Patent Publication Number: US-2010124504-A1

Title: Structure of ceiling fan blades their frames

Description:
BACKGROUND OF THE INVENTION 
     1. Field of Invention 
     The invention relates to a ceiling fan structure and, in particular, to the combination structure of ceiling fan blade and its frame. 
     2. Related Art 
     There are usually several blade frames around the motor at the center of a ceiling fan. Each blade frame is mounted with a blade. The invention pertains the technique of combining the blades with their corresponding frames. 
     In the early days, the blades are fixed on the frames in a ceiling fan. Such a combination is done by simple screw locking. For example, the blade frame is provided with a screw to go through the corresponding blade. A bolt is then used to lock the blade and the blade frame. Such a structure has some inconvenience in the disassembly because each part has to taken apart. Therefore, designs with more convenience structures start to appear. 
       FIGS. 7 to 9  show three conventional structures of the blades and their frames. 
     As shown in  FIG. 7 , the blade  50  has a through hole  501 . The blade frame  51  has a hook  511  protruding from it and forming a groove  52  in between. The blade  50  is mounted on the blade frame  51 , followed by moving their relative position so that the blade  50  is embedded in the groove  52 . Afterwards, a positioning element  53  is inserted for positioning. 
     Please refer to  FIG. 8 . The blade  60  has a through hole  601 . The blade frame  61  has a clip  611 . Inserting the clip  611  through the through hole  601  and adjusting the relative position between the blade and the blade frame, the clip fixes and positions the blade  60  on the blade frame  61 . 
     Finally, the please refer to  FIG. 9 . The blade  70  has several through holes  701  in the shape of the number  8 , formed by two holes of different diameters. An inserting part  711  on the blade frame  71  goes through the larger hole. Afterwards, the stopping part  712  on the inserting part  711  falls into the smaller hole by moving the relative position between the blade  70  and the blade frame  71 , thereby fixing them. 
     Although the above-mentioned three structures of blade and blade frame are more convenient than the conventional structure using screws, the hook, clip or inserting part is positioned on the blade after going through the corresponding through hole. They have to satisfy a certain precision in order to achieve a firm connection, so that no serious wiggles happen when the ceiling fan operates. Taking the structure in  FIG. 8  as an example, the blade may fall off as the blade moves toward the motor because the clip can depart from the blade. 
     Therefore, it is the goal of the invention to provide a structure of blade and blade frame that can be readily combined and firmly fixed without the need for a high precision as in the prior art. 
     SUMMARY OF THE INVENTION 
     It is an objective of the invention to provide a structure of blade and blade frame for a ceiling fan that is simple and convenient to assemble. 
     The invention includes: 
     a blade, whose one end has at least two through holes; 
     a blade frame, which has an inserting part for each of the through holes on the blade, each of the inserting parts having a stopping part that prevents the blade frame from leaving the blade on the exposed end from the blade; and 
     an elastic positioning element restoring its position after pressure release, which has a plurality of limiting parts each of which urges against the stopping parts after the inserting parts go through the corresponding through holes, blocking the stopping parts by sticking between the stopping parts and the blade. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will become more fully understood from the detailed description given herein below illustration only, and thus is not limitative of the present invention, and wherein: 
         FIG. 1  is a three-dimensional exploded view of the invention; 
         FIG. 2  is three-dimensional perspective view of the invention; 
         FIG. 3  is a schematic assembly view of the invention; 
         FIG. 4  is a top view of the limiting part and the inserting part in position according to the invention; 
         FIG. 5  is a side view of the limiting part and the inserting part in position according to the invention; 
         FIG. 6  is a schematic assembly view of the second embodiment of the invention; 
         FIG. 7  shows the structure of the blade and blade frame used in a first conventional ceiling fan; 
         FIG. 8  shows the structure of the blade and blade frame used in a second conventional ceiling fan; and 
         FIG. 9  shows the structure of the blade and blade frame used in a third conventional ceiling fan. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention will be apparent from the following detailed description, which proceeds with reference to the accompanying drawings, wherein the same references relate to the same elements. 
     According to an embodiment, the disclosed structure of ceiling fan blade and blade frame includes: a blade  1 , a blade frame  2 , and a positioning element  3 . 
     The blade  1  has at least two through holes  11  on one end. As shown in the drawing, the blade  1  in this embodiment has three through holes  11  arranged in a triangular shape. 
