Patent Publication Number: US-11033999-B2

Title: Clamp of bicycle workstand

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to bicycle supporting frames and more particularly, to a clamp of a bicycle workstand having relatively greater clamping effect. 
     2. Description of the Related Art 
     Taiwan Patent No. 572001 disclosed a structure of a bicycle workstand including a fixed clamp body, a movable clamp body, an adjusting base, and a controlling rod. The adjusting base is disposed on the fixed clamp body. The controlling rod is inserted through the adjusting base and protrudes out of the fixed clamp body and the movable clamp body. The section of the controlling rod protruding out of the movable clamp body is pivotably attached to a fastening rod. A fastening pressing sheet is sleeved onto the controlling rod and protrudes out of the fixed clamp body. The fastening pressing sheet can limit the axial displacement of the controlling rod, thereby adjusting the open and close condition of the movable clamp body relative to the fixed clamp body. Before the conventional bicycle workstand is used to fixedly clamp a bicycle top tube with relatively larger radius, the fastening pressing sheet should be firstly pulled to cause the controlling rod to displace to increase the distance between the movable clamp body and the fixed clamp body and accordingly decrease the pulling angle of the fastening pressing sheet and the fastening rod, thereby providing stable clamping effect. However, the operational action is a little complicated and inconvenient. 
     Besides, in the aforesaid conventional bicycle workstand, a rod is inserted in the fixed clamp body and a combination pipe and fastened by a pulling rod, enabling the fixed clamp body to swing to an appropriate angle relative to the combination pipe, so that the angle of the bicycle frame tube clamped on the bicycle workstand can be changed for benefiting the worker in the convenience of maintaining each portion and component of the bicycle. However, such effect can be achieved by other manners, unlimited to be achieved by the structure of the aforesaid patent. 
     SUMMARY OF THE INVENTION 
     It is a primary objective of the present invention to provide a clamp of a bicycle workstand, which is adapted to clamp bicycle frame tubes with different radius stably by equal clamping force and operated by convenient action. 
     It is another objective of the present invention to provide a clamp of a bicycle workstand, which enables the angle of the bicycle clamped on the bicycle workstand to be adjusted differently from the prior art, providing the user convenience in maintaining each portion and component of the bicycle. 
     To attain the above objective, the present invention provides a clamp of a bicycle workstand, which is adapted to be connected with a supporting frame for clamping a tube of a bicycle frame. The clamp includes a base, an elastic unit, an operating arm, a link unit, and a clamping unit. The base has an accommodating trough. The elastic unit has a shaft, a spring and a slide. The shaft is disposed in the accommodating trough. The spring is sleeved onto the shaft. The slide is movably disposed on the shaft. An end of the spring is abutted against an end of the accommodating trough. Another end of the spring pushes the slide. The operating arm is provided with an end having a pivotably connecting portion and another end having a pulled portion. Applying a force to the pulled portion can cause the pivotably connecting portion to pivot. The link unit has a first link and a second link pivotably connected with each other. The first link is also pivotably connected with the pivotably connecting portion of the operating arm. The second link is pivotably connected with the slide. The second link has a cam. When the first link is moved by the operating arm, the first link drives the second link to swing relative to the slide, causing the cam to move away from the shaft or move toward the shaft to press the shaft by rolling. The clamping unit has a fixed clamp body and a movable clamp body. The fixed clamp body is disposed on the base. The movable clamp body is pivotably connected with the base. The movable clamp body is also pivotably connected with the pivotably connecting portion of the operating arm. 
     As a result, applying a force to the operating arm of the present invention can drive the movable clamp body to open or close relative to the fixed clamp body. When the movable clamp body and the fixed clamp body are coupled with each other to clamp the tube of the bicycle frame, the operating arm is limited by the link unit and the elastic unit and thereby difficult to swing up. For clamping bicycle frame tubes with different radius, the effects of stable clamping by equal force and convenient operation are further provided. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an assembled perspective view of a preferred embodiment of the present invention. 
         FIG. 2  is an exploded perspective view of the preferred embodiment of the present invention. 
         FIG. 3  is a schematic view showing the usage of the preferred embodiment of the present invention connected with a supporting frame. 
         FIG. 4  is a schematic perspective view showing the appearance of the preferred embodiment of the present invention when its movable clamp body and fixed clamp body are in an open condition. 
         FIG. 5  is a schematic sectional view of  FIG. 4 . 
