Abstract:
A steering column assembly configured to couple to a steering wheel is provided. The assembly includes a steering column shaft having a first end and a second end, the second end configured to couple to the steering wheel. The assembly also includes an intermediate shaft coupled to the steering column shaft first end. The assembly further includes a steering input pinion coupled to the intermediate shaft. The assembly yet further includes a counter rotation mechanism configured to counter rotate rotational movement of the steering column assembly such that the steering wheel does not rotate.

Description:
CROSS REFERENCE TO RELATED APPLICATION 
       [0001]    This patent application claims priority to U.S. Provisional Patent Application Ser. No. 62/155,589, filed May 1, 2015, which is incorporated herein by reference in its entirety. 
     
    
     BACKGROUND 
       [0002]    The disclosure herein relates to steering column assemblies and, more specifically, to a steering column assembly with anti-rotation features. 
         [0003]    When some vehicles are fitted with systems that allow the vehicle to be driven autonomously, the steering system(s) operate while the steering wheel may be required to rotate while the vehicle is in an autonomous driving mode. The steering wheel may be utilized for non-driving functions (e.g., tray table), but rotation of the steering wheel limits such functionality. “De-clutching” the wheel, or an associated intermediate component, from a steering gear results in disengagement of the wheel, thereby requiring re-engagement if an operator wishes to manually take control of the vehicle. 
       SUMMARY OF THE INVENTION 
       [0004]    In one embodiment of the disclosure, a steering column assembly configured to couple to a steering wheel is provided. The assembly includes a steering column shaft having a first end and a second end, the second end configured to couple to the steering wheel. The assembly also includes an intermediate shaft coupled to the steering column shaft first end. The assembly further includes a steering input pinion coupled to the intermediate shaft. The assembly yet further includes a counter rotation mechanism configured to counter rotate rotational movement of the steering column assembly such that the steering wheel does not rotate. 
         [0005]    In another embodiment of the disclosure, a steering column assembly configured to couple to an operator steering input device is provided. The assembly includes a steering column shaft having a first end and a second end, the second end configured to couple to the operator steering input device. The assembly also includes an intermediate shaft coupled to the first end of the steering column shaft. The assembly further includes a counter rotation mechanism configured to counter rotate rotational movement of at least one of the steering column shaft and the intermediate shaft such that the steering input device rotates at the same ratio as the steering column assembly in the opposite rotational direction as the steering column assembly. 
         [0006]    In yet another embodiment of the disclosure, a steering column assembly configured to couple to a steering wheel is provided. The assembly includes a steering column shaft having a first end and a second end, the second end configured to couple to the steering wheel. The assembly also includes an intermediate shaft coupled to the steering column shaft first end. The assembly further includes a steering input pinion coupled to the intermediate shaft. The assembly yet further includes a counter rotation mechanism configured to counter rotate rotational movement of the steering column assembly such that the steering wheel does not rotate while maintaining coupling between the steering column shaft, the intermediate shaft and the steering input pinion. 
         [0007]    These and other advantages and features will become more apparent from the following description taken in conjunction with the drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]    The subject matter which is regarded as the invention is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which: 
           [0009]      FIG. 1  is a schematic illustration of a steering column assembly according to one embodiment of the disclosure. 
       
    
    
