Abstract:
The present invention provides a way in which the coefficient of friction between the steering column and the instrument panel may be lessened when an isolator pad is used. The reduction in friction is accomplished by impregnating the isolator pad with a lubricant.

Description:
FIELD OF THE INVENTION 
     The present invention relates generally to a steering column support structure, and more particularly to an isolator pad for a steering column support structure to reduce or eliminate unwanted noises or vibrations during operation of an automobile. 
     BACKGROUND 
     Typically an automobile&#39;s steering column is fixedly attached to the instrument panel of the automobile. Though this arrangement provides for secure support of the steering column it can cause undesirable side effects. These side effects include buzz/squeak/rattle (BSR) and noise/vibration/harshness (NVH) which are caused by the motion of the vehicle and the metal to metal contact of the steering column to the instrument panel. 
     There have been attempts to solve these problems by placing spacers or an isolator pad between the steering column and the instrument panel. Though these inventions have reduced the creation of the BSR and NVH, the coefficient of friction between the steering column and the instrument panel is increased. Since many steering columns are now made collapsible/strokable it is desirable to have a low coefficient of friction between that steering column and the instrument panel so that the collapsing/stroking feature of the steering column is not inhibited. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide a way in which the coefficient of friction between the steering column and the instrument panel may be reduced. According to the invention the isolator pad is impregnated with a lubricant thus assuring that the isolator pad will be lubricated at all times and have a long life. 
     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 an exploded perspective view illustrating the attachment of the isolator pad and the mounting bracket to the instrument panel. 
     FIG. 1 a  is a cross-sectional view of a flange of the mounting bracket mounted to the instrument panel. 
     FIG. 2 is a perspective view of the isolator pad assembled to the mounting bracket for a steering column assembly. 
     FIG. 3 is a perspective view of the top of the isolator pad. 
     FIG. 4 is a perspective view of the bottom of the isolator pad. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     An exploded perspective view of a steering column assembly is shown in FIG. 1 with the isolator pad  10  being disposed between, support bracket  20  of the instrument panel, and mounting bracket  30  of the steering column. The mechanisms shown generally at  34  are for shifting the gears of the automobile and tilting the steering wheel and are shown for orientation purposes only. 
     The support bracket  20  includes a main body  21  and a flange  23  on either side of the main body  21 . Formed in the flanges are forward openings  22   a  and rearward openings  22   b.  The openings  22   a  and  22   b  receive fasteners, the fasteners include bolts  42  which are secured with nuts  46 , which secure the mounting bracket  30  to the support bracket  20 . 
     The mounting bracket  30  includes a main body  33  with a plurality of flanges  48  formed in the sides of the main body  33 . The flanges  48  contain a depressed area  47  for receiving a spacer  44 . Formed in the depressed area  47  are forward openings  32   a  and rearward openings  32   b  which are complimentary to the openings  22   a  and  22   b  in the support bracket  20 . The main body  33  further contains openings  36  which receive portions of the isolator pad  10  thereby holding the isolator pad  10  in position during assembly. The steering shaft  40  extends through the main body  33  of the mounting bracket  30 . 
     Disposed between the mounting bracket  30  and the support bracket  20  is the isolator pad  10 . With continued reference to FIG.  1  and further reference to FIGS. 3 and 4, which demonstrate a top and bottom perspective view of the isolator pad  10  alone, the isolator pad  10  can be seem to be formed of a sheet in generally a T-shape. The T-shape includes a transverse body  13 , a longitudinal body  17  perpendicular to and extending in a first direction from the transverse body  13 , and two generally parallel longitudinal arms  11  perpendicular to and extending in a second direction from the transverse body  13 . Included in the distal ends of the transverse body  13  are molded openings  14 . The openings  14  are molded into the isolator pad  10  so as to not obstruct the fasteners  42 . The arms  11  of the isolator pad  10  extend rearward of the rearward fastener openings  32   b  and  22   b  while the longitudinal body  17  extends forward beyond the forward fastener openings  32   a  and  22   a.  Further, the longitudinal body  17  extends beyond the end of the mounting bracket  30  and bends down. Contained with in the bent portion of the longitudinal body  17  is an opening  18  through which the steering shaft  40  may extend. Throughout the surface of the isolator pad  10  are indentations  16  to facilitate compression of the isolator pad  10 . 
     Turning to FIG. 1 a,  but with continued reference to FIG. 1, a cross-section of a flange  48  of the mounting bracket  30  fastened to the support bracket  20  is shown. The flange  48  includes a depressed area  47  creating a depression  49 . The depressed area  47  contains the unenclosed openings  32   a  and  32   b  of the mounting bracket  30 . Disposed around the depressed area  47  and in the depression  49  is a spacer  44 . Thus when the mounting bracket  30  is fastened to the support bracket  20  the spacer  44  creates the enclosure for the bolt  42  which is secured with a nut  46  thereby creating pressure which affixes the spacer  44  to the depressed area  47 . In this way when a force is applied to the mounting bracket  30 , through the steering column  40 , the spacers  44  will give way, thus reducing the force absorbed by the source of the original force, in the case of an automobile the driver. 
     FIG. 2 illustrates the isolator pad  10  affixed to the mounting bracket  30  before assembly. Shown in ghost are the openings  36  which receive a portion of the isolator pad  10 . With continued reference to FIG. 2, but with further reference to FIG. 4 a bottom perspective view of the isolator pad  10  is shown. Formed into the isolator pad  10  are pegs  12 . The pegs  12  extend into the openings  36  of the mounting bracket  30  and hold the isolator pad  10  in placed before the final assembly of the mounting bracket  30  to the support bracket  20 . Further, a support structure  19  is formed into the longitudinal portion to assist in rigidity of the isolator pad  10 . 
     With reference to FIGS. 1,  3 , and  4  the isolator pad  10  may be made of several non-skid substances, examples of such substances include resins such as rubber, nylon, or other thermoset or thermoplastic materials. All perform the function of reducing unwanted noises and vibrations during operation of the vehicle, however, they increase the coefficient of friction between the mounting bracket  30  and support bracket  20 . Therefore, the isolator pad  10  may be impregnated with a lubricant; this is accomplished by mixing a lubricant with the material from which the isolator pad  10  will be formed. The lubricant may be a wax, Teflon, mineral oil, or a mixture of any of these, however it is preferably wax alone. 
     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.