Abstract:
A bicycle fastener includes a fixing assembly ( 1 ) and a fastener assembly ( 3 ). The fixing assembly ( 1 ) is fixedly mounted to the frame ( 5 ) of the bicycle, and the fastener assembly ( 3 ) is used for supporting an article. The first moveable seat ( 31 ) and the second moveable seat ( 32 ) of the fastener assembly ( 3 ) are snapped into the first fixing seat ( 11 ) and the second fixing seat ( 12 ) of the fixing assembly ( 1 ) correspondingly, so that the fastener assembly ( 3 ) and the supported article are detachedly mounted to the frame ( 5 ) of the bicycle. The bicycle fastener can facilitate the disengaging and engaging of the article, prevent wear of the surface of the article, and enhance the fixing strength of the fastener assembly.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to a fastening device for a bicycle, and more particularly to a fastening device for a bicycle having two fixed holders and two movable sockets correspondingly engaged with the two fixed holders for an object to be conveniently installed on or detached from a frame of the bicycle for enhancing the fastening strength. 
       BACKGROUND OF THE INVENTION 
       [0002]    Nowadays, the bicycle has become a type of widely used vehicle and a type of most popular goods for sports and leisure activities. For a traditional bicycle, the bicycle is generally further installed or placed with an object on a frame thereof, for enhancing the function of the bicycle and the usage convenience of the object. Especially, a bottle cage can be installed on the frame without affecting riding, for placing a water bottle and conveniently taking it, so that a bicycle rider can take the water bottle for drinking. 
         [0003]    Referring now to  FIG. 1 , an operational view of a traditional bottle cage of a bicycle is illustrated, wherein the bicycle comprises a frame  91 , a bottle cage  92  and a water bottle  93 . The frame  91  is formed with two screw holes  911 . The bottle cage  92  is a hollow bent bracket with a substantial L-shape, and two screwing elements “a” are passed through two through holes (not shown) of the bottle cage  92  and the two screw holes  911 , so that the bottle cage  92  can be screw-connected to the frame  91 . The bottle cage  92  can suitably receive a water bottle  93  which is placed from top to bottom. The water bottle  93  is retained by the bottle cage  92  without being separated from the bottle cage  92 , and the water bottle  93  can be optionally taken, placed and used by the bicycle rider. 
         [0004]    However, there are still several disadvantages existing in the bottle cage  92  during actual operation, as follows: (1) the bottle cage  92  is directly in contact with the water bottle  93 . When the water bottle  93  is taken and placed or is vibrated during riding the bicycle, the material or printing on the surface of the water bottle  93  is easily worn, so as to affect the texture and appearance of the water bottle  93 ; (2) when it is unnecessary to mount the water bottle  92  on the frame  91 , the bottle cage  92  is still mounted on the frame  91 , so as to affect the simplicity of the appearance of the bicycle; and (3) it is unsuitable for a foldable bicycle to install the bottle cage  92 , because the bottle cage  92  will affect the foldable function of the foldable bicycle. 
         [0005]    As a result, it is necessary to provide a fastening device for a bicycle to solve the problems existing in the traditional technology, as described above. 
       SUMMARY OF THE INVENTION 
       [0006]    A primary object of the present invention is to provide a fastening device for a bicycle, wherein a first movable socket and a second movable socket of the fastening assembly can correspondingly engage with a first fixed holder and a second fixed holder of the fixed assembly, so that the fastening assembly and an object supported by the fastening assembly can be detachably mounted on the fixed assembly on the frame, while the fastening assembly is connected to and support the object by a connection element. Thus, it can prevent the surface of the object from being directly in contact with the frame and worn. 
         [0007]    A secondary object of the present invention is to provide a fastening device for a bicycle, wherein the openings of the horseshoe-shape portions of the first movable socket and the second movable socket face different directions, so as to enhance the fastening strength of the fastening device for the bicycle. 
         [0008]    A third object of the present invention is to provide a fastening device for a bicycle, wherein it can detach the fastening assembly and object from the fixed assembly, so as to maintain the simplicity of the appearance of the bicycle. 
         [0009]    A fourth object of the present invention is to provide a fastening device for a bicycle, wherein the fastening assembly is suitably applied to a foldable bicycle, and the foldable bicycle can be normally folded when the fixed assembly doesn&#39;t support the fastening assembly and the object. 
         [0010]    To achieve the above object, the present invention provides a fastening device for a bicycle which comprises a fixed assembly and a fastening assembly. The fixed assembly is mounted on a frame of the bicycle, and the fastening assembly is used to support an object. A first movable socket and a second movable socket of the fastening assembly can be correspondingly engaged with a first fixed holder and a second fixed holder of the fixed assembly, so that the fastening assembly and the object supported by the fastening assembly can be detachably mounted on the frame. The fastening device for the bicycle not only can provide the convenience for detaching the object and prevent the surface of the object from being worn, but also can enhance the fastening strength of the fastening assembly. 
