Abstract:
An apparatus for supporting a steering column ( 40 ) in a vehicle ( 50 ) adjacent an instrument panel of the vehicle includes a mounting assembly ( 30 ) that connects the steering column ( 40 ) to the vehicle ( 50 ). The mounting assembly ( 30 ) includes at least one holding element ( 170 ) that has a first condition that blocks pivotal movement of the steering column ( 40 ) relative to the vehicle ( 50 ). The at least one holding element ( 170 ) has a second condition that permits pivotal movement of the steering column ( 40 ) relative to the vehicle ( 50 ) in response to impact forces urging the steering column ( 40 ) to pivot relative to the vehicle ( 50 ).

Description:
TECHNICAL FIELD 
       [0001]    The invention relates to vehicle steering columns and, in particular, relates to a mounting assembly for permitting pivotal movement of a steering column relative to a vehicle in response to impact forces upon the steering column. 
       BACKGROUND 
       [0002]    Steering columns that collapse during vehicle crashes are known in the art. During front impact vehicle crashes, the occupant of the vehicle is moved in a forward direction within the vehicle and towards the steering wheel until the occupant ultimately strikes or impacts the steering wheel. Since impact forces between the occupant and the steering wheel may be undesirably high, the steering column may be constructed to collapse in a direction away from the occupant to reduce impact reaction forces. In particular, the steering column may be constructed as a telescoping unit in which pins or rods maintain the telescoping members in an extended condition during normal operation of the vehicle but break upon occupant impact with the steering wheel to allow the telescoping members to retract within one another to reduce impact forces between the occupant and the steering wheel. 
         [0003]    While a telescoping steering column is useful for front or rear impact vehicle collisions, such telescoping steering columns do not collapse if the occupant strikes the underside of either the steering column or the steering wheel. These situations arise in military settings when the vehicle drives over or otherwise is impacted by an explosive device that causes the occupant to travel upward towards the roof of the vehicle, resulting in the occupant&#39;s legs striking the underside of the steering column and/or steering wheel with high impact forces. Therefore, there is a need in the art for a device that reduces impact forces between an occupant and the steering column when the occupant strikes the underside of the steering column and/or steering wheel. 
       SUMMARY OF THE INVENTION 
       [0004]    In accordance with an aspect of the present invention, an apparatus for supporting a steering column in a vehicle adjacent an instrument panel of the vehicle includes a mounting assembly that connects the steering column to the vehicle. The mounting assembly includes at least one holding element that has a first condition that blocks pivotal movement of the steering column relative to the vehicle. The at least one holding element has a second condition that permits pivotal movement of the steering column relative to the vehicle. The at least one holding element changes from the first condition to the second condition in response to impact forces urging the steering column to pivot relative to the vehicle. 
         [0005]    In accordance with another aspect of the present invention an apparatus for a steering column comprising a steering shaft rotatable about a steering axis to effectuate steering movement of vehicle wheels includes a mounting assembly for connecting the steering column to the vehicle adjacent an instrument panel of the vehicle. The mounting assembly includes a first bracket that is connectable to the steering column and a second bracket that is connectable to the vehicle. A hinged connection interconnects the first and second brackets for pivotal movement relative to each other. A holding element has a first condition that blocks pivotal movement of the first bracket relative to the second bracket. The holding element has a second condition that permits pivotal movement of the first bracket relative to the second bracket. The holding element changes from the first condition to the second condition in response to a predetermined amount of force applied to the steering column and urging pivotal movement of the first bracket relative to the second bracket. 
         [0006]    In accordance with another aspect of the present invention, an apparatus for supporting a steering column in a vehicle that includes a steering gear and extends in a fore-aft direction, the steering column comprising a steering shaft rotatable about a steering axis to effectuate steering movement of vehicle wheels includes a mounting assembly that pivotably connects the steering column to the vehicle. The mounting assembly has a first condition for positioning the steering column such that the steering axis extends at a first angle relative to the for-aft direction of the vehicle. The mounting assembly has a second condition for positioning the steering column such that the steering axis extends at a second, different angle relative to the fore-aft direction of the vehicle in response to impact forces urging the steering column to pivot relative to the instrument panel. A telescoping device rotatably connects the steering column to the steering gear. The telescoping device has a first length when the mounting assembly is in the first condition and a second, greater length when the mounting assembly is in the second condition. 
