Patent Publication Number: US-2011064595-A1

Title: Ever-stand fan

Description:
TECHNICAL FIELD 
     This invention relates to an electrical appliance, more particularly to an electric fan. 
     BACKGROUND OF THE INVENTION 
     In hot summer, electric fans are very popular as they produce cool air to relieve summer heat. There are more and more kinds of electric fans available on the market. An electric fan is easy to tumble down when people bump on it, and needs to be helped up and adjusted before it can go on working. This causes great inconvenience to people when they are enjoying the cool air produced therefrom. 
     SUMMARY OF THE INVENTION 
     One purpose of this invention is to provide an electric fan which can quickly right itself after falling down. It is this feature that is extremely convenient for people when in use. 
     To solve the problems above, an ever-stand fan of this invention comprises a base and a motor. An upper cover, within which there is an impeller connected with the motor, is arranged over the base. The base has a small flat surface  11  with a curved face  12  on the periphery at the center of its bottom. The motor is mounted in the inner chamber of the base. The center of gravity of the ever-stand fan lies beneath the center of the base. 
     As an improvement of the technical solution above, a top cover is arranged over the upper cover. A grid is installed on the said top cover  5  to prevent oddments from going into the fan blades. 
     As a further improvement of the technical solution above, there is a shockproof rubber piece mounted under the small flat surface. 
     It is an advantage of the present invention that, when the working ever-stand fan tumbles down, the side curve of the base comes into contact with the supporting surface. As the center of gravity of the fan lies beneath the center of the base, the fan can quickly rights itself without being helped up by hand. It is a convenient and unique feature for people when the fan is in use. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       The invention may be more completely understood in consideration of the following detailed description of embodiment of the invention in connection with the accompanying drawing, in which: 
         FIG. 1  is a cross-sectional side structural view of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     With reference to  FIG. 1 , an ever-stand fan of this invention, comprises a base  1  and a motor  2 . An upper cover  3 , within which there is an impeller  4  connected with the motor  2 , is arranged over the base  1 . The base  1  has a small flat surface  11  with a curved face  12  on the periphery at the center of its bottom. The motor is mounted in the inner chamber of the base  1 . When the working ever-stand fan tumbles down, the side curve of the base comes into contact with the supporting surface. As the center of gravity of the fan lies beneath the center of the base, the fan can quickly right itself without being helped up by hand. This feature is convenient for people when in use. 
     A top cover  5  is arranged over the said upper cover  3 . A grid  51  is installed on the said top cover  5  to prevent oddments from going in to the fan. The top cover  5  and the upper cover  3  could be manufactured as a whole or as separate parts. Wherein the inside surface of the said upper cover  3  can be designed to be an Archimedes helicoid, an involute surface, a paraboloid, a hyperboloid or a logarithmic spiral surface. The inside surface of the upper cover and the peripheral surface of impeller  4  form an air duct  7 . 
     In order to reduce the noise caused by the shake of the motor which is transmitted to the space between the base and the supporting surface, there is a rubber piece  6  mounted under the said small flat surface  11 . 
     The impeller  4  is of a centrifugal type, which is made up of several upright blades  41  distributed around. When the motor  2  drives the impeller  4  to turn, the air comes into the inner chamber of the impeller from the opening of the two ends of the blades  41  and then goes out from the gap of the blades and thus forms cool air.