         FIG. 6  is a schematic perspective view showing the appearance of the preferred embodiment of the present invention when its movable clamp body and fixed clamp body are in a close condition. 
         FIG. 7  is a schematic sectional view of  FIG. 6 . 
         FIG. 8  is a schematic sectional view of the preferred embodiment of the present invention clamping a bicycle frame tube with different radius from that in  FIG. 7 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     For the detailed description of the technical features of the present invention, a preferred embodiment is given herein below and illustrated by the accompanying drawings. 
     Referring to  FIG. 1  to  FIG. 8 , a clamp  100  of a bicycle workstand provided by a preferred embodiment of the present invention includes a base  10 , an elastic unit  20 , an operating arm  30 , a link unit  40 , and a clamping unit  50 . 
     The base  10  has an accommodating trough  11  which has an upward opening. Each of two walls of the accommodating trough  11  is provided with a first hole  12 . The accommodating trough  11  is provided therein with a protruding stopping portion  13 . An end of the base  10  is connected with the clamping unit  50  and another end of the base  10  is connected with a connecting rod  14 . The structure and function of the connecting rod  14  will be described below. 
     The elastic unit  20  has a shaft  21 , a spring  22  and a slide  23 . The spring  22  is sleeved onto the shaft  21 . The slide  23  is movably disposed on the shaft  21 . An end of the spring  22  is abutted against an end of the accommodating trough  11 . Another end of the spring  22  pushes the slide  23 . The slide  23  is a base having a bottom plate  231 , two side walls  232  located on two sides of the bottom plate  231 , and a recessed space  233  opened upwardly. Each of the two side walls  232  is provided with a first hole  234 . The shaft  21  is a rectangular shaft, an end of which is accompanied with a pressing block  211  and two bolts  212  inserted therethrough and thereby fastened to an end of the accommodating trough  11 . Another end of the shaft  21  is inserted through the recessed space  233  of the slide  23  and disposed on the protruding stopping portion  13  located in the accommodating trough  11 . The slide  23  is movable along the shaft  21  and keeps pushed by the spring  22  toward the protruding stopping portion  13  and stopped by the protruding stopping portion  13 . 
     The operating arm  30  is provided at an end thereof with a pivotably connecting portion  31  and at another end thereof with a pulled portion  32 . The pivotably connecting portion  31  has two lateral sheets  311  and an activity space  312  located between the two lateral sheets  311 . Each of the two lateral sheets  311  is provided with a first hole  313  and a second hole  314 . 
     The link unit  40  has a first link  41  and a second link  42 . The first link  41  has a top plate  411 , two side walls  412  located on two sides of the top plate  411 , and a recessed space  413  located between the two side walls  412 . Each of the two side walls  412  is provided with a first hole  414  and a second hole  415 . An end of the first link  41  is disposed in the activity space  312  of the operating arm  30 . The first link  41  is pivotably connected to the pivotably connecting portion  31  of the operating arm  30  by a third pivot  73  inserted through the first holes  414  of the first link  41  and the first holes  313  of the pivotably connecting portion  31 . The second link  42  is an elongated block provided at two ends thereof with a first hole  421  and a second hole  422 . An end of the second link  42  is inserted into the recessed space  413  of the first link  41 . The second link  42  is pivotably connected with the first link  41  by a fourth pivot  74  inserted through the second hole  422  of the second link  42  and the second holes  415  of the first link  41 . Another end of the second link  42  is accommodated in the recessed space  233  of the slide  23 . The second link  42  is pivotably connected with the slide  23  by a fifth pivot  75  inserted through the first hole  421  of the second link  42  and the first holes  234  of the slide  23 . The second link  42  has a cam  423  located between the first hole  421  and the second hole  422 . The cam  423  is provided on the bottom surface of the block and convex-arc-shaped. 
     The clamping unit  50  has a fixed clamp body  51  and a movable clamp body  52 . Each of the fixed clamp body  51  and the movable clamp body  52  has a clamp portion  511  and  521 . The fixed clamp body  51  is disposed on the base  10  and located adjacent to the first holes  12 . The movable clamp body  52  is provided with a first hole  522  and a second hole  523 . The movable clamp body  52  is pivotably connected with the base  10  by a first pivot  71  inserted through the first hole  522  of the movable clamp body  52  and the first holes  12  of the base  10 . The movable clamp body  52  is partially disposed in the activity space  312  of the operating arm  30 . The movable clamp body  52  is pivotably connected to the pivotably connecting portion  31  by a second pivot  72  inserted through the second hole  523  of the movable clamp body  52  and the second holes  314  of the pivotably connecting portion  31 . 
