Abstract:
A gear shift arrangement for a bicycle that is separate and distinct from a brake lever of the bicycle, in which the bicycle has a derailleur and a derailleur cable associated therewith, includes a single lever adapted to only perform a shifting operation of gears of the bicycle, a housing, a mounting arrangement in the housing for mounting the single lever for movement in a first pivoting direction and for movement in a second substantially linear direction, and a shift control mechanism in the housing for controlling shifting of the gears of the bicycle in a first shifting direction upon movement of the single lever in the first pivoting direction and for controlling shifting of gears of the bicycle in a second, opposite shifting direction upon movement of the single lever in the second substantially linear direction.

Description:
REFERENCE TO RELATED APPLICATION 
     The present application claims priority from U.S. Provisional Application No. 61/216,385, filed May 18, 2009. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates generally to bicycle shifters, and more particularly, is directed to a shift lever arrangement for a bicycle using a single lever movable along two orthogonal axes for shifting in different directions. 
     Conventionally, shifters for bicycles have been mounted on the handlebar, separate and apart from the brake levers. Generally, there is single lever that is rotatable in one direction for upshifting and rotatable in the opposite direction for downshifting. 
     It is, however, to provide different tactile sensations when shifting in the different directions. In this regard, U.S. Pat. No. 5,921,138 to Kojima et al discloses a first lever that is linearly movable for shifting in a first direction and a separate second lever that is pivotally movable in a second different direction for shifting in an opposite direction. However, this requires two different levers, even though the tactile sensations are different. 
     U.S. Pat. No. 7,527,137 issued May 5, 2009 to the same inventor herein, discloses a single lever that effects a braking operation and a gear shifting operation. A rod moves inside the shift lever in the linear direction, but also requires pivoting movement thereafter of the shift lever, in order to effect a shifting operation. Specifically, to provide a reverse shifting operation, a push button is depressed. As a result, a caroming surface in the shift lever engages a roller wheel to push a plunger rod in the shift lever up against the force of a linear coil spring associated therewith. The flat upper surface of the plunger rod engages the free engagement end of a cable carrier pawl  100 . Then, with the push button still depressed, the shift/brake lever is again pivoted about its pivot pin to effect the reverse shifting operation. Thus, this patent requires linear movement of a rod inside of the pivot lever, and also, pivoting movement of the lever thereafter. Further, this arrangement is greatly complicated because it also requires that the single lever be used for a braking operation as well. 
     The inventor herein has also invented an arrangement which is the subject matter of copending U.S. patent application Ser. No. 11/434,324, filed May 15, 2006 in which a single lever is used for a braking operation as well as gear shifting in both directions. In this invention, the single lever is pivoted in a first direction for performing a braking operation, pivoted in a second direction for performing a first gear shifting operation, and movable only in a linear direction in the longitudinal direction of the shift lever for performing a second opposite gear shifting operation without pivoting of the single lever. 
     This latter arrangement, however, becomes relatively complicated because of the inclusion of the braking arrangement with the single lever. 
     It is therefore desirable to provide a single lever that is used for shifting in opposite directions with different tactile sensations, but which is not used for braking. 
     OBJECTS AND SUMMARY OF THE INVENTION 
     Accordingly, it is an object of the present invention to provide a shift lever arrangement for a bicycle that overcomes the problems with the aforementioned prior art. 
     It is another object of the present invention to provide a shift lever arrangement for a bicycle that uses a single lever for shifting in both directions, without providing any braking operation. 
     It is still another object of the present invention to provide a shift lever arrangement for a bicycle in which the lever moves in pivoting motion for gear switching in one direction, and a linear motion for, gear switching in the opposite direction. 
     It is yet another object of the present invention to provide a shift lever arrangement for a bicycle that includes a shift control arrangement that uses common elements therein that interact with the shift lever during shifting in both directions. 
     It is a further object of the present invention to provide a shift lever arrangement for a bicycle that is compact, economical and easy to use. 
     In accordance with an aspect of the present invention, a gear shift arrangement is provided for a bicycle that is separate and distinct from a brake lever of the bicycle, the bicycle having a derailleur and a derailleur cable associated therewith. The gear shift arrangement includes a single lever adapted to only perform a shifting operation of gears of the bicycle, a housing, a mounting arrangement in the housing for mounting the single lever for movement in a first pivoting direction and for movement in a second substantially linear direction, and a shift control mechanism in the housing for controlling shifting of the gears of the bicycle in a first shifting direction upon movement of the single lever in the first pivoting direction and for controlling shifting of gears of the bicycle in a second, opposite shifting direction upon movement of the single lever in the second substantially linear direction. 
