Abstract:
A device for disassembling and assembling bicycle pedals comprises a bicycle crank ( 1 ), detachable pedals ( 17 ) connected with the crank ( 1 ), a fixing seat ( 11 ) arranged at an end of the crank ( 1 ), a control device arranged at the fixing seat ( 11 ) and a connection assembly between a pedal ( 17 ) and the control device. The control device also comprises an unlocking mechanism, a pushing mechanism and a rotating mechanism, wherein the pushing mechanism and the rotating mechanism are controlled by a gear mechanism. The device can conveniently and quickly disassembling and assembling bicycle pedals by one step without touching the pedals with hands.

Description:
FIELD OF THE INVENTION 
       [0001]    The invention relates to a device for disassembling and assembling bicycle pedals. 
       BACKGROUND OF THE INVENTION 
       [0002]    Bicycles are one of the most prevalent vehicles. Since the amount of bicycles increases progressively, and the size of a bicycle frame is relatively large, bicycles takes up more space. Specially, bicycle pedals bring unnecessary width while the bicycle is parked. Currently, bicycles mainly adopt two types of pedals, such as folding-type pedals and quick disassembling-type pedals. 
         [0003]    In the folding-type pedals, a pedal body can be folded. However, since the pedal body can be folded, the intensity of this type of pedal is usually insufficient. Therefore, the pedal will possibly be damaged under an excessive force. 
         [0004]    In the quick disassembling-type pedals, a coupler fixed to a crank of a bicycle is provided between the crank and one of the pedals. By toggling a lock-up mechanism, the pedal can disengage from or fit in the coupler of the crank. However, the disassemble-type pedals, after being disassembled, must be placed at other locations or carried with users, which brings the users some degree of inconvenience. 
         [0005]    Meanwhile, the pedals are located at a low level and distributed on each side of the bicycle frame respectively. The above two types of pedals not only bring users inconvenience, but also dirty the users&#39; hands when the pedals are folded or disassembled. 
       SUMMARY OF THE INVENTION 
     Technical Problem 
       [0006]    The present invention is aimed to provide a device for disassembling and assembling bicycle pedals without touching the pedals with users&#39; hands. The present invention also provides an assembly for controlling the disassembling and assembling by one step. That is to say, the bicycle pedals can be disassembled and assembled by one step without touching the pedals with hands. 
       Technical Solution 
       [0007]    One object of the invention is to provide a device for disassembling and assembling bicycle pedals. The device comprises a crank; detachable pedals connected with the crank; a fixing seat arranged at an end of the crank; a control device arranged at the fixing seat; a connection assembly between a pedals and the control device; an unlocking mechanism; a pushing mechanism; and a rotating mechanism, wherein the pushing mechanism and the rotating mechanism are controlled by a gear mechanism. 
         [0008]    The gear mechanism for controlling the pushing mechanism and the rotating mechanism at least comprises: a gear; and a driving rack and a driven rack which are engaged with said gear. 
         [0009]    The crank is provided with a fixing seat at an end at which the control device is not arranged. The fixing seat is at least provided with a dual gear. The driving rack has teeth engaged with the dual gear. 
         [0010]    A locating block for controlling a rotation of the pedal is provided on the driving rack. The locating block controls the pedal to start a rotating process after the pedal exits from the crank, due to a limiting relationship between the locating block and a support frame under procedures. 
         [0011]    The connection assembly directionally moves on a support frame. The support frame is provided with a limiting structure for limiting the movement of the pushing mechanism. A gear of the connection assembly and the support frame are coaxially pivoted to the fixing seat at the end of the crank. 
         [0012]    The connection assembly comprises a linkage. The line between two pivotal joints at both ends of the linkage is always parallel with an axis of an axle of the pedal when the pedal does not rotate. 
         [0013]    One of the pivotal joints at the both ends of the connection assembly is fixed with the support frame, while the other one of the pivotal joints is fixed with the pedal indirectly. A pivotal joint in a middle part of the linkage, which is collinear with the pivotal joints at the both ends of the connection assembly, is pivotably joined with the driven rack so as to carry out a pushing process of the pedal at a certain transmission ratio. 