         [0011]    In one embodiment of the present invention, each of the first fixed holder and the second fixed holder has a profile of a pulley having a groove on a periphery of the pulley. 
         [0012]    In one embodiment of the present invention, each of the first movable socket and the second movable socket has: a horseshoe-shape portion having an opening, and the horseshoe-shape portion used for correspondingly engaging into the groove of the first fixed holder or the second fixed holder; and two guiding portions formed on two ends of the opening of the horseshoe-shape portion for guiding the horseshoe-shape portion to engage into the groove of the first fixed holder or the second fixed holder. 
         [0013]    In one embodiment of the present invention, two guiding extension portions are further formed between the horseshoe-shape portion and the guiding portions of the second movable socket for elongating a distance between the horseshoe-shape portion and the guiding portions. 
         [0014]    In one embodiment of the present invention, the second movable socket comprises two flanges for inserting into the groove of the second fixed holder. 
         [0015]    In one embodiment of the present invention, the opening of the horseshoe-shape portion of the first movable socket faces downward, and the opening of the horseshoe-shape portion of the second movable socket faces leftward or rightward. 
         [0016]    In one embodiment of the present invention, the opening of the horseshoe-shape portion of the first movable socket faces downward, and the opening of the horseshoe-shape portion of the second movable socket faces downward. 
         [0017]    In one embodiment of the present invention, the opening of the horseshoe-shape portion of the first movable socket faces upward, and the opening of the horseshoe-shape portion of the second movable socket faces downward. 
         [0018]    In one embodiment of the present invention, an inner diameter of the horseshoe-shape portion of the first or second movable socket is substantially equal to a diameter of the groove of the first or second fixed holder, and a width of the opening of the horseshoe-shape portion is smaller than the inner diameter of the horseshoe-shape portion. 
         [0019]    In one embodiment of the present invention, each of the first fixed holder and the second fixed holder further comprises a fixed washer disposed between each of the first and second fixed holders and the frame for filling a gap between each of the first and second fixed holders and a surface profile of the frame. 
         [0020]    In one embodiment of the present invention, the fastening assembly is a container or a shelf. 
         [0021]    In one embodiment of the present invention, the fastening assembly supports a water bottle, a tool box or a tool rack by a connection element, and the connection element is selected from a banding, a retaining ring or a pair of hook and loop fasteners. 
         [0022]    In comparison with the traditional technology, the fixed assembly of the present invention is mounted on a frame of a bicycle, and the fastening device is used to support the object, so that the fastening assembly and the object supported by the fastening assembly can be detachably mounted on the frame. Thus, the fastening device for the bicycle not only can provide the convenience for detaching the object and prevent the surface of the object from being worn, but also can enhance the fastening strength of the fastening assembly. 
     
    
     
       DESCRIPTION OF THE DRAWINGS 
         [0023]      FIG. 1  is an operational view of a traditional bottle cage of a bicycle; 
           [0024]      FIG. 2  is an exploded perspective view of a fastening device for a bicycle according to a first embodiment of the present invention; 
           [0025]      FIG. 3A  is a schematic view of the fastening device for the bicycle according to the first embodiment of the present invention during the installation; 
           [0026]      FIG. 3B  is a schematic view of the fastening device for the bicycle according to the first embodiment of the present invention after the installation; 
           [0027]      FIG. 4A  is a schematic view of a fastening device for a bicycle according to a second embodiment of the present invention during the installation; 
           [0028]      FIG. 4B  is another schematic view of the fastening device for the bicycle according to the second embodiment of the present invention during the installation; 
           [0029]      FIG. 4C  is another schematic view of the fastening device for the bicycle according to the second embodiment of the present invention during the installation; and 
           [0030]      FIG. 4D  is a schematic view of the fastening device for the bicycle according to the second embodiment of the present invention after the installation; 
           [0031]      FIG. 5  is a partially cross-sectional view of a fastening device for a bicycle according to a third embodiment of the present invention; 
           [0032]      FIG. 6  is a partially cross-sectional view of a fastening device for a bicycle according to a fourth embodiment of the present invention; 
           [0033]      FIG. 7  is a perspective view of a fastening assembly of a fastening device for a bicycle according to a fifth embodiment of the present invention; 
           [0034]      FIG. 8A  is a perspective view of a fastening assembly of a fastening device for a bicycle according to a sixth embodiment of the present invention; 
           [0035]      FIG. 8B  is a perspective view of a fastening assembly of a fastening device for a bicycle according to a seventh embodiment of the present invention; 
           [0036]      FIG. 9A  is a perspective view of a fastening assembly of a fastening device for a bicycle according to an eighth embodiment of the present invention; 
           [0037]      FIG. 9B  is a perspective view of the assembly device of the fastening device for the bicycle according to the eighth embodiment of the present invention; 
           [0038]      FIG. 9C  is a perspective view of a fastening assembly of a fastening device for a bicycle according to a ninth embodiment of the present invention; 
           [0039]      FIG. 10A  is a schematic view of a fastening device for a bicycle according to a tenth embodiment of the present invention during the installation; 
           [0040]      FIG. 10B  is another schematic view of the fastening device for the bicycle according to the tenth embodiment of the present invention during the installation; and 
           [0041]      FIG. 10C  is another schematic view of the fastening device for the bicycle according to the tenth embodiment of the present invention during the installation. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0042]    The structure and the technical means adopted by the present invention to achieve the above objects, characteristics and advantages can be best understood by referring to the following detailed description of the preferred embodiments and the accompanying drawings, wherein: 
         [0043]    A fastening device for a bicycle according to the present invention can be selectively installed on a frame of a normal bicycle or a foldable bicycle for supporting an object, such as a water bottle, a tool box or a tool rack. However, the position of the bicycle for placing the object may be varied according to actual usage needs, but the present invention is not limited thereto. The directional terms, such as upper, lower, left and right, disclosed by the present invention hereinafter is corresponding to the direction relationship of a frame of a normal bicycle in relation to the ground and the front end or the rear end of the bicycle under a normal operation status, without considering the inclination angle of the frame, wherein the foregoing relative directional terms are only used to explain the arrangement relationship between elements of the present invention, but the present invention is not limited thereto. 