     The aforesaid first pivot  71 , second pivot  72 , third pivot  73 , fourth pivot  74  and fifth pivot  75  are identical in structure. As the representation, the first pivot  71  is described below and provided with detailed numerals in the figures. In this embodiment, the first pivot  71  has a rod  711  and a C-shaped retaining ring  714 . The rod  711  has a head end having an expanded portion  712  and a tail end having a groove  713 . When the rod  711  is inserted through one of the first holes  12  with the expanded portion  712  stopped against the periphery of the first hole  12 , inserted through the first hole  522  of the movable clamp body  52  and then inserted through the other first hole  12 , the C-shaped retaining ring  714  is disposed in the groove  713  to be stopped against the periphery of said the other first hole  12 . 
     The above description illustrates the structure of the present invention. The following description will illustrate the operating condition of the present invention. 
     Through the above-described structure, referring to  FIG. 4  and  FIG. 5 , during the operation of the clamp  100  of the bicycle workstand of the present invention, firstly, the operating arm  30  is applied with a force which pulls up the pulled portion  32  to the highest point, that is defined as a first position of the present invention, causing the pivotably connecting portion  31  to swing. When the pivotably connecting portion  31  swings, the first link  41  and the second link  42  are pulled up to move away from the base  10 . At the same time, the movable clamp body  52  pivotably connected with the pivotably connecting portion  31  by the second pivot  72  is also driven to pivot clockwise about the first pivot  71  to open up. Accordingly, the clamp portion  521  of the movable clamp body  52  and the clamp portion  511  of the fixed clamp body  51  are in the open condition. 
     Then, referring to  FIG. 6  and  FIG. 7 , when the clamping action is going to be performed, a tube  200  of a bicycle frame is put into the clamp portion  511  of the fixed clamp body  51 , and the pulled portion  32  of the operating arm  30  is applied with a force clockwise to be pressed down to the lowest point, that is defined as a second position of the present invention. When the operating arm  30  is moved from the first position to the second position, the pivotably connecting portion  31  swings to drive the clamp portion  521  of the movable clamp body  52  to pivot counterclockwise about the first pivot  71 . Accordingly, the clamp portion  521  of the movable clamp body  52  and the clamp portion  511  of the fixed clamp body  51  are coupled with each other to clamp the tube  200  of the bicycle frame. The connecting line connecting the third pivot  73  and the fifth pivot  75  is defined as an imaginary straight line indicated by the symbol L in the figure. When the pivotably connecting portion  31  pivots, the first link  41  and the second link  42  are also driven to pivot counterclockwise to move toward the base  10  and move the slide  23  away from the protruding stopping portion  13 , causing the spring  22  to be pushed and compressed. Because the second link  42  is pivotably connected with the slide  23  and the slide  23  is pushed by the spring  22 , the cam  423  moves toward the shaft  21  to press the shaft  21  by rolling when the first link  41  drives the second link  42  to pivot through the fourth pivot  74 . At this time, the operating arm  30  should be applied with a little more force to cause the fourth pivot  74  to pass the imaginary straight line L from the upside to the downside thereof and located below the imaginary straight line L, so that the cam  423  is tightly abutted on the upside surface of the shaft  21 . In this way, the elastic force applied by the spring  22  to the slide  23  causes the clamp portion  521  of the movable clamp body  52  stably located on the clamp portion  511  of the fixed clamp body  51  for clamping. Besides, because the fourth pivot  74  is located below the imaginary straight line L, the elastic force of the spring  22  pushing the slide  23  only keeps the fourth pivot  74  located at this position but not moves it upwardly, thereby providing the effect of locking the fourth pivot  74 . 
     When going to perform the release, the user only needs to apply an upward force to the pulled portion  32  of the operating arm  30  to move it. The above-described components will move reversely, and the fourth pivot  74  will move upwardly from the downside of the imaginary straight line L to the upside of the imaginary straight line L. Because the operating arm  30  has a relatively longer lever arm, the force applied thereto can easily overcome the pushing force applied by the spring  22  to the slide  23  and the second link  42  and the friction between the shaft  21  and the cam  423  of the second link  42  pressing the shaft  21 . When the operating arm  30  is moved to the highest position, the clamp portion  521  of the movable clamp body  52  is completely open relative to the clamp portion  511  of the fixed clamp body  51 , and the release action is accomplished. Based on this, the clamp  100  of the bicycle workstand of the present invention can certainly provide the effect of stable clamping. Besides, the shaft  21  of the present invention is configured as a rectangular shaft for the purpose of relatively larger contact area between the cam  423  and the shaft  21  to provide relatively larger frictional resistance, so that the operating arm  30  operated by the user is prevented by buffer resistance from a sudden large action. 