     The shift control mechanism includes a pulley rotatably mounted in the housing and around which the cable extends, and an actuating arrangement connected between the mounting arrangement and the pulley for controlling rotation of the pulley to either pull or release the cable in dependence upon movement of the shift lever. The pulley includes a plurality of sets of gear teeth therearound, and the actuating arrangement includes a plurality of pawls for engaging the gear teeth in dependence upon movement of the shift lever. 
     For pulling the cable, the actuating arrangement includes a rotatable element rotatably mounted in the housing and adapted to be rotated from an initial position to a first rotated position by the mounting arrangement upon movement of the single lever in the first pivoting direction. An advance pawl as one of the pawls is pivotally mounted on the rotatable element, and an advance pawl spring biases the advance pawl into engagement with a first the set of gear teeth on the pulley to rotate the pulley to the first rotated position to pull the cable, wherein the advance pawl is configured so that the advance pawl is adapted to engage and rotate the pulley only in a direction to pull the cable. 
     The actuating arrangement also includes a rotatable element spring for rotationally biasing the rotatable element to the initial position. A main pawl as one of the pawls is pivotally mounted to the housing for holding the pulley in the first rotated position when the shift lever is released and when the rotatable element and the advance pawl are rotated back to the initial position by the rotatable element spring, and a main pawl spring biases the main pawl into engagement with a second the set of gear teeth on the pulley. 
     The mounting arrangement includes a slide mounted in the housing and connected with the shift lever for substantially linear sliding movement and rotatable movement with the shift lever. There is also a limiting arrangement for preventing the substantially linear sliding movement of the slide upon movement of the single lever in the first pivoting direction. 
     The slide is adapted to be moved in the housing for substantially linear sliding movement from the initial position to a first linear slid position, upon movement of the single lever in the substantially linear direction. The actuating arrangement further includes a substantially linear biasing arrangement for biasing the slide to the initial position. A hold pawl as one of the pawls is pivotally mounted to the housing for permitting an incremental rotational movement of the pulley, and a pawl biasing arrangement on the slide biases the hold pawl into engagement with a third the set of gear teeth on the pulley upon movement of the single lever in the substantially linear direction to the first linear slid position in order to effect the incremental rotational movement of the pulley. 
     The pawl biasing arrangement includes a raised abutment that engages an end of the hold pawl upon movement of the single lever and slide in the substantially linear direction to the first linear slid position to bias the hold pawl into engagement with the third the set of gear teeth and to bias the main pawl out of engagement with the second set of gear teeth. The third set of gear teeth have a pitch greater than a width of the hold pawl to permit an incremental rotation of the pulley when the hold pawl is initially engaged therein, in a direction to release the cable. Upon return of the shift lever and slide to the initial position, the hold pawl is no longer biased into engagement with the third set of gear teeth by the pawl biasing arrangement, and the main pawl is biased into engagement by the main pawl spring with the second set of gear teeth to hold the pulley in an incrementally rotated cable release position. 
     The actuating arrangement also includes a holding arrangement for holding the advance pawl out of engagement with the first gear teeth during movement of the single lever in the substantially linear direction. 
     There is also a limiting arrangement for preventing rotational movement of the rotatable element upon movement of the single lever in the substantially linear direction. 
     The above and other objects, features and advantages of the invention will become readily apparent from the following detailed description thereof which is to be read in connection with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of one side of the shifter according to the present invention mounted on a handlebar; 
         FIG. 2  is a perspective view of the other one side of the shifter according to the present invention mounted on a handlebar; 
         FIG. 3  is a perspective view of  FIG. 1  with the second half housing shell removed; 
         FIG. 4  is a perspective view of  FIG. 1  with the second half housing shell, triple gear pulley and post sleeve removed; 
         FIG. 5  is an exploded view of the shifter according to the present invention; 
         FIG. 6  is an outer perspective view of the first half housing shell; 
         FIG. 7  is an inner perspective view of the first half housing shell; 
         FIG. 8  is an inner plan view of the first half housing shell; 
         FIG. 9  is a top outer perspective view of the second half housing shell; 
         FIG. 10  is a bottom outer perspective view of the second half housing shell; 
         FIG. 11  is a left side outer perspective view of the second half housing shell; 
