Abstract:
The invention provides a steering column assembly for a vehicle. The steering column assembly includes a bracket mountable to a vehicle. The bracket includes a pair of sides defining a channel. The steering column assembly also includes a jacket moveably positioned in the channel. The steering column assembly also includes a bolt assembly having a bolt passing through both of the bracket and the jacket. The bolt assembly is operable to urge the sides of the channel together against the jacket. The steering column assembly also includes a first rolling element pierced by the bolt assembly. The first rolling element is operably disposed between the jacket and the bracket to enhance relative movement between the jacket and the bracket.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/605,490 for a DUAL AXIS ROLLING ELEMENT FOR ADJUSTABLE STEERING COLUMN, filed on Aug. 30, 2004, which is hereby incorporated by reference in its entirety. 
     
    
     FIELD OF THE INVENTION  
       [0002]     The invention relates to steering column positionable in a vehicle and adjustable between at least two positions.  
       BACKGROUND OF THE INVENTION  
       [0003]     Vehicles often include adjustable steering columns. Adjustable steering columns are moveable along a path of adjustment between first and second positions. The path of adjustment can define a tilting path, a raking path, a telescoping path, or any combination of movements, especially tilting and telescoping or raking and telescoping. During movement along the path of adjustment the steering column, or at least a portion thereof, slides relative to some other mounting structure that is fixed relative to the vehicle.  
       SUMMARY OF THE INVENTION  
       [0004]     The invention provides a steering column assembly for a vehicle. The steering column assembly includes a bracket mountable to a vehicle. The bracket includes a pair of sides defining a channel. The steering column assembly also includes a jacket moveably positioned in the channel. The steering column assembly also includes a bolt assembly having a bolt passing through both of the bracket and the jacket. The bolt assembly is operable to urge the sides of the channel together against the jacket. The steering column assembly also includes a first rolling element pierced by the bolt assembly. The first rolling element is operably disposed between the jacket and the bracket to enhance relative movement between the jacket and the bracket.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0005]     Advantages of the present invention will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:  
         [0006]      FIG. 1  is a first perspective view of a first exemplary embodiment of the invention showing the bottom of a moveable portion of a steering column and a mounting structure attachable to a vehicle;  
         [0007]      FIG. 2  is a second perspective view of the first exemplary embodiment of the invention showing the moveable portion of the steering column;  
         [0008]      FIG. 3  is a third perspective view of the first exemplary embodiment of the invention showing the moveable portion of the steering column, a first ball track, and a ball carrier;  
         [0009]      FIG. 4  is a fourth perspective view of the first exemplary embodiment of the invention similar to  FIG. 3  and showing a second ball track covering the ball carrier;  
         [0010]      FIG. 5  is a cross-sectional view taken along section lines  5 - 5  in  FIG. 4 ;  
         [0011]      FIG. 6  is a fifth perspective view of the first exemplary embodiment of the invention showing the mounting structure attachable to the vehicle, a plurality of first ball tracks, a ball carrier, and a second ball track;  
         [0012]      FIG. 7  is a sixth perspective view of the first exemplary embodiment of the invention similar to  FIG. 6  and showing a second ball track, a first ball track, and a ball carrier covering the ball carrier shown in  FIG. 6 ;  
         [0013]      FIG. 8  is a seventh perspective view of the first exemplary embodiment of the invention showing the top of the moveable portion of the steering column and the mounting structure attachable to the vehicle;  
         [0014]      FIG. 9  is a eighth perspective view of the first exemplary embodiment of the invention showing the top of the moveable portion of the steering column and the mounting structure attachable to the vehicle; and  
         [0015]      FIG. 10  is a cross-sectional view of a second exemplary embodiment of the invention showing the bottom of a moveable portion of a steering column and a mounting structure attachable to a vehicle.  
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0016]     A plurality of different embodiments of the invention are shown in the Figures of the application. Similar features are shown in the various embodiments of the invention. Similar features have been numbered with a common two-digit reference numeral and have been differentiated by a third digit placed before the two common digits. Similar features are structured similarly, operate similarly, and/or have the same function unless otherwise indicated by the drawings or this specification. Furthermore, particular features of one embodiment can replace corresponding features in another embodiment unless otherwise indicated by the drawings or this specification.  
