Abstract:
A continuously variable transmission is disclosed for use in rotationally or linearly powered machines and vehicles. The single axle transmission provides a simple manual shifting method for the user. An additional embodiment is disclosed which shifts automatically dependent upon the rotational speed of the wheel. Further, the practical commercialization of traction roller transmissions requires improvements in the reliability, ease of shifting, function and simplicity of the transmission. The disclosed transmission may be used in vehicles such as automobiles, motorcycles, and bicycles. The transmission may, for example, be driven by a power transfer mechanism such as a sprocket, gear, pulley or lever, optionally driving a one way clutch attached at one end of the main shaft.

Description:
RELATED APPLICATIONS  
       [0001]     This application is a continuation of, and incorporates by reference in its entirety, U.S. application Ser. No. 10/418,509, filed Apr. 16, 2003, which is a continuation of U.S. application Ser. No. 10/141,652, filed May 7, 2002, which is a continuation of U.S. application Ser. No. 09/695,757, filed Oct. 24, 2000, now U.S. Pat. No. 6,419,608, which issued Jul. 16, 2002. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     1. Field of the Invention  
         [0003]     The field of the invention relates to transmissions. More particularly the invention relates to continuously variable transmissions.  
         [0004]     2. Description of the Related Art  
         [0005]     In order to provide an infinitely variable transmission, various traction roller transmissions in which power is transmitted through traction rollers supported in a housing between torque input and output discs have been developed. In such transmissions, the traction rollers are mounted on support structures which, when pivoted, cause the engagement of traction rollers with the torque discs in circles of varying diameters depending on the desired transmission ratio.  
         [0006]     However, the success of these traditional solutions has been limited. For example, in U.S. Pat. No. 5,236,403 to Schievelbusch, a driving hub for a vehicle with a variable adjustable transmission ratio is disclosed. Schievelbusch teaches the use of two iris plates, one on each side of the traction rollers, to tilt the axis of rotation of each of the rollers. However, the use of iris plates can be very complicated due to the large number of parts which are required to adjust the iris plates during shifting the transmission. Another difficulty with this transmission is that it has a guide ring which is configured to be predominantly stationary in relation to each of the rollers. Since the guide ring is stationary, shifting the axis of rotation of each of the traction rollers is difficult. Yet another limitation of this design is that it requires the use of two half axles, one on each side of the rollers, to provide a gap in the middle of the two half axles. The gap is necessary because the rollers are shifted with rotating motion instead of sliding linear motion. The use of two axles is not desirable and requires a complex fastening system to prevent the axles from bending when the transmission is accidentally bumped, is as often the case when a transmission is employed in a vehicle. Yet another limitation of this design is that it does not provide for an automatic transmission.  
         [0007]     Therefore, there is a need for a continuously variable transmission with a simpler shifting method, a single axle, and a support ring having a substantially uniform outer surface. Additionally, there is a need for an automatic traction roller transmission that is configured to shift automatically. Further, the practical commercialization of traction roller transmissions requires improvements in the reliability, ease of shifting, function and simplicity of the transmission.  
       SUMMARY OF THE INVENTION  
       [0008]     The present invention includes a transmission for use in rotationally or linearly powered machines and vehicles. For example the present transmission may be used in machines such as drill presses, turbines, and food processing equipment, and vehicles such as automobiles, motorcycles, and bicycles. The transmission may, for example, be driven by a power transfer mechanism such as a sprocket, gear, pulley or lever, optionally driving a one way clutch attached at one end of the main shaft.  