         FIG. 12  is a left side inner perspective view of the second half housing shell; 
         FIG. 13  is a right side inner perspective view of the second half housing shell; 
         FIG. 14  is a plan view of the inner facing side of the second half housing shell; 
         FIG. 15  is an outside perspective view of the slide; 
         FIG. 16  is an inside perspective view of the slide; 
         FIG. 17  is an outside plan view of  FIG. 13 ; 
         FIG. 18  is an inside plan view of  FIG. 14 ; 
         FIG. 19  is a perspective view of the shift lever; 
         FIG. 20  is a perspective view of the inner facing side of the post sleeve; 
         FIG. 21  is a perspective view of the outer facing side of the post sleeve; 
         FIG. 22  is a perspective view of the shift lever return spring; 
         FIG. 23  is a perspective view of the inner facing side of the triple gear pulley; 
         FIG. 24  is a perspective view of the outer facing side of the triple gear pulley; 
         FIG. 25  is an elevational view of the inner facing side of the triple gear pulley; 
         FIG. 26  is an elevational view of the outer facing side of the triple gear pulley; 
         FIG. 27  is an elevational view of the right side of the triple gear pulley; 
         FIG. 28  is an elevational view of the left side of the triple gear pulley; 
         FIG. 29  is a perspective view of the gear return spring; 
         FIG. 30  is a perspective view of the inner facing side of the pawl flange; 
         FIG. 31  is a perspective view of the outer facing side of the pawl flange; 
         FIG. 32  is a perspective view of the inner facing side of the hold pawl; 
         FIG. 33  is a perspective view of the outer facing side of the hold pawl; 
         FIG. 34  is a perspective view of the main pawl; 
         FIG. 35  is a perspective view of the main pawl spring; 
         FIG. 36  is a perspective view of the inner facing side of the advance pawl; 
         FIG. 37  is a perspective view of the outer facing side of the advance pawl; 
         FIG. 38  is a perspective view of the advance pawl spring; 
         FIG. 39  is a perspective view of the advance pawl retaining ring; 
         FIG. 40  is a perspective view of the return spring spacer; 
         FIG. 41  is a perspective view of the shifter according to the present invention during a gear shifting operation in a first direction; and 
         FIG. 42  is a perspective view of the shifter according to the present invention during a gear shifting operation in a first direction. 
     
    
    
     DETAILED DESCRIPTION 
     Referring to the drawings in detail, and initially to  FIGS. 1-5 , a shift arrangement  10  for a bicycle according to the present invention, includes a housing  16  to be secured to a handlebar  12  of a bicycle by a clamp  14 . 
     For discussion hereafter, reference to an inner facing side or inner facing surface will refer to the side or surface facing the rider, and reference to an outer facing side or outer facing surface will refer to the side or surface facing away from the rider. 
     Specifically, housing  16  includes a first half housing shell  18  and a second half housing shell  20  secured to first half housing shell  18  so as to encase the assembly for effecting gear shifting. 
     As shown best in  FIGS. 5-8 , first half housing shell  18  includes a planar circular outer wall  22  having an annular inturned flange  24  at the periphery thereof. Three equiangularly spaced ears  26  extend outwardly from annular inturned flange  24 , each ear  26  having a threaded opening  28  therein facing second half housing shell  20 . A central opening  30  is provided in planar outer wall  22 , with central opening  30  having a slightly oval or oblong configuration. Two raised stops  32  and  34  extend inwardly from planar outer wall  22  at the edge of central opening  30 , with stops  32  and  34  being about 100 degrees apart around central opening  30 . An arcuate guide wall  36  is also provided on the inside surface of planar outer wall  22  between stops  32  and  34  and spaced away from central opening  30 . A gap  35  is provided between the end of arcuate guide wall  36  and stop  34 , the purpose for which will become apparent from the discussion hereafter. 
     As best shown in FIGS.  5  and  9 - 14 , second half housing shell  20  also includes a planar substantially circular outer wall  40  having an annular inturned flange  42  at the periphery thereof. An annular wall  44  extends outwardly from the periphery of annular inturned flange  42 , with three equiangularly spaced ears  46  extending outwardly from annular wall  44 . Each ear  46  has a through bore  48  therein. In this regard, bolts  50  ( FIG. 1 ) extend into through bores  48  and are threadedly received in threaded openings  28  to secure second half housing shell  20  to first half housing shell  18 , with annular wall  44  seating on inturned flange  24 . 
     Annular inturned flange  42  includes an outwardly extending nose  52  of a generally frusto-conical configuration with a slight taper extending therefrom, and with a central bore  54  extending therethrough in communication with the interior of housing  16 . As shown in  FIG. 1 , nose  52  cooperates with cable adjust collar  56 , with the derailleur cable  57  extending through cable adjust collar  56  and nose  52  into the interior of housing  16 , as will be explained in greater detail hereafter. 