         [0007]    Other objects and advantages and a fuller understanding of the invention will be had from the following detailed description of the preferred embodiments and the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]      FIG. 1  is a schematic illustration of a mounting assembly for a steering column in accordance with the present invention; 
           [0009]      FIG. 2  is an exploded assembly view of the mounting assembly of  FIG. 1 ; 
           [0010]      FIG. 3A  is a side view of the steering column of  FIG. 1  when the mounting assembly is in a first condition; 
           [0011]      FIG. 3B  is a side view of the steering column of  FIG. 1  when the mounting assembly is in a second condition; 
           [0012]      FIG. 4  is a schematic illustration of a mounting assembly for a steering column in accordance with another embodiment of the present invention; 
           [0013]      FIG. 5  is an exploded assembly view of the mounting assembly of  FIG. 4 ; 
           [0014]      FIG. 6  is an enlarged view of a portion of the mounting assembly of  FIG. 5 ; 
           [0015]      FIG. 7  is a bottom view of  FIG. 5 ; 
           [0016]      FIG. 8A  is a side view of the steering column of  FIG. 4  when the mounting assembly is in a first condition; 
           [0017]      FIG. 8B  is a side view of the steering column of  FIG. 4  when the mounting assembly is in a second condition; 
           [0018]      FIG. 9A  is a schematic illustration of a mounting assembly in a first condition for use with a telescoping device; and 
           [0019]      FIG. 9B  is a side view of the mounting assembly of  FIG. 9A  in a second condition. 
       
    
    
     DETAILED DESCRIPTION 
       [0020]    The invention relates to vehicle steering columns and, in particular, relates to a mounting assembly for permitting pivotal movement of a steering column relative to the vehicle in response to impact forces upon the steering column.  FIGS. 1-3B  illustrate a mounting assembly  30  that pivotably connects a steering column  40  to a portion of a vehicle, illustrated in phantom at  50 , such as a vehicle instrument panel. Alternatively, the mounting assembly  30  may help to connect the steering column  40  to a firewall or frame (not shown) of the vehicle  50 . 
         [0021]    The steering column  40  includes a steering wheel  42  secured to a sheering shaft  45  that is rotatable about a steering axis  44  to effectuate steering movement of vehicle wheels (not shown). As shown in  FIG. 1 , the steering axis  44  may be coincident with an axis  46  that represents the fore-aft direction of the vehicle  50 . Alternatively, the steering axis  44  may extend at an angle (not shown) relative to the axis  46 . The steering column  40  may be capable of tilting and/or telescoping relative to the vehicle  50  to place the steering wheel  42  in a desired position relative to the vehicle occupant (not shown). Alternatively, the position of the steering wheel  42  within the vehicle  50  may be fixed. 
         [0022]    As shown in  FIG. 2 , the mounting assembly  30  includes a first bracket  60 , a second bracket  120 , and a pivot shaft  160  for pivotably connecting the first bracket to the second bracket. The first bracket  60  is configured to be secured to the steering column  40  and includes a first portion  62  and a second portion  80 . The first bracket  60  may, for example, be welded directly to the steering column  40  or may be secured to the steering column using fasteners or the like (not shown). The first bracket  60  includes substantially identical first and second portions  62 ,  80 . The first and second portions  62 ,  80  may be separate pieces or may be integrally formed or connected with one another (not shown). In any case, the first and second portions  62 ,  80  may be formed from a high strength, corrosion resistant material, such as metal. 
         [0023]    The first portion  62  has an elongated shape and extends from a first end  64  to a second end  66 . One or more openings  72  are positioned between the first end  64  and the second end  66  and extend entirely through the first portion  62 . Although a single opening  72  is illustrated in  FIG. 2 , those having ordinary skill will appreciate that more openings may be provided in the first portion  62 . A projection  68  extends from the first end  64  of the first portion  62  and includes an opening  70  that extends entirely through the first end. The opening  70  is sized and shaped to receive an end of the pivot shaft  160  for pivotably connecting the first portion  62  of the first bracket  60  to the second bracket  120 . The first portion  62  further includes a lower edge  74  that extends the length of the first portion. The lower edge  74  may be angled or may be co-planar (not shown) with the remainder of the first portion  62 . 
         [0024]    The second portion  80  has an elongated shape and extends from a first end  82  to a second end  84 . The second portion  80  includes one or more openings  90  positioned between the first end  82  and the second end  84 . Although a single opening  90  is illustrated in  FIG. 2 , those having ordinary skill will appreciate that more or fewer openings may be provided in the second portion  80 . The size, shape, and position of the openings  90  in the second portion  80  may correspond with or be different from the size, shape, and position of the openings  72  in the first portion  62 . A projection  86  extends from the first end  82  of the second portion  80  and includes an opening  88  that extends entirely through the first end. The opening  88  in the second portion  80  is sized and shaped to receive an end of the pivot shaft  160  for pivotably connecting the second portion of the first bracket  60  to the second bracket  120 . The second portion  80  further includes a lower edge  92  that extends the length of the second portion. The lower edge  92  may be angled or may be co-planar (not shown) with the remainder of the second portion  80 . 
