Patent Publication Number: US-2004042903-A1

Title: Combination structure of the blade rack and the blade of a ceiling fan

Description:
BACKGROUND OF THE INVENTION  
       [0001] 1. Field of the Invention  
       [0002] The present invention relates to a combination structure of the blade rack and the blade of a ceiling, and more particularly to a combination structure of the blade rack and the blade of a ceiling, wherein the included angle between the blade and the blade rack may be adjusted arbitrarily by controlling the number of the multiple adjusting members, so as to adjust the air flow rate of the ceiling fan by adjusting the relative included angle between the blade and the blade rack.  
       [0003] 2. Description of the Related Art  
       [0004] A conventional combination structure of the blade rack and the blade of a ceiling in accordance with the prior art comprises a single blade rack provided with a single blade. An included angle is defined between the blade rack and the blade.  
       [0005] As shown in FIG. 5, in the conventional combination structure of the blade rack and the blade of a ceiling in accordance with the prior art, the blade  60  may touch and stir the air by its full area, thereby producing a very large air resistance. In addition, the front end of the blade  60  is provided with an air shearing face  61  that may divide the air flow  63  into an upper air flow  64  and a lower air flow  65 . The lower air flow  65  may flow along the air guide face  62  on the bottom of the blade  60 . When the blade  60  is rotated, the air will produce a relative reaction which is absorbed by the full-area air guide face  62  of the blade  60 , and is transmitted through the blade rack into the motor in the ceiling.  
       [0006] Thus, the conventional combination structure of the blade rack and the blade of a ceiling in accordance with the prior art has the following disadvantages.  
       [0007] 1. A determined included angle is defined between the blade rack and the blade, so that the air flow rate can only be controlled by the rotation speed of blade, so that the user cannot adjust the air flow rate or velocity of the ceiling arbitrarily, thereby causing inconvenience in use.  
       [0008] 2. The air shearing area is extended from the air shearing face  61  to the air guide face  62 , so that the blade  60  has a very large air shearing area, thereby easily causing great noise during rotation.  
       [0009] 3. The air guide face  62  has a very large area, thereby producing a very large air resistance.  
       [0010] 4. The air resistance is very large, so that it needs a relatively larger power to stir the air flow, thereby consuming energy and increasing the cost of power.  
       SUMMARY OF THE INVENTION  
       [0011] The present invention has arisen to mitigate and/or obviate the disadvantage of the conventional combination structure of the blade rack and the blade of a ceiling.  
       [0012] The primary objective of the present invention is to provide a combination structure of the blade rack and the blade of a ceiling, wherein the included angle between the blade and the blade rack may be adjusted arbitrarily by controlling the number of the multiple adjusting members, so as to adjust the air flow rate of the ceiling fan by adjusting the relative included angle between the blade and the blade rack.  
       [0013] In accordance with the present invention, there is provided a combination structure of the blade rack and the blade of a ceiling, comprising a blade rack, a blade, multiple adjusting members, and at least one fixing member, wherein:  
       [0014] the multiple adjusting members are mounted between the blade and the blade rack, so that an included angle between the blade and the blade rack may be adjusted arbitrarily by controlling a number of the multiple adjusting members; and  
       [0015] the blade is fixed on the blade rack by the at least one fixing member.  
       [0016] Further benefits and advantages of the present invention will become apparent after a careful reading of the detailed description with appropriate reference to the accompanying drawings. 
     