     A cylindrical boss  58  extends inwardly from the center of the inner facing surface of circular outer wall  40  and has a substantially trapezoidal shaped upper end  60  with the longer side of substantially trapezoidal shaped upper end  60  being rounded, although the present invention is not limited to this shape. A central opening  61  is provided through cylindrical boss  58  and substantially trapezoidal shaped upper end  60 , and smaller offset openings  63  and  65  are provided in substantially trapezoidal shaped upper end  60 . A slight depression  62  is formed near the periphery of circular outer wall  40  at the inner facing surface thereof at a position approximately 70 degrees offset from nose  52  in the counterclockwise direction of  FIG. 14 , with a through opening  64  formed in the center of slight depression  62 . A raised projection  66  is formed to one side of depression  62  in the counterclockwise direction of  FIG. 14 , at the inner facing surface of circular outer wall  40  and at the inner facing surface of annular inturned flange  42 , and includes a threaded opening  68  therein. Raised projection  66  includes a triangular shaped projection  70  extending inwardly from annular inturned flange  42 . A substantially triangular recess  72  is formed in the inner facing surface of annular inturned flange  42  directly behind slight depression  62 , and extends upwardly to annular wall  44 . A circular opening  74  extends into the bottom wall of recess  72 . A U-shaped recess  76  is formed in the inner facing surface of annular inturned flange  42  to the opposite side of slight depression in the clockwise direction of  FIG. 14 , and extends the entire height thereof. Lastly, a through opening  78  extends through annular inturned flange  42 , substantially diametrically opposite U-shaped recess  76 . 
     Referring now to  FIGS. 4 ,  5  and  15 - 18 , a slide or mounting element  80  as part of a mounting arrangement  79  for the shift lever to be discussed hereafter, is slidably mounted to planar circular outer wall  22  of first half housing shell  18 . Specifically, slide  80  includes a circular disc  82  having a circular boss  84  extending from the center of the outer facing surface of circular disc  82 . Boss  84  is cut away to define a slightly raised pedestal  86  and raised walls  87   a  and  87   b  extending upwardly therefrom with a generally outer circular footprint. Raised walls  87   a  and  87   b  define a large rectangular open area  88  between raised walls  87   a  and  87   b , which is in communication with a small rectangular open area  90  between raised walls  87   a  and  87   b  through an intermediary curved open area  92  between raised walls  87   a  and  87   b , all above slightly raised pedestal  86 . A central threaded opening  94  is provided on the outer facing surface of circular disc  82  at the center thereof. A cylindrical projection  96  is provided on the outer facing surface of circular disc  82 , adjacent to small rectangular open area  90  and at a lower height than slightly raised pedestal  86 . An annular advance roller  97  ( FIG. 17 ) is rotatably mounted on cylindrical projection  96 , and is adapted to fit through gap  35 . 
     The opposite inner facing surface of slide  80  includes an elongated recess  98  having a flat end  100  at one end thereof and extends in the same lengthwise direction as large rectangular open area  88  and centered therewith. A triangular recess  102  is provided to one side of elongated recess  98  and includes a guide wall  103  as will be discussed in greater detail hereafter. A further recess  104  is provided on the opposite side of elongated recess  98  for the purpose of reducing material. In addition, a slightly arcuate raised wall  106  extends upwardly from the inner facing surface of slide  80  at a position generally inline with elongated recess  98  but near the opposite periphery of circular disc  82 . A further slightly arcuate raised wall  108  of lesser dimensions than slightly arcuate raised wall  106  extends upwardly from one outer circumferential corner of slightly arcuate raised wall  106 . 
     Slide  80  is slidably mounted to planar circular outer wall  22  of first half housing shell  18  such that the outer facing surface of slide  80  rests against the inner facing surface of first half housing shell  18  and such that raised walls  87   a  and  87   b  extend through central opening  30 . 
     A shift lever  110 , as shown in  FIGS. 5 and 19 , is attached to the outer facing surface of slide  80 , to the outside of first half housing shell  18 . Specifically, lever  110  has a generally human leg shaped appearance, with an upper leg section  112  connected to a lower leg section  114  at an angle of about 140 degrees through a knee section  116 , with the free end of lower leg section  114  including a foot  118  extending approximately at a right angle from lower leg section  114 . Upper leg section  112  includes a main body  120  having dimensions corresponding to the dimensions of large rectangular open area  88  of slide  80  and fits therein. The free end of upper leg section  112  tapers down through an arcuate reducing section  122  to a reduced dimension rectangular parallelepiped section  124 . Arcuate reducing section  122  has dimensions corresponding to the dimensions of intermediary curved open area  92  of slide  80  and fits therein, and rectangular parallelepiped section  124  has dimensions corresponding to small rectangular open area  90  and fits thereon. In this position, a through bore  126  in main body  120  is in coaxial alignment with central opening  94  of slide  80 . A rivet, bolt or the like (not shown) extends through bore  126  and central opening  94  to fixedly secure shift lever  110  to slide  80 . 