         [0044]    Referring now to  FIG. 2 , an exploded perspective view of a fastening device for a bicycle according to a first embodiment of the present invention is illustrated, wherein the fastening device for the bicycle comprises a fixed assembly  1  and a fastening assembly  3 . The fixed assembly  1  includes a first fixed holder  11  and a second fixed holder  12 , while the fastening assembly  3  includes a first movable socket  31  and a second movable socket  32 . The fastening assembly  3  is used to support an object  7 , such as a water bottle. 
         [0045]    Referring to  FIG. 2 , in the first embodiment of the present invention, the first fixed holder  11  of the fixed assembly  1  has a profile of a pulley having a groove  111  on a periphery of the pulley. Further, the center of the first fixed holder  11  is formed with a through hole  112 , wherein the first fixed holder  11  can be screw-connected to a screw hole  51  of the frame  5  by a screwing element “a”. In the embodiment, the second fixed holder  12  and the first fixed holder  11  of the fixed assembly  1  have the same profile, and the second fixed holder  12  has a groove  121  on a periphery thereof. The center of the second fixed holder  12  is formed with a through hole  122 , wherein the second fixed holder  12  can be screw-connected to a screw hole  51  of the frame  5  by a screwing element “a”. The first fixed holder  11  and the second fixed holder  12  is apart from each other a suitable distance. 
         [0046]    Referring to  FIG. 2 , in the first embodiment of the present invention, the first movable socket  31  of the fastening assembly  3  has a horseshoe-shape portion  311  and two guiding portions  312 , wherein the horseshoe-shape portion  311  is a horseshoe-shape socket structure similar to “Q” shape, and has an opening on one side thereof. An inner diameter of the horseshoe-shape portion  311  is substantially equal to a diameter of the groove  111  of the first fixed holder  11 , and a width of the opening of the horseshoe-shape portion  311  is smaller than the inner diameter of the horseshoe-shape portion  311 . The two guiding portions  312  are formed on two ends of the opening of the horseshoe-shape portion  311 . The horseshoe-shape portion  311  of the first movable socket  31  can correspondingly engage into the groove  111  of the first fixed holder  11  of the fixed assembly  1 , wherein the two guiding portions  312  are used for guiding the horseshoe-shape portion  311  to smoothly engage into the groove  111 . In the embodiment, the second movable socket  32  and the first movable socket  31  of the fastening assembly  3  have the same profile, wherein the second movable socket  32  also has a horseshoe-shape portion  321  and two guiding portions  322 . The horseshoe-shape portion  321  is a horseshoe-shape socket structure similar to “Q” shape, and has an opening on one side thereof. The two guiding portions  322  are formed on two ends of the opening of the horseshoe-shape portion  321 . The horseshoe-shape portion  321  of the second movable socket  32  can correspondingly engage into the groove  121  of the second fixed holder  12  of the fixed assembly  1 , wherein the two guiding portions  322  are used for guiding the horseshoe-shape portion  321  to smoothly engage into the groove  121 . 
         [0047]    Referring to  FIG. 2 , in the first embodiment of the present invention, the first fixed holder  11  and the second fixed holder  12  are preferably made of abrasion-proof tough material, such as metal or engineering plastic. The first fixed holder  11  and the second fixed holder  12  further comprises two fixed washers “b”, wherein one of the fixed washers “b” is disposed between the first fixed holder  11  and the frame  5 , and the other of the fixed washers “b” is disposed between the second fixed holder  12  and the frame  5 . Because the surface profile of a frame  5  is generally circular or elliptical, the fixed washers “b” can correspondingly fill a gap between each of the first and second fixed holders  11 ,  12  and the surface profile of the frame  5 . Thus, it can prevent edges of the first and second fixed holders  11 ,  12  from being impacted and damaged, and can provide an aesthetic effect. 