     The blade frame  2  has an inserting part  21  for each of the through hole  11  on the blade  1 . Each of the inserting parts  21  has a stopping part  211 . The stopping part  211  goes through the corresponding through hole  11  and exposes on the blade  1 . 
     In this embodiment, the inserting parts  21  are independent elements. They are fixed on the blade frame  2  by screws. 
     The positioning element  3  is elastic and has several limiting parts  31 . The limiting parts  31  are connected by a linking part  32  with a linear structure. After the inserting part  21  goes through the corresponding through hole  11 , the positioning element  3  is disposed so that the limiting parts  31  urge against the stopping parts  211  and block them by sticking between the stopping parts  211  and the blade  1 . 
     In this embodiment, the positioning element has limiting parts  311  on both ends to coil between the blade and the stopping parts. The two limiting parts  311  are connected by a linking part  32  with another limiting part  312  also coiling between the blade and the stopping part. The positioning element  3  is thus mounted between the stopping parts  211  and the blade  1  with the help of the inserting parts  21  on the blade frame  2 . 
     Each of the stopping parts  211  includes a first stopping part  211   a  for the limiting part  31  to block after it restores its position and a second stopping part  211   b  blocking the limiting part  31  after the inserting part  21  goes through the through hole  11 . 
     Besides, the blade  1  has a covering element  4  in this embodiment for covering the part of the inserting part  21  exposed from the blade  1  and the positioning element  3 . 
     Please refer to  FIGS. 3 to 5 . The inserting parts  21  of the blade frame  2  go through the through holes  11  of the blade  1 , so that the stopping parts  211  at the end of the inserting parts  21  expose from the blade  1 . Moreover, the positioning element  3  is pressed inward in such a way that it is slightly deformed and disposed among the inserting parts  21 . Each of the limiting parts  31  is disposed at the corresponding inserting part  21 . They restore their positions after the positioning element  3  is released. The limiting parts  31  then urge against the inserting parts  21  between the stopping parts  211  and the blade  1 . 
     Each of the limiting parts  31  of the positioning element  3  urges against the corresponding first stopping part  211   a  in parallel to the blade  1  ( FIG. 4 ). Moreover, each of the limiting parts  31  surrounds between the blade  1  and the second stopping part  211   b  to stop the second stopping part  211   b  in the normal direction of the blade  1  ( FIG. 5 ). 
     Therefore, the positioning element  3  is positioned between the inserting part  21  and the blade  1 . If one carelessly touches or pushes the limiting parts  31  or linking part  32  of the positioning element  3 , the elasticity thereof prevents the limiting parts  31  from falling off. Moreover, the two inserting parts  311  and the inserting part  312  in the drawing provide opposite blocking forces. Thus, they provide constraints on the inserting parts  21 . Taking the structure in this embodiment as an example, when the blade  1  is withdrawn outwards with respect to the blade frame  2 , the two limiting parts  311  block it. When the blade  1  is pushed inward with respect to the blade frame  2 , the limiting part  312  blocks it. In other words, it does not have same problem as in the prior art where the blade may fall off because the blade and the blade frame have a blocking force in the same direction. 
     It is clear from the above description that a primary advantage of the invention is to in the simple assembly structure between the blade and the blade frame. Such a structure can prevent the blade from falling off the blade frame. 
     There are of course many other embodiments of the invention only differing in details. Please refer to  FIG. 6  for a second embodiment of the invention. The blade  1  has four through holes  11 . The blade frame  2  has four corresponding inserting parts  21 . The positioning element  3  has a rectangular shape with two limiting part  313  protruded from and two limiting parts  314  recessed on opposite ends. The limiting elements  313 ,  314  all have an arc shape. The limiting parts  313 ,  314  are also connected using a linear structure  32 . 
     In this embodiment, the positioning element is mounted by squeezing the recessed limiting parts  314 . It is then released after the two limiting parts  313  are mounted on the corresponding inserting parts  21 . In this case, the limiting parts  313 ,  314  of the positioning element block the corresponding inserting parts  21 . Using such a structure, the blade  1  and the blade frame  2  can be positioned as in the first embodiment. 
     Although the invention has been described with reference to specific embodiments, this description is not meant to be construed in a limiting sense. Various modifications of the disclosed embodiments, as well as alternative embodiments, will be apparent to people skilled in the art. Therefore, it is contemplated that the appended claims will cover all modifications that fall within the true scope of the invention.