Abstract:
An energy absorber for protecting the occupants of a vehicle. The energy absorber includes an interior portion and a first contact surface at least partially surrounding the interior portion. The first contact surface is attachable to a structural member of the vehicle. The energy absorber also includes at least one hollow cavity extending through the interior portion in a direction substantially parallel to the first contact surface. During a vehicle collision, the first contact surface absorbs energy from occupant impact with an interior trim piece by deforming into the hollow cavity.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to an energy absorber designed to protect the occupants of a vehicle during a collision. More specifically, the invention relates to an device that absorbs energy from a collision involving a structural member of the vehicle. 
   2. Description of Related Art 
   An important issue facing vehicle manufacturers involves providing increased protection to vehicle occupants in the event of a collision. In recent years, some manufacturers have started adding energy absorbing members, or energy absorbers, to their vehicles. Such energy absorbers are typically positioned between a structural member of the vehicle body and one or more interior trim pieces. For example, an energy absorber may be positioned between the B-pillar and an interior trim piece covering the B-pillar. Other structural members where energy absorbers are typically installed include the A-pillar, the roof rail, the bumpers, and so forth. 
   During a collision involving a vehicle, occupants may move from their initial position with respect to the vehicle and impact one or more interior trim pieces such as a door trim panel, an A-pillar cover, a B-pillar cover, etc. If one or more energy absorbers are positioned between the interior trim pieces and structural members of the vehicle, the energy absorbers may reduce the likelihood of injury to the occupants. 
   There are, however, several disadvantages with known energy absorbers. For example, honeycomb structures produced from either paper (e.g., kraft, NOMEX® etc.), aluminum, or plastic have been used as energy absorbers. However, the potential for moisture absorption makes paper honeycomb undesirable for long life applications. Aluminum honeycomb is expensive to manufacture, and is also subject to corrosion and conductivity of heat and electricity. Plastic honeycomb is both difficult and expensive to manufacture. Moreover, honeycomb structures in general typically only perform well in a single impact direction. If the honeycomb is struck off-axis, its effectiveness is reduced considerably. 
   Moreover, in some vehicles, an adjustable turning loop (ATL) assembly may be positioned between the energy absorber and the interior trim member. The ATL assembly is part of the seat belt assembly, and consists of a turning loop portion and a height adjusting mechanism. The turning loop portion routes a shoulder belt portion of the seat belt over and across the shoulder of an occupant of the vehicle. The height adjusting mechanism allows the vertical position of the turning loop to be adjusted by an occupant of the vehicle, and includes a track portion and a slidable carriage which moves within the track portion. 
   There are cost and design issues associated with attaching known energy absorbers to an ATL assembly. For example, the track portion of an ATL assembly may be shaped differently (straight, curved, etc.) in different vehicles. It is desirable to provide an energy absorber that will conform to the shape of the track portion. Therefore, different energy absorbers must typically be designed for different types of vehicles. 
   Accordingly, it would be an advancement in the art to provide an energy absorber that will absorb energy from a collision even if the impact force is off-axis (i.e., not exactly perpendicular) to the energy absorber. It would be a further advancement in the art to provide an energy absorber which may be fabricated relatively easily at a lower cost than existing energy absorbers, and which may be used in conjunction with different ATL assemblies. The present invention provides these advancements in a novel and useful way. 
   SUMMARY OF THE INVENTION 
   The apparatus of the present invention has been developed in response to the present state of the art, and in particular, in response to the problems and needs in the art that have not yet been fully solved by currently available energy absorbers. Thus, an energy absorber for protecting the occupants of a vehicle is disclosed. The energy absorber includes an interior portion. A first contact surface at least partially surrounding the interior portion is also provided. The first contact surface is attachable to a structural member of the vehicle. The energy absorber also includes at least one hollow cavity extending through the interior portion in a direction substantially parallel to the first contact surface. During a vehicle collision, the first contact surface absorbs energy from occupant impact with an interior trim piece by deforming into the hollow cavity. The energy absorber also includes a second contact surface opposite the first contact surface. The second contact surface may be configured to be attached to an adjustable turning loop (ATL) assembly. 
