Patent Publication Number: US-2011048166-A1

Title: Bicycle clipless pedal with clamping force adjusting assembly

Description:
BACKGROUND OF THE INVENTION 
     1. Technical Field 
     The present invention relates to bicycle clipless pedals and more particularly, to a bicycle clipless pedal equipped with a clamping force adjusting assembly so that the clipless pedal is capable of providing an adjustable clamping force to an external shoe cleat. 
     2. Description of Related Art 
     A bicycle clipless pedal is designed to removably engage with a cleat of a cleated shoe for fastening a cyclist&#39;s foot to the pedal. As compared with the traditional pedals without a cleat retaining structure, the clipless pedals help the cyclist to pedal with less effort, to maintain rotational acceleration of the pedal, and to prevent the his/her feet from coming off from the pedals during his/her riding. For the aforementioned advantages, the clipless pedals have been extensively used in cross country bikes, mountain bikes, and racing bikes. 
     A known design of a bicycle clipless pedal, as disclosed in U.S. Pat. No. 6,708,584, is a pedal assembly that has a center tubular portion 30, a bicycle pedal 12 rotating around the center tubular portion 30, a front and rear clamping members 24 and 26 fixedly coupled to a first and second ends of the bicycle pedal 12, respectively. The &#39;584 patent also disclosed a cleat 14 for being coupled with the pedal assembly. The cleat 14 has a set of front coupling members 86, 88, and a set of rear coupling members 90, 92, for engaging the front and rear clamping members 24 and 26, respectively. A support pin 28 is coupled to the rear end of the bicycle pedal 12 and a set of torsion springs 29 are mounted on the support pin 28. Therein, one end of the spring 29 is connected with the rear clamping member 26. 
     The pedal assembly provided by the &#39;584 patent indeed provides due clamping performance at the initial stage of use because at that time the regular springiness of the torsion springs 29 ensures the firm combination between the rear clamping member 26 and the rear coupling members 90, 92. However, with the lapse of use time, fatigue failure happening to the torsion springs 29 can adversely affect the desired combination between the shoe cleat 14 and the pedal 12. As a result, the cleat 14 is likely to come off when the cyclist pedals, risking the cyclist getting muscle strains. Therefore, the &#39;584 patent lacks for a technical approach recovering the desired clamping force the pedal 12 applies to the shoe cleat 14 as a solution to fatigue failure of the torsion springs 29. 
     SUMMARY OF THE INVENTION 
     Hence, the present invention is herein disclosed to provide a bicycle clipless pedal with a clamping force adjusting assembly that solves the problem of the prior art and provides an effective adjusting means to recover the clamping performance of the clipless pedal from a weaken state thereof. 
     The primary objective of the present invention is to provide a bicycle clipless pedal with a clamping force adjusting assembly, by which adjusting assembly, a user is allowed to adjust a clamping force exerted by a rear clamping set of the pedal. 
     Another objective of the present invention is to provide a bicycle clipless pedal with a clamping force adjusting assembly, wherein the clamping force adjusting assembly can be easily operated by using a screwdriver to screw or unscrew an adjusting screw so as to adjust a clamping force of the pedal. 
     To achieve theses and other objectives of the present invention, the bicycle clipless pedal with the clamping force adjusting assembly includes a pedal axle, a pedal body coupled to and rotating around the pedal axle, and a rear clamping set connected to a rear end of the pedal body, wherein the rear clamping set includes: an assembling portion connected to the pedal body; a fastening member pivotally connected to the assembling portion, a compression spring settled in the assembling portion for providing a spring force to abut against the fastening member, and the clamping force adjusting assembly deposited at the assembling portion for adjusting a preload of the compression spring. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention as well as a preferred mode of use, further objectives and advantages thereof will be best understood by reference to the following detailed description of an illustrative embodiment when read in conjunction with the accompanying drawing, wherein: 
         FIG. 1  is a front oblique view of a bicycle clipless pedal with a clamping force adjusting assembly of the present invention; 
         FIG. 2  is a rear oblique view of the bicycle clipless pedal of the present invention; 
         FIG. 3  is an exploded view of the bicycle clipless pedal taken from the same viewpoint of  FIG. 2 ; 
         FIG. 4  is a sectional assembled view of the bicycle clipless pedal of the present invention; 
         FIG. 5  shows adjustment of the clamping force adjusting assembly of the bicycle clipless pedal; and 
         FIGS. 6 through 8  illustrate combination between a shoe cleat and the bicycle clipless pedal of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     While a preferred embodiment provided hereinafter for illustrating the concept of the present invention as described above, it is to be understood that the components of the embodiment shown in the accompanying drawings are depicted for the sake of easy explanation and need not to be made in scale. 