         [0025]    The second bracket  120  extends along an axis  124 . The second bracket  120  is made of a high strength, corrosion resistant material, such as metal. The second bracket  120  includes a base  122  that extends from a first end  126  to a second end  128 . The base  122  has a generally arcuate shape that may conform to a portion of the steering column  40  to allow the base to overlay a portion of the steering column. In particular, the base  122  may have a generally W-shaped configuration that mimics the contour of a particular steering column  40  on which the mounting assembly  30  is used. The base  122  includes one or more openings  138  positioned between the first end  126  and the second end  128  on one or both sides of the base  122 . The size, shape, number, and position of the openings  138  in the base  122  on one side of the base i.e., the left side as viewed in  FIG. 2 , correspond with the size, shape, number, and position of the openings  72  in the first portion  62  of the first bracket  60 . Likewise, the size, shape, number, and position of the openings  138  in the base  122  on the other side of the base  122 , i.e., the right side as viewed in  FIG. 2 , correspond with the size, shape, number, and position of the openings  90  in the second portion  80  of the first bracket  60 . Therefore, if either the first portion  62  or the second portion  80  of the first bracket  60  does not include openings  72  or  90 , then no corresponding openings  138  are provided in the base  122 . A flange  130  extends transversely from each side of the base  122 . 
         [0026]    The flanges  130  may extend substantially parallel to one another or may extend at an angle relative to one another (not shown). Each flange  130  has a planar shape and includes one or more openings  132  that extend entirely through the flange. The openings  132  are sized and shaped to receive fasteners (not shown) to secure the second bracket  120  to a portion of the vehicle  50 . Although four openings  132  are shown in  FIG. 2 , those having ordinary skill in the art will appreciate that more or fewer openings may be provided in the second bracket  120  depending on the construction of the portion of the vehicle  50  to which the second bracket is secured. 
         [0027]    Projections  134  extend from the first end  126  of the base  122 . The projections  134  extend away from the base  122 . Each projection  134  includes an opening  136  that is sized and shaped similar to the openings  70 ,  88  in the first and second portions  62  and  80 , respectively, of the first bracket  60 . The openings  136  are axially aligned with one another and receive opposing ends of the pivot shaft  160  for pivotably connecting the first bracket  60  to the second bracket  120 . 
         [0028]    When the mounting assembly  30  is fully assembled, the first bracket  60  is secured to the steering column  40  and the second bracket  120  is secured to a portion of the vehicle  50 . In particular, the lower edges  64 ,  92  of the first and second portions  62  and  80 , respectively, of the first bracket  60  are welded directly to the steering column  40 . Alternatively, the first and second portions  62 ,  80  of the first bracket  60  may be secured to the steering column  40  via fasteners or the like (not shown). A plurality of fasteners (not shown) extends through the openings  132  in the flanges  130  of the second bracket  120  to secure the second bracket to the vehicle  50 . The base  122  of the second bracket  120  is positioned between the first and second portions  62 ,  80  of the first bracket  60  such that the first end  126  of the second bracket  120  is aligned with the first ends  64 ,  82  of the first and second portions  62  and  80 , respectively, of the first bracket  60 . The first and second portions  62 ,  80  of the first bracket  60  extend parallel to the base  122  of the second bracket  120  and are positioned beneath the flanges  130  on the second bracket. 
         [0029]    In this configuration, the openings  136  in the projections  134  of the second bracket  120  are aligned with the openings  70 ,  88  in the projections  68 ,  86  of the first and second portions  62  and  80 , respectively, of the first bracket  60 . The openings  70 ,  88 ,  136  receive the pivot shaft  160  to pivotably connect the first bracket  60  to the second bracket  120  about an axis  164  of the pivot shaft, thereby pivotably connecting the steering column  40  mounted on the first bracket to the vehicle  50  secured to the second bracket. A pair of lock washers  162  engages the ends of the pivot shaft  160  to prevent the pivot shaft from exiting the openings  70 ,  88 ,  136 . 
         [0030]    Each opening  72  in the first portion  62  of the first bracket  60  is aligned with an opening  138  in the left side of the base  122  of the second bracket  120 , and each opening  90  in the second portion  80  of the first bracket is aligned with an opening  138  in the right side of the base of the second bracket. Each pair of aligned openings  72 ,  138  on the left side of the mounting assembly  30  and each pair of aligned openings  90 ,  138  on the right side of the mounting assembly receives a holding element  170 , such as a rivet or pin. The holding elements  170  may constitute blind rivets, pins, rods or the like and be made of, for example, metal. In particular, the holding elements  170  may be made of C1006-C1038 steel, high strength steel, 1025 low carbon steel, leaded brass wire, copper wire, and combinations thereof. Collectively, the holding elements  170  act to secure the second bracket  120  to the first bracket  60  such that pivotal movement of the first bracket relative to the second bracket and about the axis  164  of the pivot shaft  160  is blocked unless or until predetermined conditions are met. 
         [0031]    Although the holding elements  170  are illustrated and described as being metal elements that are sheared or ruptured, those having ordinary skill will appreciate that the holding elements  170  may have alternative configurations that block pivotal movement of the first bracket  60  relative to the second bracket  120  until or unless predetermined conditions are met. For example, the holding elements  170  may constitute biasing members, such as springs, cams, wedges, frictional or magnetic members or the like, or combinations thereof. 