         [0009]     In one embodiment of the invention, the transmission comprises a rotatable driving member, three or more power adjusters, wherein each of the power adjusters respectively rotates about an axis of rotation that is centrally located within each of the power adjusters, a support member providing a support surface that is in frictional contact with each of the power adjusters, wherein the support member rotates about an axis that is centrally located within the support member, at least one platform for actuating axial movement of the support member and for actuating a shift in the axis of rotation of the power adjusters, wherein the platform provides a convex surface, at least one stationary support that is non-rotatable about the axis of rotation that is defined by the support member, wherein the at least one stationary support provides a concave surface, and a plurality of spindle supports, wherein each of the spindle supports are slidingly engaged with the convex surface of the platform and the concave surface of the stationary support, and wherein each of the spindle supports adjusts the axes of rotation of the power adjusters in response to the axial movement of the platform.  
         [0010]     In another embodiment, the transmission comprises a rotatable driving member; three or more power adjusters, wherein each of the power adjusters respectively rotates about an axis of rotation that is respectively central to the power adjusters, a support member providing a support surface that is in frictional contact with each of the power adjusters, a rotatable driving member for rotating each of the power adjusters, a bearing disc having a plurality of inclined ramps for actuating the rotation of the driving member, a coiled spring for biasing the rotatable driving member against the power adjusters, at least one lock pawl ratchet, wherein the lock pawl ratchet is rigidly attached to the rotatable driving member, wherein the at least one lock pawl is operably attached to the coiled spring, and at least one lock pawl for locking the lock pawl ratchet in response to the rotatable driving member becoming disengaged from the power adjusters.  
         [0011]     In still another embodiment, the transmission comprises a rotatable driving member, three or more power adjusters, wherein each of the power adjusters respectively rotates about an axis that is respectively central to each of the power adjusters, a support member providing a support surface that is in frictional contact with each of the power adjusters, wherein the support member rotates about an axis that is centrally located within the support member, a bearing disc having a plurality of inclined ramps for actuating the rotation of the driving member, a screw that is coaxially and rigidly attached to the rotatable driving member or the bearing disc, and a nut that, if the screw is attached to the rotatable driving member, is coaxially and rigidly attached to the bearing disc, or if the screw is rigidly attached to the bearing disc, coaxially and rigidly attached to the rotatable driving member, wherein the inclined ramps of the bearing disc have a higher lead than the screw. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]      FIG. 1  is a cutaway side view of the transmission of the present invention.  
         [0013]      FIG. 2  is a partial perspective view of the transmission of  FIG. 1 .  
         [0014]      FIG. 3  is a perspective view of two stationary supports of the transmission of  FIG. 1 .  
         [0015]      FIG. 4  is a partial end, cross-sectional view of the transmission of  FIG. 1 .  
         [0016]      FIG. 5  is a perspective view of a drive disc, bearing cage, screw, and ramp bearings of the transmission of  FIG. 1 .  
         [0017]      FIG. 6  is a perspective view of a ratchet and pawl subsystem of the transmission of  FIG. 1  that is used to engage and disengage the transmission.  
         [0018]      FIG. 7  is partial perspective view of the transmission of  FIG. 1 , wherein, among other things, a rotatable drive disc has been removed.  
         [0019]      FIG. 8  is a partial perspective view of the transmission of  FIG. 1 , wherein, among other things, the hub shell has been removed.  
         [0020]      FIG. 9  is a partial perspective view of the transmission of  FIG. 1 , wherein the shifting is done automatically.  
         [0021]      FIG. 10  is a perspective view of the shifting handlegrip that is mechanically coupled to the transmission of  FIG. 1 .  
         [0022]      FIG. 11  is an end view of a thrust bearing, of the transmission shown in  FIG. 1 , which is used for automatic shifting of the transmission.  
         [0023]      FIG. 12  is an end view of the weight design of the transmission shown in  FIG. 1 .  
         [0024]      FIG. 13  is a perspective view of an alternate embodiment of the transmission bolted to a flat surface.  
         [0025]      FIG. 14  is a cutaway side view of the transmission shown in  FIG. 13 .  
         [0026]      FIG. 15  is a schematic end view of the transmission in  FIG. 1  showing the cable routing across a spacer extension of the automatic portion of the transmission.  
