,366 describes the use of a honeycomb celled material, such as that described above that expands from a dormant state to a deployed state at around the time of a crash. U.S. Pat. No. 6,702,366 does not provide for specific deployment means of the honeycomb celled material. 
     Occupant protection devices and crash energy management devices have not been provided with deployment means due to most of such devices being of a selected size and placement which merely deform to absorb crash energy or protect vehicle occupants or pedestrians. As such there has been little development of deployment means for such devices. 
     Accordingly, what remains needed in the vehicular arts are means for deploying a volume-filling mechanical structure with respect to a bolster system, which causes deployment of the volume-filling mechanical structure from a dormant state to a deployed state at around the time of a crash event. 
     SUMMARY OF THE INVENTION 
     In one embodiment herein there is provided a volume-filling mechanical structure for modifying a crash including: a bolster system defined by an outer bolster and an inner bolster; a honeycomb celled material expandable from a dormant state to a deployed state, the honeycomb celled material disposed intermediate the outer and inner bolsters cooperatively positioned with the honeycomb celled material to cover surfaces defining the honeycomb celled material in the deployed and dormant states; a means for deploying the honeycomb celled material from the dormant state to the deployed state causing the outer bolster to translate away from the inner bolster; and a tether operably connecting one end of the honeycomb celled material to the means for deploying the honeycomb celled material from the dormant state to the deployed state. 
     In another embodiment herein there is also provided a system to harness energy from deployment of an airbag to power a vehicle device including: an airbag module; an airbag disposed at the airbag module; an airbag inflator disposed at the airbag module, the airbag inflator in operable communication with the airbag to inflate the same; a spool rotatably disposed around the airbag inflator; and a tether having a first end and a second end, at least a portion of the first end of the tether is wrapped on the spool rotatable by deployment of the airbag and a second end in communication with the vehicle device; wherein the spool is receptive to rotation when loaded by impinging inflator gases from the airbag inflator to wind up the tether used to power the vehicle device. 
     In yet another embodiment herein there is provided a method attenuating a vehicle crash energy impact. The method includes attaching a volume-filling mechanical structure to a bolster system defined by an outer bolster and an inner bolster of a vehicle, wherein the volume-filling mechanical structure includes a honeycomb celled material expandable from a dormant state to a deployed state. The honeycomb celled material is disposed intermediate the outer and inner bolsters cooperatively positioned with the honeycomb celled material to cover surfaces defining the honeycomb celled material in the deployed and dormant states. The volume-filling mechanical structure further includes a means for deploying the volume-filling mechanical structure from the dormant state to the deployed state. A tether operably connects one end of the honeycomb celled material to the means for deploying the volume-filling mechanical structure from the dormant state to the deployed state and the honeycomb celled material expands via the means for deploying at about an energy impact to the vehicle causing the outer bolster to translate away from the inner bolster, and wherein the honeycomb celled material absorbs kinetic energy from the energy impact. 
     In yet another embodiment herein there is provided a motor vehicle equipped with a crash energy management structure, comprising a bolster system; a crash energy management structure connected to the bolster system, the crash energy management structure comprising a volume-filling mechanical structure connected to the bolster system, the volume-filling mechanical structure being expandable from a first volume to a second volume, wherein the second volume is larger than the first volume; an exposed bolster surface cooperatively positioned with the mechanical structure to selectively cover a surface of the first and second volumes, wherein the exposed bolster surface has a dormant state for the first volume and a deployed state for the second volume; a means for deploying expansion of the mechanical structure from the first volume to the second volume, and for regulating a transition from the dormant state to the deployed state of the exposed bolster surface; and a tether operably connecting one end of the honeycomb celled material to the means for deploying expansion of the honeycomb celled material from the first volume to the second volume. 
     The embodiments noted above provide for a mechanical, active dedicated crash energy management structure for providing crash protection and/or crash energy management, wherein the structure has a dormant (initial) state volume, but then in the event of a crash, utilizes various means of deployment that timely expand into a much larger deployed volume for providing management of energy of an expectant crash. 
     The active dedicated crash energy management structure according to the present invention directly addresses the space robbing deficiency of prior art crash energy management structures. It does this specifically by having a small dormant volume (during normal driving conditions) which allows empty space adjacent thereto for enabling a more spacious vehicle interior and styling flexibility, and only assumes a larger deployed volume just prior to, or in response to, a crash. 