   The energy absorber may be capable of conforming to match the shape of the structural member to which it is attached. For example, the first contact surface of the energy absorber and the interior portion of the energy absorber may each include at least one crease. In embodiments where the energy absorber is also attached to an ATL assembly, the energy absorber may also be capable of conforming to match the shape of the ATL assembly. Both the structural member and the ATL assembly may be straight, curved, or any other desired shape. 
   The length of the energy absorber may be the same as the length of the ATL assembly. Alternatively, the length of the energy absorber may be different than the length of the ATL assembly. 
   The interior portion of the energy absorber may include a curved portion. A hollow cavity may extend through the curved portion in a direction substantially parallel to the first contact surface. 
   The hollow cavity in the interior portion of the energy absorber may be a wide variety of shapes. For example, the hollow cavity may possess a substantially rectangular cross-section, a substantially circular cross-section, a substantially triangular cross-section, or any other suitable shape. 
   The hollow cavity may be formed by conveying an extrudable material through a die. The extrudable material may be a crystalline resin, a polypropylene resin, a PVC resin, or any other suitable material. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In order that the manner in which the above-recited and other advantages of the invention are obtained will be readily understood, a more particular description of the invention briefly described above will be rendered by reference to specific embodiments thereof which are illustrated in the appended drawings. Understanding that these drawings depict only typical embodiments of the invention and are not therefore to be considered to be limiting of its scope, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings in which: 
       FIG. 1  is a plan view of a side interior portion of a vehicle; 
       FIG. 2A  is a perspective view of the bottom side of an energy absorber; 
       FIG. 2B  is a perspective view of the top side of an energy absorber; 
       FIG. 3  is a perspective view of an ATL assembly attached to an energy absorber; 
       FIG. 4  is a perspective view of an extrusion die which may be used to prepare an energy absorber; 
       FIG. 5  is a perspective view of an energy absorber having a plurality of creases and a curved ATL assembly; 
       FIG. 6A  is a side plan view of an energy absorber that has a plurality of hollow cavities with a substantially circular cross-section; 
       FIG. 6B  is a side plan view of an energy absorber that has a plurality of hollow cavities with a substantially triangular cross-section; and 
       FIG. 6C  is a side plan view of an energy absorber that has a plurality of hollow cavities with a substantially rectangular cross-section. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   It will be readily understood that the components of the embodiments as generally described and illustrated in the Figures herein could be arranged and designed in a wide variety of different configurations. Thus, the following more detailed description of certain exemplary embodiments of the present invention is not intended to limit the scope of the invention, as claimed, but is merely representative of the embodiments of the invention. 
   Referring now to  FIG. 1  there is shown a vehicle  10 , and more particularly the construction of a side interior portion  12  of the vehicle  10 . The vehicle  10  includes a number of structural members that provide structural support to the vehicle  10 . In the embodiment shown in  FIG. 1 , the structural members include an A-pillar  14 , a B-pillar  16 , and a roof rail  18  which connects the A-pillar  14  and the B-pillar  16 . The various structural members of the vehicle  10  are typically covered by decorative trim pieces such as an upper trim piece  30 . 
   The vehicle  10  also includes a safety restraint system  20 . The safety restraint system  20  includes a seat belt having a shoulder belt portion  22 . The shoulder belt portion  22  is positioned and guided by a turning loop  24 , which routes the shoulder belt portion  22  over and across the shoulder of an occupant of the vehicle  10 . The turning loop  24  is attached to a height adjusting mechanism  26 . The height adjusting mechanism  26  includes a track portion and a slidable carriage (not shown) which moves within the track and permits an occupant to adjust the vertical position of the turning loop  24 . Because the vertical position of the turning loop  24  may be adjusted by an occupant, the turning loop  24  and height adjusting mechanism  26  are often collectively referred to as an adjustable turning loop (ATL) assembly  28 . The various elements of the ATL assembly  28  are typically covered by decorative trim pieces such as ATL trim piece  32 . 