         [0027]      FIG. 16  is a schematic end view of the cable routing of the transmission shown in  FIG. 13 . 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0028]     The following detailed description is directed to certain specific embodiments of the invention. However, the invention can be embodied in a multitude of different ways as defined and covered by the claims. In this description, reference is made to the drawings wherein like parts are designated with like numerals throughout. Furthermore, embodiments of the invention may include several novel features, no single one of which is solely responsible for its desirable attributes or which is essential to practicing the inventions herein described.  
         [0029]     The present invention includes a continuously variable transmission that may be employed in connection with any type of machine that is in need of a transmission. For example, the transmission may be used in (i) a motorized vehicle such as an automobile, motorcycle, or watercraft, (ii) a non-motorized vehicle such as a bicycle, tricycle, scooter, exercise equipment or (iii) industrial equipment, such as a drill press, power generating equipment, or textile mill.  
         [0030]     Referring to  FIGS. 1 and 2 , a continuously variable transmission  100  is disclosed. The transmission  100  is shrouded in a hub shell  40  covered by a hub cap  67 . At the heart of the transmission  100  are three or more power adjusters  1   a,    1   b,    1   c  which are spherical in shape and are circumferentially spaced equally around the centerline or axis of rotation of the transmission  100 . As seen more clearly in  FIG. 2 , spindles  3   a,    3   b,    3   c  are inserted through the center of the power adjusters  1   a,    1   b,    1   c  to define an axis of rotation for the power adjusters  1   a,    1   b,    1   c.  In  FIG. 1 , the power adjuster&#39;s axis of rotation is shown in the horizontal direction. Spindle supports  2   a - f  are attached perpendicular to and at the exposed ends of the spindles  3   a,    3   b,    3   c.  In one embodiment, each of the spindles supports have a bore to receive one end of one of the spindles  3   a,    3   b,    3   c.  The spindles  3   a,    3   b,    3   c  also have spindle rollers  4   a - f  coaxially and slidingly positioned over the exposed ends of the spindles  3   a,    3   b,    3   c  outside of the spindle supports  2   a - f.    
         [0031]     As the rotational axis of the power adjusters  1   a,    1   b,    1   c  is changed by tilting the spindles  3   a,    3   b,    3   c,  each spindle roller  4   a - f  follows in a groove  6   a - f  cut into a stationary support  5   a,    5   b.  Referring to  FIGS. 1 and 3 , the stationary supports  5   a,    5   b  are generally in the form of parallel discs with an axis of rotation along the centerline of the transmission  100 . The grooves  6   a - f  extend from the outer circumference of the stationary supports  5   a,    5   b  towards the centerline of the transmission  100 . While the sides of the grooves  6   a - f  are substantially parallel, the bottom surface of the grooves  6   a - f  forms a decreasing radius as it runs towards the centerline of the transmission  100 . As the transmission  100  is shifted to a lower or higher gear by changing the rotational axes of the power adjusters  1   a,    1   b,    1   c,  each pair of spindle rollers  4   a - f  located on a single spindle  3   a,    3   b,    3   c,  moves in opposite directions along their corresponding grooves  6   a - f.    
         [0032]     Referring to  FIGS. 1 and 3 , a centerline hole  7   a,    7   b  in the stationary supports  5   a,    5   b  allows the insertion of a hollow shaft  10  through both stationary supports  5   a,    5   b.  Referring to  FIG. 4 , in an embodiment of the invention, one or more of the stationary support holes  7   a,    7   b  may have a non-cylindrical shape  14 , which fits over a corresponding non-cylindrical shape  15  along the hollow shaft  10  to prevent any relative rotation between the stationary supports  5   a,    5   b  and the hollow shaft  10 . If the rigidity of the stationary supports  5   a,    5   b  is insufficient, additional structure may be used to minimize any relative rotational movement or flexing of the stationary supports  5   a,    5   b.  This type of movement by the stationary supports  5   a,    5   b  may cause binding of the spindle rollers  4   a - f  as they move along the grooves  6   a - f.    