     It will therefore be appreciated that rotation of shift lever  110  around the axis of through bore  126  results in corresponding rotation of slide  80  relative to first half housing shell  18 . In addition, since raised walls  87   a  and  87   b  have a generally outer circular footprint, and since central opening  30  of first half housing shell  18  has a slightly oval or oblong configuration, raised walls  87   a  and  87   b  can slide within central opening  30 . Thus, when shift lever  110  is pushed by the user in an axial direction thereof, from the outer surface of foot  118 , as shown in  FIG. 42 , raised walls  87   a  and  87   b  slide within central opening  30 . 
     Referring now to  FIGS. 5 ,  20  and  21 , a post sleeve  130  as a rotatable element of an actuating arrangement is provided in the housing  16  against the inner facing surface of slide  80 . Specifically, post sleeve  130  includes a thin generally circular plate  132  having two ears  134  and  136  extending outwardly in the plane of plate  132  and separated by an angle of about 100 degrees. A boss  138  is provided at the outer end of one ear  134  and has a post  140  extending therefrom at right angles to the plane of plate  132 , while a post  142  extends from the other ear  136  on the opposite side of plate  132 . An annular groove  141  is provided around post  140  near the free end thereof. A small opening  143  is provided on the opposite surface of ear  136 . In addition, plate  132  includes a central through bore  144 . 
     A center shaft  146  as part of the mounting arrangement  79  is fixed in central opening  61  of cylindrical boss  58  and extends through bore  144 . The free end of center shaft  146  has a post sleeve roller  145  ( FIG. 4 ) thereon which slidably fits within elongated recess  98  and which permits center shaft  146  to rotate therein. A compression spring  147  ( FIGS. 4 and 16 ) or other suitable spring member is fit within elongated recess  98  between flat end  100  thereof and post sleeve roller  145  to normally bias post sleeve roller  145  away from flat end  100 . 
     Post sleeve  130  is rotatably mounted on center shaft  146  such that post  142  extends within triangular recess  102  of slide  80 . An annular advance roller  148  is rotatably mounted on post  142  and is adapted to be guided along guide wall  103  of slide  80 , as will be discussed hereafter, during sliding movement of raised walls  87   a  and  87   b  within central opening  30 . Advance roller  148  is shown disengaged from post  142  in  FIG. 3  merely for better illustration purposes. 
     As shown in  FIGS. 5 and 22 , a coiled torsion shift lever return spring  131  is mounted against the inner facing surface of post sleeve  130 . The inner end of shift lever return spring  131  is bent to form a bent spring projection  133  that is fixed in offset opening  63 , while the outer end of shift lever return spring  131  is bent to form a bent spring projection  135  that is fixed in small opening  143  provided in ear  136  of post sleeve  130 . In this manner, shift lever return spring  131  functions to normally bias post sleeve  130  in the clockwise direction of  FIG. 3 . As a result, annular roller  148  mounted on post  142  functions to rotate slide  80  and shift lever  110  therewith. 
     As shown best in  FIGS. 3 ,  5  and  23 - 28 , a triple gear pulley  150  is rotatably mounted on cylindrical boss  58  of second half housing shell  20  at the inner facing surface of shift lever return spring  131 . Triple gear pulley  150  includes a generally cylindrical body  152  having a central through bore  153  through which cylindrical boss  58  extends. Cylindrical body  152  has a centrally located annular cable guiding groove  154  around the outer circumference thereof around which derailleur cable  57  extends. A pointed triangular nose  156  extends outwardly from the outer periphery of cylindrical body  152  and intersects with cable guiding groove  154 . Triangular nose  156  includes a cylindrical recess  158  at one side which extends partly therethrough, and an elongated slot  160  at the opposite side which extends into open communication with cylindrical recess  158 . Triangular nose  156 , as shown in  FIG. 4 , is normally oriented in a lower position to the right side thereof. In this manner, cable  57  enters housing  16  and extends within cable guiding groove  154  from a position slightly to the left of triangular nose  156 , and through elongated slot  160  and cylindrical recess  158 . A cylindrical plug  162  ( FIG. 4 ) is fixed to the free end of cable  57  that extends through cylindrical recess  158 , and is fit within cylindrical recess  158  so as to secure the free end of cable  57  to triple gear pulley  150  at pointed triangular nose  156 . A small opening  157  is provided in the inner facing surface adjacent triangular nose  156 . 