     The principle embodiment of the crash energy management structure according to the present invention is a before expansion honeycomb celled material brick (honeycomb brick) such as for example manufactured by Hexcel Corp. of Pleasanton, Calif., wherein expansion of the honeycomb brick is in a plane transverse to the cellular axis of the cells thereof, and crash crush is intended to be parallel to the cellular axis. 
     The honeycomb brick occupies anywhere from approximately 1/20th to 1/60th of the volume that it assumes when in it is fully deployed (the expansion ratio) into a deployed honeycomb celled material (deployed honeycomb), depending on the original cell dimensions and wall thickness. Honeycomb cell geometries with smaller values of the expansion ratio in general deliver larger crush forces, and the choice of the honeycomb celled material is dependent upon the crush force (stiffness) desired in a particular crash energy management application (i.e., softer or harder metals or composites). Deployed honeycomb celled material has excellent crash energy management capabilities, but only parallel to the cellular axis, as discussed hereinabove. 
     According to one embodiment herein, various devices provide for means of deploying a volume-filling mechanical structure, such as an expandable honeycomb brick located within a panel, such as exist for example in the instrument panel including the glove box panel or steering column filler. The honeycomb brick is placed so that the common cellular axis of its cells is oriented parallel to an envisioned crash axis, i.e., the direction of impact for which it is intended to serve as an energy absorber. A rigid end cap is attached, respectively, to each of the mutually opposed upper and lower end faces of the honeycomb brick (the ends which are perpendicular to the transverse plane and parallel to the crash axis). 
     In the event of a crash, either an active or passive deployment means is provided for moving the end caps away from each other so that the honeycomb brick expands in the transverse plane into the previously unoccupied transversely adjacent space. For example, movement of the end caps may be triggered by a pyrotechnic explosion, air pressure, a pneumatic spring, a tensioning of a flexible cable, a solenoid, an active material and the like. Upon expansion, this previously unoccupied space will now function efficiently for crash energy management. 
     Various embodiments are proposed which allow for returning the honeycomb celled material from the deployed state to the dormant state in the event a serious crash does not occur. While various automatic means can be envisioned, one embodiment would involve a manual reset, for example by a trained mechanic at a dealership. For example, the mechanic would compress the honeycomb celled material back to the dormant state, compress an expansion agency (i.e., a spring) and reset a catch of the deployment means holding the honeycomb celled material in the dormant state ready for expansion in the event of a forthcoming crash. 
     Accordingly, it is one embodiment herein to provide a dedicated crash energy management structure, comprising a volume-filling structure with deployment means for deploying the volume-filling structure from a small dormant state volume which in the event of a crash, timely expands into a much larger deployed volume for providing management of an expectant crash pulse. 
     This and additional features and advantages will become clearer from the following specification. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a series of perspective views of a manufacturing process to provide a prior art honeycomb celled material. 
         FIG. 2  is a perspective view of a crash energy management device according to the present invention, shown in a before expanded (dormant) state. 
         FIG. 3  is a perspective view of the crash energy management device of  FIG. 2 , shown in an expanded (deployed) state. 
         FIG. 4  is a perspective, cut-away view of a crash energy management device according to the present invention, showing an example of an active activation system. 
         FIG. 5  is a broken-away, top plan view, showing a trigger of the activation system of  FIG. 4 . 
         FIG. 6  is a schematic cross section view of a steering column assembly in conjunction with a portion of an instrument panel showing a biasing member in communication with crash energy management device via a tether in accordance with an exemplary embodiment. 
         FIG. 7  is an enlarged cross section view of the biasing member of  FIG. 6 , showing a compression spring disposed around a steering column. 
         FIG. 8  is a schematic cross section view of a tension spring used as a biasing member, showing the tension spring in the dormant state in an alternative exemplary embodiment. 
         FIG. 9  is a schematic cross section view of  FIG. 8 , showing the tension spring in the deployed state. 
         FIG. 10  is a cross section view of a coil spring mechanism depicting the biasing member as a coil spring operably connected to the tether in an alternative exemplary embodiment. 
         FIG. 11  is a cross section view of separable inner and outer bolsters having the crash energy management device disposed therebetween in accordance with an alternative exemplary embodiment. 
         FIGS. 12-14  is a progression of deployment of the crash energy management device of  FIG. 11  illustrating pivoting movement thereof and expansion thereof. 
