Abstract:
A steering lock assembly an assembly housing includes a non-linear passage that receives a cam shaft and/or cam pin. The non-linear passage provides a steering lock assembly that is shorter than steering lock assemblies having an assembly housing with a linear passage for receiving the cam shaft and cam pin.

Description:
CROSS REFERENCES TO RELATED APPLICATIONS 
       [0001]    This application claims the priority benefit of U.S. patent application No. 11/257,695, filed on Oct. 25, 2005, and U.S. Provisional Patent Application No. 60/622,128, filed on Oct. 26, 2004. 
     
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH 
       [0002]    Not Applicable. 
       BACKGROUND OF THE INVENTION 
       [0003]    This invention relates to a steering lock module, and in particular an automotive steering lock assembly including a cam shaft and/or cam pin. 
         [0004]    An automotive steering column houses a steering shaft that upon rotation changes the angular direction of vehicle wheels to steer the vehicle. A steering lock assembly mounted in the steering column includes a lock bolt engageable with the steering shaft to prevent rotation of the steering shaft, and thus the ability to steer the vehicle. A key inserted into the steering lock assembly is rotated to disengage the lock bolt from the steering shaft and start the vehicle engine. 
         [0005]    As the key is inserted into the steering lock assembly and/or the lock cylinder is rotated, the lock cylinder urges a cam pin into engagement with a switch that indicates the key has been properly inserted into the steering lock assembly. Upon rotation of the key in the lock cylinder, the lock bolt is urged out of engagement with the steering shaft by a cam shaft coupled to a lock cylinder, and the cam shaft is engaged with an ignition switch which upon rotation of the cam shaft by the lock cylinder starts the vehicle engine. In some embodiments, the switch engaging the cam pin is the ignition switch that starts the vehicle engine. 
         [0006]    A steering lock assembly housing houses the lock bolt, cam shaft, cam pin, and lock cylinder. Known steering lock assembly housings define a linear passageway through which the linear cam shaft and cam pin extend. This linear passageway, cam shaft, and cam pin define in part the shape, and thus the size, of the housing. Unfortunately, the space available in the steering column for mounting the steering lock assembly is limited. Moreover, the angle at which the key must be inserted into the steering lock assembly is limited to the axis of the linear passageway. Accordingly, a need exists for a steering lock assembly having a shape and/or size that can fit in the space available in a steering column and provide more options as to the angle of key insertion into the steering lock assembly. 
       SUMMARY OF THE INVENTION 
       [0007]    The present invention provides a steering lock assembly including an assembly housing defining a non-linear passage that receives a non-linear cam shaft and/or cam pin. The non-linear passage provides a steering lock assembly that is shorter than steering lock assemblies having an assembly housing with a linear passage for receiving the cam shaft and cam pin. In one embodiment, the cam shaft passing through the non-linear passage is articulated to accommodate the non-linear passage. In another embodiment, the cam pin is flexible to accommodate the non-linear passage. 
         [0008]    A general objective of the present invention is to provide a steering lock assembly that requires a small space in a steering column and allows for a greater range of key insertion angles. This objective is accomplished by providing a steering lock assembly having a housing defining a non-linear passage for a cam shaft and cam pin to reduce the length of the steering lock assembly compared to a steering lock assembly having a linear passage for the cam shaft and cam pin. 
         [0009]    Another objective of the present invention is to provide a cam shaft that can pass through a non-linear passage formed in an assembly housing. This objective is accomplished in one embodiment by providing an articulated cam shaft. 
         [0010]    Another objective of the present invention is to provide a cam pin that can pass through a non-linear passage formed in an assembly housing. This objective is accomplished in one embodiment by providing a cam pin having a flexible portion that passes through the non-linear portion of the passage. 