         [0032]    During normal operation of the vehicle  50  ( FIG. 3A ), the axis  44  of the steering shaft  45  is substantially co-axial with or parallel to the fore-aft direction  46  of the vehicle. In this condition, the holding elements  170  block pivotal movement of the first bracket  60  relative to the second bracket  120  and thus, the holding elements block the steering column  40  mounted on the first bracket from pivoting relative to the portion of the vehicle  50  secured to the second bracket. 
         [0033]    During a vehicle crash or other situation in which the legs or lower torso of the occupant are forced upwards towards the underside of the steering column  40  or steering wheel  42 , e.g., detonation of an explosive device underneath the vehicle, the occupant impacts the steering column and/or steering wheel with an upward force indicated at arrow F. Since the point at which the occupant impacts the steering column  40  is spaced from the pivot shaft  160  along the steering axis  44 , the impact creates a counterclockwise moment, as viewed in  FIG. 3A , about the axis  164  of the pivot shaft that tends to urge the steering column  40  to pivot in an upward direction away from the occupant and towards the instrument panel (not shown). 
         [0034]    Pivotal movement of the steering column  40  about the pivot shaft  160  and relative to the vehicle  50  is initially blocked due to the opposing reaction moment on the other side of the pivot shaft of the rigid connection between the holding elements  170  and the first and second brackets  60 ,  120 . The holding elements  170  are configured such that if the amount of force F applied to the steering column  40  by the upwardly moving occupant exceeds a predetermined amount, the holding elements will shear or rupture. In other words, if the force F of the occupant impacting the steering column  40  exceeds a predetermined amount, the holding elements  170  will fail, thereby releasing the secure connection between the first bracket  60  and the second bracket  120  and eliminating the reaction moment opposing pivotal movement of the first bracket relative to the second bracket. This allows the first bracket  60  to pivot relative to the second bracket  120  and, thus, allows the steering column  40  to pivot relative to the vehicle  50  and towards the instrument panel. 
         [0035]    Since the moving occupant continues to exert an upward force F upon the steering column  40  after the holding elements  170  fail, the steering column pivots about the pivot shaft  160  in a counterclockwise direction as indicated at R 1  and relative to the vehicle  50  towards the instrument panel. The axis  44  of the steering shaft  45  is thereby placed at an angle, indicated by α 1 , relative to the axis  46  representing the fore-aft direction of the vehicle  50 . Pivotal movement of the steering column  40  relative to the vehicle  50  and towards the instrument panel allows the steering column to move upwards with the moving occupant, thereby lowering reaction forces between the steering column and the occupant. 
         [0036]    The amount of predetermined force required to sever or release the secure holding element  170  connections between the first bracket  60  and the second bracket  120  may be adjusted to meet desired performance criterion. For instance, the size, number, and shear strength of the holding elements  170  may all be adjusted to raise or lower the amount of predetermined force required to cause failure of the holding elements to release the secure connection between the first bracket  60  and the second bracket  120 . Furthermore, the position of the holding elements  170  relative to the pivot shaft  160  may also be adjusted. In particular, as shown in  FIG. 3A , the single holding element  170  that extends through the first portion  62  of the first bracket  60  and the second bracket  120  is spaced from the axis  164  of the pivot shaft  160  by a distance indicated by d 1 . By increasing or decreasing the distance d 1 , the reaction moment of the connection between the holding element  170  and the brackets  60 ,  120  that opposes the moment created by the moving occupant impacting the steering column  40  or steering wheel  42  can likewise be increased or decreased. 
         [0037]    More specifically, increasing the distance d 1  creates a greater reaction moment at the holding element  170  connection, which thereby requires a greater impact force F by the occupant to cause failure of the holding element  170 . On the other hand, decreasing the distance d 1  creates a lesser reaction moment at the holding element  170  connection, thereby requiring a lesser impact force F by the occupant to cause failure of the holding element. Although the spacing of a single holding element  170  relative to the pivot shaft  160  is discussed for simplicity and brevity, those skilled in the art will appreciate that similar considerations are applicable for each of the holding elements in the mounting assembly  30 . 
         [0038]    It will be appreciated by those skilled in the art that the spacing of multiple holding elements  170  along the mounting assembly  30  may be symmetric or asymmetric along the length of the mounting assembly to specifically tailor the threshold amount of force F required to cause failure of the holding elements. Accordingly, the spacing of the openings  72 ,  90  in the first and second portions  62  and  80 , respectively, of the first bracket  60  and the openings  138  in the second bracket  120  may be symmetric or asymmetric along the length of the mounting assembly  30  so long as the openings are aligned to allow the holding elements  170  to block pivotal movement of the first bracket relative to the second bracket. 
         [0039]    A mounting assembly in accordance with another aspect of the present invention is illustrated in  FIGS. 4-8B . Features in  FIGS. 4-8B  that are similar to features in  FIGS. 1-3  are given the suffix “a”. The mounting assembly  230  in  FIGS. 4-8B  includes a first bracket  260 , a second bracket  360 , and a pair of pivot shafts  300  for pivotably connecting the first bracket to the second bracket. The first bracket  260  is configured to be secured to the steering column  40   a  and the second bracket  360  is configured to be secured to a portion of the vehicle  50   a , such as the instrument panel. 