         FIG. 15  is a cross section view of the honeycomb celled material disposed in a glove box door in an unexpanded form and operably connected via the tether to a passenger side inflatable restraint system. 
         FIG. 16  is a perspective view of an airbag module housing having an inflator for use as a deployment means of the honeycomb celled material. 
         FIG. 17  is a perspective view of a spool with vanes positioned around the inflator and one or more tethers attached to the spool in accordance with an exemplary embodiment. 
         FIG. 18  is an alternative embodiment of  FIG. 17  illustrating the spool disposed at one end of the inflator. 
         FIG. 19  is a side view of the perspective view illustrated in  FIG. 18 . 
         FIG. 20  is a cross section view of seals disposed intermediate the spool and the inflator. 
         FIG. 21  is a cross section view of an airbag module used for applications where the inflator pipes gas into a cushion including a roof rail air bag, for example, in accordance with alternative exemplary embodiment. 
         FIG. 22  is a perspective view of a plug in  FIG. 21  through which the tether routes through. 
         FIG. 23  is a partial perspective view of the spool and inflator illustrating attachment of tether to the spool. 
         FIG. 24  is a partial perspective view of another spool and inflator illustrating attachment of tether to the spool in accordance with an alternative embodiment. 
         FIG. 25  is a perspective view of the tether configured as a metal strap. 
         FIG. 26  is schematic a lower tether routed in a roof rail air bag, where the lower tether may be tightened using the approach described above with reference to  FIGS. 17-25 . 
         FIGS. 27-29  is a deployment progression illustrating the lower tether attached to and used to position a flap in a roof rail air bag application as it is pulled tight during deployment of the inflator. 
         FIG. 30  is a schematic of the tether attached to a portion of an airbag cushion that is pulled during deployment, in accordance with another exemplary embodiment. 
         FIG. 31  is a side view of the tether having tear stitching as an energy-absorption feature upon completion of deployment. 
         FIG. 32  illustrates a sequential assembly and operation of an alternative exemplary embodiment of a release mechanism for the tether upon completion of deployment. 
         FIG. 33  is a perspective view of one end of the tether including two folds and attached to an end cap to facilitate deployment. 
         FIG. 34  is an enlarged view of  FIG. 33  illustrating one of the to folds in detail. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     The present disclosure provides a crash energy management structure that comprises an expandable volume-filling mechanical structure for containing and cushioning occupants within the vehicle in impacts with both interior and exterior objects, wherein the volume-filling mechanical structure has means for, in the event of a crash, timely expanding into a deployed volume for providing energy absorption of an expectant crash. At around the time of a crash event in or around a vehicle and/or about energy impact is when the means for deploying the volume-filling structure may be actuated. The current disclosure employs the volume-filling mechanical structures such as honeycomb celled material  104  with a knee bolster for a driver or passenger within the vehicle. Such employment allows variation of current knee bolster design guidelines while providing for easy deployment of honeycomb celled material  104  from a dormant state to a deployed state without significant expense or complexity. 
     Referring now to the Drawings,  FIGS. 2 through 34  depict preferred embodiments of an active dedicated crash energy management structure  100  according to the present invention. 
     A honeycomb brick  102  composed of a honeycomb celled material  104  is provided, as for example according to a method of manufacture utilized to provide HOBE® bricks, as discussed hereinabove. The honeycomb brick  102  is not expanded such that it is at its most compacted state. Attached (such as for example by an adhesive) to the upper and lower faces  106 ,  108  of the honeycomb brick  102  are respective end caps  110 ,  112 . The end caps  110 ,  112  are rigid and serve as guide members for defining the configuration of the honeycombed cell material  104  between a dormant state as shown at  FIG. 2  and a deployed state as shown at  FIG. 3 . 
     The end caps  110 ,  112  need not necessarily be planar. Indeed, they do not need to have the same shape or size, but for a minimum unexpanded volume the end caps should have the same size and shape. For example, if deployed at a knee bolster area, the end caps may have a slightly curved shape generally matching the curve of the knee bolster area corresponding with a lower portion of the instrument panel extending along a width defining the vehicle. For another example, for expansion into a narrowing wedge shaped space, the end cap which moves as the honeycomb celled material expands may be shorter than the stationary end cap, so that the expanded honeycomb celled material has a complimentary wedge shape. 
