Abstract:
A shifter apparatus for manually changing gear ratio in a planetary gear transmission, said planetary gear transmission being of the type which comprises a plurality of actuators, wherein the sequential actuation of said actuators progressively causes a change of gear ratio in said planetary gear transmission. The shifter apparatus advantageously provides a single lever which can be quickly and easily shifted by a user.

Description:
TECHNICAL FIELD 
       [0001]    The present invention relates to a shifter apparatus for selectively changing gear ratio for a planetary gear transmission. 
       BACKGROUND OF THE INVENTION 
       [0002]    In high performance motor sport, such as drag racing, a popular gear transmission drive is the Lenco transmission sold by the Lenco Equipment Company. The Lenco transmission is a planetary gear transmission system. The Lenco system provides a modular system, each module having an actuator, which when actuated, causes a gear ratio change which effectively changes gear for the vehicle. A typical racing car would employ a 4 or 5 speed transmission which equates to a 3 or 4 module Lenco transmission system. 
         [0003]    To change from low to high speed gear in the Lenco system requires the progressive and sequential activation of the actuators, which requires the manual activation of a shifter apparatus. 
         [0004]    The current Lenco transmission system is sold with a mechanical shifter apparatus which comprises a plurality of levers. Each lever being linked to, and associated with, a respective actuator. Hence, to rise through the gears requires the sequential shifting of the levers in turn. 
         [0005]    Considering that in a race condition, the progressive shifting of each gear may occur very quickly, and potentially every 0.8 second, having multiple levers provides a very cumbersome arrangement. In race conditions requiring fast reaction times and the need to be sequentially and progressively actuating the actuators, the multi-lever shifter apparatus provides problematic issues in that the wrong lever could be shifted out of the required sequence. This is particularly true for those unfamiliar with the multi-lever arrangement. 
         [0006]    It is an object of the present invention to provide an alternative mechanical shifter apparatus which avoids the need to employ a cumbersome multi-lever arrangement. 
       SUMMARY OF THE INVENTION 
       [0007]    According to the present invention there is provided a shifter apparatus for manually changing gear ratio in a planetary gear transmission, said planetary gear transmission being of the type which comprises a plurality of actuators, wherein the sequential actuation of said actuators progressively causes a change of gear ratio in said planetary gear transmission, said shifter apparatus comprising: 
         [0008]    a housing which comprises a plurality of substantially horizontal tracks, said tracks being arranged above one another, the tracks comprise openings, each opening providing a passage between adjacent tracks, the openings are arranged adjacent alternating ends of the tracks when the tracks are considered sequentially from the uppermost track to the bottommost track; 
         [0009]    arranged in each track is a slider, each slider is connected to a respective one of said plurality of actuators by a linkage; wherein moving a slider from one end of the respective track to the other causes the respective actuator to actuate, each slider having a groove, said groove being formed so as to align with an opening when the slider is positioned in the respective track adjacent the opening; and 
         [0010]    a lever arranged to be manually movable between two positions, said lever is connected to a driving member, said driving member comprising a slider engaging portion, wherein said slider engaging portion is sized and arranged to be accommodated in the groove of an instant slider, wherein the slider engaging portion drives the instant slider to move from one end of the respective track to the other when the lever is moved between one position to the other position; wherein, when the groove of the instant slider is aligned with an opening to a lower adjacent track, the slider engaging portion falls through the opening and into the groove of the respective slider in the lower adjacent track; 
         [0011]    wherein, from an initial arrangement in which the slider engaging portion is located in the groove of the uppermost slider and the uppermost slider is positioned in the respective uppermost track where the respective actuator is disengaged, alternately moving the lever between the two positions causes each slider to sequentially move along the respective tracks, from uppermost to bottommost, and thereby sequentially actuate the plurality of actuators. 