         [0040]    As shown in  FIGS. 5-7 , the first bracket  260  includes a base  262  that extends along an axis  264  from a first end  266  to a second end  268 . The first bracket  260  may be formed from a high strength, corrosion resistant material, such as metal. A series of first openings  270  and second openings  272  extend through the base  262  of the first bracket  260 . The first and second openings  270 ,  272  are sized and shaped to act as pass-through openings for fasteners (not shown) that connect the second bracket  360  to the vehicle  50   a . A series of third openings  274  also extend through the base  262  of the first bracket  260 . The third openings  274  are sized and shaped to receive fasteners (not shown) to secure the first bracket  260  to the steering column  40   a . Although  FIG. 5  illustrates a pair of each of the first, second, and third openings  270 ,  272 ,  274 , those having ordinary skill will appreciate that more or fewer first, second, and third openings may be provided in the base to meet desired mounting criterion. 
         [0041]    Side walls  280  extend from each side of the base  262  such that the side walls extend substantially parallel to one another. An opening  282  extends entirely through each side wall  280  at the first end  266  of the base  262 . The openings  282  are axially aligned with one another and are sized and shaped to receive an end of each pivot shaft  300  for pivotably connecting the first bracket  260  to the second bracket  360 . One or more additional openings  284  extend through each side wall  280  between the first end  266  and the second end  268  of the base  262 . Although  FIG. 5  illustrates a single opening  284  in each side wall  280 , those having ordinary skill will appreciate that more openings may be provided in either or both of the side walls. 
         [0042]    Secondary walls  290  extend from the first end  266  of the base  262 . Each secondary wall  290  is positioned inward of each respective side wall  280  such that the secondary walls are spaced closer together than the side walls  280 . The secondary walls  290  and the side walls  280  extend substantially parallel to one another. An opening  292  extends entirely through each secondary wall  290  at the first end  266  of the base  262 . The openings  292  are axially aligned with one another and with the openings  282  in the side wall  280 . The openings  292  are sized and shaped to receive an end of each pivot shaft  300  for pivotably connecting the first bracket  260  to the second bracket  360 . Although  FIG. 5  illustrates that each pair of openings  282 ,  292  receives an end of separate pivot shafts  300 , those having ordinary skill will appreciate that a single pivot shaft may extend through all four openings in accordance with the present invention. 
         [0043]    The second bracket  360  is substantially similar to the first bracket  260  and includes a base  362  that extends along an axis  364  from a first end  366  to a second end  368 . The second bracket  360  may be formed from a high strength, corrosion resistant material, such as metal. A series of first and second openings  374 ,  376  extend through the base  362  of the second bracket  360 . The first and second openings  374 ,  376  are sized and shaped to receive fasteners (not shown) to secure the second bracket  360  to the vehicle  50   a . A series of third recesses or openings  378  and fourth openings  380  also extend through the base  362  of the second bracket  360 . The third and fourth openings  378 ,  380  are sized and shaped to act as pass-through openings for fasteners (not shown) that connect the first bracket  260  to the steering column  40   a . Although  FIG. 5  illustrates a pair of each of the first, second, third, and fourth openings  374 ,  376 ,  378 ,  380 , those having ordinary skill will appreciate that more or fewer first, second, third, and fourth openings may be provided in the base to meet desired mounting criterion. 
         [0044]    A side wall  390  extends on each side of the base  362  such that the side walls extend substantially parallel to one another. An opening  392  extends entirely through each side wall  390  at the first end  366  of the base  362 . The openings  392  are axially aligned with one another and are sized and shaped to receive an end of each pivot shaft  300  for pivotably connecting the first bracket  260  to the second bracket  360 . One or more additional openings  394  extend through each side wall  390  between the first end  366  and the second end  368  of the base  362 . Although a single opening  394  is illustrated in each side wall  390  in  FIG. 5 , those having ordinary skill will appreciate that more or fewer openings may be provided in either or both of the side walls. The size, number, shape, and position of the openings  394  on one side of the base  362 , i.e., the left side as viewed in  FIG. 5 , of the second bracket  360  are configured to correspond with the size, number, shape, and position of the openings  284  on the left side of the first bracket  260 . Likewise, the size, number, shape, and position of the openings  394  on the other side of the base  362 , i.e., the right side as viewed in  FIG. 5 , of the second bracket  360  are configured to correspond with the size, number, shape, and position of the openings  284  on the right side of the first bracket  260 . 