         [0048]    Referring to  FIG. 2 , in the first embodiment of the present invention, although the first fixed holder  11  and the second fixed holder  12  are mounted on the frame  5  by the screwing element “b”, the present invention is not limited thereto. For example, the first fixed holder  11  and the second fixed holder  12  can be mounted on the frame  5  by a banding, a retaining ring or welding. 
         [0049]    As described above, the fastening assembly  3  is used to support an object  7 . In the first embodiment of the present invention, the fastening device for the bicycle discloses that the fastening assembly  3  is connected to a water bottle, but the present invention is not limited thereto. For example, the fastening assembly  3  can be connected to a receiving container (such as a tool box) or a rack (such as a too rack). Alternatively, the fastening assembly  3  is a container or a shelf itself. 
         [0050]    Referring to  FIG. 3A , in the first embodiment of the present invention, a schematic view of the fastening device for the bicycle according to the first embodiment of the present invention during the installation is illustrated, wherein the direction thereof is from the frame  5  to the fastening device for the bicycle, while the frame  5  is omitted. The first movable socket  31  and the second movable socket  32  of the fastening assembly  3  are preferably made of abrasion-proof tough material, such as metal or engineering plastic. In the embodiment, the opening of the horseshoe-shape portion  311  of the first movable socket  31  faces downward, while the opening of the horseshoe-shape portion  321  of the second movable socket  32  also faces downward. In installation, the fastening assembly  3  is moved toward the fixed assembly  1  from top to bottom, so that the opening of the horseshoe-shape portion  311  of the first movable socket  31  of the fastening assembly  3  is disposed over the groove  111  of the first fixed holder  11 , and the opening of the horseshoe-shape portion  321  of the second movable socket  32  is disposed over the groove  121  of the second fixed holder  12 . 
         [0051]    Referring to  FIG. 3A , because the opening of the horseshoe-shape portion  311  of the first movable socket  31  is smaller than the diameter of the groove  111  and the opening of the horseshoe-shape portion  321  of the second movable socket  32  is smaller than the diameter of the groove  121 , the guiding portions  312  of the first movable socket  31  can engage with the groove  111  of the first fixed holder  11 , and the guiding portions  322  of the second movable socket  32  can engage with the groove  121  of the second fixed holder  12 . However, when the fastening assembly  3  continuously abuts downward, the opening of the horseshoe-shape portion  311  of the first movable socket  31  and the opening of the horseshoe-shape portion  321  of the second movable socket  32  will be elastically expanded. 
         [0052]    Then, referring to  FIG. 3B , a schematic view of the fastening device for the bicycle according to the first embodiment of the present invention after the installation is illustrated, wherein the viewing direction thereof is from the frame to the fastening device for the bicycle, while the frame  5  is omitted. When the opening of the horseshoe-shape portion  311  of the first movable socket  31  and the opening of the horseshoe-shape portion  321  of the second movable socket  32  are temporarily expanded, the horseshoe-shape portion  311  of the first movable socket  31  and the horseshoe-shape portion  321  of the second movable socket  32  can be engaged into the groove  111  of the first fixed holder  11  and the groove  121  of the second fixed holder  12 , so as to engage with each other. Thus, the fastening assembly  3  will not be separated from the fixed assembly  1 . Besides, in the embodiment, except for applying an upward force to separate the fastening assembly  3  from fixed assembly  1 , other side forces (such as downward, leftward, rightward and etc) can not separate the fastening assembly  3  from fixed assembly  1 . Therefore, the fastening device for the bicycle can provide the detachably fastening function on the frame  5  of the bicycle. Furthermore, two sets of assembly structures can enhance the fastening strength for the object  7 . Especially, the fastening strength of a normal column-shape object can be enhanced. 
         [0053]    Furthermore, when it is unnecessary to install the object  7  (such as water bottle), only the two fixed holders  11 ,  12  with small volume are remained on the frame  3 , the simplicity of the appearance of the bicycle will not be affected. Especially, the fastening device for the bicycle is suitably applied to a foldable bicycle. After detaching the fastening assembly  3 , only the two fixed holders  11 ,  12  with small volume are remained on the frame of the foldable bicycle, so that the normally folding function of the foldable bicycle will not be interfered. 