     An activation mechanism  114  is connected to the end caps  110 ,  112 . The activation mechanism  114  controls the state of the honeycomb-celled material in that when activated, a rapid expansion from the dormant state to the deployed state occurs. One or more installation brackets  115  may be connected to one of the end caps  110 ,  112  so that the crash management structure  100  is connectable to a selected component of a motor vehicle. Alternatively, one of the end caps  110 ,  112  may be fixedly secured directly to a selected component of the motor vehicle without any installation brackets, as discussed more fully herein. 
     An example of an activation mechanism  114  is shown at  FIGS. 4 and 5 . An expansion agency in the form of a highly compressed spring  116  is situated abuttingly between the end caps  110 ,  112 . The spring  116  is held highly compressed selectively by a trigger  118 . The trigger  118  includes a disk  120  which is rotatably mounted to an end cap  110 , wherein the disk has a pair of opposed fingers  122  which are receivable by a pair of opposed slots  124  formed in the end cap. In an active form, the activation mechanism  114  is triggered by a signal from a crash sensor  126  which signal is interpreted by an electronic control module  128 , which in response sends an activation signal to a solenoid  130 . The activation signal causes a rotation of the disk  120  so as to cause the fingers  122  to fall into the slots  124  and thereupon the spring to rapidly decompress resulting in the honeycombed cell material to rapidly expand from the dormant state of  FIG. 2  to the deployed state of  FIG. 3 . Other expansion agencies besides a compressed spring may include a pyrotechnic device or a pressurized air cylinder. Alternatively, the activation mechanism may be passive and mechanically triggered by a crash due to crash induced movement of vehicle components. 
       FIGS. 6  though  15  show illustrative examples of knee bolster compartment placements  140  of the active dedicated crash energy management structure  100 . Placements  140  may also, for example, be located at a glove box door for a passenger ( FIGS. 11-15 ) or located between the instrument panel retainer  342  and the steering column filler  144  for a driver ( FIGS. 6 and 7 ). 
     Referring now to  FIGS. 6 and 7 , placement  140  includes a steering column assembly illustrated in conjunction with a portion of an instrument panel  142  extending from a retainer  143  corresponding with a lower steering column shroud area or steering column filler  144 . The steering column assembly  140  includes a hand wheel  146  operably coupled to a steering column  148 . A housing  150  is fixedly secured relative to steering column  148  indicated generally at  152 . Bearings  154  are disposed at either end defining housing  150  rotatably supporting steering column  148 . 
     A biasing member  155  is disposed in housing  150 . In an exemplary embodiment, biasing member includes a compression spring  156  compressed against bearing  154  proximate hand wheel  146  via a disk  158  slidably disposed in housing  150 . Disk  158  includes an aperture  160  aligned with steering column  148  allowing steering column  148  therethrough. Disc  148  further includes one end  162  of a tether  164  operably coupled thereto and extending therefrom. An opposite end  166  of tether  164  is operably coupled to first rigid end cap  110 , which in turn is coupled to honeycomb celled material  104 . The honeycomb celled material is disposed in a dormant state in a space  168  defined between an outer bolster  170  and an inner bolster  172  defining the steering column filler panel  144 . 
     The deployment mechanism for expanding the honeycomb celled material in an exemplary embodiment and still referring to  FIGS. 6 and 7 , includes a sensing system (not shown) for a drivers side air bag (not shown) to actuate the drivers side lower energy management system. The system uses tether  164  to attach the expandable honeycomb material  104  to compression spring  156  mounted around steering column  148  within housing  150 . A sleeve  174  is disposed between spring  156  and housing  150  to facilitate translation of a movable end  176  of spring  156  within housing  150 . In an exemplary embodiment, sleeve  174  is a nylon sleeve. When the vehicle detects a collision, a solenoid  178  or other mechanism releases spring  156 . The energy stored in spring  156  expands the metallic honeycomb material  104  via tether  164 . In an exemplary embodiment, aluminum honeycomb material  104  is used, which expands to 60 times its original thickness and can be deployed with 1/10 the energy the material manages when deployed. 
     The expandable honeycomb celled material  104  can be mounted in the lower or upper portion of the steering column filler  144  and tether  164  can either pull up or down. As such, the deployment mechanism described above is suitable for use in deployment of an energy management system for the lower steering column shroud area. An energy management deployment system as described can be easily carried from one vehicle design to another with minimal work. Furthermore, such a system requires less packaging space than a design with a separate deployment system. 