   The ATL assembly  28  may be attached to one or more structural members of the vehicle  10 . For example, in the embodiment shown in  FIG. 1 , the track portion of the ATL assembly  28  is attached to the B-pillar  16 . Any suitable attachment mechanism may be used, such as a threaded fastener, a tongue and groove fastener, or the like. 
   The ATL assembly  28  may conform to the shape of the structural member to which it is attached. For example, in  FIG. 1 , the B-pillar  16  has a substantially flat surface. The ATL assembly  28  conforms to the shape of the B-pillar  16 , i.e., the ATL assembly  28  also has a substantially flat surface which rests against the substantially flat surface of the B-pillar  16 . In alternative embodiments, the B-pillar  16  and the ATL assembly  28  may be substantially curved, or any other desired shape. 
   During a collision involving the vehicle  10 , an object (e.g., a barrier or another vehicle) may strike the vehicle  10 . Some or all of the energy of the striking object may be transferred to one or more structural members and/or the ATL assembly  28 . For example, in a side impact collision, an object may strike the side of the vehicle  10  at the location of the B-pillar  16 . The energy of the striking object may be transferred to the B-pillar  16 , causing it to collapse inward. If an ATL assembly  28  is attached to the B-pillar  16 , energy may be further transferred to the ATL assembly  28 , causing it too to collapse inward. This chain of events may cause one or more interior trim pieces to strike an occupant of the vehicle  10 . 
   One way to absorb impact energy from occupants striking interior trim pieces in a vehicle crash is to attach an energy absorber (not shown in  FIG. 1 ) to one or more of the structural members of the vehicle  10 . For example, an energy absorber may be attached to the B-pillar  16 . When the B-pillar  16  is struck and begins to collapse inward, the energy absorber may absorb some of the energy from the collapsing B-pillar  16 . The energy absorber may therefore dissipate impact energy that would otherwise be transferred to vehicle occupants from contact with the interior trim pieces. Accordingly, the energy absorber may reduce the chance of injury to an occupant of the vehicle  10  during a collision. 
     FIG. 2A  shows a perspective view of the bottom side  36  of an embodiment of an energy absorber  34 . As shown, the energy absorber  34  includes an interior portion  38 . The interior portion  38  includes a straight portion  40  and a first contact surface  42  which borders the straight portion  40  on its bottom side  36 . 
     FIG. 2B  shows a perspective view of the top side  44  of an embodiment of an energy absorber  34 . The energy absorber  34  includes a second contact surface  46  which borders the straight portion  40  of the interior portion  38  on its top side  44 . 
   The first contact surface  42  may be configured to be attached to a structural member of the vehicle  10 , such as the B-pillar  16 . For example, referring to  FIGS. 2A and 2B  collectively, two holes  48  and  50  may extend through the first contact surface  42 , the interior portion  38 , and the second contact surface  46 . A piercing tool may be used to create the holes  48  and  50 . Any suitable attachment mechanism may be inserted through the holes  48  and  50  and into matching holes (not shown) in the B-pillar  16  to attach the first contact surface  42  to the B-pillar  16 . For example, a pair of threaded bolts may be used. In one embodiment, the bolts may have a larger diameter than the holes  48  and  50 , and be held in place by resistance. Of course, in alternative embodiments the energy absorber  34  may be attached to any structural member of the vehicle  10  using any number of known attachment mechanisms. 