         [0054]    Referring to  FIGS. 4A and 4B , schematic views of a fastening device for a bicycle according to a second embodiment of the present invention during the installation are illustrated, wherein the direction thereof is from the frame  5  to the fastening device for the bicycle, while the frame  5  is omitted. The second embodiment of the present invention is similar to the first embodiment of the present invention, and substantially uses reference numerals of the first embodiment, wherein the difference therebetween is that: the opening of the horseshoe-shape portion  311  of the first movable socket  31  still faces downward, but the opening of the horseshoe-shape portion  321  of the second movable socket  32  is change to face rightward or leftward. As shown in  FIG. 4A , when installing the fastening assembly  3 , a lower end of the fastening assembly  3  is firstly inclined to the left of the figure, and the horseshoe-shape portion  311  of the first movable socket  31  is inclined and engaged into the groove  111  of the first fixed holder  11  from the upper right to the lower left of the figure, to form an engagement connection. 
         [0055]    Referring to  FIGS. 4C and 4D , schematic views of a fastening device for a bicycle according to a second embodiment of the present invention during and after the installation are illustrated, wherein the direction thereof is from the frame  5  to the fastening device for the bicycle, while the frame  5  is omitted. After the foregoing steps, the foregoing engaged first fixed holder  11  is used as a pivot point of rotation to rotate the fastening assembly  3  along a counterclockwise direction for moving the lower end of the fastening assembly  3  from the left to the right of the figure, so that the horseshoe-shape portion  321  of the second movable socket  32  is engaged into the groove  121  of the second fixed holder  12  to form an engagement connection. In such a way, the fastening assembly  3  will be not separated from the fixed assembly  1  outward. Even though a force from other directions (such as upper, lower, left, right or inclined direction) is applied, the fastening assembly  3  is uneasy to be entirely separated from the fixed assembly  1  because the opening of the horseshoe-shape portion  311  of the first movable socket  31  of the fastening assembly  3  is vertical to the opening of the horseshoe-shape portion  321  of the second movable socket  32 . 
         [0056]    In the second embodiment of the present invention, the fastening device for the bicycle can surely provide the detachably fastening function on the frame  5  of the bicycle, and can further enhance the fastening strength for the object  7 . In addition, when it needs to take the fastening assembly  3 , the foregoing installation steps can be reversely executed, as follows: the first fixed holder  11  is used as a pivot point of rotation to rotate the fastening assembly  3  along a clockwise direction for separating the second movable socket  32  on the lower end of the fastening assembly  3  from the second fixed holder  12  from the right to the left of the figure. Then, the fastening assembly  3  is forced from the lower left to the upper right to separate the first movable socket  31  from the first fixed holder  11 , so that the fastening assembly  3  can be taken from the frame  5 . The two-step operation not only can enhance the strength of fastening the fastening assembly  3  on the frame  5 , but also can be carried out by a single hand. Further, the direction of the opening of the second movable socket  32  on the lower end of the fastening assembly  3  can be adjusted according to the individual favorite and habit of a bicycle rider, such as the opening of the horseshoe-shape portion  321  faces leftward. 
         [0057]    As described above, in the first embodiment of the present invention, the direction of the opening of the first movable socket  31  is the same as the direction of the opening of the second movable socket  32 . In the second embodiment of the present invention, the direction of the opening of the first movable socket  31  is different from (vertical to) the direction of the opening of the second movable socket  32 . However, the present invention is not limited thereto. The direction of the opening of the first movable socket  31  and the direction of the opening of the second movable socket  32  can be arrangement combinations of any directions, only if the engagement connection between the first movable socket  31  and the first fixed holder  11  and the engagement connection between the second movable socket  32  and the second fixed holder  12  can be simultaneously done or done in turn. 
         [0058]    Referring now to  FIG. 5 , a partially cross-sectional view of a fastening device for a bicycle according to a third embodiment of the present invention is illustrated. The third embodiment of the present invention is similar to the first embodiment of the present invention, and substantially uses reference numerals of the first embodiment, wherein the difference therebetween is that: the fastening device for the bicycle further comprises an object  7 , such as a water bottle. The object  7  has a sheath  71 , and one side of the sheath  71  has a first hook and loop fastener “c”, i.e. a first connection element. Further, the fastening assembly  3  is a curved plate corresponding to the shape of the sheath  71 , and a surface of the curved plate (i.e. the fastening assembly  3 ) facing the sheath  71  is provided with a second hook and loop fastener “d”, i.e. a second connection element, wherein the first hook and loop fastener “c” is correspondingly connected to the second hook and loop fastener “d”, so that the fastening assembly  3  and the sheath  71  can be detachably connected to each other. Because the water bottle  7  will not wear against other elements (such as the frame  5 ) during taking or placing, it will not cause the wear of the surface material or printing portion of the water bottle  7 , so that the texture and appearance of the water bottle  7  can be maintained. 