         [0011]    The foregoing and other objects and advantages of the invention will appear from the following description. In the description, reference is made to the accompanying drawings which form a part hereof, and in which there is shown by way of illustration a preferred embodiment of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0012]      FIG. 1  is a side view of a steering lock assembly incorporating the present invention; 
           [0013]      FIG. 2  is a cross sectional view of the steering lock assembly along line  2 - 2  of  FIG. 1 ; 
           [0014]      FIG. 3  is a perspective, exploded view of the steering lock assembly of  FIG. 1 ; 
           [0015]      FIG. 4  is a perspective view of the cam shaft of  FIG. 3 ; and 
           [0016]      FIG. 5  is a cross sectional view of the cam shaft along line  5 - 5 . 
       
    
    
       [0017]    Before a preferred embodiment of the invention is explained in detail, it is to be understood that the invention is not limited in its application to the details of the construction and the arrangements of components set forth in the following description or illustrated in the drawings. The invention is capable of other embodiments and of being practiced or being carried out in various ways. Also, it is understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. 
       DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0018]    As shown in  FIGS. 1-3 , a steering lock assembly  10  suitable for mounting in a steering column of a vehicle includes a lock bolt  12  that is engageable with a steering shaft. Upon rotation, the steering shaft changes the angular direction of vehicle wheels to steer the vehicle. The lock bolt  12  selectively engages the steering shaft to prevent rotation of the steering shaft, and thus the ability to steer the vehicle. Preferably, a cylinder lock assembly actuable by a key actuates the steering lock assembly  10  to selectively engage the lock bolt  12  with the steering shaft. In the embodiment disclosed herein, an ignition switch  14  forming part of the steering lock assembly  10  is actuated to start the vehicle when the lock bolt  12  is disengaged from the steering shaft. 
         [0019]    The steering lock assembly  10  includes an assembly housing  20  having a lock bolt portion  22  extending from a cylindrical portion  26 . The cylindrical portion  26  extends between a cylindrical forward end  28  and a cylindrical rearward end  30 . The cylindrical forward end  28  extends along a first longitudinal axis  42  toward the lock bolt portion  22 . The cylindrical rearward end  30  extends along a second longitudinal axis  44  past the lock bolt portion  22 . The first longitudinal axis  42  defines an angle with the second longitudinal axis  44  to shorten the overall length of the assembly housing  20  compared to a housing having coaxial forward and rearward ends. The forward and rearward ends  28 ,  30  of the assembly housing  20  define a non-linear passageway  46  through the assembly housing  20  having a non-linear section  48  at the junction of the forward and rearward ends  28 ,  30 . 
         [0020]    The assembly housing  20  is preferably formed as a single piece with the lock bolt portion  22  and cylindrical portion  26  formed from a metal, such as a zinc die cast alloy, aluminum, and the like. Although a housing  20  formed as a single piece is preferred, the assembly housing  20  can be formed from, a plurality of portions that are joined together using methods known in the art, such as welding, bolting, and the like, without departing from the scope of the invention. Moreover, although the present invention is especially suitable for a housing  20  formed from a non-resilient material, such as a metal, the assembly housing  20  can be formed from any material, such as plastic, ceramic, and the like without departing from the scope of the invention. 
         [0021]    The lock bolt portion  22  of the assembly housing  20  reciprocally houses the lock bolt  12 , and includes a concave upper surface  54  that receives the vehicle steering shaft. A cavity  56  formed in the lock bolt portion  22  intersects the passageway  46  of the assembly housing  20  and opens to the upper surface  54 . The cavity  56  receives the lock bolt  12  and a lock bolt spring  52 , and is covered by a lock bolt cover  60 . The lock bolt spring  52  biases the lock bolt  12  into engagement with the steering shaft. The lock bolt cover  60  is fixed relative to the assembly housing  20  by a snap belt  70 , and limits movement of the lock bolt  12  out of the cavity  56 . 
