Abstract:
An apparatus ( 10 ) for use in a vehicle comprises a steering shaft ( 12 ) rotatable about a first axis (B) and an activatable lock ( 18 ) operatively coupled with the steering shaft for preventing rotation of the steering shaft. The lock ( 18 ) is deactivated by a key ( 19 ). A vehicle steering wheel ( 20 ) includes a hub portion ( 130 ) and is non-rotatably connected to the steering shaft ( 12 ) by the hub portion for joint rotation with the steering shaft. The apparatus ( 10 ) further comprises an inflatable vehicle occupant protection device ( 70 ) attached to the steering wheel ( 20 ). A movable member ( 200 ) blocks axial movement of the steering wheel ( 20 ) relative to the steering shaft ( 12 ). A housing ( 160 ) encircles a portion of the steering shaft ( 12 ) and the hub portion ( 130 ). The housing ( 16 ) includes at least one opening ( 194 ). The movable member ( 200 ), upon rotation of the steering wheel ( 20 ) relative to the housing ( 16 ), moves from a first position in which the movable member is not aligned with the opening ( 194 ) to a second position in which the movable member is aligned with the opening to permit access to the movable member.

Description:
TECHNICAL FIELD 
     The present invention relates to an apparatus for use with a steering wheel assembly. More particularly, the invention is directed to an apparatus for use in a vehicle having a steering wheel mounted on a rotatable steering shaft, an air bag module mounted on the steering wheel, and a lock for preventing rotation of the steering shaft and the steering wheel. 
     BACKGROUND OF THE INVENTION 
     As a means for deterring and preventing vehicle theft, most vehicles are equipped with a locking mechanism for preventing rotation of the vehicle steering shaft. The typical locking mechanism is deactivated when a vehicle-specific ignition key is inserted into a corresponding ignition keyhole arranged on the steering column and the key is subsequently turned. When the vehicle is parked (i.e., the vehicle ignition is turned OFF and the key is removed), it is typical for the steering wheel to be oriented such that the vehicle is pointed for travel in a generally straight line. 
     Most new vehicles are also equipped with a driver-side inflatable vehicle occupant protection device in the form of an air bag module mounted to the vehicle steering wheel to help protect the driver of the vehicle from injury in certain types of vehicle collisions. Because of the relatively high cost of an unactuated driver-side air bag module, theft of these steering wheel mounted air bag modules has become common. 
     Recently, so-called “integrated” steering wheel assemblies have been suggested in which a driver-side air bag module is incorporated into a steering wheel assembly prior to installation of the steering wheel assembly in the vehicle. As a result, theft of such an integrated air bag module involves theft of the entire integrated steering wheel assembly, which is more costly to replace than just an air bag module. 
     Accordingly, it is an object of the present invention to provide an apparatus for preventing the theft of an integrated steering wheel assembly having a driver-side air bag module incorporated in the assembly. 
     SUMMARY OF THE INVENTION 
     The present invention is an apparatus for use in a vehicle that uses a key to energize the vehicle&#39;s electrical system. The apparatus comprises a steering shaft rotatable about a first axis and an activatable lock operatively coupled with the steering shaft for preventing rotation of the steering shaft. The lock is deactivated by the key. A vehicle steering wheel assembly has a hub portion. The steering wheel assembly is non-rotatably connected to the steering shaft by the hub portion for joint rotation with the steering shaft. The apparatus further comprises an inflatable vehicle occupant protection device for helping to protect the driver of the vehicle in a vehicle collision. The inflatable vehicle occupant protection device is attached to the steering wheel. A movable member blocks axial movement of the steering wheel relative to the steering shaft. A housing encircles a portion of the steering shaft and the hub portion of the steering wheel. The housing includes at least one transversely extending opening. The movable member, upon rotation of the steering wheel relative to the housing, moves from a first position in which the movable member is not aligned with the opening to a second position in which the movable member is aligned with the opening to permit access to the movable member. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The foregoing and other features of the present invention will become apparent to those skilled in the art to which the present invention relates upon reading the following description with reference to the accompanying drawings, in which: 
     FIG. 1 is a schematic view, partly in section, of a vehicle steering assembly and a steering column constructed in accordance with a first embodiment of the present invention; 
     FIG. 2 is a view taken along line  2 — 2  in FIG. 1; 
     FIG. 3 is a sectional view taken along line  3 — 3  in FIG. 1; 
     FIG. 4 is a view taken along line  4 — 4  in FIG. 1; 
     FIG. 5 is a schematic view, partly in section, of a vehicle steering assembly and a steering column constructed in accordance with a second embodiment of the present invention; 
     FIG. 6 is a sectional view taken along line  6 — 6  in FIG. 5; 
     FIG. 7 is a schematic view, partly in section, of a vehicle steering assembly and a steering column constructed in accordance with a third embodiment of the present invention; 
     FIG. 8 is a sectional view taken along line  8 — 8  in FIG. 7; 
     FIG. 9 is a schematic view, partly in section, of a vehicle steering assembly and a steering column constructed in accordance with a fourth embodiment of the present invention; and 
     FIG. 10 is a sectional view taken along line  10 — 10  in FIG.  9 . 
