Patent Publication Number: US-6991431-B2

Title: Ceiling fan blade

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a ceiling fan blade capable of producing full wind pressure and much wind. The solution of the present invention is to form a front wind receiving surface, a rear wind receiving surface and a wavy wind guide surface on the ceiling fan blade. With these structures the present invention can effectively increase the wind pressure and the wind; in addition, sinuous flow is substantially reduced when the blade is rotating. 
   2. Description of the Prior Arts 
   Conventional ceiling fan blades are normally arranged on a motor in a radial way, and the ceiling fan blades are simple plate structure, which has been used for long time, but there are still some defects need to be improved: 
   First, the radial arranged ceiling fan blades occupy much installation space. 
   Second, the radial arranged ceiling fan blade is simple plate structured, the wind that it can produce is limited. 
   The present invention has arisen to mitigate and/or obviate the afore-described disadvantages of the conventional ceiling fan blade. 
   SUMMARY OF THE INVENTION 
   The primary object of the present invention is to provide a ceiling fan blade capable of producing full wind pressure and much wind, on the surface of the ceiling fan blade is formed a front wind receiving surface and a rear wind receiving surface, wherein a tangent angle of the rear wind receiving surface is greater than that of the front rear wind receiving surface, the two wind receiving surfaces can effectively increase the wind pressure and produce more wind. 
   The secondary object of the present invention is to provide a ceiling fan blade capable of producing full wind pressure and much wind, wherein a wavy wind guide surface is formed between the two wind receiving surfaces, with this wavy wind guide surface sinuous flow can be substantially reduced when the blade is rotating. 
   The present invention will become more obvious from the following description when taken in connection with the accompanying drawings, which shows, for purpose of illustrations only, the preferred embodiments in accordance with the present invention. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of a ceiling fan blade in accordance with the present invention; 
       FIG. 2  is an operational view of the ceiling fan blade in accordance with the present invention; 
       FIG. 3  is a cross sectional view of the ceiling fan blade in accordance with a first embodiment of the present invention; 
       FIG. 4  is a cross sectional view of the ceiling fan blade in accordance with a second embodiment of the present invention; 
       FIG. 5  is another cross sectional view of the ceiling fan blade in accordance with a first embodiment of the present invention; 
       FIG. 6  is a perspective view of a ceiling fan blade in accordance with a third embodiment of the present invention; 
       FIG. 7  is a cross sectional view of the ceiling fan blade in accordance with a fourth embodiment of the present invention; 
       FIG. 8  is a cross sectional view of the ceiling fan blade in accordance with a fifth embodiment of the present invention. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
   Referring to  FIGS. 1–3 , wherein a ceiling fan blade  10  in accordance with the present invention is adapted to be mounted on a lifting mechanism  30  of a motor  20 . 
   The ceiling fan blade  10  is defined at an upper side of a wind-receiving surface  11  which is parallel to the radial direction with an arc-shaped front wind-receiving surface  111 . The front wind-receiving surface  111  forms a tangent angle α with respect to the horizontal line, the tangent angle α is same as that of normal type ceiling fan. Furthermore, next to the front wind receiving surface  111  are sequentially formed a wavy wind guide surface  112  and an arc-shaped rear wind-receiving surface  113  which forms a tangent angle β with respect to the horizontal line. The tangent angle β of the rear wind-receiving surface  113  is greater than the tangent angle α of the front wind-receiving surface  111 . 
   Referring particularly to  FIG. 2 , wherein the ceiling fan blade  10  is mounted on the lifting mechanism  30  of the motor  20 . When the motor  20  works, the ceiling fan blade  10  starts to rotate, the wind-receiving surface  11  begins to receive wind. The front wind-receiving surface  111  at the upside of the wind-receiving surface  11  will use the tangent angle α to push a part of the air downward, such that the ceiling fan blade  10  gradually moves upward around the lifting mechanism  30 . Whereas the wavy wind guide surface  112  will smoothly guide the rest air that is not pushed downward by the front wind-receiving surface  111  to the rear wind-receiving surface  113 , and reduce the sinuous flow to the least level. After most of the air is guided to the rear wind-receiving surface  113 , and the rear wind-receiving surface  113  will produce more strong pushing force with its tangent angle β to push the air downward, and accordingly cause a more strong reactive force. Since the tangent angle β of the rear wind-receiving surface  113  is greater than that α of the front wind-receiving surface  111  (it is also greater than that of conventional ceiling fan blade), the air has been guided by the wavy wind guide surface  112  to the path that corresponds to the rear wind-receiving surface  113 , and thus the rear wind-receiving surface  113  is able to produce more strong wind and wind pressure (no great resistance is generated by air). By virtue of the wavy wind guide surface  112  which is able to more stably guide the air and the gradually increased tangent angle, the ceiling fan blade is capable of producing more wind and more strong wind pressure. 
   Besides the above-mentioned characteristic structure, the ceiling fan blade in accordance with the present invention further has other varied structures. With reference to  FIG. 4 , wherein the ceiling fan blade  10  is defined at an upside of a wind-receiving surface  11  with a flat front wind-receiving surface  40 , and to the wavy wind guide surface  112  is connected a flat rear wind-receiving surface  41 . 
   It is noted that, as shown in  FIG. 5 , the ceiling fan blade  10  in accordance with another preferred embodiment of the present invention is formed at its inner edge with an inner arc portion  42 , and at its outer edge with an outer arc portion  43 . The inner arc portion  42  and the outer arc portion  43  form a wavy structure, with this wavy structure the air can be pushed outward during the rotation of the ceiling fan blade, such that, besides smoothly guiding the air to flow outward with the wavy wind guide surface  112 , the ceiling fan blade of the present invention is also able to produce much more wind with the outer arc portion  43 . 
   Besides the structures of the outer and the inner arc portions  43 ,  42 , the inner and the outer edges of the ceiling fan blade in accordance with the present invention also can be straight-formed as shown in  FIG. 6 . With reference to  FIGS. 7 and 8 , wherein the inner and the outer arc portions  42 , 43  also can be separately made. 
   Thereby in summary from above described, and  FIGS. 1 ,  2 ,  3 ,  4 ,  5  and  7 , in the present invention, a projection of the ceiling fan blade is formed as an oblong shape with two long sides which are approximately parallel and two short sides and any cross section of the ceiling fan blade parallel to the long sides has an S shape. Furthermore, the front wind-receiving surface, wavy wind guide surface  112 , and rear wind-receiving surface  113  are arranged along the long sides. The tangent angle of the rear-wind-receiving surface  113  is greater than that of the front wind-receiving surface  111 . 
   Furthermore, in  FIGS. 1 and 6 , it is illustrated that any cross section of blade parallel to the short sides has an S shape. Moreover in  FIG. 2 , it is illustrated that any cross section of the front wind receiving surface of the blade parallel to the short sides has a single arc shape. 
   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.