Patent Publication Number: US-2007114752-A1

Title: Method of making a composite bicycle frame and a jig device used in the method

Description:
BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The invention relates to a composite bicycle frame, more particularly to a method of making the composite bicycle frame and a jig device used in the method.  
      2. Description of the Related Art  
       FIG. 1  illustrates a conventional jig device for making a composite bicycle frame, wherein metal and composite plastic components of the composite bicycle frame are assembled and adhered to each other by a resin, and are then positioned on the conventional jig device. The jig and the bicycle frame mounted thereon are subsequently sent into a heating chamber for curing to form a unitary frame assembly. The conventional jig device is used for positioning a frame body  1  and a fork body  2  of the composite bicycle frame during the curing process. The frame body  1  includes a triangular frame part  101 , an upper rear fork  102  made of a composite plastic material, a lower rear fork  103  made of a composite plastic material, and two rear fork pawls  104  made of metal. The triangular frame part  101  includes a five-way tube  105 , a seat tube  106  connected to the five-way tube  105 , a head tube  107  confronting the seat tube  106 , a top tube  108  connected between the head tube  107  and the seat tube  106 , and a down tube  108 ′ connected between the head tube  107  and the five-way tube  105 . The fork body  2  includes a straight tube  201 , two prong members  202  each made of a composite plastic material, and two rear fork pawls  203  each made of metal.  
      The conventional jig device includes a wheeled platform  3 , a five-way tube positioning unit  4  mounted on the platform  3 , a supporting unit  4 ′ disposed opposite to the five-way tube positioning unit  4 , a head tube positioning unit  5  located to one side of the five-way tube positioning unit  4  and the supporting unit  4 ′, a first pawl positioning unit  5 ′ located to the other side of the five-way tube positioning unit  4  and the supporting unit  4 ′, a tube positioning unit  6  disposed between the five-way tube positioning unit  4  and the supporting unit  4 ′, an upper rear fork positioning unit  6 ′ disposed between the supporting unit  4 ′ and the first pawl positioning unit  5 ′, a second pawl positioning unit  7  disposed outwardly of the first pawl positioning unit  5 ′, a tube positioning unit  7 ′ disposed opposite to the second pawl positioning unit  7 , and a prong supporting unit  8  disposed between the second pawl positioning unit  7  and the tube positioning unit  7 ′.  
      During assembly, the five-way tube  105  is positioned on the platform  3  through the five-way tube positioning unit  4 , the seat tube  106  is pressed and positioned by the tube positioning unit  6  and has one end supported by the supporting unit  4 ′, the head tube  107  is positioned by the head tube positioning unit  5 , the rear fork pawl  104  is positioned by the first pawl positioning unit  5 ′, the upper rear fork  102  is positioned by the upper rear fork positioning unit  6 ′, and the fork body  2  is positioned through the second pawl positioning unit  7 , the tube positioning unit  7 ′ and the prong supporting unit  8 .  
      Although the aforementioned conventional jig device can achieve its intended purpose, the platform  3  occupies a substantial space, and must be provided with a plurality of positioning units to permit stable positioning of the frame body  1  and the fork body  2  of the composite bicycle frame and to maintain accurate positional relationship between adjacent components. Furthermore, the structures of the positioning units are complicated, and are difficult to operate. Finally, since the frame body  1  and the fork body  2  are sent to the heating chamber through the platform  3  for curing, the number of the frame assemblies that can be heated within the heating chamber is limited, thereby resulting in a slow process and low productivity.  
     SUMMARY OF THE INVENTION  
      Therefore, an object of the present invention is to provide a method of making a composite bicycle frame by which the number of pre-assembled frame parts of the composite bicycle frame that can be heated and cured in a heating chamber can be increased, thereby increasing the manufacturing productivity of the composite bicycle frame.  
      Another object of the present invention is to provide a jig device that is used in the method of making a composite bicycle frame, that can be hung, that has a small volume and a simple structure, that is easy to operate, that allows uniform heating of a pre-assembled frame part of the composite bicycle frame that is mounted on the jig device, and that is adjustable so as to precisely position the pre-assembled frame part of the composite bicycle frame on the jig device.  