     Please refer to  FIGS. 1 and 2  for a bicycle clipless pedal with a clamping force adjusting assembly of the present invention. The clipless pedal has a pedal axle  10  coupled with a crank arm (not shown) of a bicycle, a pedal body  20  coupled to and rotating around the pedal axle  10 , a front coupling portion  21  provided at a front end of the pedal body  20 , and a rear clamping set  30  connected to a rear end of the pedal body  20 . 
     As shown in  FIGS. 3 and 4 , the rear clamping set  30  includes an assembling portion  31 , a fastening member  40 , a compression spring  53 , and the clamping force adjusting assembly  50 . 
     The assembling portion  31  is connected to the rear end of the pedal body  20 . A tubular structure  32  is provided at a bottom of the assembling portion  31  and two retaining blocks  34  flank the assembling portion  31 . 
     The fastening member  40  includes a pivot portion  41 , a spring-stop portion  42  connected to a lower edge of the pivot portion  41  and corresponding to an end of the tubular structure  32 , and a coupling board  43  connected from above to the pivot portion  41 . The pivot portion  41  is formed with a transversely extending through hole  411  for allowing a pin  44  of the assembling portion  31  to pass therethrough, so as to connect the pivot portion  41  with the assembling portion  31  while the fastening member  40  is allowed to change its position angularly around the pin  44 . The pivot portion  41  has an open end  412  contacting upper surfaces of the retaining blocks  34 . In the present embodiment, the pin  44  includes a first pin part  441  and a second pin part  442  that are axially combined in a tight fit inside a pin hole  311  of the assembling portion  31 . Outer ends of the first pin part  441  and the second pin part  442  are received in the through hole  411  of the fastening member  40  so that the fastening member  40  can rotate around the first pin part  441  and the second pin part  442 . 
     The compression spring  53  is settled in the tubular structure  32  and abuts against the spring-stop portion  42  of the fastening member  40 . 
     The clamping force adjusting assembly  50  includes an adjusting screw  51  and an adjusting socket  52 . The adjusting socket  52  is settled in the tubular structure  32 . A slot  54  and a retaining protuberance  55  are formed on the tubular structure  32  and the adjusting socket  52  positionally corresponding to each other to be coupled mutually for preventing relative rotation between the adjusting socket  52  and the tubular structure  32 . The adjusting socket  52  has a first end formed as a spring-stop portion  521 . Thereby, two ends of the compression spring  53  abut against the two spring-stop portions  42 ,  521  respectively. A second end of the adjusting socket  52  is provided with a threaded hole  522  so that the adjusting screw  51  coming through a through hole  321  formed at one end of the tubular structure  32  can get screwedly coupled with the threaded hole  522 . 
     Thereby, a user can reach a head of the adjusting screw  51  with a screwdriver or the like through the through hole  321  of the tubular structure  32 , and then adjust the adjusting screw  51 . Since the adjusting socket  52  is rotationally restricted in the tubular structure  32 , according to the arrangement of the threads on the adjusting screw  51  and in the threaded hole  522 , when the adjusting screw  51  is rotated in one direction, the adjusting socket  52  is driven to move toward the compression spring  53 , and, on the contrary, when the adjusting screw  51  is rotated in the other direction, the adjusting socket  52  is driven to move away from the compression spring  53 . Thus, rotation of the adjusting screw  51  makes the adjusting socket  52  move linearly in the tubular structure  32  and compress or release the compression spring  53 , thereby changing a preload of the compression spring  53 . 