         [0017]     Referring now to  FIG. 1 , in a first exemplary embodiment of the invention, a steering column assembly includes a mounting structure  10  fixedly mountable in a vehicle. The mounting structure  10  of the first exemplary embodiment of the invention includes a bracket  12 . The bracket  12  is u-shaped, or channel-like. The bracket  12  defines a longitudinal slot  14  extending along a substantially longitudinal path. As will be set forth in greater detail below, the longitudinal slot  14  supports/guides a moveable portion of a steering column during movement along a path of telescopic adjustment. The bracket  12  also defines a second longitudinal slot  16  extending along a substantially longitudinal path for supporting/guiding the moveable portion of the steering column during movement along a path of telescopic adjustment. The longitudinal slots  14 ,  16  are disposed generally at the bottom of the bracket  12 . As used herein, the bottom of the bracket  12  is the end of the bracket  12  that is generally farthest from the driver.  
         [0018]     The bracket  12  also defines an arcuate slot  18 , best shown in  FIG. 6 , extending along a substantially arcuate path. As will be set forth in greater detail below, the arcuate slot  18  supports/guides a moveable portion of a steering column during movement along a path of raking adjustment. The bracket  12  also defines a second arcuate slot  20  extending along a substantially arcuate path for supporting/guiding the moveable portion of the steering column during movement along a path of raking adjustment. The arcuate slots  18 ,  20  are disposed generally at the top of the bracket  12 . As used herein, the top of the bracket  12  is the end of the bracket  12  that is generally closest to the driver.  
         [0019]     Referring now to  FIGS. 1 and 2 , a moveable portion  22  of a steering column is guided/supported for movement by the mounting structure  10 . The moveable portion  22  of the first exemplary embodiment of the invention includes a jacket  24 . The jacket  24  is received in the channel defined by the bracket  12 . It is noted that some minor structural details of the jacket  24  shown in the various figures are inconsistent with one another. For example, the side of the jacket  24  shown in  FIGS. 1 and 2  is different than the side of the jacket  24  shown in  FIGS. 3-9 . These differences demonstrate that the invention can be practiced in several different embodiments. To enhance the clarity of description, the jacket  24  has been commonly numbered in all Figures showing the first embodiment of the invention.  
         [0020]     The jacket  24  is moveable along a path of telescopic movement between a plurality of positions. As will be described in greater below, the path of movement in the first exemplary embodiment of the invention is defined by the longitudinal slots  14 ,  16  for telescoping movement and the arcuate slots  18 ,  20  for raking movement. Generally, the jacket  24  supports a steering shaft  26 , best shown in  FIG. 9 . The steering shaft  26  defines a mounting end  28 , a steering wheel being mounted on the mounting end  28 . The movement of jacket  24  along the paths of movement allows the steering shaft  26  to be moved to position the steering wheel as desired by the driver of the vehicle. The paths of movement can define tilting movement, raking movement, telescoping movement, or any combination of tilting and telescoping movements or raking and telescoping movements.  
         [0021]     The jacket  24  is moveable between at least two positions along the path of telescoping movement. The jacket  24  can be moveable between more than two positions along the path of telescoping movement. The jacket  24  can be infinitely adjustable as that term is used in the art.  
         [0022]     Referring to  FIGS. 1, 2  and  5 , the jacket  24  defines first and second apertures  30 ,  32  generally adjacent to the bottom of the jacket  24 . As will be set forth in greater detail below, the first and second apertures  30 ,  32  support/guide the jacket  24  during movement along a path of telescoping adjustment. The jacket  24  also defines a slot  34  extending between first and second openings  36 ,  38 . As will be set forth in greater detail below, the slot  34  supports/guides the jacket  24  during movement along a path of raking and telescoping adjustment. In alternative embodiments of the invention, the slot  34  could be formed as two distinct, spaced slots.  