         [0033]     As shown in  FIGS. 4 and 7 , the additional structure may take the form of spacers  8   a,    8   b,    8   c  attached between the stationary supports  5   a,    5   b.  The spacers  8   a,    8   b,    8   c  add rigidity between the stationary supports  5   a,    5   b  and, in one embodiment, are located near the outer circumference of the stationary supports  5   a,    5   b.  In one embodiment, the stationary supports  5   a,    5   b  are connected to the spacers  8   a,    8   b,    8   c  by bolts or other fastener devices  45   a - f  inserted through holes  46   a - f  in the stationary supports  5   a,    5   b.    
         [0034]     Referring back to  FIGS. 1 and 3 , the stationary support  5   a  is fixedly attached to a stationary support sleeve  42 , which coaxially encloses the hollow shaft  10  and extends through the wall of the hub shell  40 . The end of the stationary support sleeve  42  that extends through the hub shell  40  attaches to the frame support and preferentially has a non-cylindrical shape to enhance subsequent attachment of a torque lever  43 . As shown more clearly in  FIG. 7 , the torque lever  43  is placed over the non-cylindrical shaped end of the stationary support sleeve  42 , and is held in place by a torque nut  44 . The torque lever  43  at its other end is rigidly attached to a strong, non-moving part, such as a frame (not shown). A stationary support bearing  48  supports the hub shell  40  and permits the hub shell  40  to rotate relative to the stationary support sleeve  42 .  
         [0035]     Referring back to  FIGS. 1 and 2 , shifting is manually activated by axially sliding a rod  11  positioned in the hollow shaft  10 . One or more pins  12  are inserted through one or more transverse holes in the rod  11  and further extend through one or more longitudinal slots  16  (not shown) in the hollow shaft  10 . The slots  16  in the hollow shaft  10  allow for axial movement of the pin  12  and rod  11  assembly in the hollow shaft  10 . As the rod  11  slides axially in the hollow shaft  10 , the ends of the transverse pins  12  extend into and couple with a coaxial sleeve  19 . The sleeve  19  is fixedly attached at each end to a substantially planar platform  13   a,    13   b  forming a trough around the circumference of the sleeve  19 .  
         [0036]     As seen more clearly in  FIG. 4 , the planar platforms  13   a,    13   b  each contact and push multiple wheels  21   a - f.  The wheels  21   a - f  fit into slots in the spindle supports  2   a - f  and are held in place by wheel axles  22   a - f.  The wheel axles  22   a - f  are supported at their ends by the spindle supports  2   a - f  and allow rotational movement of the wheels  21   a - f.    
         [0037]     Referring back to  FIGS. 1 and 2 , the substantially planar platforms  13   a,    13   b  transition into a convex surface at their outer perimeter (farthest from the hollow shaft  10 ). This region allows slack to be taken up when the spindle supports  2   a - f  and power adjusters  1   a,    1   b,    1   c  are tilted as the transmission  100  is shifted. A cylindrical support member  18  is located in the trough formed between the planar platforms  13   a,    13   b  and sleeve  19  and thus moves in concert with the planar platforms  13   a,    13   b  and sleeve  19 . The support member  18  rides on contact bearings  17   a,    17   b  located at the intersection of the planar platforms  13   a,    13   b  and sleeve  19  to allow the support member  18  to freely rotate about the axis of the transmission  100 . Thus, the bearings  17   a,    17   b,  support member  18 , and sleeve  19  all slide axially with the planar platforms  13   a,    13   b  when the transmission  100  is shifted.  