         [0045]    Secondary walls  400  extend from the first end  366  of the base  362 . Each secondary wall  400  is positioned inward of each respective side wall  390  such that the secondary walls are spaced closer together than the side walls. The secondary walls  400  and the side walls  390  extend substantially parallel to one another. An opening  402  extends entirely through each secondary wall  400 . The openings  402  are axially aligned with one another and with the openings  392  in the side wall  390 . The openings  402  are sized and shaped to receive an end of each pivot shaft  300  for pivotably connecting the first bracket  260  to the second bracket  360 . Although  FIG. 5  illustrates that each pair of openings  392 ,  402  receives a pivot shaft  300 , those having ordinary skill will appreciate that a single pivot shaft may extend through all four openings in accordance with the present invention. 
         [0046]    An extension  414  extends from and between each pair of walls  390 ,  400 . As shown in  FIG. 6 , each extension extends at an angle, indicated by α 2 , relative to the base  360 . The angle α 2  may be in the range of about 0° to about 90°. In particular, the angle α 2  may be about 50°. In any case, the extensions  414  have the same angle α 2  and, thus, extend substantially parallel to one another. 
         [0047]    When the mounting assembly  230  is fully assembled, the first bracket  260  is secured to the steering column  40   a  and the second bracket  360  is secured to a portion of the vehicle  50   a . In particular, a plurality of fasteners (not shown) extends through the third openings  374  in the first bracket  260  to secure the first bracket to the steering column  40   a . A plurality of fasteners (not shown) also extends through the first and second openings  374 ,  376  in the second bracket  360  to secure the second bracket to the vehicle  50   a . The second bracket  360  is then positioned overlying the first bracket  260  such that the openings  392 ,  402  in the walls  390 ,  400  of the second bracket  360  are aligned with the openings  282 ,  292  in the walls  280 ,  290  of the first bracket  260 . 
         [0048]    The openings  282 ,  292 ,  392 ,  402  on one side of the mounting assembly  230 , i.e., the left side as viewed in  FIG. 5 , receive the ends of one pivot shaft  300  to pivotally secure the left side of the first bracket  260  to the second bracket  360  about an axis  302 . Likewise, the openings  282 ,  292 ,  392 ,  402  on the other side of the mounting assembly  230 , i.e., the right side as viewed in  FIG. 5 , receive the ends of another pivot shaft  300  to pivotally secure the right side of the first bracket  260  to the second bracket  360  about an axis  302 . In combination, the pivot shafts  300  pivotally connect the steering column  40   a  mounted on the first bracket  260  to the portion of the vehicle  50   a  secured to the second bracket  360 . A pair of lock washers (not shown) engages the ends of each pivot shaft  300  to prevent the pivot shafts from exiting the openings  282 ,  292 ,  392 ,  402 . 
         [0049]    Each opening  284  in the side walls  280  of the first bracket  260  is aligned with an opening  394  in the side wall  390  of the second bracket  360 . Each pair of aligned openings  284 ,  394  on both sides of the mounting assembly  230  receives a holding element  320  that is similar or identical to the holding element  170  used in the mounting assembly  30  of  FIGS. 1-3B . Collectively, the holding elements  320  act to secure the second bracket  360  to the first bracket  260  such that pivotal movement of the first bracket relative to the second bracket and about the axes  302  of the pivot shafts  300  is blocked unless or until predetermined conditions are met. 
         [0050]    When the first and second brackets  260 ,  360  are secured to one another in this manner, the first and second openings  270 ,  272  in the first bracket are aligned with the first and second openings  374 ,  376 , respectively, in the second bracket. As noted, fasteners (not shown) extend through the first and second openings  374 ,  376  in the second bracket  360  to secure the second bracket to the portion of the vehicle  50   a . The first and second openings  270 ,  272  in the first bracket  260  are sized and shaped to accommodate any portion of the fasteners that extends through the first and second openings  374 ,  376  in the second bracket and towards the first bracket such that the fasteners do not interfere with the operation of the mounting assembly  230 . 
         [0051]    Likewise, when the first and second brackets  260 ,  360  are secured to one another, the third openings  274  in the first bracket are aligned with the third and fourth openings  378 ,  380 , respectively, in the second bracket. As noted, fasteners (not shown) extend through the third openings  274  in the first bracket  260  to secure the first bracket to the steering column  40   a . The third and fourth openings  278 ,  280  in the second bracket  360  are sized and shaped to accommodate any portion of the fasteners that extends through the third openings  274  in the first bracket and towards the second bracket such that the fasteners do not interfere with the operation of the mounting assembly  230 . 
         [0052]    During normal operation of the vehicle ( FIG. 8A ), the axis  44  of the steering shaft  45  is substantially co-axial with or parallel to the fore-aft direction  46   a  of the vehicle  50   a . In this condition, the holding elements  320  block pivotal movement of the first bracket  260  relative to the second bracket  360  and, thus, the holding elements block the steering column  40   a  mounted on the first bracket from pivoting relative to the vehicle  50   a  secured to the second bracket. 