     It will be appreciated that cable guiding groove  154  divides the outer circumference of triple gear pulley  150  into an inner circumferential section and an outer circumferential section. A first set of inner gear teeth  164  extend from the inner circumferential section and a second set of outer gear teeth  166  extend from the outer circumferential section, respectively, both starting from a position immediately above triangular nose  156  and extending upwardly and around triple gear pulley  150  to a position approximately diametrically opposite to triangular nose  156 . It will be appreciated that inner gear teeth  164  have a generally symmetrical trapezoidal appearance, while outer gear teeth  166  each have the same inclination in a direction toward triangular nose  156  and have a greater pitch than gear teeth  164 . As a result, and as will be appreciated from the discussion hereafter, gear teeth  166  are slightly offset from gear teeth  164 . A third set of outer gear teeth  168  extend around the outer circumferential section from a position slightly spaced from the end of the second set of outer gear teeth  166  to a position adjacent to the opposite side of triangular nose  156 . Gear teeth  168  have a generally symmetrical trapezoidal appearance. 
     As shown in  FIGS. 5 and 29 , a coiled torsion gear return spring  165  is mounted between second half housing shell  20  and triple gear pulley  150 . The inner end of gear return spring  165  is bent to form a bent spring projection  167  that is fixed in offset opening  65  of second half housing shell  20 , while the outer end of gear return spring  165  is bent to form a bent spring projection  169  that is fixed in small opening  157  adjacent triangular nose  156  of triple gear pulley  150 . In this manner, gear return spring  165  functions to normally bias gear return spring  165  in the counterclockwise direction of  FIG. 4 . 
     As shown best in  FIGS. 3-5 ,  30  and  31 , a pawl flange  170  is fixed to the outer facing surface of second half housing shell  20 . Pawl flange  170  includes a plate  171  having a main section  172  and a finger section  174  extending therefrom. Finger section  174  includes a through bore  176  through which a bolt  178  ( FIGS. 3 and 4 ) extends from the outer facing side thereof into threaded engagement with threaded opening  68  to fixedly secure pawl flange  170  to second half housing shell  20 . Pawl flange  170  further includes a short post  180  extending from the inner facing surface thereof at a left end position of main section  172  of plate  171  and a tall post  182  extending from the inner facing surface thereof at a lower position on main section  172  of plate  171 . 
     As shown in  FIGS. 3-5 ,  32  and  33 , a hold pawl  184  as part of an actuating arrangement is rotatably mounted on tall post  182  of pawl flange  170 . Hold pawl  184  includes a pawl lever  186  having a substantially central through bore  188  which is mounted on tall post  182 . A downwardly inclined pawl catch  190  is provided at one end of pawl lever  186  for engaging with gear teeth  166  of triple gear pulley  150 , to be described hereafter. Further, a post  192  extends from the outer facing surface of pawl lever  186  at the end thereof opposite pawl catch  190  for engagement with the upper arcuate surface of further slightly arcuate raised wall  108 . 
     As shown in  FIGS. 3-5  and  34 , a main pawl  194  as part of an actuating arrangement is then rotatably mounted on long post  182  of pawl flange  170  on top of hold pawl  184 . Main pawl  194  includes a pawl lever  196  having an upper engagement surface  197  and a through bore  198  at one end by which main pawl  194  is mounted on tall post  182 . A downwardly inclined pawl catch  200  is provided at an opposite end of pawl lever  196  for engaging with gear teeth  164  of triple gear pulley  150 , to be described hereafter. Further, a post  202  extends from the outer facing surface of pawl lever  196  at the end thereof adjacent pawl catch  200  for engagement with the upper arcuate surface of slightly arcuate raised wall  106 . 
     A main pawl spring  204  normally biases pawl catch  200  into engagement with gear teeth  164 , as shown in  FIGS. 3 and 4 . Specifically, main pawl spring  204  includes a cylindrical base  206  with a central through bore  208  through which tall post  182  extends. A first spring arm  210  extends from cylindrical base  206  at the inner facing end thereof and engages with the inner surface of annular inturned flange  42 . A second L-shaped spring arm  212  extends from cylindrical base  206  at the outer facing end thereof and engages with upper engagement surface  197  of pawl lever  196 . As a result, when an external force is applied to remove pawl catch  200  from gear teeth  164 , spring arms  210  and  212  are tensioned, so that when the external force is removed, spring arms  210  and  212  force main pawl  194  in the counterclockwise direction of  FIG. 13  to force pawl catch  200  into engagement with gear teeth  164 . 
     As shown in  FIGS. 3-5 ,  36  and  37 , an advance pawl  214  as part of an actuating arrangement is rotatably mounted on post  140  of post sleeve  130 . Advance pawl  214  includes a pawl lever  216  having a lower engagement surface  217  and a through bore  218  at one end by which advance pawl  214  is mounted on post  140  of post sleeve  130 . An upwardly inclined pawl catch  220  is provided at an opposite end of pawl lever  216  for engaging with gear teeth  168  of triple gear pulley  150 , to be described hereafter. 