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
     FIG. 1 illustrates a vehicle steering wheel assembly  10  and a vehicle steering column  12  constructed in accordance with the present invention. The steering wheel assembly  10  includes an armature  20 . An non-removable cover  30  is attached to the armature  20 . The cover  30  has a continuous outer surface  32 , which extends uninterruptedly over a central area of the steering wheel assembly  10 . An inner surface  34  of the cover  30  has a side wall portion  36  and an end wall portion  38 . The inner surface  34  defines a cavity  40  in the central area of the cover  30 . The cavity  40  may include a horn pad arrangement  42  and/or an occupant sensing device (not shown) such as a capacitive plate. In accordance with the illustrated embodiment of the invention, the cover  30  is made of a homogeneous urethane material. 
     The steering wheel assembly  10  includes an inflatable air bag  70  (shown schematically in FIG. 1) and an actuatable inflator  80  for, when actuated, inflating the air bag. The air bag  70  is located in the cavity  40  in the cover  30  between the inner surface  34  of the cover and the portion of the inflator  80  extending into the cavity. The inflator  80  is attached to the armature  20  in a known manner (not shown). A retaining ring  72  secures the air bag  70  to the inflator  80 . 
     A metal hub  130  is partially located in an axial passage  122  through a base portion  104  of the armature  20 . The hub  130  is an annular part that is centered on the axis B. The hub  130  is preferably cast into the armature  20  and is thus fixed to the armature. Alternatively, it should be understood that the hub  130  could be formed integrally with the armature  20  as a one-piece cast part. 
     The hub  130  has first and second end portions  132  and  134 , respectively (FIG.  3 ). The first end portion  132  is disposed within the passage  122  in the armature  20 . The second end portion  134  extends axially beyond the base portion  104  of the armature  20 . 
     An axially extending surface  138  defines a central passage  140  through the hub  130 , which extends from the first end portion  132  to the second end portion  134 . The passage  140  is centered on the axis B. The surface  138  has a first section  142  adjacent the first end portion  132  of the hub  130  and a second section  144  adjacent the second end portion  134  of the hub. The first section  142  of the surface  138  is splined, and the second section  144  of the surface  138  is smooth and tapered. 
     The base portion  104  of the armature  20  further includes a transversely extending aperture  150  (FIGS. 2 and 3) defined by a transversely extending surface  152 . The surface  152  which extends through the base portion  104  of the support plate and through the hub  130  attached to the support plate. The aperture  150  is centered on an axis C, which is offset from the axis B. A portion of the transversely extending aperture  150  intersects the axially extending central passage  140  in the hub  130 . The aperture  150  has a tapered end  154 . 
     The steering column  12  includes a cylindrical steering shaft  14  centered on the axis B, which is the axis of rotation for the steering shaft. As shown in FIG. 3, the steering shaft  14  includes a main portion  160  and an upper end portion  162 . The upper end portion  162  has a tapered surface  166  for mating with the tapered second section  144  of the surface  138  in the passage  140  through the hub  130 . The upper end portion  162  further includes a splined surface  168  for meshing with the splined surface in the first section  142  of the surface  138  in the hub  130 . An arcuate groove  180  (FIG. 1) is located in the upper end portion  162  of the steering shaft  14 . 
     The steering column  12  includes a stationary housing  16  (FIG. 1) surrounding the upper end portion  162  of the steering shaft  14 . The housing  16  has a cylindrical portion  190  and a cup portion  192 . The cylindrical portion  190  encircles the upper end portion  162  of the steering shaft  14 . The cup portion  192  surrounds the armature  30  and the hub  130 . The cup portion  192  of the housing includes a transversely extending opening  194 . The opening  194  is alignable with the aperture  150  in the base portion  104  of the armature  20  upon rotation of the steering wheel assembly  10  and the steering shaft  14  relative to the housing  16 . 
     The steering column  12  further includes a known key-operated ignition locking mechanism, indicated schematically at  18  in FIG.  1 . The locking mechanism  18  is operable to lock the steering shaft  14  and thereby prevent rotation of the steering shaft. The locking mechanism  18  is deactivated by the insertion and subsequent rotation of a vehicle-specific ignition key  19 . Future “key” systems, such as an electronic smart key that may not require rotation of the key, are also envisioned. 