         [0023]     Referring now to  FIGS. 1-5 , a rolling element  40  is disposed between the bracket  12  and the jacket  24  to enhance relative movement between the bracket  12  and the jacket  24 . The rolling element  40  includes a first ball track member  42 , a ball carrier  44 , and a second ball track member  46 . The first ball track member  42  of the first exemplary embodiment of the invention is a stamped member fixedly associated with the jacket  24 . In alternative embodiments of the invention, the first ball track member  42  could be integrally formed with either the jacket  24  or the bracket  12 . The first ball track member  42  defines first and second ball tracks  48 ,  50 . The first ball track member  42  also defines a slot  64  to accommodate telescoping movement of the jacket  24 . The ball carrier  44  includes a frame  52  and a plurality of rollers, such as rollers  54 ,  56 . The rollers  54 ,  56  are movably support by the frame  52  for rotational movement. The roller  54  contacts and moves in the first ball track  48 . The roller  56  contacts and moves in the second ball track  50 . The second ball track member  46  of the first exemplary embodiment of the invention is a powdered-metal member fixedly associated with the frame  52 . The second ball track member  46  defines third and fourth ball tracks  58 ,  60 . The third ball track  58  opposes the first ball track  48  and the roller  54  contacts and moves in the third ball track  58 . The fourth ball track  60  opposes the second ball track  50  and the roller  56  contacts and moves in the fourth ball track  60 . A second rolling element  62  is constructed similarly with respect to the rolling member  40  and is disposed between the bracket  12  and the jacket  24 , on an opposite side of the jacket  24  relative to the rolling element  42 , to enhance relative movement between the bracket  12  and the jacket  24 .  
         [0024]     The rollers of the exemplary embodiment of the invention provide at least two benefits over known sliding arrangements. First, the rollers increase the likelihood of relatively constant friction between the moveable portion of the steering column and the mounting structure. Generally, a sliding arrangement will require a higher initial force to overcome static friction and begin movement of the moveable portion of the steering column, with respect to the force required to overcome dynamic friction during movement. Second, the rollers allow the moveable portion of the steering column and the mounting structure to be clamped together with greater force than a sliding arrangement. As a result, the connection between the moveable portion of the steering column and the mounting structure enjoys increased stiffness.  
         [0025]     A bolt assembly includes a bolt  66  extending through the arcuate slots  18 ,  20 , the second ball track member  46 , the ball carrier  44 , the slot  64 , the slot  34 , and the second rolling element  60 . The bolt assembly of the exemplary embodiment of the invention also includes a nut engageable with the bolt  66  to urge the sides of the channel of the bracket  12  together. During telescoping movement of the jacket  24  relative to the bracket  24 , the first ball track member  42  moves along a telescoping path  68  relative to the bolt  66 , the second ball track member  46 , and the ball carrier  44 . The rollers of the ball carrier  44 , such as rollers  54  and  56 , enhance movement by reducing the force required to move the jacket  24  relative to the bracket  12  compared to a bushing. Also, the amount of force required to move the jacket  24  is substantially constant over the path  68 . The length of the path  68  corresponds to the length of the slot  64 .  
         [0026]     Referring now to  FIGS. 6 and 7 , a third rolling element  70  is disposed between the bracket  12  and the jacket  24  to enhance relative movement between the bracket  12  and the jacket  24 . The third rolling element  70  includes a first ball track member  72 , a ball carrier  74 , and a second ball track member  76 . The first ball track member  72  of the first exemplary embodiment of the invention is a stamped member fixedly associated with the jacket  24 . The first ball track member  72  defines first and second ball tracks  78 ,  80 . The first ball track member  72  also defines a slot  84  to accommodate raking movement of the jacket  24 . The ball carrier  74  includes a frame  82  and a plurality of rollers, such as rollers  86 ,  88 . The rollers  86 ,  88  are movably support by the frame  82  for rotational movement. The roller  86  contacts and moves in the first ball track  78 . The roller  88  contacts and moves in the second ball track  80 . The second ball track member  76  of the first exemplary embodiment of the invention is a powdered-metal member fixedly associated with the frame  82 . The second ball track member  76  defines third and fourth ball tracks  90 ,  92 . The third ball track  90  opposes the first ball track  78  and the roller  86  contacts and moves in the third ball track  90 . The fourth ball track  92  opposes the second ball track  80  and the roller  88  contacts and moves in the fourth ball track  80 . A fourth rolling element (not visible) is constructed similarly with respect to the rolling member  70  and is disposed between the bracket  12  and the jacket  24  to enhance relative movement between the bracket  12  and the jacket  24 .  