         [0022]    An antennae housing  38  mounted to the cylindrical forward end  28  of the assembly housing  20  receives the cylinder lock assembly. The cylinder lock assembly can be any cylinder lock assembly known in the art engageable with a cam shaft  32  and cam pin  34  forming part of the steering lock assembly  10 . In the embodiment disclosed herein, the cylinder lock assembly receives a key, and upon rotation of the key urges the cam pin  34  rearwardly into engagement with the ignition switch  14  mounted to the rearward end  30  of the assembly housing  20  and rotates the rotatable cam shaft  32  to disengage the lock bolt  12  from the steering shaft. 
         [0023]    The rotatable cam shaft  32  is disposed in the cylindrical portion  26  of the assembly housing  20  through the cylindrical forward end  28  and passes through the non-linear passageway  46 . The cam shaft  32  includes a proximal end  62  and a distal end  64 . The proximal end  62  extends substantially parallel to the first longitudinal axis  42  and engages the lock cylinder received in an antennae housing  38  mounted to the cylindrical forward end  28  of the assembly housing  20 . The distal end  64  of the cam shaft  32  extends substantially parallel to the second longitudinal axis  44  and past the lock bolt portion  22 . A cam surface  66  formed on the distal end  64  of the cam shaft  32  engages the lock bolt  12  mounted in the lock bolt portion  22  for reciprocal movement orthogonal to the second longitudinal axis  44  of the cylindrical rearward end  30 . 
         [0024]    As shown in  FIGS. 3 and 4 , preferably, the cam shaft  32  is an assembly including a forward shaft  68  coupled to a rearward shaft  72 . The forward shaft  68  is received in the cylindrical forward end  28 , and extends substantially parallel to the first longitudinal axis  42  from a proximal end  74  to a distal end  76 . The proximal end  74  of the forward shaft  68  corresponds to the proximal end  62  of the cam shaft  32 . The rearward shaft  72  is received in the cylindrical rearward end  30  of the assembly housing  20 , and extends substantially parallel to the second longitudinal axis  44  past the lock bolt portion  22  of the assembly housing  20 . The cam surface  66  is formed on the rearward shaft  72  between a proximal end  78  and a distal end  82  of the rearward shaft  72 . The distal end  82  of the rearward shaft  72  corresponds to the distal end  64  of the cam shaft  32 , and is supported by an end cover  84  received in the cylindrical rearward end  30  of the assembly housing  20 . 
         [0025]    The forward shaft distal end  76  is rotatably coupled to the proximal end  78  of the rearward shaft  72  by a ball and socket joint  86  that allows the cam shaft  32  to pass through the non-linear section  48  of the non-linear passageway  46  formed through the assembly housing  20 . The ball and socket joint  86  includes a socket  88  formed on the distal end  76  of the forward shaft  68  that receives a ball  92  formed on the proximal end  78  of the rearward shaft  72 . The ball  92  has rounded sides  94  in the direction of the second longitudinal axis  44  that allows the ball  92  to pivot relative to the socket  88  as the cam shaft  32  rotates in the passageway  46  formed in the assembly housing  20 . Of course, the ball  92  can be formed on the distal end  76  of the forward shaft  68  which is received in a socket  88  formed on the proximal end  78  of the rearward shaft  72  without departing from the scope of the invention. 
         [0026]    As shown in  FIGS. 3-5  the socket  88  defines a cavity  96  having a non-circular cross section that receives the complementary non-circular cross section shaped ball  92  formed on the proximal end  78  of the rearward shaft  72 . Advantageously, the non-circular cross section of the ball  92  and socket  88  ensure that the forward and rearward shafts  68 ,  72  rotate together to actuate the lock bolt  12 . Although a ball  92  and socket  88  having complementary polygonal cross sections in the form of a square is shown, the ball  92  and socket  88  can have any non-circular cross sectional shape, such as a polygon, circle with a key or teeth, and the like, that ensures both forward and rearward shafts  68 ,  72  rotate together, without departing from the scope of the invention. Moreover, although an articulated cam shaft  32  is preferred, any cam shaft or cam shaft assembly that can pass through a non-linear section of a non-linear passageway, such as a single flexible shaft cam shaft, two or more shafts coupled end to end by universal joints, and the like, can be used without departing from the scope of the invention. 