     A spring pin (or roll pin)  200  secures the steering wheel assembly  10  against axial movement relative to the steering shaft  14 . The spring pin  200  is a hollow cylindrical member, which is preferably made of metal, but could be made of another material, such as a hard plastic. The spring pin  200  is centered on the axis C and includes parallel, cylindrical inner and outer surfaces  202  and  204 , respectively (FIG.  3 ). The diameter of the outer surface  204  of the spring pin  200  is normally slightly larger than the diameter of the transversely extending aperture  150  in the base portion  104  of the support plate  100 . The spring pin  200  further includes an axially extending slot  206  (FIG.  1 ), which extends throughout the entire length of the pin. The slot  206  provides the spring  200  pin with the ability to radially contract and expand as is known in the art. 
     To attach the steering wheel assembly  10  to the steering shaft  14 , the hub  130  in the armature  20  is placed over the steering shaft such that the upper end portion  162  is received in the passage  140  through the hub. The splined section  142  of the surface  138  in the passage  140  meshes with the splined surface  168  of the steering shaft  14 . The steering wheel assembly  10  is oriented so that the groove  180  in the splined surface  168  of the steering shaft  14  radially aligns with the transversely extending aperture  150  in the armature  20 . 
     As the steering wheel assembly  10  is pushed onto the wheel shaft  14 , the tapered surfaces  144  and  166  seat against one another. The end of the hub  130  also comes into contact with a radially extending surface  164  on the upper end portion  162  of the steering shaft  14  (FIG.  1 ). The groove  180  in the steering shaft  14  and the transversely extending aperture  150  now extend co-linearly along the axis C. 
     With the ignition key  19  inserted into the locking mechanism  18  and rotated so the locking mechanism is deactivated, the steering wheel assembly  10  and the steering shaft  14  are rotated relative to the housing  16  until the opening  194  in the housing aligns with the aperture  150  in the support plate  100 . The alignment of the opening  194  and the aperture  150  preferably occurs when the steering wheel assembly  10  is rotated approximately 180°, placing the steering wheel assembly in an unusual orientation. 
     The spring pin  200  is then inserted through the opening  194  in the housing  16  and into the transversely extendingly aperture  150  through the tapered end  154  of the aperture in the armature  20 . The tapered end  154  causes the spring pin  200  to contract radially as the pin is pushed into the aperture  150 . Inside the aperture  150 , the outer surface  204  of the spring pin  200  engages the surface  152  defining the aperture and the surface  182  defining the semi-circular groove  180  in the steering shaft  14 . The spring pin  200  exerts a radially outwardly directed biasing force against the surfaces  152  and  182 . The engagement of the spring pin  200  and the surfaces  152  and  182  of the aperture  150  and the groove  180 , respectively, prevents axial movement of the steering wheel assembly  10  relative to the steering shaft  14 . 
     The aforementioned structure and process for attaching the steering wheel assembly  10  to the steering shaft  14  requires the steering wheel assembly to be rotated in order for the opening  194  and the aperture  150  to be aligned and to provide access for the insertion of the roll pin  200 . Accordingly, the vehicle&#39;s ignition key  19  must be in the locking mechanism  18  so that the locking mechanism is deactivated and the steering wheel assembly  10  can be rotated to the proper orientation. The apparatus described above thus prevents removal of the steering wheel assembly  10  without the ignition key  19 , thereby helping to prevent theft of the steering wheel and air bag assembly. 
     Likewise, removal of the steering wheel assembly  10  requires that the ignition key  19  be inserted into the locking mechanism  18  and rotated so that the locking mechanism is deactivated. The steering wheel assembly  10  is then rotated to align the opening  194  and the aperture  150 . When the opening  194  and the aperture  150  are aligned, spring pin  200  is removed from its position in the aperture  150  in the armature  20 . This is accomplished by forcing a portion of the spring pin  200  out of the aperture  150  that it can be pulled from the aperture, as is known in the art. 
     FIGS. 5 and 6 illustrate a steering wheel assembly  220  and a steering shaft  230  constructed in accordance with a second embodiment of the present invention. In the second embodiment of FIGS. 5 and 6, reference numbers identical to those of the first embodiment of FIGS. 1-4 are used to designate parts that are identical to parts in the first embodiment. 