         [0014]    Another object of the invention is to provide an assembly for controlling, by one step, disassembling and assembling the device as described above. The assembly comprises two devices for disassembling and assembling a pedals at both sides of a bicycle, respectively and independently; a central actuating mechanism for controlling the two devices for disassembling and assembling the pedals independently; and a central control seat fixed to a bottom bracket, for fixing the central control mechanism, wherein an actuating ring is at least provided at the bearing between the central actuating mechanism and one of the two devices at one side of the bicycle. 
         [0015]    The central actuating mechanism at least comprises a gear and a rack engaged with the gear. 
         [0016]    The actuating ring is at least fixed with a rack at a side. 
         [0017]    The trajectory of the actuating ring is parallel with an axis of the bottom bracket the bicycle. 
         [0018]    At contact points between the actuating ring and a transmission mechanism in the central actuating mechanism, balls are provided to reduce frictions. 
       Technical Effect 
       [0019]    As a result, the device for disassembling and assembling bicycle pedals and the assembly for controlling the disassembling and assembling by one step according to the present invention have advantages of disassembling and assembling bicycle pedals without touching the pedals with users&#39; hands. Furthermore, the operation of the actuating mechanism can couple other folding steps. This can conveniently and quickly disassemble and assemble the bicycle pedals. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0020]      FIG. 1  is a perspective view schematically showing the structure of example 1 of the invention; 
           [0021]      FIG. 2  is an exploded view showing the structure of example 1 of the invention; 
           [0022]      FIG. 3  is a partial exploded view showing a control device when a pedal just enters into a rotating process according to example 1 of the invention; 
           [0023]      FIG. 4  is a perspective view showing the pedal after it separates from a crank and rotates according to example 1 of the invention; 
           [0024]      FIG. 5  is a partial perspective exploded view showing the an assembly for controlling the disassembling and assembling by one step according to example 1 of the invention; 
           [0025]      FIG. 6  is a perspective exploded view showing the structure of a control device according to example 2 of the invention; 
           [0026]      FIG. 7  is a schematic view showing another structure of example 2 of the invention; 
           [0027]      FIG. 8  is a schematic view showing an actuating ring according to example 2 of the invention; 
           [0028]      FIG. 9  is a schematic view showing a central actuating mechanism according to example 2 of the invention; 
           [0029]      FIG. 10  is a perspective exploded view showing a structure of a control device which does not operate according to example 3 of the invention; 
           [0030]      FIG. 11  is a perspective exploded view showing a structure of the control device which is operating according to example 3 of the invention; 
           [0031]      FIG. 12  is a partial perspective exploded schematic view of an assembly for controlling disassembling and assembling by one step according to example 3 of the invention; 
           [0032]      FIG. 13  is a perspective schematic view showing the structure of the assembly for controlling disassembling and assembling by one step which does not operate according to example 3 of the invention; and 
           [0033]      FIG. 14  is a perspective schematic view showing the structure of the assembly for controlling disassembling and assembling by one step after the pedal has been disassembled or assembled. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0034]    The invention will be further illustrated by various examples with reference to attached drawings. 
       Example 1 
       [0035]    A device for automatically disassembling and assembling bicycle pedals and an assembly for controlling the disassembling and assembling by one step are shown in  FIGS. 1-5 . In order to facilitate illustration, only one bicycle pedal is shown together with mechanisms connected thereto. In the figures, a fixing seat  11  is fastened to an end of a crank  1 . An unlocking mechanism comprises a pedal  17  provided with an annular groove  131  at an end of an axle thereof; a coupler  12  fixed on the crank; a clamper  14  with a tuber, matching with the annular groove  131 ; and an unlocking bar  41  for controlling the movement of the clamper  14 . The unlocking bar  41  is fixed with a driving rack  4  of a pushing mechanism and a rotating mechanism of the pedal  17  as well as a transmission rack  43  at a bottom bracket, so as to form a general actuating assembly. The fixing seat  11  forms, on its inner face relative to the crank  1 , a concave for merely limiting the directional movement of the damper  14 . That is to say, the crank is situated between the unlocking mechanism and the pedal. The damper  14  is provided with balls  15  for reducing frictions with the concave of the fixing seat. The movement of the clamper  14  can be controlled by pulling the unlocking bar  41 , such that the clamper  14  snaps into or exits from the end of the axle of the pedal so as to control the unlock or lock state of the pedal. 