     Referring now to  FIGS. 8 and 9 , biasing member  155  includes a tension spring  180 . This deployment mechanism is a tension spring system that includes tension spring  180  pulled to store the energy needed to deploy an expandable aluminum honeycomb bolster system. Tension spring  180  is housed in a cylinder housing  150 , similar to the housing  150  used with compression spring  156  in  FIGS. 6 and 7 . Cylinder housing  150  for tension spring  180  has a length substantially equal to a length of the spring free length (see  FIG. 9 ) and a length (L) of the desired bolster protection indicated generally at  182 . The system uses tether  164  attached to tension spring  180  at end  162  and an opposite end  166  operably coupled to the unexpanded aluminum honeycomb celled material  104 . When the crash sensor  126  senses a collision a solenoid (not shown) releases tension spring  180 . The released spring pulls in tether  164  forcing the aluminum honeycomb material to expand as described above. 
     Referring now to  FIG. 10 , a coil spring mechanism  184  is illustrated depicting biasing member  155  as a coil spring  186  in an alternative exemplary embodiment. Coil spring mechanism includes a housing  250  having an opening  190  receptive to tether  164  extending therethrough. A spool  192  is rotatably disposed within housing  250 . One end  162  of tether  164  is coiled around spool  192  while an opposite end thereof is operably coupled to first rigid end cap  110 , which in turn is coupled to honeycomb celled material  104 , with reference to  FIG. 6 . Coil spring  186  is operably connected to spool  192 , both of which are disposed within housing  250 . Coil spring  186  is receptive to storing energy to deploy the honeycomb celled material  104  by coiling tether  164  proximate end  162  around spool  192 . 
     In an exemplary embodiment, coil spring  186  is wound to store the energy needed to deploy an expandable aluminum honeycomb bolster system. The system uses tether  164  attached to coil spring  186  at end  162  and the opposite end  166  attached the unexpanded aluminum honeycomb material  104  (e.g., dormant state). When the crash sensor or sensing and diagnostic module (SDM) senses a collision, a solenoid (not shown), but similar to solenoids  130 ,  170 , releases the spring mechanism. The released spring  186  reels in tether  164  forcing the aluminum honeycomb material to expand within the bolster system similar to that as described with reference to  FIG. 6 . 
     Referring now to  FIGS. 11-14 , another alternative exemplary embodiment of a deployment mechanism for honeycomb celled material  104  is illustrated. In particular, instrument panel  142  is shown in conjunction with a glove box panel door  188  defined by outer bolster  170  and inner bolster  172 . Inner and outer bolsters are separable indicated generally at  191  in  FIG. 12 . Honeycomb celled material  104  is disposed in a dormant state ( FIG. 12 ) in a space  168  defined between outer bolster  170  and inner bolster  172  defining the glove box panel door  188 . Opposite end  166  of tether  164  is operably coupled to first rigid end cap  110 , which in turn is coupled to honeycomb celled material  104 . 
     One end  193  of the second rigid end cap  112  opposite the first rigid end cap  110  having material  104  therebetween is pivotally engaged with inner bolster  172  generally indicated at  194 . In an exemplary embodiment as illustrated, pivot  194  includes a hinge  194 . Hinge  194  is anchored to inner bolster  172  via a plate  196  pivotally extending therefrom. Plate  196  is fastened to inner bolster  172  using a mechanical fastener, such as a threaded bolt  198  extending through an aperture  199  in plate  196  and threadably received in inner bolster  172  as best seen in  FIG. 11 . 
     The first and second rigid end caps  110 ,  112 , respectively are disposed substantially parallel to surfaces defining the inner and outer bolsters  172 ,  170 , respectively, in a first plane corresponding to an Y-axis as in  FIG. 12 . End  166  of tether  164  is operably coupled to the first rigid end cap  110  and is receptive to pivoting end caps  110  and  112  about hinge  194  pulling the honeycomb celled material  104  into a second plane substantially transverse to the first plane allowing the honeycomb celled material to expand as best seen in  FIG. 14 . The second plane corresponds to an X-axis substantially normal to the Y-axis illustrated in  FIG. 12 . The expansion of the honeycomb celled material  104  ( FIG. 14 ) prevents further pivoting of the second rigid end cap  112  about hinge  194  as the honeycomb celled material  104  is allowed to expand in space  168  intermediate the inner and outer bolsters  172 ,  170 , respectively. 