         [0038]     Now referring to  FIGS. 3 and 4 , stationary support rollers  30   a - l  are attached in pairs to each spindle leg  2   a - f  through a roller pin  31   a - f  and held in place by roller clips  32   a - l.  The roller pins  31   a - f  allow the stationary support rollers  30   a - l  to rotate freely about the roller pins  31   a - f.  The stationary support rollers  30   a - l  roll on a concave radius in the stationary support  5   a,    5   b  along a substantially parallel path with the grooves  6   a - f.  As the spindle rollers  4   a - f  move back and forth inside the grooves  6   a - f  the stationary support rollers  30   a - l  do not allow the ends of the spindles  3   a,    3   b,    3   c  nor the spindle rollers  4   a - f  to contact the bottom surface of the grooves  6   a - f  to maintain the position of the spindles  3   a,    3   b,    3   c,  and to minimize any frictional losses.  
         [0039]      FIG. 4  shows the stationary support rollers  30   a - l,  the roller pins,  31   a - f,  and roller clips  32   a - l,  as seen through the stationary support  5   a,  for ease of viewing. For clarity, i.e., too many numbers in  FIG. 1 , the stationary support rollers  30   a - l,  the roller pins,  31   a - f  and roller clips  32   a - l,  are not numbered in  FIG. 1 .  
         [0040]     Referring to  FIGS. 1 and 5 , a concave drive disc  34 , located adjacent to the stationary support  5   b,  partially encapsulates but does not contact the stationary support  5   b.  The drive disc  34  is rigidly attached through its center to a screw  35 . The screw  35  is coaxial to and forms a sleeve around the hollow shaft  10  adjacent to the stationary support  5   b  and faces a driving member  69 . The drive disc  34  is rotatively coupled to the power adjusters  1   a,    1   b,    1   c  along a circumferential bearing surface on the lip of the drive disc  34 . A nut  37  is threaded over the screw  35  and is rigidly attached around its circumference to a bearing disc  60 . One face of the nut  37  is further attached to the driving member  69 . Also rigidly attached to the bearing disc  60  surface are a plurality of ramps  61  which face the drive disc  34 . For each ramp  61  there is one ramp bearing  62  held in position by a bearing cage  63 . The ramp bearings  62  contact both the ramps  61  and the drive disc  34 . A spring  65  is attached at one end to the bearing cage  63  and at its other end to the drive disc  34 , or the bearing disc  60  in an alternate embodiment, to bias the ramp bearings  62  up the ramps  61 . The bearing disc  60 , on the side opposite the ramps  61  and at approximately the same circumference contacts a hub cap bearing  66 . The hub cap bearing  66  contacts both the hub cap  67  and the bearing disc  60  to allow their relative motion. The hub cap  67  is threaded or pressed into the hub shell  40  and secured with an internal ring  68 . A sprocket or pulley  38  is rigidly attached to the rotating driving member  69  and is held in place externally by a cone bearing  70  secured by a cone nut  71  and internally by a driver bearing  72  which contacts both the driving member  69  and the hub cap  67 .  
         [0041]     In operation, an input rotation from the sprocket or pulley  38 , which is fixedly attached to the driver  69 , rotates the bearing disc  60  and the plurality of ramps  61  causing the ramp bearings  62  to roll up the ramps  61  and press the drive disc  34  against the power adjusters  1   a,    1   b,    1   c.  Simultaneously, the nut  37 , which has a smaller lead than the ramps  61 , rotates to cause the screw  35  and nut  37  to bind. This feature imparts rotation of the drive disc  34  against the power adjusters  1   a,    1   b,    1   c.  The power adjusters  1   a,    1   b,    1   c,  when rotating, contact and rotate the hub shell  40 .  
         [0042]     When the transmission  100  is coasting, the sprocket or pulley  38  stops rotating but the hub shell  40  and the power adjusters  1   a,    1   b,    1   c,  continue to rotate. This causes the drive disc  34  to rotate so that the screw  35  winds into the nut  37  until the drive disc  34  no longer contacts the power adjusters  1   a,    1   b,    1   c.    
