Abstract:
An adjustable cross beam for a vehicle. The cross beam includes two members that are configured to be adjustably coupled to form a cross beam of variable span. The modular nature of the members and adjustability allows the cross beam to be used in a variety of vehicles, thereby reducing necessary cross beam inventory and excess spare parts.

Description:
TECHNICAL FIELD 
   The invention generally relates to automotive structural components, and more particularly, to an adjustable-width cross beam for an automobile. 
   BACKGROUND 
   Typical vehicle bodies have a frame with a pair of vertical pillars on opposite sides of the vehicle body at the juncture of an engine compartment and a passenger compartment. The pillars are connected by a cross beam at the cowl of the vehicle body forward of an instrument panel. The cross beam provides cross car stiffness, assists in managing side impact loads, and supports the steering column and air bags. The cross beam also provides support for the dashboard, glove compartment, and various instruments of an instrument panel. 
   The cross beam also serves integrally with the instrument panel to receive the electronic control modules, wiring harnesses, and duct work. Cross beams are usually vehicle type specific, meaning that separate vehicle types have individually designed and manufactured cross beams with vehicle specific mounting locations for the steering wheel, airbags, and other components. A particular vehicle type may have more than one unique cross beam, such as for left and right hand drive models of the same vehicle. 
   Designing and manufacturing a unique cross beam for each vehicle type requires additional resources and tooling. Additionally, unused cross beams are typically scrapped after production ceases of a particular vehicle type. 
   There exists a need for a cross beam that will provide increased commonality between vehicle types, reduced design and manufacturing costs, reduced piece-part costs, lower the amount of unused parts, as well as lower inventory costs. Additionally, the need exists for a cross beam that may be used for both left and right hand drive vehicles to further reduce design time and costs. 
   SUMMARY 
   A telescopic cross beam assembly is disclosed. The telescopic cross beam assembly includes a first structural member having a first pillar attachment end and an adjustable coupling end, and a second structural member having a second pillar mounting end and a receiving end, wherein said receiving end selectively engages said coupling end to allow said cross beam assembly to span a distance between two pillars of said vehicle. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of an automotive instrument panel, generally illustrating the location of the vehicle cross beam, according to an embodiment. 
       FIG. 2  is a perspective view of the cross beam of  FIG. 1 . 
       FIG. 3  illustrates a perspective view of a portion of the crossbeam of  FIG. 2 , showing the adjustable attachment of the members of the crossbeam. 
       FIG. 4  illustrates an alternate embodiment of an adjustable cross beam. 
   

   DETAILED DESCRIPTION 
     FIG. 1  illustrates a vehicle  10  to include a driver structural pillar  14 , a passenger structural pillar  16 , and a cross beam  20  connecting the two pillars. An instrument panel  18  is generally a collection of gauges and controls along with the aesthetic packaging typically supplied in a vehicle and supported by cross beam  20 . Cross beam  20  may include a central support  22 , a driver support  24  and a passenger support  26 . As illustrated, driver support  24  is coupled to driver structural pillar  14 , and passenger support  26  is coupled to passenger structural pillar  16 . Cross beam  20  may also support a steering column  28 , an airbag  30 , a wiring harness (not shown), a radio (not shown) and various other desired items. 
   With reference to  FIG. 2 , cross beam  20  is illustrated in greater detail. In the embodiment shown, cross beam  20  includes a first member  42  and a second member  44 . First member  42  includes an upper arm  46  and a lower arm  48 . First member  42  further includes an adjustable coupling end  50 , a pillar attachment end  52 , a steering column attachment  54 , and auxiliary attachments  56 . Second member  44  includes an upper arm  66  and a lower arm  68 . Second member  44  further includes a receiving end  70 , a pillar attachment end  72 , a glove compartment attachment  74 , and auxiliary attachments  76 . As illustrated, adjustable coupling end  50  of first member  42  and receiving end  70  of second member  44  are adjustably coupled to allow for axial movement therebetween, as discussed in greater detail below. Thus provided, cross beam  20  may be adjusted to span varying distances between the driver structural pillar  14  and the passenger structural pillar  16 . 
