Patent Publication Number: US-2006006707-A1

Title: Seat post assembly for a bicycle

Description:
BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      This invention relates to a seat post assembly, and more particularly to a seat post assembly for a bicycle that is not only provided for positioning the seat with support beam, but also facilitating the inclination-angle adjustment of the seat.  
      2. Description of the Prior Arts  
      As shown in  FIG. 1 , a conventional seat  1  for a bicycle must be additionally provided at the bottom surface with two metal support arms  2 , and then it can be assembled on a seat post  3 . The seat post  3  includes a rod portion  301  inserted in a seat tube of a bicycle, a lower mounting-base  302  mounted on top end of the rod portion  301  and an upper mounting-base  303 . The opposite surfaces of lower and the upper mounting-base  302 ,  303  each formed with grooves corresponding to the support arms  2 . The support arms  2  will be clamped and positioned in the grooves after the upper and the lower mounting-base  302  and  303  are locked with each other. Through this way, the seat  1  is indirectly mounted on the seat post  3 .  
      Although the seat  1  can be mounted on the seat post  3  by means of the support arms  2 , in real use, the support arms  2  are assembled on the seat  1  after the seat  1  is completely made. Thereby, not only the seat  1  will be increased in weight, but also the cost will be high and the assembly will also be inconvenient. Furthermore, it is not convenient for the user that the inclination angle of the seat  1  is impossible to be adjusted once the seat  1  is mounted on the seat post  3  through the support arms  2 .  
      To overcome the above-mentioned disadvantages, someone invented another type seat with support beam. The support beam is integratedly formed on the bottom side of the seat by plastic ejection, which is not only capable of reducing the weight of the seat, but also can save the production cost, and no other extra assembly process is required. However, the problem is that the inclination angle for this type seat also cannot be adjusted.  
      The present invention has arisen to mitigate and/or obviate the afore-described disadvantages.  
     SUMMARY OF THE INVENTION  
      The primary object of the present invention is to provide a seat post assembly for a bicycle that is not only provided for positioning the seat with support beam, but also facilitating the inclination-angle adjustment of the seat.  
      The seat post assembly in accordance with one aspect of the present invention is designed to position the seat with support beam. The support beam is integratedly formed on a bottom surface of the seat and extending in a longitudinal direction thereof, the support beam have a “ ”-shaped cross section, on the bottom of the support beam longitudinally formed with two outward-protruded locking blocks, the seat post assembly comprises: a post; a head mounted on top of the post and laterally provided with two opposite threaded positioning surfaces, and an axial hole passing through the threaded positioning surfaces; two clamp elements assembled to both sides of the head and located in axial direction of the axial hole, each of the clamp elements provided with a threaded jointing surface corresponding to the threaded positioning surface, a through hole corresponding to the axial hole and passing through the threaded jointing surface, and a locking groove corresponding to one of the locking block; and a locking unit capable of passing through the through hole of the clamp elements and the axial hole of the head, enabling the clamp elements to be releasably locked with the head, and positioning the locking blocks of the support beam into the locking groove.  
      The present invention will become more obvious from the following description when taken in connection with the accompanying drawings, which show, for purpose of illustrations only, the preferred embodiments in accordance with the present invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is an assembly perspective view of a conventional seat post assembly for a bicycle;  
       FIG. 2  is an exploded view of a seat post assembly and a seat for a bicycle in accordance with a first preferred embodiment of the present invention;  
       FIG. 3  is an assembly perspective view of a seat post assembly and a seat for a bicycle in accordance with the first preferred embodiment of the present invention;  
       FIG. 4  is an assembly cross sectional view of a seat post assembly and a seat for a bicycle in accordance with the first preferred embodiment of the present invention;  
       FIG. 5  is an operational view for showing the seat post assembly in accordance with the present invention is being adjusted the inclination angle;  
       FIG. 6  is an exploded view of a seat post assembly in accordance with a second preferred embodiment of the present invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
      Referring to  FIGS. 2-4 , a seat post assembly for a bicycle in accordance with a first preferred embodiment of the present invention is provided for positioning a seat  100  with a support beam  110 . The support beam  110  is integratedly formed on the bottom surface of the seat  100  by plastic ejection and located in the longitudinal direction of the seat  100 . The support beam  110  has a “ ”-shaped cross section, on the bottom of the support beam  110  is longitudinally formed with two locking blocks  111  which protrude outward. The seat post assembly includes: a post  10 , a head  20 , two clamp elements  30  and a locking unit  40 .  