     In the above described manner, the unexpanded honeycomb celled material  104  is packaged in the instrument panel such that end caps  110  and  112  are substantially parallel to a show surface (e.g., exposed surface of instrument panel or panel door within occupant compartment of vehicle). Disposing the honeycomb celled material parallel to the show surface enables better packaging and a more spacious vehicle interior. 
       FIG. 15  illustrates another exemplary embodiment of a deployment mechanism for expanding the honeycomb celled material  104  for a knee bolster system. More specifically, a glove box  200  having a glove box door  202  substantially flush with the instrument panel  142  is illustrated. Glove box door  202  includes inner bolster  172  and outer bolster  170  with honeycomb celled material  104  disposed therebetween. As described with reference to FIGS.  6  and  11 - 14 , honeycomb celled material  104  includes end caps  110  and  112  fixed at opposing ends thereof. 
     End cap  110  is receptive to coupling with end  166  of tether  164  to aid in deployment or extend honeycomb celled material  104  into a deployed state. In an exemplary embodiment as illustrated, end cap  110  is a plastic upper carrier to aid in deployment of material  104 . 
     End cap  110  as illustrated includes a wedge  204  extending from opposing ends defining end cap  110  (only one shown). Each wedge  204  is defined by a pointed portion extending in a void  168  defined between inner and outer bolsters  172 ,  170 , respectively, where honeycomb celled material  104  is absent and in the dormant state. Although wedge  204  is described to be disposed at opposing ends of cap  110 , it is contemplated that wedge  204  may extend an entire length thereof or along any portion defining a length cap  110 . In this manner, wedge  204  facilitates expansion of outer bolster  170  from inner bolster  172  when honeycomb celled material  104  is activated to be deployed and extend to fill void  168  between inner and outer bolsters  172  and  170 . Wedge  204  thus guides and facilitates expansion of honeycomb celled material  104 . 
     An opposite end of tether  164  is operably connected to a passenger side inflatable restraint (PSIR) system  210 , such as a passenger side inflatable airbag (not shown). End  162  of tether  164  is attached to the passengers side airbag such that when the air bag is deployed, tether  164  is pulled forcing the expanding honeycomb celled material  104  to expand the glove box door and fill the space  168  between the glove box door defined by inner and outer bolsters  172 ,  170 , respectively. 
     The expandable honeycomb material is aluminum in an exemplary embodiment and can be mounted in the lower or upper portion of the glove box door and the tether can either pull up or down. When the pull direction is up as illustrated in  FIG. 15 , it will be recognized that a coupling (not shown) is needed to permit the glove box door to open. 
     The above described deployment mechanism requires less packaging space than a design with a dedicated deployment system for the expandable honeycomb celled material. Furthermore, use of the PSIR to deploy the honeycomb celled material reduces cost and mass compared to a system with a dedicated deployment mechanism. 
     In another exemplary embodiment referring to  FIGS. 16-29 , another deployment mechanism harnessing energy from a PSIR system is described.  FIG. 16  illustrates an airbag module  302 . The air bag module  302  includes a housing  304 , an inflator  306 , and a cushion or inflatable airbag (not shown) that is attached to housing  304  using numerous existing methods known in the art. 
     Referring now to  FIG. 17 , inflator  306  has gas outlet ports  308  where inflator gas is released upon inflator deployment. A spool  310  with vanes  312  is positioned around inflator  306  so that the vanes  312  align with the inflator gas outlet ports  308 . One or more tethers  314 ,  316  are attached to the spool  310 . Tether  314  may route to a component inside the air bag module  302  while tether  316  may route to a different component outside the air bag module  302 . Tether  316  passes through an aperture  318  in air bag housing  304  and through a plug  320  lining aperture  318  so that tether  316  is not cut by an edge of the airbag housing  304  defining aperture  318 . 
     Upon deployment of inflator  306 , the inflator gases exit gas outlet ports  308  and contact spool vanes  312 . Spool  310  then starts to rotate and tethers  314 ,  316  are wrapped onto spool  310 . Tethers  314 ,  316  can be used to power a function either internal to or external to the air bag module  302 . 