         [0012]    The shifter apparatus advantageously provides a single lever which can be quickly and easily shifted by a user. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]    An illustrative example of a preferred embodiment of the present invention will now be described with reference to the accompanying figures, in which: 
           [0014]      FIG. 1  is a view of a shifter apparatus according to a preferred embodiment; 
           [0015]      FIGS. 2   a  to  2   e , show the slider mechanism of the shifter apparatus of  FIG. 1  progressing from lowest to highest gear; 
           [0016]      FIG. 3  is a cross-sectional view along lines A-A of  FIG. 2   a;    
           [0017]      FIG. 4  is a rear view of the shifter apparatus of  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0018]      FIGS. 1 and 4  show the shifter apparatus  10  mounted on the casing of a planetary gear transmission drive  12  by way of a mounting frame  14  which can be bolted onto the drive  12 . The transmission drive  12  illustrated is the LENCO CS3 sold by Lenco Racing Transmissions of California, USA. The LENCO CS3 is a modular system. The illustrated drive has four modules which equates to a five-speed transmission. The mounting frame  14 , as shown, consists of base arms  16  integrally formed with the shifter apparatus  10 . 
         [0019]    To progress from low gear to high gear in the LENCO transmission requires the sequential actuation of actuators  18   a,    18   b,    18   c,    18   d.  The actuation of each actuator  18   a,    18   b,    18   c,    18   d  causes a gear ratio change in the transmission drive  12 . The actuators  18   a,    18   b,    18   c,    18   d  shown are in the form of pivotal members which are pivoted between an actuated position and a deactuated position. Each actuator  18   a ,  18   b,    18   c,    18   d  is self-locking in each position until a sufficient force is applied to cause the actuator  18   a,    18   b,    18   c,    18   d  to pivot. 
         [0020]    As shown, each actuator  18   a,    18   b,    18   c,    18   d  is connected to one end of a linkage  20   a,    20   b,    20   c,    20   d.  The other end of the linkage  20   a,    20   b,    20   c,    20   d  is connected to a slider  22   a,    22   b,    22   c,    22   d  of the shifter apparatus  10 . The movement of a slider  22   a,    22   b,    22   c,    22   d  causes movement of the linkage  22   a,    22   b,    22   c,    22   d  with sufficient force to cause the movement of the actuator  18   a,    18   b,    18   c,    18   d,  hence actuating the actuator  18   a,    18   b,    18   c,    18   d.  The linkage  20   a,    20   b,    20   c,    20   d  is connected at each end by bolts. 
         [0021]    The slider mechanism is shown clearly in  FIGS. 2   a - 2   e  and  3 . A housing  24  is provided with a number of substantially horizontal tracks  26   a,    26   b,    26   c,    26   d.  In the embodiment illustrated, four tracks  26   a,    26   b,    26   c,    26   d  are shown. The tracks  26   a,    26   b ,  26   c,    26   d  are arranged above one another. The tracks  26   a,    26   b,    26   c,    26   d  comprise openings  28   a,    28   b,    28   c  positioned adjacent alternating ends of the arrangement of tracks  26   a,    26   b,    26   c,    26   d.  The openings  28   a,    28   b,    28   c  provide a passage between adjacent tracks  26   a,    26   b,    26   c,    26   d.    
         [0022]    Each track  26   a,    26   b,    26   c,    26   d  comprises guide rails  30  extending along the length of the track  26   a,    26   b,    26   c,    26   d  and projecting from the upper and lower surfaces of the track  26   a,    26   b,    26   c,    26   d.    
         [0023]    Within each track  26   a,    26   b,    26   c,    26   d  is arranged a slider  22   a,    22   b,    22   c,    22   d . Each slider  22   a,    22   b,    22   c,    22   d  is formed of two pieces  32   a,    32   b  having mating projections and holes. One projection  34  comprises a screw threaded end  38  to allow the respective linkage  22   a,    22   b,    22   c,    22   d  to be bolted thereto. Plastic spacers  40  are arranged between the two pieces  32   a,    32   b  on the intermediate projections. The spacers  40  provide a gap between the two pieces  32   a,    32   b  which allows the slider  22   a ,  22   b,    22   c,    22   d  to straddle the guide rails  30  on the track  26   a,    26   b,    26   c,    26   d.    
         [0024]    Each slider  22   a,    22   b,    22   c,    22   d  is formed with a groove  42   a,    42   b,    42   c,    42   d . The groove  42   a,    42   b,    42   c,    42   d  is formed and shaped so as to align with an opening  28   a,    28   b,    28   c  between tracks  26   a,    26   b,    26   c,    26   d  when the slider  22   a,    22   b,    22   c,    22   d  is positioned adjacent the opening  28   a,    28   b,    28   c.    
