Abstract:
A steering column mounting bracket is provided with break-away capsules integrally formed therewith from the same material as the mounting bracket allowing the capsules to have a more consistent break-away load and reduce noise within the cabin of a vehicle.

Description:
FIELD OF THE INVENTION 
     The present invention relates generally to steering column support structures, and more particularly to a steering column support structure including capsules that securely hold the steering column to the instrument panel without hindering the collapse of the steering column during an accident. 
     BACKGROUND 
     It is desirable to have a steering column of a vehicle that is securely attached to the frame of the automobile so as to ensure safe operation thereof for the life of the automobile. Generally, this is accomplished by bolting the steering column to the instrument panel which is further secured to the frame of the automobile. However, it has become desirous to allow for the steering column to disengage from the instrument panel and collapse upon the application of a force during an accident. 
     It is known in the art to attempt to solve these contradictory goals by using polymer capsules (such as disclosed in commonly assigned U.S. Pat. No. 5,390,955, herein incorporated by reference) to support the mounting bracket of the steering column that are designed in such a way as to break-away under a given force. Thus, the steering column is allowed to axially collapse upon the application of a force in the event of an accident. 
     However, the polymer capsule may change in shape which can cause the capsules to “creep.” This creep may cause buzz/squeak/rattle (BSR) problems which are unwanted during the operation of the vehicle. Furthermore, the polymer capsules can become damaged prior to installation thus requiring the disposal of the part. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide a break-away capsule that will overcome the disadvantages of the prior art polymer capsules. This object will be accomplished by forming the capsule from the same material as the remainder of the steering column mounting bracket. This will allow the capsules to have a more consistent break-away load, not be susceptible to BSR, and not break unintentionally during installation. 
     Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood however 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 illustrating the attachment of the steering column mounting bracket to the instrument panel; 
     FIG. 2 is a cross-sectional view of the break-away capsules of the mounting bracket affixed to a support bracket of the instrument panel taken along line  2 — 2  of FIG. 1; 
     FIG. 3 is a perspective view of a mounting bracket containing four mounting areas with a first embodiment of the present invention; and 
     FIG. 4 is a perspective view of a mounting bracket containing two mounting areas with a second embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1 illustrates the mounting bracket  10  in its assembled orientation with the support bracket  13  and the instrument panel  12 . However, for illustrative purposes, FIG. 1 does not include the fasteners affixing the mounting bracket  10  to the support bracket  13 . Such fasteners are shown in place, in detail, in FIG.  2 . 
     Referring to FIG. 1 the mounting bracket  10  includes a main body  11 , a bore  24  extend through the main body  11  for receiving a steering shaft therein (not shown). A pair of rearward flanges  14  and forward flanges  22  are disposed on opposite sides of the main body  11 . The rearward flanges  14  include a lower flange body  15  and an upper flange structure  25 , which define openings  28 . Openings  28  allow limited movement of the mounting bracket  10  relative to the support bracket  13 . Break-away capsules  16  are contained within the openings  28 . The break-away capsules of the present invention are molded break-away capsules. The break-away capsules  16  include a center body  18  with a pair of outwardly extending tabs  20  interconnected to the lower flange body  15  which defines part of the opening  28 . In one embodiment, the mounting bracket and break-away capsules arc made of the same material. In one embodiment, the break-away capsules are further molded as one piece with the mounting bracket. In one embodiment, the breakaway capsules and the mounting bracket are further made of magnesium. A fastener opening  26  is contained within the center body  18 . The fastener opening  26  allows for the insertion of fasteners to affix the mounting bracket  10  to the support bracket  13 . 
     FIG. 2 is a cross-sectional view of a flange  14  of the mounting bracket  10  affixed to the support bracket  13 . The center body  18  of the break-away capsule  16  is affixed to the flange  14  through the tabs  20 . The tabs  20  may be formed in any shape and size so as to allow for a varied release load. A bolt  30  is inserted through an opening  34  in the support bracket  13 , and through the opening  26  in the center body portion  18  of the break-away capsule  16 . The bolt  30  is then secured into place with a nut  32 . The head of bolt  30  is disposed against support bracket  13  and nut  32  is disposed against breakaway capsule  16 . Through this interlock the mounting bracket flange  14  of mounting bracket  10  is affixed to the support bracket  13  through the tabs  20 . 
     FIG. 3 illustrates a perspective view from the front side of the mounting bracket  10 . The mounting bracket  10  includes a main body  11  and a bore  24  through which a steering shaft (not shown) may be inserted. Formed to the sides of the main body  11  are flanges. Included in this embodiment are forward flanges  22  and rearward flanges  14  placed on opposite sides of the main body  11 . Rearward flanges  14  further include an upper flange structure  25  defining an opening  28 . Upper flange structure  25  provides a limit to the movement allowed of the mounting bracket  10 . Contained within the opening  28  of the rearward flanges  14  are the break-away capsules  16 . In this embodiment the center body  18  of the break-away capsule  16  is a relatively small cylinder attached to the flange  14  inside of the opening  28  with tabs  20 . The tabs  20  are the portions of the break-away capsule  16  that actually break-away upon the imposition of a large force. The tabs  20  may be changed in shape, size, and material to achieve the desired break-away resistance. When the tabs  20  are broken the mounting bracket  10  is free to move along its axis. 
     Illustrated in FIG. 4 is a second embodiment of the present invention wherein like numerals designate similar elements. The mounting bracket  50  of this embodiment includes a main body  11  including a bore  24  through the main body  11  to receive a steering shaft (not shown) when fully assembled. However, this embodiment includes only rearward flanges  51  and eliminates the upper flange structures  25  of FIG.  3 . Further, the center body  52  of the break-away capsules  56  have a larger size and a more distinct shape. The break-away capsules  56  still retain the break-away tabs  58 . Furthermore, the size and shape of tabs  58  may be selected to obtain the desired break-away resistance. However, due to the fact that no upper flange structure is present in this embodiment the mounting bracket  50  is not hindered in its movement once the tabs  58  release. 
     Continuing reference to FIGS. 3 and 4 it can be seen that features from the two embodiments may be interchanged creating several variations (two are illustrated). Thus, for example, the break-away capsules  16  of FIG. 3 may be placed in the mounting bracket  50  of FIG.  4 . In a second example the upper flange structure  25 , as in FIG. 3, may be placed around the break-away capsules  56  of FIG.  4  and the upper flange structure  25  of the embodiment of FIG. 3 may be removed as in FIG.  4 . 
     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, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.