         [0043]     Referring to  FIGS. 1, 6 , and  7 , a coiled spring  80 , coaxial with the transmission  100 , is located between and attached by pins or other fasteners (not shown) to both the bearing disc  60  and drive disc  34  at the ends of the coiled spring  80 . During operation of the transmission  100 , the coiled spring  80  ensures contact between the power adjusters  1   a,    1   b,    1   c  and the drive disc  34 . A pawl carrier  83  fits in the coiled spring  80  with its middle coil attached to the pawl carrier  83  by a pin or standard fastener (not shown). Because the pawl carrier  83  is attached to the middle coil of the coiled spring  80 , it rotates at half the speed of the drive disc  34  when the bearing disc  60  is not rotating. This allows one or more lock pawls  81   a,    81   b,    81   c,  which are attached to the pawl carrier  83  by one or more pins  84   a,    84   b,    84   c,  to engage a drive disc ratchet  82 , which is coaxial with and rigidly attached to the drive disc  34 . The one or more lock pawls  84   a,    84   b,    84   c  are preferably spaced asymmetrically around the drive disc ratchet  82 . Once engaged, the loaded coiled spring  80  is prevented from forcing the drive disc  34  against the power adjusters  1   a,    1   b,    1   c.  Thus, with the drive disc  34  not making contact against the power adjusters  1   a,    1   b,    1   c,  the transmission  100  is in neutral and the ease of shifting is increased. The transmission  100  can also be shifted while in operation.  
         [0044]     When operation of the transmission  100  is resumed by turning the sprocket or pulley  38 , one or more release pawls  85   a,    85   b,    85   c,  each attached to one of the lock pawls  81   a,    81   b,    81   c  by a pawl pin  88   a,    88   b,    88   c,  make contact with an opposing bearing disc ratchet  87 . The bearing disc ratchet  87  is coaxial with and rigidly attached to the bearing disc  60 . The bearing disc ratchet  87  actuates the release pawls  85   a,    85   b,    85   c  because the release pawls  85   a,    85   b,    85   c  are connected to the pawl carrier  83  via the lock pawls  81   a,    81   b,    81   c.  In operation, the release pawls  85   a,    85   b,    85   c  rotate at half the speed of the bearing disc  60 , since the drive disc  34  is not rotating, and disengage the lock pawls  81   a,    81   b,    81   c  from the drive disc ratchet  82  allowing the coiled spring  80  to wind the drive disc  34  against the power adjusters  1   a,    1   b,    1   c.  One or more pawl tensioners (not shown), one for each release pawl  85   a,    85   b,    85   c,  ensures that the lock pawls  81   a,    81   b,    81   c  are pressed against the drive disc ratchet  82  and that the release pawls  85   a,    85   b,    85   c  are pressed against the bearing disc ratchet  87 . The pawl tensioners are attached at one end to the pawl carrier  83  and make contact at the other end to the release pawls  85   a,    85   b,    85   c.  An assembly hole  93  (not shown) through the hub cap  67 , the bearing disc  60 , and the drive disc  34 , allows an assembly pin (not shown) to be inserted into the loaded coiled spring  80  during assembly of the transmission  100 . The assembly pin prevents the coiled spring  80  from losing its tension and is removed after transmission  100  assembly is complete.  
         [0045]     Referring to  FIGS. 1, 11 ,  12 , and  15 , automatic shifting of the transmission  100 , is accomplished by means of spindle cables  602 ,  604 ,  606  which are attached at one end to a non-moving component of the transmission  100 , such as the hollow shaft  10  or the stationary support  5   a.  The spindle cables  602 ,  604 ,  606  then travel around spindle pulleys  630 ,  632 ,  634 , which are coaxially positioned over the spindles  3   a,    3   b,    3   c.  The spindle cables  602 ,  604 ,  606  further travel around spacer pulleys  636 ,  638 ,  640 ,  644 ,  646 ,  648  which are attached to a spacer extension  642  which may be rigidly attached to the spacers  8   a,    8   b,    8   c.  As more clearly shown in  FIGS. 11 and 12 , the other ends of the spindle cables  602 ,  604 ,  606  are attached to a plurality of holes  620 ,  622 ,  624  in a non-rotating annular bearing race  816 . A plurality of weight cables  532 ,  534 ,  536  are attached at one end to a plurality of holes  610 ,  612 ,  614  in a rotating annular bearing race  806 . An annular bearing  808 , positioned between the rotating annular bearing race  806  and the non-rotating annular bearing race  816 , allows their relative movement.  