     Referring to  FIGS. 4 and 5 , the above adjustment controlled by rotation of the adjusting screw  51  is illustrated by means of some sectional assembled views of the pedal. Rotation of the adjusting screw  51  makes the adjusting socket  52  move inside the tubular structure  32  toward the compression spring  53 . At this time, the compression spring  53  is compressed between the two spring-stop portions  521 ,  42 . As a result, the elastic preload of the compression spring  53  increases, meaning spring-stop portion  42  of the fastening member  40  receives an increased pushing force. The fastening member  40  thus swings around the pin  44  along a direction as indicated by the arrow A, so that the fastening member  40  provides an enhanced clamping force to a rear coupling portion  62  (as shown in  FIGS. 1 through 3 ) of a shoe cleat  60  coupled with the pedal body  20 . On the contrary, when the adjusting socket  52  moves away from the compression spring  53 , the preload of the compression spring  53  decreases; thereby releasing the clamping force provided by the fastening member  40  to the rear coupling portion  62 . 
     Referring back to  FIGS. 1 through 3 , the rear coupling portion  62  of the shoe cleat  60  has a horizontal coupling surface  621  depressed from an upper surface  601  of the shoe cleat  60 . The coupling board  43  has its upper surface formed with a downward inclined surface  431  and has its lower surface formed as a horizontal coupling surface  432 . When the shoe cleat  60  is coupled with the pedal body  20 , the horizontal coupling surface  432  of the coupling board  43  and the horizontal coupling surface  621  of the shoe cleat  60  retain mutually. 
     The combination between the shoe cleat  60  and the disclosed clipless pedal is explained below with reference to  FIGS. 6 ,  7 , and  8 . 
     As shown in  FIG. 6 , the shoe cleat  60  has its front end downward reaching a lower surface of the front coupling portion  21 . 
     Referring to  FIG. 7 , the rear coupling portion  62  exerts a downward force to the downward inclined surface  431  of the coupling board  43  so that the fastening member  40  swings around the pin  44  in a direction indicated by arrow B and has its spring-stop portion  42  compressing the compression spring  53 , causing the rear coupling portion  62  to pass by the coupling board  43 . 
     As shown in  FIG. 8 , the shoe cleat  60  is now coupled with the pedal body  20 , and the compression spring  53  restores to abut against the spring-stop portion  42  again, while the horizontal coupling surface  432  of the coupling board  43  and the horizontal coupling surface  621  of the shoe cleat  60  retain mutually. 
     From the above description, it is learned that the elastic preload of the compression spring  53  determines the clamping force of the coupling board  43  applying to the rear coupling portion  62 . When the compression spring  53 , after a long period of use, suffers from fatigue failure that weakens the clamping force of the pedal, the clamping force adjusting assembly  50  can be operated to increase the preload of the compression spring  53  so as to recover the due clamping performance of the coupling board  43  providing to the rear coupling portion  62 . The elastic preload of the compression spring  53  can be easily adjusted by rotating the adjusting screw  51  in the clamping force adjusting assembly  50  with a screwdriver. Therefore, the clamping force adjusting assembly  50  is easy to operate on a user&#39;s own, and allows the user to freely adjust the clamping performance according to his preference. 
     However, it is to be noted that the best clamping performance relies on the most appropriate clamping force but not the greatest one. The relative contact between the retaining blocks  34  and the open end  412  of the pivot portion  41  prevents the fastening member  40  from excessively swinging toward the shoe cleat  60  and excessively pressing the rear coupling portion  62 . Such design, in view of safety, helps to prevent undue engagement between the shoe cleat  60  and the pedal body  20  that obstructs later disassembly. 
     The present invention has been described with reference to the preferred embodiment and it is understood that the embodiment is not intended to limit the scope of the present invention. Moreover, as the contents disclosed herein should be readily understood and can be implemented by a person skilled in the art, all equivalent changes or modifications which do not depart from the concept of the present invention should be encompassed by the appended claims.