         [0036]    Referring to  FIG. 2  and  FIG. 3 , a support frame  2  is pivotably joined with the fixing seat  11  on the crank  1 . A connection assembly comprising sliders  31 ,  32  and  33  can directionally move on the support frame  2 . The support frame  2  has a limiting stopper  27  for limiting the movement of a driven rack  22  of the pushing mechanism, and a locating hole  23   a  for limiting the slide of a locking piece  23 . Meanwhile, the sliders  31 ,  32  and  33  constitute three sliding assemblies slidable directionally, each having a limiting structure for limiting the movement between each other. That is to say, when the sliders are completely pulled apart, the total length of the three sliders will not exceed a predetermined value which is longer than the travel distance of the pedal axle  13  completely exiting from the coupler  12 , due to their limiting structures. 
         [0037]    An aperture  29   a  in the slider  33  is fixed with an aperture  29  in the support frame  2  via a rivet  223 . In addition, an aperture  35   a  in the slider  33  is hinged to an aperture  35  at one end of a linkage  3 , while an aperture  36   a  of the slider  31  is hinged with the other end  36  of the linkage. An end protrusion  311   a  of the slider  31  is fixed with an annular groove  311   b  of the pedal axle. The pedal  17  is indirectly connected with the support frame  2  via the slider  31  of the three sliding assemblies, and can move directionally relative to the support frame (the movement in a pushing process of the pedal). As the travel distance of the pedal  17  exiting from the crank  1  is relatively long, in order to prevent the interference between the pushing mechanism and a chain of the bicycle, the driven rack  22  has an aperture  34   a  hinged with an aperture  34  in the middle part of the linkage, such that the travel distance of the driven rack  22  is scaled up by the linkage  3 . An end hinge  35  of the linkage  3  is hinged with the aperture  35   a  of the slider  33 , and the slider  33  is fixed with the support frame  2 , therefore, the end hinge point  35  is indirectly fixed to the support frame  2  through the slider  33 . The hinge point  36  at the other end of the linkage  3  is hinged with the slider  31 , and the slider  31  is fixed to the pedal, therefore, the hinge point  36  of the linkage  3  is fixed with the pedal  17  indirectly. 
         [0038]    As such, the driving rack  4  drives the driven rack  22  via the gear  21  on the support frame  2 , and then the driven rack  22  pushes the sliding assemblies with a certain travel distance ratio, such that the pedal fixed to an end of the sliding assemblies exits from the coupler  12  of the crank  1 . 
         [0039]    When the pedal driven by the driven rack  22  does not exit from the coupler  12 , the locking piece  23  moving in a direction perpendicular to the moving direction of the driven rack  22  is always situated between the support frame  2  and the driven rack  22 . The locking piece  23  is provided with a locating block  28  which fits into the locating hole  23   a  of the support frame. The locating block  28  is sheathed with a spring  24  which is arranged between the locking piece  23  and the support frame  2 . The spring  24  applies a force to the locking piece  23  which in turn presses the driven rack  22 . When the driven rack drives the pedal to exit from the coupler  12 , the locking piece  23  abuts against the rear end of the driven rack  22  into a lock-up position under the elastic force of the spring  24 , in order to prevent the driven rack  22  from traveling backwards. The locking piece  23  and the support frame  2  are hinged to a linkage having two parts for unlocking. Said linkage having two parts is formed of a rod  25  and a rod  25   a  hinged together. The end of the rod  25  which is not hinged with the rod  25   a  is hinged to the bottom of the support frame  2 . The end of the rod  25   a  which is not hinged with the rod  25  is hinged to the bottom of the locking piece  23 . Therefore, when the hinged end  26  of said linkage having two parts is pressed, the locking piece  23  will be moved in a direction opposite to the direction in which the spring  24  is applying a force, such that the locking piece  23  will move away from the lock-up position to an unlocked position. 
         [0040]    Referring to  FIG. 3  and  FIG. 4 , when the rotating mechanism does not operate or the rotating mechanism has restored back, an end  26   a  of a fixing seat cap  11   a  just presses the hinged end  26  of the linkage having two parts, to keep the unlocked state. When a rotating process is started, the hinged end  26  of the linkage having two parts is released from the end  26   a  of the fixing seat cap  11   a  such that the locking piece  23  enters into the lock-up position in which the driven rack  22  is prevented from traveling backwards. 