         [0046]     Referring to  FIG. 15 , the transmission  100  is shown with the cable routing for automatic shifting.  
         [0047]     As shown in  FIGS. 1, 9 ,  11 , and  12 , the weight cables  532 ,  534 ,  536  then travel around the hub shell pulleys  654 ,  656 ,  658 , through holes in the hub shell  40 , and into hollow spokes  504 ,  506 ,  508  (best seen in  FIG. 12 ) where they attach to weights  526 ,  528 ,  530 . The weights  526 ,  528 ,  530  are attached to and receive support from weight assisters  516 ,  518 ,  520  which attach to a wheel  514  or other rotating object at there opposite end. As the wheel  514  increases its speed of rotation, the weights  526 ,  528 ,  530  are pulled radially away from the hub shell  40 , pulling the rotating annular bearing race  806  and the non-rotating annular bearing race  816  axially toward the hub cap  67 . The non-rotating annular bearing race  816  pulls the spindle cables  602 ,  604 ,  606 , which pulls the spindle pulleys  630 ,  632 ,  634  closer to the hollow shaft  10  and results in the shifting of the transmission  100  into a higher gear. When rotation of the wheel  514  slows, one or more tension members  9  positioned inside the hollow shaft  10  and held in place by a shaft cap  92 , push the spindle pulleys  630 ,  632 ,  634  farther from the hollow shaft  10  and results in the shifting of the transmission  100  into a lower gear.  
         [0048]     Alternatively, or in conjunction with the tension member  9 , multiple tension members (not shown) may be attached to the spindles  3   a,    3   b,    3   c  opposite the spindle pulleys  630 ,  632 ,  634 .  
         [0049]     Still referring to  FIG. 1 , the transmission  100  can also be manually shifted to override the automatic shifting mechanism or to use in place of the automatic shifting mechanism. A rotatable shifter  50  has internal threads that thread onto external threads of a shifter screw  52  which is attached over the hollow shaft  10 . The shifter  50  has a cap  53  with a hole that fits over the rod  11  that is inserted into the hollow shaft  10 . The rod  11  is threaded where it protrudes from the hollow shaft  10  so that nuts  54 ,  55  may be threaded onto the rod  11 . The nuts  54 ,  55  are positioned on both sides of the cap  53 . A shifter lever  56  is rigidly attached to the shifter  50  and provides a moment arm for the rod  11 . The shifter cable  51  is attached to the shifter lever  56  through lever slots  57   a,    57   b,    57   c.  The multiple lever slots  57   a,    57   b,    57   c  provide for variations in speed and ease of shifting.  
         [0050]     Now referring to  FIGS. 1 and 10 , the shifter cable  51  is routed to and coaxially wraps around a handlegrip  300 . When the handlegrip  300  is rotated in a first direction, the shifter  50  winds or unwinds axially over the hollow shaft  10  and pushes or pulls the rod  11  into or out of the hollow shaft  10 . When the handlegrip  300  is rotated in a second direction, a shifter spring  58 , coaxially positioned over the shifter  50 , returns the shifter  50  to its original position. The ends of the shifter spring  58  are attached to the shifter  50  and to a non-moving component, such as a frame (not shown).  