   The straight portion  40  of the interior portion  38  includes a plurality of hollow cavities  52   a ,  52   b ,  52   c  and  52   d  which extend through the interior portion  38  in a direction substantially parallel to the first contact surface  42  and the second contact surface  46 . In a collision involving the vehicle  10 , the second contact surface  46  may absorb energy from occupant impact with one or more interior trim pieces. For example, in a side impact collision, the second contact surface  46  may deform into the plurality of hollow cavities  52   a ,  52   b ,  52   c  and  52   d  in order to absorb energy from an occupant&#39;s impact with one or more interior trim pieces, such as the trim pieces that cover the B-pillar  16 , the ATL assembly  28 , roof rail  18 , and the like. This may provide increased protection to the occupants of the vehicle  10 . 
   The interior portion  38  of the energy absorber  34  also includes a first curved portion  54  and a second curved portion  56 . A plurality of hollow cavities  52   e  and  52   f  extend through the first curved portion  54  in a direction substantially parallel to the first contact surface  42 . Similarly, a plurality of hollow cavities  52   g  and  52   h  extend through the second curved portion  56  in a direction substantially parallel to the first contact surface  42 . The first and second curved portions  54  and  56  may enhance the ability of the energy absorber  34  to absorb energy from a collision in which a vehicle occupant strikes the interior trim pieces at an angle that is not exactly perpendicular to the straight portion  40  of the energy absorber  34 . However, the invention should not be construed as requiring one or more curved portions. 
   In one embodiment, an energy absorber  34  may be placed between a structural member of the vehicle and an ATL assembly  28 . For example, with reference to  FIG. 3 , the energy absorber  34  may be placed between the ATL assembly  28  and the B-pillar  16 . In particular, the ATL assembly  28  may include a hole  58 . A threaded bolt  60  may be inserted through the hole  58  in the ATL assembly  28  and a similar hole  48  in the energy absorber  34 . To attach the ATL assembly  28  and the energy absorber  34  to the B-pillar  16 , the threaded bolt  60  may then be threaded into a mating feature in the B-pillar  16 . Of course, the use of a threaded bolt  60  is exemplary only; any number of suitable attachment mechanisms may be used, including tongue and groove fasteners, threaded screws, and the like. 
   In embodiments where the energy absorber  34  is attached to an ATL assembly  28 , the energy absorber  34  may be about equal to the length of the ATL assembly  28 , as shown in FIG.  3 . Alternately, the energy absorber  34  may be made longer than the ATL assembly  28  to provide additional energy absorbing capability near the ends of the ATL assembly  28 . 
   As noted previously, the energy absorber  34  may be formed by conveying an extrudable material through an extrusion die  62 . Referring now to  FIG. 4 , there is shown a perspective view of an extrusion die  62  which may be used to prepare an energy absorber  34  in accordance with the invention. The extrusion die  62  may include a die body  64  and a die plate  66 . The die body  64  may include a support portion  68  and a shaping portion  70 . The support portion  68  may include an entrance cavity (not shown). The die plate  66  may include an exit cavity  72  which matches the shape of the energy absorber  34  to be extruded. A plurality of protrusions  74   a ,  74   b ,  74   c ,  74   d ,  74   e ,  74   f ,  74   g  and  74   h  matching the hollow cavities  52   a ,  52   b ,  52   c ,  52   d ,  52   e ,  52   f ,  52   g  and  52   h  shown above in  FIGS. 2A and 2B  may extend from the support portion  68 , through the shaping portion  70 , and into the die plate  66 . 
   Both the die body  64  and the die plate  66  may include a plurality of recesses  76   a ,  76   b , and  76   c . Each recess  76  may be configured to receive an attachment mechanism  78  which may attach the die body  64  to the die plate  66 . For example, the die body  64  and the die plate  66  may be held together by three bolts  78   a ,  78   b , and  78   c  which may be threaded through the recesses  76   a ,  76   b , and  76   c.    
   An extrudable material suitably heated to its molten state may enter through the entrance cavity in the support portion  68 . The molten extrudable material may then flow into the shaping portion  70 , where it may be extruded past the protrusions  74  and into the desired form of the energy absorber  34 . During this process, cooling may occur so that the energy absorber  34  may maintain its shape upon leaving the exit cavity  72 . Additional details about the extrusion die  62  and the extrusion process generally will be readily apparent to those of ordinary skill in the art. 