         [0059]    As described above, the fastening assembly  3  is used to support an object  7 , wherein the water bottle described in the fastening device for the bicycle of the third embodiment of the present invention is connected to the second hook and loop fastener “d” of the fastening assembly  3  by the first hook and loop fastener “c” of the sheath  71 . In the third embodiment of the present invention, although the sheath  71  is firstly used to cover the object  7  (water bottle) and then connected to the fastening assembly  3 , the present invention is not limited thereto. For example, the fastening assembly  3  may be used and connected with a receiving container (such as a tool box) or a rack (such as a too rack). Alternatively, the fastening assembly  3  is a container or a shelf itself. In addition, the object  7  (water bottle) can omit the sheath  71  and be directly attached with the first hook and loop fastener “a” to be connected with the second hook and loop fastener “d” of the fastening assembly  3 . Besides, the water bottle  7  can be mounted on the fastening assembly  3  by a banding or retaining ring. 
         [0060]    Referring now to  FIG. 6 , a partially cross-sectional view of a fastening device for a bicycle according to a fourth embodiment of the present invention is illustrated, wherein the fourth embodiment of the present invention is similar to the third embodiment of the present invention, and substantially uses reference numerals of the third embodiment, wherein the difference therebetween is that: the first fixed holder  11  and the second fixed holder  12  of the fastening assembly  3  have different cross-sectional shape, and are not mounted with the fixed washer “b”. As shown in  FIG. 5 , in the third embodiment of the present invention, according to the cross-sectional shape of the first fixed holder  11  and the second fixed holder  12 , the groove  111  and  121  are formed on a central portion of the periphery thereof, so that the cross-sectional shape thereof is substantially a H shape; As shown in  FIG. 6 , in the fourth embodiment of the present invention, according to the cross-sectional shape of the first fixed holder  11 ′ and the second fixed holder (not shown), the groove  111 ′ is formed on one side of the periphery close to the frame  5 , so that the cross-sectional shape thereof is substantially a T shape. Thus, similarly, the groove  111 ′ can be engaged with a horseshoe-shape portion  311 ′ of a first movable socket  31 ′. Therefore, the fourth embodiment of the present invention can reduce the thickness of the first fixed holder  11 ′, the second fixed holder (not shown), the corresponding first movable socket  31 ′ and the corresponding second movable socket  32 . 
         [0061]    Referring now to  FIG. 7 , a perspective view of a fastening assembly of a fastening device for a bicycle according to a fifth embodiment of the present invention is illustrated, wherein the fifth embodiment of the present invention is similar to the first embodiment of the present invention, wherein the difference therebetween is that: a fastening assembly  3   a  comprises a first movable socket  31   a  and a second movable socket  32   a , each of which is carried out by a one-piece bent frame. The profile of the first movable socket  31   a  and that of the second movable socket  32   a  are different. As shown in  FIG. 7 , each of the first movable socket  31   a  and the second movable socket  32   a  is substantially a main structure of continuous W-shape bent frame which is preferably made of metal material having strength and elasticity, such as aluminum. In the embodiment, the first movable socket  31   a  has a horseshoe-shape portion  311   a  and two guiding portions  312   a , while the second movable socket  32   a  has a horseshoe-shape portion  321   a , two guiding portions  322   a  and two guiding extension portions  323   a , wherein the two guiding extension portions  323   a  are further formed between the horseshoe-shape portion  321   a  and the two guiding portions  322   a  for elongating a distance between the horseshoe-shape portion  321   a  and the two guiding portions  322   a . Therefore, when installing the fastening assembly  3 , the second movable socket  32   a  is firstly in contact with the second fixed holder  12 . Then, the first movable socket  31  can be aligned with the first fixed holder  11  (as shown in  FIG. 2 ) by the guidance of the two guiding extension portions  323   a , so as to simultaneously finish the engagement operations. In another embodiment, the guiding extension portions (not shown) may be formed on the first movable socket  31   a . In comparison with the first embodiment of the present invention which needs to simultaneously align the two movable sockets with the two fixed holders, the fifth embodiment of the present invention can generate a guidance function, so that the alignment operations of the two movable sockets and the two fixed holders can be done in turn and easily carried out. 
         [0062]    Referring now to  FIG. 8A , a perspective view of a fastening assembly of a fastening device for a bicycle according to a sixth embodiment of the present invention is illustrated, wherein the sixth embodiment of the present invention is similar to the first embodiment of the present invention, wherein the difference therebetween is that: a fastening assembly  3   b  comprises a first movable socket  31   b  and a second movable socket  32   b , each of which is carried out by a plate. The profile of the first movable socket  31   b  and that of the second movable socket  32   b  are different. As shown in  FIG. 8A , the first movable socket  31   b  is similar to the first movable socket  31  of the first embodiment of the present invention, wherein the first movable socket  31   b  has a horseshoe-shape portion  311   b  and two guiding portions  312   b  for providing a function for engaging and connecting with the first fixed holder  11  (as shown in  FIG. 2 ). But, the second movable socket  32   b  is formed with two flange s 321   b  which are bent from an outer portion to an inner portion by punching, wherein the second movable socket  32   b  can be inserted into the groove  121  of the second fixed holder  12  (as shown in  FIG. 2 ) to generate a retaining function. Because the first movable socket  31  can engage and connect with the first fixed holder  11  and the second movable socket  32   b  can be retained in the second fixed holder  12 , the fastening assembly  3   b  can fixedly mounted on the fixed assembly  1 . In another embodiment, the two flanges (not shown) may be formed on the first movable socket  31   b . Thus, in various embodiments of the present invention, the two sets of the fixed holders and the movable socket are not limited to have the same type, size and function. 