      The post  10 , a lower end of which can be inserted in a seat tube on a frame of a bicycle (not shown).  
      The head  20  is inserted in top of the post  10  and laterally provided with two opposite threaded positioning surfaces  21  which are formed in the shape of concave cone, and an axial hole  22  passes through the threaded positioning surfaces  21 .  
      The clamp elements  30  are assembled to both sides of the head  20  and located in axial direction of the axial hole  22 . Each of the clamp elements  30  is provided with a convex-cone-shaped threaded jointing surface  31  which corresponds to the threaded positioning surface  21 , a through hole  32  passing through the threaded jointing surface  31  which corresponds to the axial hole  22 , and a locking groove  33  corresponds to the locking block  111 .  
      The locking unit  40  includes a screw bolt  41  which can pass through the through holes  32  of the clamp elements  30  and the axial hole  22  of the head  20 , and further includes a screw nut  42  can be screwed with the screw bolt  41 .  
      As shown in  FIGS. 3 and 4 , when the threaded jointing surfaces  31  of the clamp elements  30  are locked with the threaded positioning surfaces  21  of the head  20 , the locking blocks  111  of the support beam  110  can be inserted in the locking groove  33 , respectively. The screw bolt  41  can be screwed with the screw nut  42  after passing through the through holes  32  of the clamp elements  30  and the axial hole  22  of the head  20 . After that, the clamp elements  30  are releasably locked with the head  20 , so that the locking blocks  111  of the support beam  110  is positioned in the locking grooves  32 . Through this way, the seat  100  is assembled on the seat post and then the seat post is inserted in a seat tube on the frame of the bicycle.  
      Referring to  FIGS. 4 and 5 , when wants to adjust the inclination angle of the seat  100 , the user only needs to disengage the threaded jointing surfaces  31  of the clamp elements  30  from the threaded positioning surfaces  21  of the head  20  by loosening a little the locking unit  40 . Then turning the clamp element  30 , the seat  100  is driven to rotate relative to the head  20 , so that the inclination angle of the seat  100  relative to the post  10  is changed. At this moment, the inclination angle of the seat  100  is fixed by tightening the locking unit  40 .  
      Hence, the seat post assembly in accordance with the present invention has the advantages as follows:  
      The seat post assembly of the present invention is not only provided for positioning the seat  100  having support beam  110  so as to reduce the weight and save the production cost, but also facilitating inclination-adjustment of the seat  100  according to the user&#39;s needs.  
      Referring to  FIG. 6 , a seat post assembly for a bicycle in accordance with a second embodiment of the present invention is shown, which is similar to that of the first embodiment. The only difference is that a locking unit  50  in the second embodiment is designed for quick assembly and disassembly. The locking unit  50  comprises a shaft  51  capable of inserting through the through holes  32  of the clamp elements  30  and the axial hole  22  of the head  20 ; a cam lever  52  which is pivotally connected to a first end of the shaft  51 ; and a quick-locking member  53  which is screwed with a second end of the shaft  51 . The cam lever  52  is used to quick change the distance between the two clamp elements  30 , so as to tighten or release the clamp elements  30 . By this means, it also can achieve the same effect and function of the seat post assembly in the first embodiment.  
      While we have shown and described various embodiments in accordance with the present invention, it should be clear to those skilled in the art that further embodiments may be made without departing from the scope of the present invention.