      According to one aspect of this invention, a process of making a composite bicycle frame comprises the steps of: positioning an uncured pre-assembled frame part of the composite bicycle frame on a jig which includes a base plate and a positioning device, the pre-assembled frame part including a metal part and a plastic part; conveying the jig along with the pre-assembled frame part into a heating chamber through a conveying device while the base plate is hung on the conveying device; heating and curing the pre-assembled frame part that is hung on the conveying device in the heating chamber so that the pre-assembled frame part forms a unitary body; and cooling the unitary body.  
      According to another aspect of this invention, a jig device is provided for supporting an uncured composite bicycle frame during the curing of the uncured composite bicycle frame in a heating chamber. The uncured composite bicycle frame includes at least one of an uncured first pre-assembled frame part, and an uncured second pre-assembled frame part. The uncured first pre-assembled frame part includes a triangular frame part made of metal, an upper rear fork made of a composite plastic material, a lower rear fork made of a composite plastic material, and two rear fork pawls made of metal. The triangular frame part includes a five-way tube, a seat tube connected to the five-way tube, a head tube, a down tube connected between the head tube and the five-way tube, and a top tube connected between the head tube and the seat tube. The uncured second pre-assembled frame part includes a front fork which has a front tube made of metal, two prong members made of a composite plastic material and branching from the front tube, and two front fork pawls made of metal. The jig device comprises a jig adapted to support one of the first and second pre-assembled frame parts. The jig includes a base plate which has a hanging element to hang the base plate on a support, and a positioning device associated with the base plate and adapted to position the first or second pre-assembled frame part on the base plate.  
      According to still another aspect of this invention, a jig device is provided for supporting an uncured pre-assembled frame part of a composite bicycle frame during the curing of the pre-assembled frame part in a heating chamber. The jig device comprises a base plate which has a hanging element to hang the base plate on a support, a positioning device mounted adjustably on the base plate and adapted to position the pre-assembled frame part on the base plate, and an adjustment unit disposed between the base plate and the positioning device to adjust the position of the positioning device on the base plate.  
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiments with reference to the accompanying drawings, of which:  
       FIG. 1  is a schematic view of a conventional jig device used in the method of making a composite bicycle frame;  
       FIG. 2  is a flow chart, illustrating the steps involved in making a composite bicycle frame according to the present invention;  
       FIG. 3  is a perspective view, illustrating a pre-assembled frame part of the composite bicycle frame positioned on a first jig of a jig device according to the present invention;  
       FIG. 4  is an exploded perspective view of the first jig of the jig device of the present invention;  
       FIG. 5  is an assembled schematic view of the first jig;  
       FIG. 6  is a sectional view taken along line VI-VI of  FIG. 3 ;  
       FIG. 7  is a sectional view taken along line VII-VII of  FIG. 3 ;  
       FIG. 8  is a fragmentary schematic view of a tube positioning unit of the jig device shown in  FIG. 3 ;  
       FIG. 9  is a view similar to  FIG. 8 , but illustrating the tube positioning unit of the jig device which is moved away from a seat tube;  
       FIG. 10  is an exploded perspective view of a second jig of the jig device of the present invention; and  
       FIG. 11  is an assembled sectional view of the second jig in a state of use.  
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
      Before the present invention is described in greater detail, it should be noted that like elements are denoted by the same reference numerals throughout the disclosure.  
      Referring to FIGS.  3  to  9 , a jig device according to a preferred embodiment of the present invention includes a first jig  100  which is provided for supporting a first uncured pre-assembled frame part  200  of the composite bicycle frame during the curing of the first uncured pre-assembled frame part  200  in a heating chamber (not shown). The first uncured pre-assembled frame part  200  includes a triangular frame part  210  made of metal, an upper rear fork  220  made of a composite plastic material, a lower rear fork  230  made of a composite plastic material, and two rear fork pawls  240  made of metal. The triangular frame part  210  includes a five-way tube  250 , a seat tube  260  connected to the five-way tube  250 , a head tube  270  opposite to the seat tube  260 , a down tube  280  connected between the head tube  270  and the five-way tube  250 , and a top tube  290  connected between the head tube  270  and the seat tube  260 .  
      The first jig  100  includes a base plate  10  and a positioning device. The positioning device includes a five-way tube positioning unit  20 , an adjustment unit ( 30 ,  50 ), a pawl positioning unit  40 , and a tube positioning unit  60 .  