     Spool  310  can be disposed around inflator  306  and positioned either at middle portion of inflator  306  as shown in  FIG. 17  or spool  310  can be positioned at an end of inflator  306  as shown in  FIG. 18 . In  FIG. 18 , spool  310  is retained to a stud  326  extending from one end of the inflator  306  with a nut  328 . In  FIG. 17 , spool  310  is optionally held in a middle portion of inflator  306  by protrusions  330  extending from housing  304 . Alternatively, protrusions may extend from the inflator (not shown) or by a separate piece such as a cushion retainer or a clip (not shown). 
     Referring now to  FIG. 19 , after spool  310  completes rotation, an optional reverse travel prevention feature  332  is optionally included to prevent reverse travel of the spool  310 . It is envisioned that the reverse travel prevention feature  332  is made of a springy material and engage the spool vanes  312  or some other feature on the spool such as a protrusion (not shown). The reverse travel prevention feature  332  is optionally a component of the airbag module housing  304  or an adjacent structure (not shown). 
     To prevent binding of inflator  306  as a result of corrosion, to create smooth bearing surfaces  333 , and to seal inflation gases, it may be desirable to have seals  334  as illustrated in  FIG. 20 . The seals  334  can be of various configurations and may be located where spool  310  could otherwise contact a stationary portion of airbag module  302 . Seals  334  may be fabricated of silicone, for example, but is not limited thereto. 
       FIG. 21  shows a portion of airbag housing  304  that is used for applications where an inflator  324  pipes gas into a cushion (not shown). The cushion includes a roof rail air bag (not shown). A spool  322  is attached to the end of inflator  324  using nut  328 . Housing  304  includes a first portion  336  and a second portion  338  threaded or otherwise mechanically attached thereto. Referring to  FIGS. 21 and 22 , the plug  320  through which tether  316  routes through is of a different shape than that shown in  FIG. 17 . In  FIGS. 21 and 22 , plug  320  includes an outer ring  340  configured to keep inflator gases inside housing  304 . Seals (not shown) can be used to prevent gas leakage and create smooth surfaces for the spool  322  to interface with. In addition, a cup  341  is optionally included to help direct inflator gases toward an outlet hole  343  in housing  304 . 
     Tethers  314 ,  316  can be made of various materials. If a fabric is used, tethers  314 ,  316  may be attached to spool  310 ,  322  in several manners. As shown in  FIGS. 17 and 23 , tether  314 ,  316  is sewn around a clip  342 ,  344  that is placed into holes  346 ,  348  on spool  310 ,  322 . As shown in  FIG. 24 , tether  314 ,  316  is optionally disposed around a protrusion (tab)  350  in spool  310 ,  322 . It is also possible to have a tether  314 ,  316  that is a metal strap  352  as shown in  FIG. 25 . In this case, metal strap  352  is configured with a bent tab  354  placed into hole  346  on spool  310 ,  322 . Alternatively or in addition, metal strap  352  may be welded to spool  310 ,  322 . 
     A system having inflator  306  and spool  310 ,  322  having tether  314 ,  316  operably attached as in the exemplary embodiments described above with reference to  FIGS. 17-25  may be used to power numerous functions within a vehicle. For example, such a system may be used to extend a knee bolster as described with reference to  FIGS. 6-15 . 
     As shown in  FIG. 26 , a lower tether  356  is routed in a roof rail air bag  358 , where the lower tether  356  may be tightened using the approach described above with reference to  FIGS. 17-25 . A tether guide  360  is optionally used to help route tether  356  into housing  304 . 
     As shown in the deployment progression in  FIGS. 27-29 , lower tether  356  may be attached to and used to position a flap  362  in a roof rail air bag application as it is pulled tight during deployment of inflator  306 . 
     In addition, as shown in  FIG. 30 , it may be possible to attach tether  314  to a portion of an airbag cushion  364  and pull that portion of cushion  364  in during deployment, in accordance with another exemplary embodiment. 
     In all cases, initial slack may or may not be present in tether  314 ,  316 . The amount of slack present is optionally used to tune the timing and aggressiveness of the pull on tether  314 ,  316 . When a function of a pulling tether  314 ,  316  is completed, there are several ways to prevent excessive tension buildup in tether  314 ,  316 . In one example, tether  314 ,  316  can be made from a stretchable material that will stretch once the function is completed. Alternatively, tether  314 ,  316  optionally includes an energy-absorption feature. One such energy-absorption feature, for example, includes tear stitching  366 , as illustrated in  FIG. 31 . 