         [0051]     As seen more clearly in  FIG. 10 , the handlegrip  300  is positioned over a handlebar (not shown) or other rigid component. The handlegrip  300  includes a rotating grip  302 , which consists of a cable attachment  304  that provides for attachment of the shifter cable  51  and a groove  306  that allows the shifter cable  51  to wrap around the rotating grip  302 . A flange  308  is also provided to preclude a user from interfering with the routing of the shifter cable  51 . Grip ratchet teeth  310  are located on the rotating grip  302  at its interface with a rotating clamp  314 . The grip ratchet teeth  310  lock onto an opposing set of clamp ratchet teeth  312  when the rotating grip  302  is rotated in a first direction. The clamp ratchet teeth  312  form a ring and are attached to the rotating clamp  314  which rotates with the rotating grip  302  when the grip ratchet teeth  310  and the clamp ratchet teeth  312  are locked. The force required to rotate the rotating clamp  314  can be adjusted with a set screw  316  or other fastener. When the rotating grip  302 , is rotated in a second direction, the grip ratchet teeth  310 , and the clamp ratchet teeth  312  disengage. Referring back to  FIG. 1 , the tension of the shifter spring  58  increases when the rotating grip  302  is rotated in the second direction. A non-rotating clamp  318  and a non-rotating grip  320  prevent excessive axial movement of the handlegrip  300  assembly.  
         [0052]     Referring to  FIGS. 13 and 14 , another embodiment of the transmission  900 , is disclosed. For purposes of simplicity, only the differences between the transmission  100  and the transmission  900  are discussed.  
         [0053]     Replacing the rotating hub shell  40  are a stationary case  901  and housing  902 , which are joined with one or more set screws  903 ,  904 ,  905 . The set screws  903 ,  904 ,  905  may be removed to allow access for repairs to the transmission  900 . Both the case  901  and housing  902  have coplanar flanges  906 ,  907  with a plurality of bolt holes  908 ,  910 ,  912 ,  914  for insertion of a plurality of bolts  918 ,  920 ,  922 ,  924  to fixedly mount the transmission  900  to a non-moving component, such as a frame (not shown).  
         [0054]     The spacer extension  930  is compressed between the stationary case  901  and housing  902  with the set screws  903 ,  904 ,  905  and extend towards and are rigidly attached to the spacers  8   a,    8   b,    8   c.  The spacer extension  930  prevents rotation of the stationary supports  5   a,    5   b.  The stationary support  5   a  does not have the stationary support sleeve  42  as in the transmission  100 . The stationary supports  5   a,    5   b  hold the hollow shaft  10  in a fixed position. The hollow shaft  10  terminates at one end at the stationary support  5   a  and at its other end at the screw  35 . An output drive disc  942  is added and is supported against the case  901  by a case bearing  944 . The output drive disc  942  is attached to an output drive component, such as a drive shaft, gear, sprocket, or pulley (not shown). Similarly, the driving member  69  is attached to the input drive component, such as a motor, gear, sprocket, or pulley.  
         [0055]     Referring to  FIG. 16 , shifting of the transmission  900  is accomplished with a single cable  946  that wraps around each of the spindle pulleys  630 ,  632 ,  634 . At one end, the single cable  946  is attached to a non-moving component of the transmission  900 , such as the hollow shaft  10  or the stationary support  5   a.  After traveling around each of the spindle pulleys  630 ,  632 ,  634  and the spacer pulleys  636 ,  644 , the single cable  946  exits the transmission  900  through a hole in the housing  902 . Alternatively a rod (not shown) attached to one or more of the spindles  3   a,    3   b,    3   c,  may be used to shift the transmission  900  in place of the single cable  946 .  
         [0056]     The foregoing description details certain embodiments of the invention. It will be appreciated, however, that no matter how detailed the foregoing appears in text, the invention can be practiced in many ways. As is also stated above, it should be noted that the use of particular terminology when describing certain features or aspects of the invention should not be taken to imply that the terminology is being re-defined herein to be restricted to including any specific characteristics of the features or aspects of the invention with which that terminology is associated. The scope of the invention should therefore be construed in accordance with the appended claims and any equivalents thereof.