      The base plate  10  includes a substantially triangular loop part composed of interconnected first, second and third bars  11 ,  12 ,  13 , and an extension part  17  extending outwardly from the first bar  11 . The extension part  17  has a hanging element in the form of a hanging hole  111 . The first to third bars  11 ,  12 ,  13  cooperatively define a triangular cutout portion  15 . Each of the first to third bars  11 ,  12 ,  13  is provided with a plurality of through holes  16  to reduce the weight of the base plate  10  and to allow air to ventilate through the base plate  10 .  
      The five-way tube positioning unit  20  includes a positioning member  21  connected to the base plate  10  in a perpendicular manner and adapted to support the five-way tube  250  on the first jig  100 , and a connecting member  22  adapted to fix the five-way tube  250  to the positioning member  21 . The positioning member  21  is cylindrical, and has a screw hole  211  formed therein. The connecting member  22  has a shank portion  222 , a screw portion  221  extending downwardly from a bottom end of the shank portion  222  to engage the screw hole  211 , and a head portion  223  connected to a top end of the shank portion  222  and provided with a lever  224 . The five-way tube  250  is secured to the five-way tube positioning unit  20  by turning the lever  224  of the head portion  223 , as best shown in  FIG. 6 .  
      The adjustment unit includes a slidable adjusting unit  30  and a rotary plate unit  50 . The slidable adjusting unit  30  is disposed on one side of the five-way tube positioning unit  20 , and has a slide plate  31  fastened slidably to the extension part  17  of the base plate  10  through a first fastening member  32 . The slide plate  31  includes a slide slot  311  extending along the length of the extension part  17 , and a groove  312  formed in a bottom face of the slide plate  31 . The slide plate  31  is engaged slidably with the extension part  17  through the groove  312 . The first fastening member  32  passes through the slide slot  311 , and engages the extension part  17  so as to fix releasably and adjustably the slide plate  31  to the extension part  17 .  
      The rotary plate unit  50  is mounted pivotally on the second bar  12  of the base plate  10 , and is disposed between the base plate  10  and the five-way tube positioning unit  20 . As best shown in  FIGS. 4, 6  and  7 , the rotary plate unit  50  includes a rotatable plate  51  mounted between the positioning member  21  and the base plate  10  and rotatable relative to the base plate  10 , an extension plate  52  connected telescopically to the rotatable plate  51 , a second fastening member  53  to fix releasably the extension plate  52  to the rotatable plate  51 , and a third fastening member  54  to fix releasably the rotatable plate  51  to the second bar  12  of the base plate  10 . The rotatable plate  51  has a slide groove  511  formed in a top face thereof and extending along the length of the rotatable plate  51 , and a curve slot  512  formed on one side of the engaging groove  511  for extension of the third fastening member  54  therethrough. The extension plate  52  has an engaging portion  521  provided on a bottom portion thereof to engage slidably the slide groove  511 , and an elongated guide hole  522  extending along the length of the extension plate  52  for passing of the second fastening member  53  therethrough.  
      As best shown in  FIGS. 4 and 6 , the pawl positioning unit  40  is fastened on top of the slidable adjusting unit  30 , and includes a fixed member  41  connected to the slide plate  31 , a rod member  42  inserted into the fixed member  41 , a set of fasteners adapted to position the rear fork pawls  240  on two opposite ends of the rod member  42 , respectively, and a locking member  44  to lock tightly the rod member  42  to the fixed member  41 . In this embodiment, the set of fasteners includes a pin  43  having a head portion  431  and a shank portion  433  connected to the head portion  431 , and a nut member  432  attached to the shank portion  433 . A lever  434  is provided on the head portion  431  of the pin  43 , and is operated to move the head portion  431  towards or away from the nut member  432 .  
      As best shown in  FIGS. 7, 8  and  9 , the tube positioning unit  60  is disposed on the rotary plate unit  50 , and includes a supporting member  61  connected to the extension plate  52  and adapted to support the seat tube  260  on the base plate  10 , and a press member  62  connected to the supporting member  61  and adapted to press the seat tube  260  against the supporting member  61 . The supporting member  61  has a notch  611  formed in a top portion thereof. The press member  62  has a lever  621 , and a press piece  622  that is movable toward or away from the notch  611  through operation of the lever  621  to press or release the seat tube  260 .  
      A preferred embodiment of a method for making a composite bicycle frame according to the present invention is illustrated in  FIG. 2 . In the method, the composite bicycle frame is made by heating and curing an uncured pre-assembled frame part of the composite bicycle frame.  
