Abstract:
A rotation structure rotates a rotatable segment via the attraction between a number of electromagnetic elements disposed on another rotatable segment around a screw and a magnet disposed on another rotatable segment. The rotated angle of the rotatable segment can be controlled by selectably magnetizing the electromagnetic elements in response to an instruction generated by pressing a button formed on another rotatable segment.

Description:
BACKGROUND 
     1. Technical Field 
     The present disclosure relates to rotation structures and, particularly, to an automatic rotation structure. 
     2. Description of Related Art 
     Currently, rotation structures used in cellular phones must be manually rotated by users. This is an inconvenience. Also, repeated operations of rotation may strain the user&#39;s fingers. 
     What is needed, therefore, is a rotation structure which can overcome the above-mentioned problems. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       Many aspects of the present embodiments can be understood with reference to the figures. The components in the figures are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present embodiments. Moreover, in the figures, like reference numerals designate corresponding parts throughout the several views. 
         FIG. 1  is an exploded, isometric, schematic view of an exemplary embodiment of a rotation structure. 
         FIG. 2  is an exploded, isometric, schematic view of the rotation structure of  FIG. 1 , viewed from another angle. 
         FIG. 3  is an assembled, isometric, schematic view of the rotation structure of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIGS. 1-2 , a rotation structure  1  includes a first rotatable segment  12 , a second rotatable segment  14 , a connecting portion  16 , a controller  18 , and a drive device  20 . 
     The first rotatable segment  12  includes a first base  120  and a first cover  130 . The first base  120  includes a first bottom  121 , a first sidewall  122 , and a button  123 . The first bottom  121  is a flat plate and includes a first circular section  121   a  and a first elliptical section  121   b . The first elliptical section  121   b  extends from the first circular section  121   a  along the radial direction of the first circular section  121   a . A first through hole  124  is defined in the center of the first circular section  121   a . The first sidewall  122  perpendicularly extends from the edge of the first bottom  121 . 
     The button  123  is formed on the first sidewall  122  for generating the control instruction of the rotation structure  1 . The button  123  includes a first end  123   a  and a second end  123   b . If the first end  123   a  is pressed, a clockwise rotation instruction is triggered. If the second end  123   b  is pressed, an anti-clockwise rotation instruction is triggered. 
     The first cover  130  is substantially the same as the first base  120  in shape for fittingly covering the first base  120 . The first cover  130  and the first base  120  corporately define an accommodating space. 
     The second rotatable segment  14  is substantially similar to the first rotatable segment  12  in shape and includes the counterparts of the first rotatable segment  12 . For example, the second segment  14  includes a second base  140  and a second cover  150 . The second base  140  includes a second bottom  141  and a second sidewall  142 . The second bottom  141  is a flat plate and includes a second circular section  141   a  and a second elliptical section  141   b . A second through hole  144  is defined in the center of the second circular section  141   a.    
     The connecting portion  16  includes a pair of nuts  160  and a screw  162 . The screw  162  includes a first threaded end  162   a , a second threaded end  162   b , and a flange  162   c . The flange  162   c  is a circular plate and interconnects the first threaded end  162   a  and the second threaded end  162   b . The diameter of the flange  162   c  is greater than that of the first threaded end  162   a  and the second threaded end  162   b . The flange  162   c  is configured for positioning the connecting portion  16  between the first rotatable segment  12  and the second rotatable segment  14 . 
     The drive device  20  includes a number of electromagnetic elements  200 , and a permanent magnet  201 . The electromagnetic element  200  can be any electromagnetic element, such as iron wrapped with a coil of wire. The electromagnetic elements  200  can be magnetized by applying a current to the coil of wire. The permanent magnet  201  can be attracted by the magnetized electromagnetic element  200  for providing the force to drive the rotation structure  1 . 
     The controller  18  is configured for controlling the rotated angle of the rotation structure  1  according to the control instruction generated by the button  123 . 
     In assembly, the electromagnetic elements  200  are disposed on the first bottom  121  around the first through hole  124  at a predetermined angle θ. The angle θ is the smallest angular step of the rotation structure  1 . The permanent magnet  201  is fixed on a second bottom  141  of the second rotatable segment  14  and positioned in the effective range of the electromagnetic elements  200 . 
     The first rotatable segment  12  is rotatably connected to the screw  162  by inserting the first threaded end  162   a  of the screw  162  through the first through hole  124  and tightening the nut  160  on the first threaded end  162   a . The second rotatable segment  14  is rotatably connected to the screw  162  by inserting the second threaded end  162   b  of the screw  162  through the second through hole  144  and tightening the nut  160  on the second threaded end  162   b.    
     The controller  18  is electrically connected to the button  123  and the electromagnetic elements  200 . 
     In use, also referring to  FIG. 3 , the button  123  is pressed to generate the control instruction. The controller  18  changes the position of the magnetized electromagnetic element  200  at a direction determined by the control instruction. The magnetized electromagnetic element  200  attracts the permanent magnet  201  fixed on the second rotatable segment  14  and drives the second rotatable segment  14  to rotate about the screw  162 . Therefore, the second rotatable segment  14  follows the changes of the magnetized electromagnetic element  200  and rotates to different positions. 
     When the button  123  is no longer pressed, the controller  18  stops changing the position of the magnetized electromagnetic element  200 . The second rotatable segment  14  remains at the position where the permanent magnet  201  and the magnetized electromagnetic element  200  are aligned. 
     It is understood that the speed of the position change of the magnetized electromagnetic element  200  can be preset through the controller  18 . Therefore, the second rotatable segment  14  can rotate at different rate according to the preset value. 
     The rotation structure  1  uses magnetism to drive the second rotatable segment  14  to rotate. The rotation position of the second rotatable segment  14  can be controlled by manipulating the electromagnetic elements  200 . Therefore, the rotation structure  1  can work more conveniently. 
     While certain embodiments have been described and exemplified above, various other embodiments will be apparent to those skilled in the art from the foregoing disclosure. The present invention is not limited to the particular embodiments described and exemplified but is capable of considerable variation and modification without departure from the scope of the appended claims.