     An advance pawl spring  222  normally biases pawl catch  220  into engagement with gear teeth  168 , as shown in  FIGS. 3 ,  4  and  38 . Specifically, advance pawl spring  222  includes a cylindrical base  224  with a central through bore  226  mounted on boss  138  of post sleeve  130  below advance pawl  214 . A first L-shaped spring arm  228  extends from cylindrical base  224  at the outer facing end thereof and engages with the side edge of thin generally circular plate  132  of post sleeve  130 . A second L-shaped spring arm  230  extends from cylindrical base  224  at the inner facing end thereof and engages with lower engagement surface  217  of advance pawl  214 . As a result, when an external force is applied to remove pawl catch  220  from gear teeth  168 , spring arms  228  and  230  are tensioned, so that when the external force is removed, spring arms  228  and  230  force advance pawl  214  in the counterclockwise direction of  FIG. 3  to force pawl catch  220  into engagement with gear teeth  168 . 
     As shown in  FIGS. 3-5  and  39 , an advance pawl retaining ring  232  is snap fit onto post  140  of post sleeve  130 , and is held in annular groove  141  thereof, in order to retain advance pawl  214  and advance pawl spring  222  in position. 
     Further, as shown in  FIGS. 5 and 40 , a return spring spacer  234  is mounted on substantially trapezoidal shaped upper end  60  of cylindrical boss  58  between post sleeve  130  and triple gear pulley  150 . Specifically, return spring spacer  234  includes a substantially circular plate  236  with a center substantially trapezoidal shaped through bore  238  of the same shape and dimensions as substantially trapezoidal shaped upper end  60  so as to fit therearound. As a result, return spring spacer  234  is not rotatable. An arcuate flange  240  extends in a coplanar manner from the edge of circular plate  236  for an angle of approximately 90 degrees, and has opposite inclined  242  and  244 . 
     In operation, in the neutral or rest position in which no gear change occurs, pawl catch  220  of advance pawl  214  sits on arcuate flange  240  of return spring spacer  234  and is thereby out of engagement with gear teeth  168 . At this time, also, pawl catch  200  of main pawl  194  is biased by main pawl spring  204  into engagement with gear teeth  164  so that the particular gear of the derailleur stays in position. Hold pawl  184  is not biased into engagement with gear teeth  166 , but may fall into one of these teeth by means of gravity. 
     For shifting in a direction to pull cable  57  in a first shifting direction denoted by arrow  101 , the person rotates shift lever  110  in a first pivoting direction of arrow  246  in  FIG. 41 , that is, in the counterclockwise direction thereof. Because slide  80  is fixed to shift lever  110 , slide  80  also rotates in the same counterclockwise direction of  FIG. 3 . In this position, compression spring  147  maintains the centered position of slide  80 . The amount of rotation of slide  80  is limited by advance roller  97  between stops  32  and  34  of first half housing shell  18 . In addition, advance of first roller  97 , during the initial rotation, is rotated to a position away from gap  35 , and in front of arcuate guide wall  36 , which prevents linear movement of shift lever  110 , that is, which only allows rotational movement thereof. Arcuate guide wall  36  and advance roller  97  form a limiting arrangement  99  for preventing the substantially linear sliding movement of slide  80  upon movement of the single lever  110  in the first pivoting direction, that is, these elements form arrangement  99  for limiting movement of the single lever only in a rotational direction. Further, because advance roller  148  abuts against guide wall  103  of slide  80 , post sleeve  130  also rotates in this counterclockwise direction. During this movement, advance pawl  214  rotates with post sleeve  130  and thereby moves past arcuate flange  240  of return spring spacer  234 . As a result, advance pawl  214  is no longer restrained by arcuate flange  240  and is biased by advance pawl spring  222  into engagement with gear teeth  168 . Continued rotation causes advance pawl  214  to thereby rotate triple gear pulley  150  in the counterclockwise direction of  FIG. 3  in order to pull cable  57 . During this movement, main pawl  194  is caused to move out of a gear tooth  164  by the force of this rotation and against the force of main pawl spring  204 , and then be forced into engagement of the next gear tooth  164  by spring  204 . Since shift lever  110  can be rotated a distance to effect up to four gear shiftings in a single movement, main pawl  194  would repeat this operation, that is, be moved out of one gear tooth  164  and into the next gear tooth  164 , and so on, during this gear shifting operation. In like manner hold pawl  184  would perform a similar operation since it is not restrained at all. 