      The pre-assembled frame part may be the first uncured pre-assembled frame part  200  which includes the triangular frame part  210 , the upper rear fork  220 , the lower rear fork  230 , and the rear fork pawls  240 . In step (A), the first uncured pre-assembled frame part  200  is positioned on the first jig  100 . In particular, the five-way tube  250  is positioned through the five-way tube positioning unit  20 , and the slidable adjusting unit  30  is slid relative to the extension part  17  so that the pawl positioning unit  40  is aligned properly with the rear fork pawls  240 . By turning the rotatable plate  51  and by sliding the extension plate  52  relative to the rotatable plate  51 , the tube positioning unit  60  can be aligned properly with the seat tube  260 . As such, the first uncured pre-assembled frame part  200  can be stably positioned on the base plate  10 , and the distance between the five-way tube  250  and the rear fork pawls  240  can be accurately controlled.  
      In step (B), after the first uncured pre-assembled frame part  200  is positioned on the first jig  100 , the first jig  100  is hung on a hook  310  of a conveying device  300  through the hanging hole  111 . Through the conveying device  300 , the first jig  100  together with the first uncured pre-assembled frame part  200  are sent to a heating chamber (not shown).  
      In step (C), the first uncured pre-assembled frame part  200  is heated in the heating chamber so that the first uncured pre-assembled frame part  200  is cured and formed into a unitary body. In step (D), the unitary body is cooled after the first jig  100  together with the first uncured pre-assembled frame part  200  are removed from the heating chamber.  
      The advantages of using the method and the jig device of the present invention are summarized as follows:  
      1. Since the base plate  10  of the first jig  100  is small and lightweight, and since the first jig  100  is hung vertically on the hook  310  of the conveying device  300 , the heating chamber can accommodate a larger number of pre-assembled frame parts to be cured. The present invention thus increases the production rate of the bicycle frame compared to the conventional jig device of  FIG. 1 .  
      2. Due to the provision of the slidable adjusting unit  30  and the rotary plate unit  50 , adjustment of the positioning device can be easily performed. In particular, the slidable movement of the slide plate  31  relative to the extension part  17  permits adjustment of the pawl positioning unit  40  relative to the five-way tube positioning unit  20 . The rotatable movement of the rotatable plate  51  relative to the base plate  10 , and the sliding movement of the extension plate  52  permit adjustment of the position of the tube positioning unit  60 . Therefore, the first jig  100  is suitable for use with the uncured pre-assembled frame parts of different sizes. In addition, since the first uncured pre-assembled frame part  200  can be stably and properly positioned on the base plate  10 , the resulting size of the first uncured pre-assembled frame part  200  may be controlled easily and precisely.  
      3. By hanging the first jig  100  with the first uncured pre-assembled frame part on the conveying device  300  and by conveying the same into the heating chamber, and through the presence of the cutout portion  15  and the through holes  16  in the base plate  10 , the first uncured pre-assembled frame part  200  can be heated uniformly.  
      Referring to  FIGS. 10 and 11 , there is shown a second jig  100 ′ for supporting a second uncured pre-assembled frame part  400  of the composite bicycle frame during the curing of the second uncured pre-assembled frame part  400  in a heating chamber. The second uncured pre-assembled frame part  400  includes a front fork which has a front tube  410  made of metal and two prong members  420  branching from the front tube  410  and made of a composite plastic material, and two front fork pawls  430  made of metal.  
      The second jig  100 ′ includes a base plate  10 ′ and a positioning device. The positioning device includes slidable adjusting unit  30 , a pawl positioning unit  40  fastened on top of the slidable adjusting unit  30 , a rotary plate unit  50  mounted on the base plate  10 ′ and disposed distal from the slidable adjusting unit  30 , and a tube positioning unit  60  fastened on top of the rotary plate unit  50 . The base plate  10 ′, in this embodiment, is configured as an elongated bar, and has a hanging element in the form of a hanging hole  111 ′ formed in one end of the bar. The front fork pawls  430  are positioned on the second jig  100 ′ through the pawl positioning unit  40 , and the front tube  410  is positioned through the tube positioning unit  60 . When the second uncured pre-assembled frame part  400  is mounted on the second jig  100 ′, the effect obtained is similar to that when using the first jig  100 .  
      While the present invention has been described in connection with what is considered the most practical and preferred embodiments, it is understood that this invention is not limited to the disclosed embodiments but is intended to cover various arrangements included within the spirit and scope of the broadest interpretation so as to encompass all such modifications and equivalent arrangements.