       FIG. 32  illustrates a sequential assembly and operation of an alternative exemplary embodiment of a release mechanism for tether  314 ,  316 . One end  368  of tether  314 ,  316  is attached to a piece  370  that is initially releasably retained by a block  372  slidably disposed between a pair of receiving members  374 ,  376 . When tether  314 ,  316  is pulled so that the function is complete, piece  370  at one end of tether  314 ,  316  is released from block  372 , since a cavity  378  receiving piece  370  is exposed from being between members  374 ,  376 . It will be recognized by one skilled in the pertinent art however, that there are numerous ways in which to hold onto and release a tether from a mechanism, other than the components described with reference to  FIG. 32 . For example, it is envisioned that tether  314 ,  316  can contact a knife edge and be cut by the knife edge once the tether has been pulled to a location where the function is complete. It will be further recognized that block  372  can be operably attached to first rigid end cap  110 . 
     Referring now to  FIGS. 33 and 34 , first and second rigid end caps  110  and  112 , respectively, are illustrated having unexpanded honeycomb celled material  104  disposed therebetween. One end  166  of tether  164  is operably coupled to first rigid end cap  110 . In particular, one end  166  of tether  164  operably attached to the first rigid end cap is defined by first and second portions  380  and  382 , respectively, having an intermediate portion  384  therebetween. A flat broad side defining one surface of intermediate portion  384  of tether  164  is affixed to first rigid end cap  110 . Intermediate portion is defined by outboard ends  386  and  388  corresponding to folds  390  and  392 , respectively, defining the corresponding first and second portions  380 ,  382 , respectively, extending from the outboard ends  386 ,  388  of the intermediate portion. The first and second portions  380 ,  382  each defining terminal ends opposite corresponding folds  390 ,  392  are coupled to each other generally indicated at  394  as best seen in  FIG. 33 . First and second portions  380 ,  382  direct energy from the deployment means (not shown) to translate outer bolster  170  rearward (FIGS.  6  and  11 - 15 ). 
     More specifically, as tether  164  unfolds at the corresponding folds  390 ,  392 , outer bolster  170  is forced to translate rearward providing a path for honeycomb celled material  104  to expand. The fold initiates rotation and proper orientation of the unexpanded aluminum honeycomb material and directs the energy from the deployment system operably connected to end  162  of tether  164  to translate the outer bolster  170  rearward providing a path for the honeycomb celled material  104  as it expands. Tether folds  390 ,  392  permit the unexpanded honeycomb celled material to be packaged in the instrument panel  142 , parallel to a show surface. When the crash sensor or SDM senses a collision, tether  164  is pulled. When the tether folds  390 ,  392  unfold, the outer bolster  170  is forced to translate rearward and the honeycomb celled material  104  is pulled into the proper deployment orientation. In this manner, the outer bolster  170  can be deployed without an added mechanism while enabling a more spacious vehicle interior. 
     In an exemplary embodiment, expandable aluminum honeycomb celled material  104  is used to provide energy management for protection of unbelted occupants. The honeycomb material is installed between the instrument panel retainer or inner bolster  172  and the steering column filler or outer bolster  170 , in an unexpanded state. When the vehicle sensors detect a frontal collision, a sensor generates a signal to a deployment mechanism to actuate and expand honeycomb celled material  104  via tether  164  pulling on first rigid end cap  110  operably coupled to a movable end of the honeycomb celled material. The honeycomb celled material then expands forcing the outer bolster  170  rearward toward a selected bolster zone. This deployment can be accomplished using various means as described above in the exemplary embodiments and understood and appreciated by those skilled in the pertinent art. 
     The aluminum honeycomb material expands to 60 times its original thickness and can be deployed with 1/10 the energy the material manages when deployed. The use of the metallic honeycomb celled material, such as aluminum, for example, can improve protection of occupants, as well as improve spaciousness or a balance of both. 
     The above described exemplary embodiments provide an energy management deployment system that can be easily carried from one vehicle design to another with minimal work and allows easy tuning for specific vehicle parameters and accommodation of a larger range of occupant sizes. Furthermore, the energy management deployment system increases crash performance, while enabling a more spacious interior and more styling flexibility. For example, the energy management deployment system compensates for angled glove box door and steering column filler designs, while providing a parallel loading surface when needed. 
     To those skilled in the art to which this invention appertains, the above-described preferred embodiment may be subject to change or modification. Such change or modification can be carried out without departing from the scope of the invention, which is intended to be limited only by the scope of the appended claims.