Abstract:
The invention discloses a rotatable apparatus including a base and a main body attached thereon. The rotatable apparatus utilizes a gear cooperating with a rack to make the main body rotate and further move along the rack during the rotation of the main body, so as to prevent the main body from colliding with the base.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The invention relates to a rotatable apparatus, and more particularly to a rotatable apparatus which utilizes a gear to cooperate with a rack, so as to prevent a main body of the rotatable apparatus from colliding with a base during the rotation. 
         [0003]    2. Description of the Prior Art 
         [0004]    The horizontal length of the conventional liquid crystal display (LCD) is usually longer than the vertical length, such that the user can obtain a broader view in horizontal direction. Recently, as technology has been developed gradually, the personal computer (PC) has more and more functions. Consequently, rotatable LCD has been developed for the user to operate these various functions. In other words, the user may rotate the LCD by 90 degrees based on individual needs, so as to obtain a broader view in the vertical direction. 
         [0005]    In the prior art, when the user wants to rotate an LCD from horizontal to vertical, he/she needs to lift the LCD by a specific distance to prevent the LCD from colliding with a plane or a base during the rotation. Afterward, the LCD is rotated to a fixed position. According to the aforesaid mechanism of the convention LCD, it is not very convenient for the user to operate, and the design is also more complicated. 
         [0006]    Therefore, the scope of the present invention is to provide a rotatable apparatus to solve the aforesaid problem. 
       SUMMARY OF THE INVENTION 
       [0007]    A scope of the invention is to provide a rotatable apparatus which utilizes a gear to cooperate with a rack, such that a main body of the rotatable apparatus is capable of moving upward and downward along the rack during the rotation, so as to prevent the main body from colliding with a base. 
         [0008]    According to a preferred embodiment, the rotatable apparatus of the invention comprises a base, a holder, a rack, an auxiliary fastening member, a gear and a main body. The holder has a first end and a second end, and the holder is mounted onto the base via the first end. The rack is mounted onto the second end of the holder; it has a front side and a back side, wherein a plurality of teeth are provided on the front side, and a guide rail is provided on the back side. The auxiliary fastening member has a guide groove cooperating with the guide rail of the rack, such that the auxiliary fastening member is capable of moving upward and downward along the rack. The auxiliary fastening member also has a protrusion which protrudes from the guide groove. The gear has a first side and a second side. The first side of the gear is rotatably attached to the protrusion of the auxiliary fastening member, and the gear is meshed with the teeth of the rack. The main body is attached to the second side of the gear. 
         [0009]    In the aforesaid preferred embodiment, the rotation of the main body together with the gear is actuated by applying an external force on the main body to make the gear rotate relative to the teeth of the rack; at the same time, the guide groove of the auxiliary fastening member moves relative to the guide rail of the rack. Consequently, the main body rotates and moves relative to the base. In other words, when the user wants to rotate the main body of the rotatable apparatus by a specific angle, the main body is capable of moving upward and downward along the rack due to the cooperation between the gear and the rack. When the base of the rotatable apparatus is placed on a plane, and the horizontal length of the main body is longer than the vertical length, the main body is capable of rotating and moving upward along the rack, such that the user can rotate the main body by a specific angle, and the invention can prevent the main body from colliding with the base. 
         [0010]    The advantage and spirit of the invention may be understood by the following recitations together with the appended drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE APPENDED DRAWINGS 
         [0011]      FIG. 1A  is a back perspective view illustrating the rotatable apparatus according to a first preferred embodiment of the invention. 
           [0012]      FIG. 1B  is a back perspective view illustrating the main body (shown in  FIG. 1A ) being rotated by 90 degrees. 