     DETAILED DESCRIPTION 
       [0010]    Referring now to the Figure, where the invention will be described with reference to specific embodiments, without limiting same,  FIG. 1  illustrates an exemplary steering system  10  for use in a vehicle (not shown). Steering system  10  enables the operator of the vehicle to control the direction of the vehicle through the manipulation of a steering column assembly  12 , which is mechanically connected to road wheels  14 . Steering system  10  may also be equipped with a self-steering mechanism  15  such as an Advanced Driver Assistance System (ADAS) or the like. 
         [0011]    Steering column assembly  12  generally includes an upper column shaft  16 , a lower column shaft  18 , a steering wheel  20 , an intermediate shaft  24 , and a steering gear assembly  30 . In the exemplary embodiment, steering wheel  20  is disposed at upper column shaft  16 , and steering column assembly  12  is movable between a deployed position and a stowed position. In the deployed position, the operator can apply a rotational force to steering column assembly  12 . In the stowed position, portions of steering column assembly  12  such as steering wheel  20  are disposed away from the driver toward a vehicle instrument panel (not shown), which provides increased space for the driver. 
         [0012]    A column universal joint  22  couples the lower column shaft  18  to the intermediate shaft  24 , which is secured at its other end to a lower column universal joint  26 . A pinion shaft  28  is coupled at one end to universal joint  26  and to a pinion gear  29  of steering gear assembly  30  at the other end. Gear assembly  30  also includes an elongate rack  32 , and the opposed axial ends of rack  32  are coupled to the vehicle&#39;s road wheels  14  (only one shown) through steering linkage that includes tie rods  34  (only one shown) each secured to rack  32  at an inner tie rod end  35 , and to one of a pair of steering knuckles  36  (only one shown) at an outer tie rod end  37 . 
         [0013]    When the vehicle operator turns steering wheel  20  or self-steering mechanism  15  turns some portion of steering column assembly  12 , a rotational force is applied to rotate pinion gear  29 . The movement of pinion gear  29  causes substantially linear movement of rack  32  in the direction of arrows  38 , which in turn manipulates tie rods  34  and knuckles  36  in order to reposition road wheels  14 . 
         [0014]    In the exemplary embodiment, steering system  10  includes a counter rotation mechanism  50  that is configured to counter-rotate a portion of steering column assembly  12  when the vehicle is in an autonomous, semi-autonomous, or selectively autonomous driving mode, such that no rotation of steering wheel  20  is caused by operation of pinion gear  29 . For example, counter rotation mechanism  50  may be a mechanism such as that described in U.S. Pat. No. 6,955,623, the contents of which are incorporated herein by reference in entirety. 
         [0015]    Counter rotation mechanism  50  is operably coupled to steering column assembly  12  to actively apply opposite rotation to steering wheel  20  to give the impression that wheel  20  is “locked out” (i.e., not moving). System  10  may include more than one counter rotation mechanism  50  in some embodiments. Counter rotation mechanism  50  may be operably coupled to steering column assembly  12  at various locations in certain embodiments. In some embodiments, mechanism  50  is disposed in a first location  100  between intermediate shaft  24  and pinion gear  29 . In other embodiments, a second location  102  for the counter rotation mechanism  50  is between intermediate shaft  24  and steering column shaft  18 . In other embodiments, a third location  104  for the counter rotation mechanism  50  is between steering column shaft  16  and steering wheel  20 . 
         [0016]    In alternative embodiment, counter rotation mechanism  50  may interpose the counter motion within a shaft. For example, mechanism  50  may be disposed within intermediate shaft  24 , or within shafts  16 ,  18 . 
         [0017]    Accordingly, the disclosure provides steering column assemblies with a counter-rotation mechanism for a vehicle equipped with an Advanced Driver Assistance System (ADAS) or the like. 
         [0018]    In one embodiment, the steering system enables the steering wheel to be stationary (non-rotating) when in the ADAS mode or self-steering mode, by using the counter rotation mechanism such as an “Active Front Steer” mechanism. As the self-steering mechanism guides the vehicle along its route, the steering gear (e.g., rack &amp; pinion) input shaft rotates. However, the counter rotation mechanism, which may be positioned between the steering column shaft and the gear input shaft, counter-rotates the same or substantially the same degree to cause no visible rotation of the steering wheel to the operator. 
         [0019]    Accordingly, the counter rotation mechanism actively applies opposite rotation to the wheel to give the impression the wheel is not rotating and not engaged to column shaft  16 . As such, one advantage is that the wheel and steering system is always available for taking manual control of the vehicle by an operator. 
         [0020]    The counter rotation mechanism may be located between the I-shaft and the steering input pinion, between the I-shaft and the column steering shaft, and/or between the column steering shaft and the wheel. The counter rotation mechanism may also be located to interpose the counter motion within a shaft, such as the I-shaft or the steering shaft, which may require separation of components. 
         [0021]    Accordingly, the counter rotation mechanism facilitates variable ratio steering and enables zero ratio steering. 
         [0022]    While the invention has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the invention is not limited to such disclosed embodiments. Rather, the invention can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the invention. Additionally, while various embodiments of the invention have been described, it is to be understood that aspects of the invention may include only some of the described embodiments. Accordingly, the invention is not to be seen as limited by the foregoing description.