         [0053]    During a vehicle crash or other situation in which the legs or lower torso of the occupant are forced upwards towards the underside of the steering column  40   a  or steering wheel  42   a , e.g., detonation of an explosive device underneath the vehicle, the occupant impacts the steering column and/or steering wheel with an upward force indicated at F. Since the point at which the occupant impacts the steering column  40   a  is spaced from the pivot shafts  300  along the steering axis  44   a , the impact creates a counterclockwise moment, as viewed in  FIG. 8A , about the axes  302  of the pivot shafts that tends to urge the steering column to pivot in an upward direction away from the occupant and towards the instrument panel. 
         [0054]    Pivotal movement of the steering column  40   a  about the pivot shafts  302  and relative to the vehicle  50   a  is initially blocked due to the opposing reaction moment on the other side of the pivot shafts of the rigid connection between the holding elements  320  and the first and second brackets  260 ,  360 . The holding elements  320  are configured such that if the amount of force F applied to the steering column  40   a  by the upwardly moving occupant exceeds a predetermined amount, the holding elements will shear or rupture. In other words, if the force F of the occupant impacting the steering column  40   a  exceeds a predetermined amount, the holding elements  320  will fail, thereby releasing the secure connection between the first bracket  260  and the second bracket  360 , and eliminating the reaction moment opposing pivotal movement of the first bracket relative to the second bracket. This allows the first bracket  260  to pivot relative to the second bracket  360  and, thus, allows the steering column  40   a  to pivot relative to the vehicle  50   a  and towards the instrument panel. 
         [0055]    Since the moving occupant continues to exert an upward force F upon the steering column  40   a  after the holding elements  320  fail, the steering column pivots about the pivot shafts  300  in a counterclockwise direction as indicated at R 2  and relative to the vehicle  50   a . The axis  44   a  of the steering shaft  45   a  is thereby placed at an angle, indicated at α 3 , relative to the axis  46   a  representing the fore-aft direction of the vehicle  50   a . Pivotal movement of the steering column  40   a  relative to the vehicle  50   a  and towards the instrument panel allows the steering column to move upwards with the moving occupant, thereby lowering reaction forces between the steering column and the occupant. 
         [0056]    In the mounting assembly  230  of  FIGS. 5-8B , pivotal movement of the first bracket  260  relative to the second bracket  360  and, thus, of the steering column  40   a  relative to the portion of the vehicle  50   a  is regulated. In particular, the extensions  414  on the second bracket  360  act as stops to prevent the first bracket  260  from pivoting relative to the second bracket  360  in the counterclockwise direction R 2  more than a predetermined amount. Before the holding elements  320  fail, the base  262  of the first bracket  260  extends substantially parallel to the base  362  of the second bracket  360 . Since the extensions  414  on the second bracket  360  extend at an angle α 2  relative to the base  362 , the extensions likewise extend at the angle α 2  relative to the base  262  of the first bracket  260 . In other words, prior to failure of the holding elements  320 , the projections  310  of the base  262 , are angularly offset from the extensions  414  on the second bracket  360  by the angle α 2 . 
         [0057]    Following failure of the holding elements  320  due to the impact between the occupant and the steering column  40   a , the first bracket  260  pivots with the moving steering column  40   a  and relative to the second bracket  360  in the counterclockwise direction R 2 . Therefore, the projections  310  on the first bracket  260  pivot relative to the extensions  414  on the second bracket  360 . Pivoting of the first bracket  260  relative to the second bracket  360  is thereby permitted over the entire angle α 2  until the extensions  310  on the first bracket engage the projections  414  on the second bracket, thereby ceasing relative pivotal movement between the steering column  40   a  and the vehicle  50   a . By adjusting the angle α 2  of the projections  414  on the second bracket  360 , the amount of pivotal movement of the steering column  40   a  relative to the vehicle  50   a , i.e., the degree of the angle α 2 , can be limited to a predetermined amount to meet specific design criterion. 
         [0058]    Similar to the mounting assembly  30  illustrated in  FIGS. 1-3B , the amount of predetermined force required to release the secure holding element  320  connections between the first bracket  260  and the second bracket  360  in the mounting assembly  230  of  FIGS. 5-8B  may be adjusted to meet desired performance criterion. For instance, the size, number, and shear strength of the holding elements  320  may all be adjusted to raise or lower the amount of predetermined force required to cause failure of the holding elements  320  to release the secure connection between the first bracket  260  and the second bracket  360 . Furthermore, the distance, indicated by d 2  in  FIG. 8A , of one or more of the holding elements  320  relative to the pivot shafts  300  may also be adjusted. It will be appreciated by those skilled in the art that the spacing of the holding elements  320  along the mounting assembly  230  may be symmetric or asymmetric along the length of the mounting assembly. Accordingly, the spacing of the openings  284 ,  394  in the first bracket  260  and the second bracket  360  may be symmetric or asymmetric along the length of the mounting assembly  230  so long as the openings are aligned to allow the holding elements  320  to block pivotal movement of the first bracket relative to the second bracket. 