         [0063]    Referring now to  FIG. 8B , a perspective view of a fastening assembly of a fastening device for a bicycle according to a seventh embodiment of the present invention is illustrated, wherein the seventh embodiment of the present invention is similar to the sixth embodiment of the present invention, wherein the difference therebetween is that: the profile of the second movable socket  32   b  is different. As shown in  FIG. 8B , the second movable socket  32   b  is formed with two flanges  321   b  which are bent from an outer portion to an inner portion by punching and the two flanges  321   b  is formed on one side edge and a lower edge thereof. Meanwhile, the second movable socket  32   b  is formed with an outer flange  321   b ′ which are bent from an outer portion to an inner portion by punching and the outer flanges  321   b ′ is formed on the other side edge thereof. The outer flanges  321   b ′ can provide an elastic engagement function. Thus, the seventh embodiment of the present invention can use an operation mode similar to the second embodiment of the present invention in  FIGS. 4A to 4C . Firstly, the horseshoe-shape portion  311   b  of the first movable socket  31   b  of the fastening assembly  3   b  can be engaged into the groove  111  of the first fixed holder  11  (not shown) to form an engagement connection. Then, the first movable socket  31   b  is used as a pivot point of rotation to rotate the fastening assembly  3   b  for engaging the second movable socket  32  on the lower end of the fastening assembly  3   b  into the second fixed holder  12  (not shown) to form a retaining engagement connection, wherein the outer flanges  321   b ′ has the engagement function to fixedly mount the fastening assembly  3   b  on the fixed assembly  1 . 
         [0064]    Referring to  FIGS. 9A and 9B , perspective view of a fastening assembly of a fastening device for a bicycle according to an eighth embodiment of the present invention are illustrated, wherein the eighth embodiment of the present invention is similar to the first embodiment of the present invention, and substantially uses reference numerals of the first embodiment, wherein the difference of the eighth embodiment is that: the opening of the horseshoe-shape portion  311  of the first movable socket  31  and the opening of the horseshoe-shape portion  321  of the second movable socket  32  face downward. Except for the horseshoe-shape portion  321 , the second movable socket  32  further has a guiding portion  322 . As shown in  FIG. 9B , the fastening assembly  3  is used to support a water bottle  8 , and the fastening assembly  3  comprises two wing plates  33  symmetrically arranged on sides of the water bottle  8  and having a curved profile corresponding to the water bottle. Preferably, a width of an outer end of the two wing plates  33  is greater than that of an inner end thereof. The fastening assembly  3  further comprises a bottom plate  34  for supporting a bottom of the water bottle  8 , and the bottom plate  34  is substantially Y-shape, but not limited thereto. A bottom of the first movable socket  31  comprises an engagement projection  35  for engaging the first fixed holder  11  (not shown) into the first movable socket  31 . 
         [0065]    Furthermore, the water bottle  8  further comprises a bottle sheath  81 , and the sheath  81  is preferably made of water-proof and thermal-insulation soft material. The water bottle  8  is received in the bottle sheath  81 ; and the bottle sheath  81  comprises two inserted portions  811 , wherein the two inserted portions  811  are substantially pocket-like, and can be inserted by the two wing plates  33 , so that the bottle sheath  81  can be connected to the fastening assembly  3 . Moreover, the bottle sheath  81  can have another inserted portion  811  corresponding to the bottom plate  34 , wherein the inserted portion  811  is substantially belt-like, and can be inserted by the a root portion of the bottom plate  34 , so that a bottom of the bottle sheath  81  can be connected to the fastening assembly  3 . In addition, the bottle sheath  81  has an opening for exposing an opening of the water bottle  8 , so that a user can conveniently use the water bottle  8 . The bottle sheath  81  further comprises a zipper  812  for conveniently taking the water bottle  8  from the bottle sheath  81  and placing the water bottle  8  into the bottle sheath  81 . As described above, the bottle sheath  81  can generate a function of protecting the water bottle  8  from being worn and generate a thermal insulation effect. 