     According to the second embodiment, the second end portion  134  of the hub  130  includes a clamping sleeve  240 . The clamping sleeve is formed by a pair of opposed flanges  242 A and  242 B that project radially outward from the second end portion  134 . The flanges  242 A and  242 B are separated by a space  244 . One of the flanges  242 A has a threaded opening  248 , and the other flange  242 B has a clearance opening  249 . The openings  248  and  249  extend along a common axis. A clamping screw  250  is received in the openings  248  and  249 . When tightened, the screw  250  clamps the second end portion  134  of the hub  130  to the upper end portion  162  of the steering shaft  230 . 
     An opening  252  (FIG. 6) is formed in the portion of the housing  16  surrounding the upper end portion  162  of the steering shaft  230  and the hub  130 . In a similar fashion to the first embodiment, the opening  252  is alignable with the clamping screw  250  when the steering wheel assembly  220  is rotated to a predetermined orientation. As with the first embodiment, in order to install or remove the steering wheel assembly  220 , the vehicle&#39;s ignition key  19  must be present in the locking mechanism  18  so that the steering wheel assembly can be rotated. Thus, the steering wheel assembly  220  and the steering shaft  230  according to the second embodiment help to prevent theft of the steering wheel assembly. 
     FIGS. 7 and 8 illustrate a steering wheel assembly  270  and a steering shaft  280  constructed in accordance with a third embodiment of the present invention. In the third embodiment of FIGS. 7 and 8, reference numbers identical to those of the first embodiment of FIGS. 1-4 are used to designate parts that are identical to parts in the first embodiment. 
     According to the third embodiment, an upper end portion  282  of the steering shaft  280  includes a first outer surface portion  284  having splines and a second outer surface portion  286  defined by a plurality of planar surfaces  288 . The second outer surface portion  286  is positioned near the middle of the first outer surface portion  284 . 
     The second end portion  134  of the hub  130  includes a threaded opening  290 , which is aligned axially with the second outer surface portion  286  of the steering shaft  280 . A setscrew  292  is received in the threaded opening  290  and, when tightened, clamps the second end portion  134  of the hub  130  against one of the planar surfaces  288  on the upper end portion  162  of the steering shaft  230 . 
     An opening  294  is formed in the portion of the housing  16  surrounding the upper end portion  162  of the steering shaft  280  and the hub  130 . In a similar fashion to the first and second embodiments, the opening  294  is alignable with the setscrew  292  when the steering wheel assembly  270  is rotated to a predetermined orientation. As with the first embodiment, in order to install or remove the steering wheel assembly  270 , the vehicle&#39;s ignition key  19  must be present in the locking mechanism  18  to deactivate the locking mechanism so that the steering wheel assembly can be rotated. Thus, the steering wheel assembly  270  and the steering shaft  280  of the third embodiment help to prevent theft of the steering wheel assembly. 
     FIGS. 9 and 10 illustrate a steering wheel assembly  300  and a steering shaft  310  constructed in accordance with a fourth embodiment of the present invention. In the fourth embodiment of FIGS. 9 and 10, reference numbers identical to those of the first embodiment of FIGS. 1-4 are used to designate parts that are identical to parts in the first embodiment. 
     According to the fourth embodiment, an upper end portion  312  of the steering shaft  300  includes an internally threaded bore  314  and an outer surface portion  316 . 
     A fastener cover  302  supports a fastener  304  on the hub  130 . The fastener  304  has a screw-threaded stem  306  and a gear-driven head  308 , and is rotatable about the axis B relative to the hub  130 . 
     When the hub  130  is first received loosely over the steering shaft  310 , a lower end portion of the fastener  304  guides the stem  306  into the screw-threaded bore  314  in the steering shaft  310 . A gear tool (not shown) is then inserted through an opening  320  in the housing  16  and is used to rotate the head  308  of the fastener  304 . The stem  306  is screwed into the bore  34 , which draws the hub  130  downward over the steering shaft  310  to establish a press fit between the inner surface of the hub  130  and the outer surface  316  of the shaft. 
     In a similar fashion to the other embodiments, the opening  320  is alignable with the fastener  304  when the steering wheel assembly  300  is rotated to a predetermined orientation. Further, in order to install or remove the steering wheel assembly  300 , the vehicle&#39;s ignition key  19  must be present in the locking mechanism  18  to deactivate so that the steering wheel assembly can be rotated. Thus, the steering wheel assembly  300  and the steering shaft  310  of the fourth embodiment help to prevent theft of the steering wheel assembly. 
     From the above description of the invention, those skilled in the art will perceive improvements, changes and modifications. It is contemplated that the invention described herein could be used with a so-called “drive-by-wire” system which does not have a steering shaft. Such improvements, changes and modifications within the skill of the art are intended to be covered by the appended claims.