         [0041]    In addition, the support frame  2  is provided with a limiting stopper  27  corresponding to a bump  27   a  on the driven rack  22 . Therefore, the travel distance of the driven rack  22  is controlled by the limiting stopper  27  within a certain travel distance. Furthermore, when the driven rack is brought to the designed travel distance which is sufficient for the pedal to exit from the coupler  12  of the crank, the pedal starts to rotate relative to the crank. As a result, when the driving rack  4  drives the driven rack  22  so as to cause the pedal to exit from the coupler  12  of the crank, a limiting stopper  42  of the driving rack  4  always contacts with the support frame  2  to prevent the support frame  2  from rotating. When the driving rack  4  drives the driven rack  22  to reach the limiting stopper  27  on the support frame, the driven rack  22  cannot continue to move. At this time, the limiting stopper  42  of the driving rack  4  just disengages from the support frame  2 . As a result, when the driving rack  4  continues to move in the original direction, the support frame  2  is no longer limited by the limiting stopper  42  of the driving rack, and then the pedal starts to rotate. 
         [0042]    As such, at the beginning of the rotating process, the hinge point  26  of the linkages  25  and  25   a  with both ends hinged to the support frame  2  and the locking piece  23  respectively, is no longer limited by the end  26   a  of the fixing seat  11 . The locking piece  23  then abut against the end of the driven rack  22  under the elastic force of the spring  24  to prevent the driven rack  22  from traveling backwards. In the circumstance, when the pedal completely exits from the coupler  12  of the crank and starts to rotate, the movement of the driven rack  22  is limited in both directions by the limiting stopper  27  on the support frame and the locking piece  23  slidable on the support frame. Therefore, the movement of the linkage  3  hinged to the driven rack  22  and the movement of the sliding assemblies hinged to the end of the linkage is limited. Meanwhile, the slider  33  of the sliding assemblies is fixed with the support frame  2 , so after the pedal fixed to the slider  31  exits from the coupler  12  of the crank  1 , it is indirectly fixed to the support frame  2  during the rotating process. When the driven rack  22  is not driven by the driving rack  4 , the driving rack  4  starts to drive the support frame  2 , such that the pedal indirectly fixed to the support frame  2  starts to rotate. 
         [0043]    The pedal  17  can rotate relative to the pedal axle. A magnet  20  is fixed at a certain position of the pedal  17 . A magnet  20   a  corresponding to the magnet  20  is fixed at a corresponding position of the general actuating assembly. In this situation, in the rotating process of the pedal  17 , the magnet  20  cooperate with the magnet  20   a  on the general actuating assembly, so that the surface of the rotated pedal  17  is substantial parallel to the crank  1 , and thus the width of the bicycle is further reduced after the pedal is folded, as shown in  FIG. 4 . 
         [0044]    If a user wants to let the pedal restore back to be fastened in the coupler  12  of the crank, he can just pull an actuating rack in an inverse direction, and then the corresponding rotating, pushing and fastening processes are performed. 
         [0045]    Referring to  FIG. 5 , in order to control the pedals  17  at both sides of the bottom bracket of the bicycle by one step, a central control seat  71  is fixed on the bottom bracket  7  of the bicycle. A central control enclosure  71   a  is fixed on the central control seat. An edge  74   a  of the central control enclosure  71   a  serves as a sliding guide of an actuating rack  74 . A gear  76  is fixed to the central control seat  71  and engages with the actuating rack  74  and a pushing rack  72 . The pushing rack  72  is provided, at one end, with a groove  75  which may contain an actuating ring  6 . The groove  75  is provided with balls  73  on a face contacting with the actuating ring  6  so as to reduce frictions therebetween. The inner face of the actuating ring has a ring shape, such that when the crank rotates, the central actuating mechanism can contact with the groove  75  of the pushing rack  72  with even angles. In addition, the actuating rack  74  engages with a gear  77   a.  The gear  77   a  is coaxially fixed to a seat post  77 . In the circumstance, when the seat post is bended, the gear  77   a  and the actuating rack  74  engaged with the gear  77   a  are driven. The actuating rack  74  drives the pushing rack  72  via the gear  76 . Then the pushing rack  72  drives the actuating ring  6  to move in a direction parallel to the axis of the bottom bracket. Therefore, a rack  61  fixed to the actuating ring  6  drives the dual gear  44  which is arranged on a fixing seat  16  and engages with the rack  61 , and the transmission rack  43  being a part of the general actuating assembly is driven. As a result, through the step of bending the seat post  77 , and through cascade coupling drive, the downstream unlocking, pushing and rotating processes are performed by a simple process of bending the seat post so as to achieve the object of the invention. 