         [0066]    Referring to  FIG. 9C , a perspective view of a fastening assembly of a fastening device for a bicycle according to a ninth embodiment of the present invention is illustrated, wherein the ninth embodiment of the present invention is similar to the eighth embodiment of the present invention, and substantially uses reference numerals of the eighth embodiment, wherein the difference therebetween is that: the two wing plates  33  further have a banding  36 , and the two wing plates  33  are formed with a plurality of slots (unlabeled), respectively, for the banding  36  to pass therethrough. The banding  36  can be detachably tied between the two wing plates  33  by using hook and loop fasteners, retaining rings or other elements. Therefore, the water bottle  8  can be directly mounted on the fastening assembly  3  by the banding  36 . Besides, in consideration of the anti-skid and scratch-resistant properties of the contact area between the fastening assembly  3  and the water bottle  8 , a soft cushion can be further disposed on a suitable position of the contact area between the fastening assembly  3  and the water bottle  8 . 
         [0067]    Referring to  FIGS. 10A to 10C , schematic views of a fastening device for a bicycle according to a tenth embodiment of the present invention during the installation are illustrated, wherein the direction thereof is a perspective inclined direction from the frame  5  to the fastening device for the bicycle, while the frame  5  is omitted. The tenth embodiment of the present invention is similar to the first and eighth embodiment of the present invention, and substantially uses reference numerals of the first and eighth embodiment, wherein the difference of the tenth embodiment is that: the opening of the horseshoe-shape portion  311  of the first movable socket  31  of the fastening assembly  3  faces upward, while the opening of the horseshoe-shape portion  321  of the second movable socket  32  faces downward. Except for the horseshoe-shape portion  311 , the first movable socket  31  further has a guiding portion  312 . As shown in  FIGS. 10A to 10C , an installation operation between the first movable socket  31  and the second movable socket  32  of the fastening assembly  3  and the first fixed holder  11  and the second fixed holder  12  of the fixed assembly  1  is illustrated. 
         [0068]    Firstly, as shown in  FIG. 10A , a front end of the fastening assembly  3  is lowered and a rear end thereof is raised to be in an inclined state, and then the fastening assembly  3  moves toward the fixed assembly  1  from the top to the bottom, so that the opening of the horseshoe-shape portion  311  of the first movable socket  31  close to the front end of the fastening assembly  3  is located below the groove  111  of the first fixed holder  11 . Meanwhile, the second movable socket  32  on the rear end of the fastening assembly  3  is located at a position higher than the height of the second fixed holder  12  without any contact therebetween. 
         [0069]    Then, as shown in  FIG. 10B , the first movable socket  31  of the fastening assembly  3  continues to be moved upward along the groove  111  of the first fixed holder  11 , while the first fixed holder  11  correspondingly passes through the opening of the horseshoe-shape portion  311  and the guiding portions  312  of the first movable socket  31  in turn until abutting against a lower end of the horseshoe-shape portion  311  of the first movable socket  31 . At that time, the second movable socket  32  on the rear end of the fastening assembly  3  is lowered to a position equal to the height of the second fixed holder  12 , and the opening of the horseshoe-shape portion  321  of the second movable socket  32  is located above the groove  121  of the second fixed holder  12 . 
         [0070]    Finally, as shown in  FIG. 10C , the horseshoe-shape portion  321  of the second movable socket  32  is engaged into the groove  121  of the second fixed holder  12  downward to form an engagement connection. Meanwhile, the first movable socket  31  is lowered a distance, but the first fixed holder  11  is relatively raised a distance and stopped at the guiding portions  312  of the first movable socket  31 , so that the first movable socket  31  will not be separated from the first fixed holder  11 . Thus, the fastening assembly  3  is fastened on the fixed assembly  1  without outward separation. When the fastening assembly  3  is fastened on the fixed assembly  1 , the guiding portions  312  of the first movable socket  31  where the first fixed holder  11  is stopped is preferably an engagement portion, so as to strengthen the fastening effect of the fastening assembly  3 . 
         [0071]    On the other hand, when it needs to detach the fastening assembly  3  from the fixed assembly  1 , the foregoing steps can be reversely executed, and the operation is very simple. In addition, the guiding portions  312  of the first movable socket  31  of the fastening assembly  3  has a suitable length design according to the size and distance of the first fixed holder  11  and the second fixed holder  12  of the fixed assembly  1 . When the second movable socket  32  is engaged with the second fixed holder  12 , the first movable socket  31  will not be separate from the first fixed holder  11 . As described above, in comparison with the traditional fastening device for the bicycle (especially, a bottle cage) which may cause the wear of the material or printing on the surface of the water bottle due to the vibration or taking operation during riding the bicycle, may affect the simplicity of the appearance of the bicycle when it is unnecessary to mount the water bottle or may be unsuitable for a foldable bicycle, the fastening device for the bicycle of the present invention as shown in  FIG. 2  can prevent the surface of the water bottle from being worn and can enhance the fastening strength and the detachment convenience thereof. In addition, the fastening device for the bicycle can be replaced by other tool box or tool rack, so as to add the function of the bicycle.