     When the rotational force on shift lever  110  is released, post sleeve  130  is biased in the clockwise direction by shift lever return spring  131 . Because advance roller  148  abuts against guide wall  103  of slide  80 , slide  80  and shift lever  110  also rotate in this clockwise direction. Because of the configuration of pawl catch  220  of advance pawl  214 , pawl catch  220  is caused to move in and out of gear teeth  168  during this return movement. In other words, advance pawl  214  is configured to move triple gear pulley  150  only in the counterclockwise direction. It is note that the tension on cable  57  would normally force triple gear pulley  150  back in the clockwise direction. However, to retain triple gear pulley  150  is this changed gear position, main pawl  194  engages gear teeth  164  and holds triple gear pulley  150  in position, because there is no rotational force of advance pawl  214  on triple gear pulley  150 . In this regard, cable  57  is pulled to effect a shifting operation in first direction denoted by arrow  101 . 
     For shifting in the opposite direction, the person linearly moves shift lever  110  in the direction of arrow  248  in  FIG. 42  in a second substantially linear direction. Preferably, there is no rotational movement of shift lever  110 , that is, movement is purely linear. Since slide  80  is fixed to shift lever  110 , slide  80  also moves in this linear direction. As such, advance roller  97  on slide  80  moves through gap  35  on first half housing shell  18 . 
     Specifically, post sleeve or second roller  145  around the free end of center shaft  146  slidably moves within elongated recess  98  of slide  80  against the force of compression spring  147 . In addition, advance roller  148  rides along guide wall  103  of slide  80 . This arrangement of post sleeve roller  145  within elongated recess  98  of slide  80  and advance roller  148  riding along guide wall  103  of slide  80  together form an arrangement  199  for limiting movement of the single lever in a linear direction. It will be appreciated, however, that post sleeve  130  does not slide and is therefore stationary at this time. As a result, advance pawl  214  is restrained by arcuate flange  240  of return spring spacer  234 , and is thereby out engagement with gear teeth  168  during this entire shifting operation. 
     During this sliding movement, slightly arcuate raised wall  106  of slide  80  engages post  202  of main pawl  194  to move downwardly inclined pawl catch  200  out of engagement with gear teeth  164  of triple gear pulley  150 . At the same time, slightly arcuate raised wall  108  abuts post  192  of hold pawl  184  to move downwardly inclined pawl catch  190  into engagement with gear teeth  166  of triple gear pulley  150 . Therefore, at this time, triple gear pulley  150  is held in position only by hold pawl  184 . The spacing or pitch of gear teeth  166  is greater than the width of pawl catch  190  so that, during this initial engagement, triple gear pulley  150  is caused, by the pull force from cable  57 , to rotate slightly in the clockwise direction of  FIG. 3  by a slight distance equal to the difference between the spacing or pitch of gear teeth  166  and the width of pawl catch  190 , until pawl catch  190  abuts against the edge of the respective gear tooth  166  to hold triple gear pulley  150  in position. 
     When the linear force applied to shift lever  110  is released, compression spring  147  forces slide  80  to move linearly to its original position. As a result, slightly arcuate raised wall  108  no longer abuts post  192  of hold pawl  184 , whereby downwardly inclined pawl catch  190  can be moved out of engagement with gear teeth  166  of triple gear pulley  150 . This occurs by reason of the tension on cable  57  moving triple gear pulley  150  in the clockwise direction of  FIG. 3 , whereby hold pawl  184  is forced by this rotation out of engagement with gear teeth  166 . At the same time, slightly arcuate raised wall  106  of slide  80  no longer engages post  202  of main pawl  194 , whereby main pawl spring  204  forces main pawl  194  to move in the counterclockwise direction of  FIG. 3 . However, triple gear pulley  150  already rotated slightly in the clockwise direction of  FIG. 3 , as described above. As a result, there is no gear tooth  164  for main pawl  194  to engage. Therefore, triple gear pulley  150  starts to rotate in the clockwise direction of  FIG. 3  by reason of the tension on cable  57 , until downwardly inclined pawl catch  200  of main pawl  194  engages the next tooth  166  and is forced into this next tooth  166  by main pawl spring  204  in order to hold triple gear pulley  150  in this position. As a result, cable  57  is released to effect a shifting operation in a second opposite direction denoted by arrow  103  in  FIG. 42 . 
     It will be appreciated that various modifications can be made to the invention within the scope of the claims. For example, rather than shift lever  110  moving only in a linear direction during the reverse shifting operation, it can move in a slightly arcuate path in which it also rotates slightly while moving linearly. Further, it is possible to effect the linear movement of shift lever  110  after shift lever  110  is first rotated a small distance. In this regard, reference in the claims to substantially linear covers all of these arrangements. 
     Having described specific preferred embodiments of the invention with reference to the accompanying drawings, it will be appreciated that the present invention is not limited to those precise embodiments and that various changes and modifications can be effected therein by one of ordinary skill in the art without departing from the scope or spirit of the invention as defined by the appended claims.