Abstract:
A steering column restraining device for a vehicle, wherein the vehicle includes a steering column mounted to a steering column support bracket. The steering column restraining device comprises a first bracket mounted to the steering column support bracket and a second bracket mounted to a floorboard of the vehicle. The first bracket and the second bracket are interconnected using a strap extending therebetween. The device thereby minimizes upward translation of the steering column during impact, which maximizes the effectiveness of the airbag and further minimizes potential injury to the driver.

Description:
FIELD OF THE INVENTION 
     The present invention relates to vehicle safety devices and, more particularly, to a vehicle safety device having a tether strap mounted to a steering column support bracket to minimize uplift of the steering column during a vehicle collision. 
     BACKGROUND OF THE INVENTION 
     As is well known, vehicle safety and crash worthiness is an ongoing concern in the development of new vehicles. Since the 1960&#39;s, automobile manufactures have made considerable strides in the developed of various safety devices and systems intended to protect the vehicle occupants during a collision. In recent designs, vehicle airbags have been introduced and widely used in conjunction with other restraint systems to protect the occupant. An airbag is commonly mounted in the steering wheel to absorb momentum of the driver relative to the steering wheel and column. However, during a severe impact, the engine and front structural members are commonly forced rearward toward the passenger compartment. In many cases, this force may cause the steering wheel and column to rotate upwardly, thereby causing the airbag to be deployed in a less-than-ideal position. That is, the airbag may be deployed at a greater inclined angle than the pre-impact position. This greater inclined deployment angle of the airbag may not afford maximum protection to the driver during a collision. 
     Attempts have been made to improve the structural integrity of the vehicle between the engine compartment and the passenger compartment to minimize the intrusion into the passenger compartment during a collision. One design employs a tube disposed transversely between the A-pillars of the vehicle for supporting the steering column of the vehicle. This design is commonly known as a cross-car tube. The cross-car tube is coupled to the plenum to provide increased rigidity in the vehicle and further minimize the rotation of the steering column during impact. However, this design is disadvantageous in that it requires additional space in the dashboard area, which is not available in many modern vehicle designs. Furthermore, this design increases the weight and manufacturing cost of the vehicle. 
     Accordingly, there exists a need in the relevant art to provide a system capable of minimizing the rotation of the steering column during impact in limited space applications. Furthermore, there exists a need in the relevant art to provide a system to maintain the steering column position during impact so as to improve the effectiveness of a steering wheel-mounted airbag. 
     SUMMARY OF THE INVENTION 
     According to a preferred embodiment of the present invention, a steering column restraining device for a vehicle having an advantageous construction is disclosed. The vehicle includes a steering column mounted to a steering column support bracket. The steering column restraining device comprises a first bracket mounted to the steering column support bracket and a second bracket mounted to a floorboard of the vehicle. The first bracket and the second bracket are interconnected using a strap extending therebetween. The device minimizes upward translation of the steering column during impact, thereby maximizing the effectiveness of the airbag and further minimizing potential injury to the driver. 
     Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood 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 spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein: 
     FIG. 1 is a perspective view of a vehicle incorporating the steering column restraining device according to the present invention; 
     FIG. 2 a  is a perspective view of a steering column support bracket and the steering column restraining device adapted for use in a left-hand drive vehicle; 
     FIG. 2 b  is a perspective view of a steering column support bracket and the steering column restraining device adapted for use in a right-hand drive vehicle; and 
     FIG. 3 is an inboard view of the steering column restraining device adapted for use in a left-hand drive vehicle. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The following description of the preferred embodiment is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses. For example, the steering column restraining device of the present invention may have utility in any vehicle where translation of a steering column or other feature must be minimized during vehicle impact. 
     Referring to the figures, a steering column-restraining device  10  is shown for use within a vehicle  12 . Vehicle  12  includes a steering column support bracket  14  fixedly mounted to a plenum  16 . Steering column support bracket  14  is adapted to receive and support a steering column  18 . Specifically, steering column  18  is fixed to steering column support bracket  14  using conventional means, such as bolts, to provide proper positioning of a steering wheel  20  within vehicle  12 . Steering column support bracket  14  is further mounted to an intermediate bracket  21  and various other mounting structures. Intermediate bracket  21  is generally disposed between steering column support bracket  14  and an engine  23  of vehicle  12 . As can be appreciated by one skilled in the art, during a severe frontal collision, the lower dash panel and engine  23  of vehicle  12  may be forced rearward against the intermediate bracket  21 . This rearwardly directed force might act upon steering column support bracket  14  at a position below plenum  16 . Consequently, the rearwardly-directed force may produce a moment in steering column support bracket  14  about plenum  16 , thereby causing steering column support bracket  14  and steering wheel  20  to be translated generally upward. This generally upward translation may cause an airbag  22  disposed in steering wheel  20  to be deployed in a generally upward direction, which may not maximize the effectiveness of airbag  22 . 