         [0027]     The bolt  66  extends through the arcuate slots  18 ,  20 , the slot  84 , the frame  82 , the second ball track member  76 , the slot  34 , and the fourth rolling element. The second ball track members  46 ,  76  are disposed back-to-back with respect to one another in the first exemplary embodiment of the invention. During raking movement of the jacket  24  relative to the bracket  12 , the second ball track member  76  and ball carrier  74  move along a raking path  94  relative to the bracket  12  and the first ball track member  72 . The rollers of the ball carrier  74 , such as rollers  86  and  88 , enhance movement by reducing the force required to move the jacket  24  relative to the bracket  12  compared to a bushing. Also, the amount of force required to move the jacket  24  is substantially constant over the path  94 . The length of the path  94  corresponds to the length of the slots  18 ,  20 .  
         [0028]     The rolling elements  40 ,  62  and  70  are disposed at the top of the jacket  24 . Referring now to  FIG. 1 , a pair of rolling elements  96 ,  98  are disposed at the bottom of the jacket  24  to enhance telescoping movement between the bracket  12  and the jacket  24 . The rolling element  96  includes a first ball track member  100 , a ball carrier (not visible), and a second ball track member  102 . The rolling element  98  includes a first ball track member  104 , a ball carrier  106 , and a second ball track member  108 . A bolt (not shown extends through apertures  30 ,  32 , the second ball track members  102 ,  108 , the ball carriers of the rolling elements  96 ,  98  including ball carrier  106 , the first ball track members  100 ,  104 , and the slots  14 ,  16 . In alternative embodiments of the invention, additional rolling elements could be disposed at the bottom of the jacket  24  to enhance raking movement. Rotation or raking at the bottom of the jacket  24  is greater than at the top of the jacket  24  and rolling elements for telescoping movement may suffice, however, additional rolling elements may be desirable. Alternatively, the ball tracks of the rolling elements may be modified accommodate slight rotation of the jacket  24  relative to the bracket  12 .  
         [0029]     Referring now to  FIG. 10 , in a second exemplary embodiment of the invention, a mounting structure  110  is fixedly mountable in a vehicle. The mounting structure  110  includes a bracket  112 . The bracket  112  defines first and second arcuate slots  118 ,  120  extending along a substantially arcuate path and for supporting/guiding the moveable portion of the steering column during movement along a path of raking adjustment. A moveable portion  22  of a steering column is guided/supported for movement by the mounting structure  110 . The moveable portion  122  of the first exemplary embodiment of the invention includes a jacket  124 . The jacket  124  is received in the channel defined by the bracket  112 . The jacket  124  defines a slot  134  extending between first and second openings  136 ,  138  for supporting/guiding the jacket  124  during movement along a path of raking and telescoping adjustment.  
         [0030]     A rolling element  140  is disposed between the bracket  112  and the jacket  124  to enhance relative movement between the bracket  112  and the jacket  124 . The rolling element  140  includes a first ball track member  142 , a ball carrier  144 , and a second ball track member  146 . First and second rolling elements  170 ,  171  are disposed on opposite sides of the bracket  112  to enhance raking movement. The rolling element  170  includes a first ball track member  172 , a ball carrier  174 , and a second ball track member  176 . The rolling element  171  includes a first ball track member  173 , a ball carrier  175 , and a second ball track member  177 .  
         [0031]     While the invention has been described with reference to an exemplary embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims.