Patent Abstract:
A hidden ceiling fan includes a motor as a power source which has a top end fastened to a ceiling and a spindle connecting to a plurality of vanes. The bottom of the motor has a cover plate. There is a shield plate beneath the vanes to couple with at least one luminous element on the bottom side thereof. The invention provides a shielding function and can agitate air thoroughly to rapidly lower temperature and keep temperature evenly.

Full Description:
FIELD OF THE INVENTION  
       [0001]     The present invention relates to a ceiling fan and particularly to a ceiling fan that has a luminous function and hidden rotary vanes to agitate indoor air to achieve even temperature.  
       BACKGROUND OF THE INVENTION  
       [0002]     Referring to  FIGS. 1 and 2 , a conventional ceiling fan is fixedly hung on the ceiling and aims to save space on the floor and generate a greater amount of indoor airflow to cool a wider area in a room. But it also has drawbacks, such as (1) interfering light: a pendant fan generally has large vanes  1  which create interference of a light source  2  mounted onto the ceiling during fast rotation, as a result blinking is generated constantly. Although some new deigns have put the light source  2  under the fan, some of the light still project to the rotating vanes and the ceiling and the light is reflected to the rotating vanes and blinking still occurs at a mitigated degree. In such an environment for a prolonged period of time, people&#39;s vision suffers, and mental fatigue and irritation might take place; (2) unsafety: the pendant fan is installed in an open (unguarded) condition. The fast rotating vanes give people an unsafe feeling. Moreover, in order to spare air intake area, the bracing spot on the upper side is very small but has to carry a large and heavy main body. As a result, some pendant fans often sway left and right after being used for a period of time, and give people a constant uneasiness; (3) against spatial principle: according to the structural principle, the pendant fan has to spare a large area for the air intake purpose. Hence it is preferably to be hung closer to the floor. Such an arrangement would make the vanes close to the heads of people. It gives an oppressive feeling. This is especially noticeable in the modern houses where the distance between the floor and ceiling is usually not very large due to cost consideration. Hence to install the pendant fan in such an environment is against spatial and aesthetic principle. For the newer design that places the light source  2  below the vanes  1 , the space constraint is even worse; (4) insufficient airflow: the conventional fan and pendant fan has constant airflow directions, especially the pendant fan. The airflow in the fan is uneven because the airflow at the front tip is very strong while at the other angles is very small or even absent. Moreover, with the pendant fan blowing air directly to the floor, dusts are disturbed and cause ill effect to people&#39;s respiratory tracts. This is especially keen in the air-conditioning environment.  
         [0003]     Because of the disadvantages mentioned above, the ceiling fan is usually not practical to be used in bedrooms, study or small and medium stores.  
       SUMMARY OF THE INVENTION  
       [0004]     Therefore the primary object of the invention is to provide a hidden ceiling fan that is safer and may be fixedly fastened beneath the ceiling. The vanes are hidden so that their rotation is not visible to human eyes. The unsafe feeling may be eliminated, and aesthetic appealing improves. A plurality of luminous elements may be attached to the lower side so that the luminous elements will not be interfered by the rotating vanes. Thus people&#39;s vision is not affected.  
         [0005]     Another object of the invention is to provide a hidden ceiling fan that has a thickness only ⅓ to ¼ of a conventional pendant fan so that its distance from the floor is greater than the conventional pendant fan&#39;s, and is spaced from people&#39;s heads at a greater distance. Therefore it can avoid creating oppressive feeling to people.  
         [0006]     Yet another object of the invention is to provide a hidden fan that can generate airflow like natural wind to agitate the indoor air and create even temperature without dead angles. In the open space, it can generate an effect like a blower to dispel heated air in the room rapidly.  
         [0007]     The foregoing, as well as additional objects, features and advantages of the invention will be more readily apparent from the following detailed description, which proceeds with reference to the accompanying drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]      FIG. 1  is a schematic view of a conventional pendant fan.  
         [0009]      FIG. 2  is a side view of a conventional pendant fan.  
         [0010]      FIG. 3  is an exploded view of an embodiment of the present invention.  
         [0011]      FIG. 4  is a perspective view of the present invention.  
         [0012]      FIG. 5  is a bottom view of the present invention.  
         [0013]      FIG. 6  is a schematic view of airflow directions of the present invention installed on the ceiling.  
         [0014]      FIG. 7  is a side view of an embodiment of the present invention.  
         [0015]      FIG. 8  is a bottom view of the vanes showing the airflow direction.  
         [0016]      FIG. 9  is another schematic view of airflow directions of the present invention installed on the ceiling.  