     To minimize the upward translation of steering column  18  and steering wheel  20 , steering column restraining device  10  passively restrains steering column support bracket  14  during a collision. As best seen in FIGS,  2   a ,  2   b , and  3 , steering column restraining device  10  includes an upper mounting bracket  24  mounted to a sidewall  26  of steering column support bracket  14 . Upper mounting bracket  24  includes an elongated slot  28  and an aperture  30 . Aperture  30  is adapted to receive a threaded stud (not shown), such as a rivet-stud and bolt, therethrough that is fixedly mounted to steering column support bracket  14 . Preferably, upper mounting bracket  24  is made of a high strength steel. It should be appreciated that upper mounting bracket  24  may have any shape conducive to mating with steering column support bracket  14 . Likewise, upper mounting bracket  24  may be mounted to steering column support bracket  14  using other mounting method known in the art, such as welding or by employing a tapping plate and bolt assembly. 
     Steering column restraining device  10  further includes a lower mounting bracket  32  mounted to a floorboard  34  of vehicle  12 . Preferably, lower mounting bracket  32  is mounted to a center support or tunnel  36  commonly present in vehicle designs having a transmission belt housing or floorpan formation. Lower mounting bracket  32  includes a base portion  38  and an upturned portion  40 . Base portion  38  includes a plurality of apertures  42  and upturned portion  40  includes an elongated slot  44 . The plurality of apertures  42  are each adapted to receive a fastener  45  therethrough for mounting lower mounting bracket  32  to tunnel  36 . Preferably, lower mounting bracket  32  is made of a high strength steel. 
     It should be appreciated that upper mounting bracket  24  and lower mounting bracket  32  may have any shape conducive to mating with steering column support bracket  14  and tunnel  36 , respectively. Likewise, upper mounting bracket  24  and lower mounting bracket  32  may be mounted using other mounting method known in the art, such as welding. Still further, steering column restraining device  10  may be employed in vehicles having the steering wheel mounted on the left-side (see FIG. 2 a ) or right-side (see FIG. 2 b ). 
     Steering column restraining device  10  still further includes a tether or strap  46  interconnecting upper mounting bracket  24  and lower mounting bracket  32 . Specifically, strap  46  extends through elongated slot  28  of upper mounting bracket  24  and elongated slot  44  of lower mounting bracket  32 . Strap  46  is made of a flexible material, such as kevlar braid, nylon webbing, or the like. Such material is selected for its strength and minimal elongation during loading. Preferably, strap  46  is made of a 7-panel nylon webbing having a width of approximately 1-¾″ to reduce material costs. However, kevlar braid having a width of approximately 1-⅜″ may also be used. Strap  46  is fastened to upper mounting bracket  24  and lower mounting bracket  32  using an overlapped and sewn connection; however, other connection methods known in the art may be used. 
     During assembly, steering column restraining device  10  is mounted within vehicle  12  such that upper mounting bracket  24  is secured to sidewall  26  of steering column support bracket  14  and lower mounting bracket  32  is secured to tunnel  36 . Preferably, strap  46  would have a length sufficient to conveniently install, yet would not require extensive deflection or rotation of steering column support bracket  14  before restricting movement of steering column support bracket  14 . 
     In operation, steering column restraining device  10  of the present invention minimizes the upward rotation or translation of steering column support bracket  14 . Consequently, upward rotation or translation of steering column  18  and steering wheel  20  are also minimized, thereby retaining steering wheel  20  in approximately a pre-impact position. In other words, as the vehicle front end and engine are forced rearward during a severe collision, the intermediate bracket and various other vehicle components are then forced rearward and cause steering column support bracket  14  to rotate about plenum  16 . Steering column restraining device  10  minimizes the rotation of steering column support bracket  14  by resisting the upward translation of steering column support bracket  14  relative to floorboard  34  or tunnel  36 . Specifically, upper mounting bracket  24 , lower mounting bracket  32 , and strap  46  withstand the loads forcing steering column support bracket  14  upward, thereby maintain the pre-impact position of steering column  18  and steering wheel  20 . By way of non-limiting example, steering column restraining device  10  may carry an approximate load of 1600-2000 pounds during an impact. By maintaining the pre-impact position of steering wheel  20  and, thus, airbag  22 , it is believed that the effectiveness of airbag  22  can be maximized. 
     As should be appreciated, the steering column restraining device according to the present invention dramatically reduces the upward translation and rotation of the steering column and steering wheel, thereby improving the performance of a driver&#39;s airbag. By way of non-limiting example, a reduction in chest acceleration of a test dummy of 7.3 g&#39;s (gravitational acceleration) is realized in the Federal Motor Vehicle Safety Standard 208 test for a vehicle having the steering column restraining device according to the present invention relative to a baseline vehicle. Moreover, the steering column restraining device according to the present invention eliminates the need for a cross-car tube, thereby maximizing vehicle packaging. 
     The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention. Such variations or modifications, as would be obvious to one skilled in the art, are intended to be included within the scope of the following claims.