         [0046]    In addition, the actuating ring  6  can also be fixed to the pushing rack  72 , and the rack  61  engaged with the dual gear  44  is not fixed to the actuating ring  6 . Moreover, like the pushing rack  72 , a groove  75  is formed at one end of the rack  61  for containing the actuating ring  6 . The groove  75  is further provided with balls for reducing frictions with the actuating ring  6 . This can also achieve the object of the invention. 
       Example 2 
       [0047]    In this example, in order to make the pedals directionally move relative to the axis of the pedal coupler, the sliding assemblies described in example 1 are removed. Instead, a linkage is used, of which a pivotal joint is fixed to the pedal indirectly and another pivotal joint may move directionally relative to the coupler of the pedal. As such, the two pivotal joints on the linkage can ensure the directional movement of the pedal. 
         [0048]    Referring to  FIGS. 6 and 7 , a fixing frame  222  is pivotably joined to the fixing seat at the end of the crank in the same way as that of example 1. A gear  221  is pivotably joined on the fixing frame  222 . Meanwhile, the fixing frame  222  is also provided with a chute  224  and a limiting stopper  225  for limiting a driven rack  223 . The driven rack is also provided with a tuber  224   a  corresponding to the chute  224  of the fixing frame  222 , and a stopping protrusion  225   a.  There are locking piece  226  and a spring  226   a  as those in example 1. A pivotal joint  333   b  at one end of a linkage  333  is pivotably joined with an aperture  333   a  in the fixing frame  222 , while a pivotal joint  223   a  in the middle part of the linkage  333  is pivotably joined with an aperture  223   b  in the driven rack  223 . Moreover, a pivotal joint  334  at the other end of the linkage  333  is fixed to a fixing block  227  of the pedal, while another pivotal joint  335  in the middle part of the linkage is hinged with a post  227   b  which can move directionally in a groove  227   a  of the fixing block  227 . In addition, the pivotal joints  333   b  and  334  at two ends of the linkages are collinear with the pivotal joints  223   a  and  335  in the middle parts of the linkages. The line on which the four joints are located is always parallel to the axis of the pedal axle when the pedal does not rotate. 
         [0049]    As such, the fixing block  227  maintains its directional movement through the pivotal joint  334  at the end of the linkage which is fixed to the fixing block  227 , and through the post  227   b  hinged to the pivotal joint  335  in the middle part of the linkage. In addition, the linkage maintains its directional movement through the pivotal joint  223   a  pivoted to the driven rack  223 , and through the pivotal joint  333   b  pivoted to the fixing frame. Therefore, in a pushing process of the pedal, the pedal fixed to the fixing block  227  is always moving in a direction parallel to the axis of the pedal axle. After the pushing process of the pedal finishes, the pedal is stationary relative to the fixing frame  222 , due to the locking piece  226  and the limiting stopper  225  on the fixing frame  222 . When the pedal starts to rotate, an actuating rack engages with the gear  221 , and then drives the fixing frame  222  to rotate, such that the pedal being stationary relative to the fixing frame  222  enters into a rotating process. Similar to example 1, one rack (a continuous gear mechanism) can be used to drive three processes step-by-step. 
         [0050]    Further referring to  FIGS. 8 and 9 , an outer ring  6   b  is shown. An annular concave is formed in an interior of the outer ring  6   b.  Three supporting blocks  6   c  are fixed to an inner ring  6   a  which has an inner diameter less than that of the outer ring, and are arranged inside the annular concave of the outer ring  6   b.  As such, the outer and inner rings can only move by way of relative rotation and therefore constitute an actuating ring  6  which can move directionally along the axis of a bottom bracket. 