         [0017]      FIG. 10  is yet another schematic view of airflow directions of the present invention installed on the indoor ceiling.  
         [0018]      FIG. 11  is an exploded view of a second embodiment of the present invention.  
         [0019]      FIG. 12  is a side view of the second embodiment of the present invention installed on the ceiling.  
         [0020]      FIG. 13  is a perspective view of the present invention coupled with luminous elements. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0021]     Please referring to  FIGS. 3 and 4 , the hidden ceiling fan according to the present invention includes a power source  10  such as a motor which has a top side fastened to a ceiling a. The power source  10  has a spindle  11  in the center with the periphery connecting to a plurality of rotary arms  12 . Each of the rotary arms  12  has an outer end fastened to a vane  13  which is a flat plate (or a plate formed with a helical surface). The elevation of the bottom side of the vanes  13  is lower than the bottom side of the power source  10 . There is a cover plate  14  attached to the bottom side of the power source  10  to mask the power source  10  and the rotary arms  12 . A thin shield plate  15  is provided beneath the vanes  13 . The shield plate  15  has an opening  151  in the center. The opening  151  has a diameter smaller than the outer diameter of the cover plate  14 . The shield plate  15  has an outer diameter  15  greater than the diameter of the perimeter formed by the vanes  13 . The shield plate  15  further has a plurality of screw struts  152  on the top surface to run through apertures  154  formed on the bottom of Z-shape fastening rods  153  and to couple with nuts  155  for fastening. The fastening rods  153  have the top end fastened to the ceiling a. Referring to  FIG. 5  for the bottom view and  FIG. 6  for the installation condition.  
         [0022]     Referring to  FIGS. 2 and 7 , when the hidden ceiling fan of the invention is installed on the ceiling a, its thickness is about ⅓ to ¼ of a conventional pendant fan. Hence its bottom is spaced from the floor and people&#39;s heads at a greater distance, and can eliminate the oppressive feeling occurred. Moreover, rotation of the vanes  13  is invisible when people look upwards. Thus the unsafe or uneasy feeling may be eliminated. When the vanes  13  rotate, airflow moves in two directions. One lifts upwards through the center of the vanes  13  and flows downwards along the peripheral edges of the vanes  13  as shown in  FIG. 6 . The other leaves the fan in the tangent direction and ventilates the air of the entire room constantly like water flow in a laundry machine (referring to  FIGS. 8 and 9 ). With the air circulating constantly, people at any location in the room can receive the airflow like natural wind. And the airflow can reach a wider scope rather than limit to a certain angle below the vanes  13 . Thus it overcomes the problem of the conventional fan that has a stronger wind beneath the fan but cannot reach remote corners.  
         [0023]     When the invention is used with an air conditioning system, the cool air at a lower side in the room will be carried upwards, and agitated by the vanes  13  and flow outwards and downwards. It also can match the airflow direction of the cool air. The vanes  13  of the invention may rotate in the positive direction or in the reverse direction to ventilate the air rapidly to the entire room to create even temperature. Hence the problem of feeling too cool beneath the fan but not cool enough at the remote corners may be resolved.  
         [0024]     Refer to  FIG. 10  for the invention is installed in an open space. When the vanes  13  rotate, they function like a blower to carry the cool air from ambience outside the doors or windows into the room, and agitate the indoor air of a higher temperature and disperse outdoors. Hence it can dispel heat rapidly, and also can carry outside cool air to the vanes  13  to be agitated, and generate wind to dispel heat and produce a cooling effect.  
         [0025]     Refer to  FIGS. 11 and 12  for a second embodiment of the invention. It is constructed largely like the first embodiment set forth above. The difference is that the top end of the Z-shape fastening rod  153  is fastened to the periphery of the cover plate  14 , and the aperture  154  on the lower end is rested on the top surface of the shield plate  15  and coupled with the screw strut  152  and fastened by the nut  155  to fasten the shield plate  15  and the cover pate  14  together  
         [0026]     It is to be noted that, a plurality of luminous elements  20  such as lighting bulbs may be mounted on the lower side of the shield plate  15  (referring to  FIG. 13 ) on the outer side so that when the vanes  13  rotate the light emitted by the luminous elements  20  is not interfered, and no blinking is generated. As the luminous elements  20  project light to the ceiling that is reflected downwards, brightness can be enhanced. In addition, the invention has a small thickness, and rotation of the vanes  13  is not visible to people&#39;s eyes, and can be fabricated at a smaller size, it is more aesthetic appealing and easier to be incorporated in the interior design to meet modern spatial aesthetic requirements. Because of these advantages, the invention is more adaptable to small rooms such as bedroom, study and the like.

Technology Classification (CPC): 5