         [0027]    The ball and socket joint  86  rotates about a point  98  defined by the intersection of the first and second longitudinal axes  42 ,  44 . Preferably, the first and second longitudinal axes  42 ,  44  intersect at a point within the ball and socket joint  86  to minimize the space required for the cam shaft  32  to rotate within the assembly housing  20 . Of course, the first and second longitudinal axes  42 ,  44  can intersect at a point outside of the ball and socket joint  86  with the assembly housing  20  sized to accommodate the additional space required for the cam shaft  32  to rotate in the non-linear passageway  46  formed through the assembly housing  20  without departing from the scope of the invention. 
         [0028]    An inner passageway  102  formed through the cam shaft  32  between the cam shaft ends  62 ,  64  receives the cam pin  34  that moves longitudinally through the cam shaft  32  to engage the ignition switch  14 . The cam pin  34  includes a proximal end  104  and a distal end  106 , and is longitudinally biased by a cam spring  36  received in the inner passageway  102 . The proximal end  104  of the cam pin  34  engages the cylinder lock assembly and the distal end  106  of the cam pin  34  engages the ignition switch  14 . Preferably, the cam pin  34  is formed from a resilient material, such as acetal, that bends to allow the cam pin  34  to pass through the non-linear section  48  of the non-linear passageway  46 . However, any resilient material can be used without departing from the scope of the invention. 
         [0029]    As shown in  FIGS. 2 and 3  in a preferred embodiment, the cam pin  34  is a molded single piece. The distal end  106  of the cam pin  34  is substantially rigid and extends through a portion of the inner passageway  102  formed through the rearward shaft  72 . The proximal end  104  of the cam pin  34  is flexible and extends through a portion of the inner passageway  102  formed through the ball and socket joint  86  and the forward shaft  68 . The proximal and distal ends  104 ,  106  are joined by a plug  110  disposed in an enlarged portion of the inner passageway  102  formed in the proximal end  78  of the rearward shaft  72 . Preferably, the distal end  106  of the cam pin  34  is joined to the plug  110  offset from the plug longitudinal center axis which is coaxial with the second longitudinal axis  44  to minimize the bending required of the distal end  106  to pass through the ball and socket joint  86 . Of course, the pin can be formed from more than one piece without departing from the scope of the invention. 
         [0030]    The end cover  84  is received in the cylindrical rearward end  30  of the assembly housing  20 , and is fixed relative to the assembly housing  20  by a snap belt  114 . An aperture  112  formed through the end cover  84  receives the distal end  64  of the cam shaft  32  to support the cam shaft distal end  64 . The ignition switch  14  is mounted to the end cover  84  to fix the ignition switch  14  relative to the assembly housing  20  and align the ignition switch  14  with the cam pin  34  which engages the ignition switch  14  through the aperture  112 . 
         [0031]    In use, a user inserts a key into the cylinder lock assembly. Rotation of the key in the cylinder lock assembly rotates the articulated cam shaft  32  to retract the lock bolt  12  from the steering shaft and actuate the ignition switch  14 . Simultaneously, the cylinder lock assembly longitudinally moves the cam pin  34  to actuate the switch  14 . Advantageously, forming the cylindrical forward end  28  of the assembly housing  20  at an angle relative to the cylindrical rearward end  30  reduces the space required in the steering column to mount the steering lock assembly  10  and allows more ergonomical options, such as a range of key insertion angles. 
         [0032]    While there has been shown and described what are at present considered the preferred embodiment of the invention, it will be obvious to those skilled in the art that various changes and modifications can be made therein without departing from the scope of the invention defined by the appended claims. Therefore, various alternatives and embodiments are contemplated as being within the scope of the following claims particularly pointing out and distinctly claiming the subject matter regarded as the invention.