     In other usage conditions such as the condition as shown in  FIG. 8  that the tube  300  of the bicycle frame has a larger radius than that of the aforesaid tube  200  of the bicycle frame, the clamp  100  of the bicycle workstand of the present invention is operated in a way that the tube  300  of the bicycle frame is put between the movable clamp body  52  and the clamp portion  511  of the fixed clamp body  51  in the open condition and then the pulled portion  32  of the operating arm  30  is pressed down clockwise to cause the movable clamp body  52  to pivot to a position where the clamp portion  521  thereof and the clamp portion  511  of the fixed clamp body  51  clamp the tube  300  of the bicycle frame and cause the first link  41  and the second link  42  to pivot counterclockwise to move toward the base  10 . At this time, because the tube  300  of the bicycle frame has the relatively larger radius, the distance between the clamp portion  521  of the movable clamp body  52  and the clamp portion  511  of the fixed clamp body  51  coupled with each other is relatively larger. In the process that the pulled portion  32  of the operating arm  30  is pressed down, the slide  23  is also moved away from the protruding stopping portion  13 , the fourth pivot  74  also passes the imaginary straight line L from the upside to the downside thereof and located below the imaginary straight line L, and the cam  423  of the second link  42  also presses the shaft  21  by rolling and is tightly abutted on the shaft  21 . Besides, based on the acting principle of the spring, the elastic force applied to the slide  23  by the spring  22  is equal in magnitude to the elastic force applied to the slide  23  in the aforesaid case that the relatively thinner tube  200  of the bicycle frame is clamped. In other words, the force applied to the movable clamp body  52  by the spring  22  is also equal to the force in the aforesaid case that the relatively thinner tube  200  is clamped. In this way, the force of the clamping unit  50  clamping the relatively thicker tube  300  will be equal to the force of clamping the aforesaid relatively thinner tube  200 , and has the effect of stable clamping. 
     It can be known from the above description that the movable clamp body  52  and the fixed clamp body  51  can stably clamp the tube  200  or  300  of the bicycle frame with different radius, that is operated by simple and convenient action, not only completely solving the aforesaid problem that the operation of the conventional bicycle workstand is complicated and inconvenient, but also having the effect of stable clamping by constant force. Besides, the friction provided by the cam  423  pressing the shaft  21  by rolling can provide buffer resistance to prevent the operation from a sudden large action, thereby avoiding accidental injury to the user. 
     Furthermore, before the clamp  100  of the bicycle workstand of the present invention is in use, it can be accompanied with a seat tube  80  to be connected with and a supporting frame  90 . 
     As shown in  FIG. 3 , the seat tube  80  has a connection pipe  81  and a combination pipe  82 . The connection pipe  81  is connected with the supporting frame  90 . The supporting frame  90  has two foot rods  91  stably disposed on the floor. The combination pipe  82  has a combination hole  821  (referring to  FIG. 5 ) penetrating through two ends of the combination pipe  82 . The combination hole  821  has a protruding stopping portion  822  dividing the combination hole  821  into a large radius portion  823  and a small radius portion  824 . A quick release unit  83  is disposed at the small radius portion  824  of the combination hole  821 . The quick release unit  83  has a threaded rod  831 . The threaded rod  831  is inserted through the small radius portion  824  and accompanied with a nut  832 . The nut  832  is screwed onto the threaded rod  831  and stopped against the protruding stopping portion  822 . The connecting rod  14  is disposed at the large radius portion  823  of the combination hole  821 . The connecting rod  14  is rotatable relative to the seat tube  80 . The connecting rod  14  has a threaded hole  141 . The threaded rod  831  is tightly screwed into the threaded hole  141 . In this way, the base  10  can be swayed relative to the seat tube  80  to change the relative angle between the bicycle workstand and the tube  200  or  300  of the bicycle frame clamped thereon for benefiting the worker in maintaining each portion and component of the bicycle. As a result, the present invention is certainly capable of adjusting the angle of the bicycle clamped on the bicycle workstand differently from the prior art, providing the user convenience in maintaining each portion and component of the bicycle.