   Referring now to  FIG. 3 , the adjustable coupling end  50  and the receiving end  70  are illustrated in greater detail. Adjustable coupling end  50  is illustrated wherein upper arm  46  is a cylindrical tube extending within upper arm  66  of second member  70 . Lower arm  48  is illustrated as a rectangular tube that extends into lower arm  68 . As illustrated, first member  42  and second member  44  are sized to matingly couple with a close tolerance between upper arms  46 ,  66 , and between lower arms  48 ,  68 . First member  42  and second member  44  may be welded about the perimeter of an axial end  80  of second member  44 . Thus provided, cross beam  20  may be installed in vehicles  10  of varying distances between pillars  14 ,  16  by adjusting the span of cross beam  20 . This adjustment may be made before or during installation of cross beam  20  in vehicle  10 . While securing first member  42  to second member  44  is illustrated in a preferred embodiment by welding, it would be appreciate that other known means of securing structural members may be employed, or that no securing means may be employed, as desired. 
   As best seen in  FIG. 2 , upper arms  46 ,  66  of cross beam  20  are illustrated in a preferred embodiment to be located about a common axis to provide cross-car stiffness and side impact resistance for vehicle  10 . Preferably, upper arms  46 ,  66  are located between driver structural pillar  14  and passenger structural pillar  16 . As best seen in  FIG. 3 , the attachment of upper arms  46 ,  66  provides a portion of cross beam  10 , having a portion of upper arm  66  with a portion of upper arm  46  interposed therein, that will have a higher moment of inertia than either upper arm  46  or upper arm  66  alone, thereby providing resistance to buckling of cross beam  20  during a side impact. As would be appreciated, manufacturing a one-piece upper arm with a tuned buckling resistance, such as provided in the present embodiment, would require additional cost and complexity. Therefore, this coupling arrangement provides a cross beam  10  manufactured with tubular portions for cost efficiency, manufacturing simplicity and side impact resistance. The diameters and thicknesses of upper arms  46 ,  66  may be tuned to provide a desirable level of impact resistance. Auxiliary attachments  56 ,  76  may be perimeter welded or clamped to upper arms  46 ,  66 , and not through bolted, so as not to reduce the desired moment of inertia. 
   As illustrated in  FIGS. 2 and 3 , lower arms  48 ,  68  of cross beam  20  preferably lie within separate axes. In this embodiment, lower arms  48 ,  68  do not contribute significantly to cross car stiffness, but would provide some degree of buckling resistance for upper arms  46 ,  66 . 
   As illustrated in  FIG. 4 , an alternate embodiment of cross beam  20  is illustrated as cross beam  120  that includes a first member  142  and a second member  144 . First member  142  includes an upper arm  146  and a lower arm  148 . First member  142  further includes an adjustable coupling end  150 , a pillar attachment end (not shown), a steering column attachment (not shown), and auxiliary attachments (not shown). Second member  144  includes an upper arm  166  and a lower arm  168 . First member  142  further includes a receiving end  170 , a pillar attachment end (not shown), a glove compartment attachment (not shown), and auxiliary attachments (not shown). As illustrated, adjustable coupling end  150  and receiving end  170  are adjustably coupled to allow for axial movement therebetween, as discussed in greater detail below. Thus provided, cross beam  120  may be adjusted to span varying distances between the driver structural pillar  14  and the passenger structural pillar  16  of vehicle  10 . 
   The adjustable coupling end  150  and the receiving end  170  are illustrated in greater detail. Adjustable coupling end  150  is illustrated wherein upper arm  146  is a cylindrical tube extending within upper arm  166  of second member  170 . Lower arm  148  is preferably a stamped channel that extends into lower arm  168  which is also a stamped channel. As illustrated, first member  142  and second member  144  are sized to matingly couple with a close tolerance between upper arms  146 ,  166 , and between lower arms  148 ,  168 . First member  142  and second member  144  may be welded about the perimeter of an axial end  180  of second member  144 , or adjustable slots  182  may be provided within lower arms  148 ,  168  to allow fasteners  184  to join lower arms  148 ,  168 . Thus provided, cross beam  120  may be installed in vehicles  10  of varying distances between pillars  14 ,  16  by adjusting the span of cross beam  120 . 
   The present embodiments have been described with reference to certain exemplary embodiments thereof. However, it will be readily apparent to those skilled in the art that it is possible to embody the invention in specific forms other than those of the exemplary embodiments described above. For example, though the embodiment of the modular instrument panel described herein includes three separate, non-integral portions, other embodiments within the scope of this invention may comprise two or more such portions. This and other variations may be made without departing from the spirit of the invention. The exemplary embodiments are merely illustrative and should not be considered restrictive in any way. The scope of the invention is defined by the appended claims and their equivalents, rather than by the preceding description.