         [0025]    Driving a slider  22   a,    22   b,    22   c,    22   d  from one end of the respective track  26   a ,  26   b,    26   c,    26   d  to the other end causes the attached linkage  20   a,    20   b,    20   c,    20   d  to move and in turn move the attached actuator  18   a,    18   b,    18   c,    18   d,  thereby actuating the actuator  18   a,    18   b,    18   c,    18   d.    
         [0026]    The sliders  22   a,    22   b,    22   c,    22   d  are moved in their tracks  26   a,    26   b,    26   c,    26   d  by the manual manipulation of a lever  44 . The lever  44  is arranged to be moved back and forth between two positions. 
         [0027]    Pivotally attached to the lever  44  is a driving arm  46 . The driving arm  46  comprises a slider engaging protrusion  48  which, initially, is arranged to sit in the groove  42   a  of the uppermost slider  22   a,  see  FIG. 3 . 
         [0028]    In order to progress from lowest to highest gear, a user needs only to alternately move the lever  44  back and forth between its two positions. 
         [0029]    Initially, when the LENCO transmission  12  is in lowest gear, whereby no actuators  18   a,    18   b,    18   c,    18   d  are actuated. The sliders  22   a,    22   b,    22   c,    22   d  are arranged as shown in  FIG. 2   a , with the protrusion  48  of the driving arm  46  sitting in the groove  42   a  of the uppermost slider  22   a.    
         [0030]    To rise to the next gear, the lever  44  is moved whereby the driving arm  46  pushes the uppermost slider  22   a  along its track  26   a  to the other end. Moving the slider  26   a  causes the linkage  20   a  to move and thereby actuate the connected actuator  18   a . At the other end, the groove  42   a  of the uppermost slider  22   a  aligns with the opening  28   a  and the protrusion  48  of the driving arm  46  falls under gravity through the opening  28   a  into the groove  42   b  of the second slider  22   b  in the adjacent track  26   b,  see  FIG. 2   b.    
         [0031]    Moving the lever  44  back to its original position causes the second slider  22   b  to move along its track  26   b  to the other end. Again, this causes the associated actuator  18   b  to actuate. The protrusion  48  of the driving arm  46  then falls through the next opening  28   b  into the groove  42   c  of the next slider  22   c  arranged in the adjacent track  26   c,  see  FIG. 2   c.    
         [0032]    The process proceeds until all sliders  22   a,    22   b,    22   c,    22   d  have been moved and all actuators  18   a,    18   b,    18   c,    18   d  have been actuated, at which point the LENCO transmission  12  is in the highest gear, see  FIG. 2   e.    
         [0033]    The shifter apparatus  10  is further adapted to allow the reverse sequential progression from high to low gear. This is facilitated by a biasing actuator arrangement which comprises a second lever  50  which is arranged so as to be manually gripped while gripping the main lever  44 . The second lever  50  is connected to a spring  52  and an arm  54  which, in turn, is connected to the driving arm  46 . When the second lever  50  is actuated, the spring  52  biases the driving arm  46  to want to rise. 
         [0034]    Consequently, by moving the lever  44  back and forth between the two positions while actuating the second lever  50 , the slider mechanism works in reverse from that described before. When an instant slider  22   d  is aligned with an upper opening  28   c,  the protrusion  48  of the driving arm  46  rises (as opposed to falling) to the slider  22   c  arranged in the upper adjacent track  26   c.    
         [0035]    As shown in  FIG. 4 , the slider mechanism is enclosed by a cover  56 , through which the driving arm  46  can extend. 
         [0036]    In the embodiment described, all the components can be formed of aluminium which, while durable, is beneficially light enough to benefit weight considerations in racing car conditions. It will be appreciated that the components could be made of other suitable metals. 
         [0037]    While the embodiment described is suited to a five-speed transmission, it will be appreciated that the shifter apparatus could be readily adapted for use with transmission of lesser or greater speeds by providing less or more, as appropriate, sliders, tracks and linkages. 
         [0038]    Furthermore, it is envisioned that the shifter apparatus  10 , described, could be adapted for a four-speed transmission simply by removing the lowest slider  22   d  from its track  26   d  and inserting some form of plug which would block opening  28   c . Consequently, when the transmission is in highest gear, the protrusion  48  of the driving arm  46  is prevented from falling through opening  28   c  and remains in the groove  42   c  of slider  22   c.