         [0051]    A central actuating mechanism comprises two V-shaped movable rods  18 . The hinge  18   a  of the V-shaped rods is movable. The both ends of the two V-shaped rods are hinged to the inner rings  6   a  of two actuating rings  6 , respectively. A rack  61  is fixed on the outer ring for driving the control device downstream. A bottom bracket seat  11   c  is fixed on the bottom bracket, which is further provided with a guide rail  19   a  along which the actuating rings move. A locating block  19   b  corresponding to the locating guide rail is fixed on the inner ring of the actuating ring. Through toggling the hinge  18   a  of the V-shaped rods, the V-shaped rods drive the actuating rings to move directionally along the axis of the bottom bracket, such that the control assembly downstream is driven by a transmission mechanism. 
       Example 3 
       [0052]    In this example, unlocking, pushing and rotating processes are driven by at least two racks, i.e., a gear mechanism. The separated and distributed discontinuously gear mechanism, i.e., more than two racks fixed with each other, can engage with gears in corresponding processes of disassembling and assembling pedal, under given procedures. As such, through driving the gear mechanism, the gear mechanism respectively drives gears corresponding to the unlocking, pushing and rotating processes according to the given procedures, such that the pedal can be disassembled and assembled by one step according to the procedures. 
         [0053]    As shown in  FIGS. 10 and 11 , the three steps of disassembling or assembling pedal are carried out by three independent racks respectively. The principle of the unlocking process is the same as that of example 1. In particular, a rack  93   a  is used for pushing the pedal to separate from the crank. A rack  95  makes it possible for the pedal separated from the crank to rotate, together with the fixing frame  9 , relative to the crank. The racks  93   a  and  95  are fixed together to form a general actuating assembly. If the actuating direction of the unlocking bar is reverse to that of the general actuating assembly, the unlocking bar engages with the general actuating assembly consisting of the pushing rack  93   a  and the rotating rack  95  via an intermediate gear  96 . Otherwise, if the actuating direction of the unlocking bar  97  is the same as that of the general actuating assembly, the unlocking bar, the pushing rack and the rotating rack may be fixed together to be a general actuating assembly as in example 1. The fixing frame  9  is pivotably joined with the fixing seat at the end of the crank as in example 1. A rotating gear  94  which rotates the fixing frame  9  is also fixed on the fixing frame  9 . In addition, the rotating gear  94  is also provided with a limiting stopper  94   a.  The device for exiting the pedal from the bicycle crank comprises two racks  91   a  and  91   b  hinged to each other by one end. The rack  91   a  is fixed with the pedal at its unhinged end. The two engaged racks are provided with a torsion spring at their hinge  91   c , such that the teeth of the two racks are perpendicular to each other by the torsional force of the torsion spring when the pedal is not pushed. As such, the rack  91   b  will not strike on the bicycle chain. 
         [0054]    If the actuating assembly is driven, the unlocking bar  97  carries out the unlocking process directly or indirectly. After the unlocking process finishes, the pushing rack  93   a  of the actuating assembly engages with a dual gear  93 , and then drives the rack  91   a  engaged with the dual gear  93 . At this time, an arc-shaped end  92  of the fixing frame  9 , which contacts with the rack  91   b,  presses the rack  91   b  to escape from the torsional force of the torsion spring at the hinge  91   c  for hinging the rack  91   a  and the rack  91   b , such that the teeth of the pushing rack  91   b  are parallel with those of the rack  91   a.  As such, the racks  91   a  and  91   b  form a continuous and complete rack, and are driven by the pushing rack  93   a  such that the pedal exits from the crank. The dual gear  93  is pivoted with the rotating gear  94  coaxially. In the pushing process, a protrusion  94   b  on the rotating rack  95  always contacts with the limiting stopper  94   a  on the rotating gear  94 , which limits the rotating process. When the pedal is completely separated from the crank, the protrusion  94   b  on the rotating rack  95  is no longed limited by the limiting stopper  94   a  on the rotating gear  94 . At this time, the rotating rack  95  drives the fixing frame  9  fixed with the rotating gear  94  to rotate together. Then, the pedal on the fixing frame  9  will rotates together with the fixing frame  9 , which achieves the object of the present invention. The pushing process is carried out during the rotating process. That is to say, when the rotating rack  94   b  engages with the rotating gear  94 , the pushing rack  93   a  also engages with the gear  93 . This ensures the precision of the pushing rack  93   a  being engaging with the gear  93 . 