   As stated previously, an ATL assembly  28  may conform to the shape of the structural member to which it is attached. Similarly, the energy absorber  34  may conform to the shape of a structural member and/or an ATL assembly  28  to which it is attached. One way in which this may be accomplished is by manufacturing the energy absorber  34  using an extrudable, flexible material such as a crystalline resin, a polypropylene resin, a polyvinyl chloride, or “PVC” resin, or the like. If an extrudable, flexible material is used, the energy absorber  34  may more readily conform to match the shape of a structural member than if such a material is not used. However, the invention should not be construed as requiring an extrudable, flexible material. 
   Another way in which an energy absorber may be made to conform to the shape of a structural member and/or an ATL assembly  28  is by the addition of one or more creases  80 , as shown in FIG.  5 . The energy absorber  79  shown in  FIG. 5  includes six creases  80   a ,  80   b ,  80   c ,  80   d ,  80   e , and  80   f . These creases  80  extend through the first contact surface  42 , the interior portion  38 , and the second contact surface  46 .  FIG. 5  also shows an ATL assembly  82  having a curved shape. As illustrated in  FIG. 5 , the plurality of creases  80  in the energy absorber  79  make it easier to bend the energy absorber  79 , thus simplifying the process of fitting the energy absorber  79  around the curved ATL assembly  28 . Because the energy absorber  79  is capable of conforming to differently shaped structural members and/or ATL assemblies, the energy absorber  79  may be used on differently shaped structural members and/or ATL assemblies within the same vehicle  10 , and/or within different types of vehicles  10 . 
   The creases  80  may be formed in the energy absorber  79  by calendering. In particular, a plurality of wheels (not shown) may be provided adjacent to the exit of the extrusion die  62 . As the extrusion exits the extrusion die  62 , the wheels may be configured to form the creases  80  in the energy absorber  79  in a known manner. 
   Referring now to  FIGS. 6A ,  6 B, and  6 C, there are shown side plan views of energy absorbers  84   a ,  84   b , and  84   c  in accordance with the invention. The hollow cavities within the interior portion  38  of the energy absorber  34  may possess any suitable shape. For example,  FIG. 6A  depicts hollow cavities  86   a ,  86   b ,  86   c , and  86   d  possessing a substantially circular cross-section.  FIG. 6B  depicts hollow cavities  88   a ,  88   b ,  88   c ,  88   d ,  88   e , and  88   f  possessing a substantially triangular cross-section. Finally,  FIG. 6C  depicts hollow cavities  90   a ,  90   b ,  90   c , and  90   d  possessing a substantially rectangular cross-section. Differently shaped hollow cavities possess different levels of resistance to being crushed. For example, the hollow cavities  86  having a substantially circular cross-section are less resistant to being crushed than the hollow cavities  88  having a substantially rectangular cross-section. Of course, the differently shaped hollow cavities  86 ,  88 , and  90  depicted in  FIGS. 6A-6C  are exemplary only; an energy absorber in accordance with the invention may include hollow cavities having any number of other shapes. 
   From the above discussion, it will be appreciated that many of the problems associated with known energy absorbers are addressed by the teachings of the present invention. The present invention provides an energy absorber that will absorb energy from a collision even if the impact force is off-axis (i.e., not exactly perpendicular) to the energy absorber. In addition, an energy absorber in accordance with the invention may be fabricated relatively easily at a lower cost than existing energy absorbers, and may be used on differently shaped structural members and/or ATL assemblies within the same vehicle, or within different types of vehicles. 
   The present invention may be embodied in other specific forms without departing from its essential characteristics as broadly described herein and claimed hereinafter. The described embodiments are to be considered in all respects only as illustrative, and not restrictive. The scope of the invention 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.