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
     [0017]FIG. 1 is a partially cut-away perspective view of a combination structure of the blade rack and the blade of a ceiling in accordance with a preferred embodiment of the present invention;  
     [0018]FIG. 2 is an exploded perspective view of the combination structure of the blade rack and the blade of a ceiling as shown in FIG. 1;  
     [0019]FIG. 3 is a side plan cross-sectional view of the combination structure of the blade rack and the blade of a ceiling as shown in FIG. 1;  
     [0020]FIG. 4 is a schematic operational view of the combination structure of the blade rack and the blade of a ceiling as shown in FIG. 3; and  
     [0021]FIG. 5 is a schematic plan view of a conventional combination structure of the blade rack and the blade of a ceiling in accordance with the prior art. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
     [0022] Referring to the drawings and initially to FIGS.  1 - 3 , a combination structure of the blade rack and the blade of a ceiling in accordance with a preferred embodiment of the present invention comprises a blade rack  20 , a blade  30 , multiple adjusting members  40 , and at least one fixing member  50 .  
     [0023] The blade rack  20  has a first end secured on a rotation seat  10  to rotate therewith, and a second end provided with a combination portion  21 . The combination portion  21  of the blade rack  20  is an elongated dovetail-shaped channel, and has a top face and a bottom face each provided with an oblique retaining edge  210 . The blade rack  20  has a top formed with at least one fixing portion  22  extending into the combination portion  21  of the blade rack  20 . Preferably, the fixing portion  22  of the blade rack  20  is a screw bore communicating with the combination portion  21  of the blade rack  20 , so that the fixing member  50  may be screwed into the fixing portion  22  of the blade rack  20 .  
     [0024] The blade  30  has a width relatively smaller than half of that of the conventional blade. The blade  30  has one end provided with a combination portion  31  mounted in the combination portion  21  of the blade rack  20 . The combination portion  31  of the blade  30  has a tapered shape, and has a top face and a bottom face each provided with an oblique retaining edge  310 . The retaining edge  310  of the combination portion  31  of the blade  30  is formed with at least one recessed fixing portion  311  aligning with the fixing portion  22  of the blade rack  20 . Thus, the fixing member  50  may be screwed into the fixing portion  22  of the blade rack  20 , and may be fixed in the recessed fixing portion  311  of the retaining edge  310  of the combination portion  31  of the blade  30 , thereby fixing the blade  30  on the blade rack  20 . The retaining edge  310  of the combination portion  31  of the blade  30  is formed with an adjusting slot  40  for receiving the multiple adjusting members  40 .  
     [0025] Each of the multiple adjusting members  40  is a sheet-shaped structure, and is received in the adjusting slot  40  of the retaining edge  310  of the combination portion  31  of the blade  30 , and retained by the retaining edge  210  of the combination portion  21  of the blade rack  20 .  
     [0026] The fixing member  50  is a screw that may be screwed into the fixing portion  22  of the blade rack  20  and fixed in the recessed fixing portion  311  of the retaining edge  310  of the combination portion  31  of the blade  30 , thereby fixing the blade  30  on the blade rack  20 .  
     [0027] In such a manner, as shown in FIG. 3, the multiple adjusting members  40  may be received in the adjusting slot  312  of the retaining edge  310  of the top face and the bottom face of the combination portion  31  of the blade  30 , and retained by the retaining edge  210  of the top face and the bottom face of the combination portion  21  of the blade rack  20 .  
     [0028] Alternatively, as shown in FIG. 4, the multiple adjusting members  40  may be received in the adjusting slot  312  of the retaining edge  310  of the bottom face of the combination portion  31  of the blade  30 , and retained by the retaining edge  210  of the bottom face of the combination portion  21  of the blade rack  20 .  
     [0029] Accordingly, in the combination structure of the blade rack and the blade of a ceiling in accordance with the present invention, the multiple adjusting members  40  are mounted between the blade  30  and the blade rack  20 . Thus, the included angle between the blade  30  and the blade rack  20  may be arbitrarily adjusted easily and conveniently by controlling the number of the multiple adjusting members  40  in the adjusting slot  40  of the retaining edge  310  of the combination portion  31  of the blade  30 .  
     [0030] In conclusion, the combination structure of the blade rack and the blade of a ceiling in accordance with the present invention has the following advantages.  
     [0031] 1. The included angle between the blade  30  and the blade rack  20  may be adjusted arbitrarily, so that the combination structure of the blade rack and the blade may produce air flow rates of different strengths by adjusting the relative angles between the blade  30  and the blade rack  20 , so as to satisfy different requirements.  
     [0032] 2. The blade  30  has a width relatively smaller than half of that of the conventional blade, so that the relative cross-sectional area is relatively smaller, and the air shearing area is relatively smaller, thereby reducing the noise due to the air shearing action.  
     [0033] 3. The blade  30  has a width relatively smaller than half of that of the conventional blade, so that the relative cross-sectional area is relatively smaller, thereby reducing the relative air resistance.  
     [0034] 4. The relative air resistance is relatively smaller, so that it needs a relatively smaller power to stir the air flow, thereby saving energy and decreasing the cost of power.  
     [0035] While the preferred embodiment of the present invention has been shown and described, it will be apparent to those skilled in the art that various modifications may be made in the embodiment without departing from the spirit of the present invention. Such modifications are all within the scope of the present invention.