           [0013]      FIG. 2  is a schematic diagram illustrating the rotation of the rotatable apparatus shown in  FIG. 1A . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0014]    Referring to  FIGS. 1A and 1B ,  FIG. 1A  is a back perspective view illustrating the rotatable apparatus  10  according to a first preferred embodiment of the invention.  FIG. 1B  is a back perspective view illustrating the main body  22  (shown in  FIG. 1A ) being rotated by 90 degrees. As shown in  FIG. 1A , the rotatable apparatus  10  comprises a base  12 , a holder  14 , a rack  16 , an auxiliary fastening member  18 , a gear  20 , and a main body  22 . The main body  22  may be a display device. In this embodiment, the main body  22  is an LCD. The holder  14  has a first end  140  and a second end  142 . The holder  14  is mounted onto the base  12  via the first end  140 . The rack  16  is mounted onto the second end  142  of the holder  14  and has a front side  160  and a back side  162 . A plurality of teeth are provided on the front side  160 , and a guide rail is provided on the back side  162 . In another preferred embodiment, the holder  14  and the rack  16  are monolithically formed. 
         [0015]    As shown in  FIG. 1B , the auxiliary fastening member  18  has a guide groove  180  cooperating with the guide rail  162  of the rack  16 , such that the auxiliary fastening member  18  is capable of moving upward and downward along the rack  16 . The auxiliary fastening member  18  also has a protrusion  182  which protrudes from the guide groove  180 . The gear  20  has a first side and a second side. The first side of the gear is rotatably attached to the protrusion  182  of the auxiliary fastening member  18 , and the gear  20  is meshed with the teeth of the rack  16 . The main body  22  is attached to the second side of the gear  20 . 
         [0016]    In the aforesaid embodiment, the rotation of the main body  22  together with the gear  20  is actuated by applying an external force on the main body  22  to make the gear  20  rotate relative to the teeth of the rack  16 ; at the same time, the guide groove  180  of the auxiliary fastening member  18  moves relative to the guide rail  162  of the rack  16 . In other words, when the user wants to rotate the main body  22  of the rotatable apparatus  10  by a specific angle, the main body  22  is capable of moving upward and downward along the rack  16  due to the cooperation between the gear  20  and the rack  16 , as shown in  FIGS. 1A and 1B . When the main body  22  rotates from the state shown in  FIG. 1A  to the state shown in  FIG. 1B , the main body  22  moves upward along the rack  16 , so as to prevent the main body  22  from colliding with the base  12  or the plane where the base  12  is placed. When the main body  22  rotates from the state shown in  FIG. 1B  to the state shown in  FIG. 1A , the main body  22  moves downward along the rack  16 . Furthermore, the gear  20  is rotatably attached to the protrusion  182  of the auxiliary fastening member  18  by a hinge (not shown in the figures), such that the main body  22  can be rotataed by a specific angle and be fixed at the specific angle. 
         [0017]    In the aforesaid embodiment, the rotatable apparatus  10  further comprises a resilient member  24 , as shown in  FIG. 1A . The resilient member  24  is positioned between the rack  16  and the auxiliary fastening member  18 , so as to assist the gear  20  in rotating relative to the rack  16 . Accordingly, it is easier for the user to rotate the main body  22 . The resilient member  24  may be a line spring or the like. 
         [0018]    Referring to  FIG. 2 ,  FIG. 2  is a schematic diagram illustrating the rotation of the rotatable apparatus  10  shown in  FIG. 1A . As shown in  FIG. 2 , to prevent the main body  22  from colliding with the base  12  or the plane where the base  12  is placed, the rotatable apparatus  10  can be further designed to satisfy an inequality (equation 1) as follows: 
         [0000]        R ×θ&gt;√{square root over (L 2   +W   2 )} −W.    Equation 1 
         [0019]    In equation 1, L represents half of the length of the main body  22 , W represents half of the width of the main body  22 , R represents the radius of the gear  20 , and θ represents a desired angle with which the main body  22  is rotated. Furthermore, R×θ represents the distance which the main body  22  moves up while the main body  22  is rotated by the angle θ. 
         [0020]    Compared to the prior art, when the user wants to rotate the main body  22  of the rotatable apparatus  10  by a specific angle θ, the main body  22  is capable of moving upward along the rack  16  due to the cooperation between the gear  20  and the rack  16 , so as to prevent the main body  22  from colliding with the base  12  or the plane where the base  12  is placed. Accordingly, the invention simplifies the complicated structure of the prior art, and it is more convenient and practical for the user. 
         [0021]    With the example and explanations above, the features and spirits of the invention will be hopefully well described. Those skilled in the art will readily observe that numerous modifications and alterations of the device may be made while retaining the teaching of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.