         [0055]    Referring to  FIGS. 12 ,  13  and  14 , the central actuating mechanism at the central axle of the bicycle comprises a fixing seat  8  fixed to the bottom bracket  7  of the bicycle and a fixing seat cap  8   a.  A gear  85  with a tuber  85   a  is pivoted to the fixing seat cap  8   a . Moreover, the gear  85  engages with a pushing rack  83  and an actuating rack  86 . A groove  88   a  which may contain an actuating ring  88  is formed at one end of the pushing rack  83 . The groove  88   a  has a width W which is larger than the thickness D of the actuating ring  88 . The actuating ring  88  has an interior being an annular shape. Furthermore, an unlocking bar  82  with depressed part and a rack  81  are fixed at one end in an exterior of the actuating ring  88 . Alternatively, the actuating ring  88  may have an exterior being an annular shape. The unlocking bar  82  and the rack  81  are fixed at one end in an interior of the actuating ring  88 . The rack  81  can engage with a dual gear  87  fixed on the fixing seat  19  which is arranged at the end of the crank, under given procedures. The dual gear  87  has a groove  84   a  which can engage with the locking bar  84 . When the central actuating mechanism is not actuated, the groove  84   a  of the dual gear  87  engages with one end of the locking bar  84 , the other end of the locking bar  84  is provided with a pin  84   b  for withstanding the spring  82   b.  This engagement is enforced by the spring  82   b  on the locking bar so as to ensure the lock-up state in which a rotation of the dual gear  87  is limited. At this time, the depressed on the unlocking bar  82  of the actuating ring  88  contacts with the circular protrusion  82   a  (which can be substituted by a bearing) on the locking bar  84 , while the rack  81  on the actuating ring  88  is not engaged with the dual gear  87 . Meanwhile, the groove  88   a  at one end of the pushing rack  83  does not contact with the actuating ring  88 , while the actuating rack  86  is not engaged with the rack  85 . 
         [0056]    The seat post is bended such that a gear  89  fixed therewith drives the actuating rack  86 . The actuating rack  86  then engages with the gear  85 . The actuating rack  86  then drives the pushing rack  83  engaged with the gear  85 , accordingly drives the actuating ring  88  to move. This causes the locking bar  84  to be disengaged from the groove  84   a  on the dual gear  87 . The above steps are called the unlocking process. The unlocking process is performed by the bulge of the unlocking bar  82  fixed on the actuating ring  88  pressing upon the circular protrusion  82   a  of the locking bar  84 . In this way, the unlocking bar  82  makes it possible for the locking bar  84  to escape from the elastic force of the spring  82   b  under pressure. Then the locking bar  84  disengages from the groove  84   a  on the dual gear  87 , which achieves the unlocking purpose. In the unlocking process, the rack  81  fixed to the actuating ring  88  does not engage with the dual gear  87 . When the circular protrusion  82   a  on the locking bar  84  is completely situated on the bulge of the unlocking bar  82 , that is to say, only after the unlocking process completes, the rack  81  engages with the dual gear  87  to drive the transmission rack  44 , such that the subsequent processes of disassembling and assembling pedal are performed. 
         [0057]    In the restoring process of disassembling and assembling the pedal, the actuating rack  86  drives the pushing rack  83  so as to restore the actuating process downstream. If the actuating process downstream restores, the rack  81  fixed to the actuating ring  88  disengages from the dual gear  87 . Meanwhile, the groove  84   a  of the dual gear  87  just rotates to engage with the locking bar  84 . The locking bar  84  engages with the groove  84   a  of the dual gear  87  under the elastic force of the spring  82   b,  which achieves the lock-up purpose. When the actuating rack  86  engages with the gear  85 , the groove  88   a  of the pushing rack  83  always engages with the actuating ring  88 . Therefore, after the lock-up process finishes, the actuating rack  86  does not engage with the gear  85 . At this time, the actuating ring no longer moves, while the groove  88   a  of the pushing rack  83  still engages with the actuating ring  88 . If the actuating rack  86  is driven continuously, an end  85   b  of the actuating rack presses against the tuber  85   a  on the gear  88 . This causes the gear  85  to rotate with a certain angle in a direction which is opposite to that in the restoring process, and therefore move a certain distance in a direction which is opposite to that in the former restoring process. As such, the actuating ring  88  does not contact with the groove  88   a  of the pushing rack  83  again so as to restore back to the initial actuating state. Accordingly, the object of the present invention is achieved.