         [0059]    Due to the configuration of the mounting assemblies  30 ,  230  of the present invention, the steering column  40 ,  40   a  is only pivotable relative to the vehicle  50 ,  50   a  when the occupant impacts the underside of the steering column or steering wheel  42 ,  42   a . Therefore, any forces or impact applied in a downward manner to the steering column  40 ,  40   a  or steering wheel  42 ,  42   a  do not result in pivotal movement of the steering column relative to the vehicle  50 ,  50   a . In other words, forces applied in a downward manner upon the steering column  40 ,  40   a  or steering wheel  42 ,  42   a  that impart a clockwise moment to the steering column about the axis  164 ,  302 , e.g., during ingress or egress from the vehicle when the occupant steps on or otherwise applies downward forces to the steering column, do not cause the holding elements  170 ,  320  to fail. Therefore, the first bracket  60 ,  260  remains blocked from pivoting relative to the second bracket  120 ,  360 , respectively. This is due to the supplemental reaction moment from the steering column  40 ,  40   a  being urged against the vehicle  50 ,  50   a  that opposes the clockwise moment of the occupant applying downward forces to the steering column. The combination of reaction moments from the mounting assembly  30 ,  230  and the steering column  40 ,  40   a  is far greater than the opposing moment of the occupant applying downward forces to the steering column such that the holding elements  170 ,  320  do not fail during vehicle egress and ingress. 
         [0060]    If a downward force is applied to the steering column  40 ,  40   a  in a direction opposite to the direction of the force F, the holding elements  170 ,  320  will not shear or rupture. The first bracket  60 ,  260  is urged into engagement with the second bracket  120 ,  360  to prevent pivotal movement of the brackets relative to each other. Accordingly, a vehicle occupant may step on the steering column  40 ,  40   a  upon entering or leaving the vehicle without shearing or rupturing the holding elements  170 ,  320 . 
         [0061]    In another aspect of the present invention illustrated in  FIGS. 9A-9B , either of the mounting assemblies  30 ,  230  of the present invention may be used in combination with a telescoping device  500  that is secured to a steering gear  510 . Although  FIGS. 9A-9B  illustrate the mounting assembly  30  and steering column  40  of  FIGS. 1-5 , the mounting assembly  230  and steering column  40   a  of  FIGS. 5-8B  could likewise be used in accordance with the telescoping device  500 . In  FIGS. 9A-9B , features that are similar to those used in  FIGS. 1-8B  use the same reference number. 
         [0062]    In  FIG. 9A , the mounting assembly  30  secures the steering column  40  to a portion of the vehicle  50 , such as the instrument panel. The mounting assembly  30  is in an initial condition in which the holding elements  170  prevent the steering column  40  from pivoting relative to the vehicle  50 . The telescoping device  500  mechanically connects the steering shaft  45  of the steering column  40  to the steering gear  510  for helping to steer the vehicle wheels via the steering wheel  42 . The telescoping device  500  may include first and second members  502 ,  504  that mechanically connect the steering shaft  45  to the steering gear  510  such that rotation of the steering wheel  42  is transferred through the steering shaft and to the steering gear. 
         [0063]    The first and second members  502 ,  504  of the telescoping device  500  may be mounted within one another to allow for relative axial movement between the first and second members while preventing relative rotational movement between the first and second members. In this configuration, the telescoping device  500  accounts for changes in the distance between the steering shaft  45  and the steering gear  510  while maintaining the ability to transfer rotational movement of the steering shaft to the steering gear. In particular, the telescoping device  500  is secured to both the steering shaft  45  and the steering gear  510  by universal joints or U-joints  506 . 
         [0064]    In the initial condition of the mounting assembly  30 , the telescoping device  500  has a first, contracted length, indicated by L 1 , which substantially corresponds with the distance between the steering shaft  45  and the steering gear  510 . When the holding elements  170  fail due to the force F of the occupant impacting the underside of the steering column  40  or steering wheel  42 , the steering column rotates in the clockwise direction, indicated by R 3 , about the pivot shaft  160  and relative to the vehicle, as shown in  FIG. 9B . This rotation of the steering column  40  causes the steering shaft  45  to rotate in the direction R 3  away from the steering gear  510 , thereby increasing the distance between the steering shaft and the steering gear. 
         [0065]    As the steering shaft  45  moves away from the steering gear  510 , the first and second members  502 ,  504  of the telescoping device  500  move axially relative to one another in a telescoping manner such that the telescoping device reaches a condition that has a second, extended length, indicated by L 2 , which is longer than the first length L 1 . The universal joint connections  506  between the telescoping device  500  and the steering shaft  45  and steering gear  510 , respectively, ensure that the telescoping device maintains the ability to transfer rotational movement of the steering shaft to the steering gear during extension of the telescoping device under the influence of the steering column  40  rotating in the direction R 3 . 
         [0066]    The preferred embodiments of the invention have been illustrated and described in detail. However, the present invention is not to be considered limited to the precise construction disclosed. Various adaptations, modifications and uses of the invention may occur to those skilled in the art to which the invention relates and the intention is to cover hereby all such adaptations, modifications, and uses which fall within the spirit or scope of the appended claims.