Abstract:
An exemplary fixing device includes an elastically deformable sleeve and a screw extendable through the sleeve. The sleeve includes a hollow column and multiple flanges extending outwardly from an outer circumferential face of the column. A plate assembly incorporating the fixing device is also provided.

Description:
BACKGROUND 
       [0001]    1. Technical Field 
         [0002]    The disclosure generally relates to fixing devices for attaching things together, and particularly to a fixing device for securing a printed circuit board to a panel. 
         [0003]    2. Description of Related Art 
         [0004]    Generally, various electronic components are mounted on a printed circuit board of an electronic device. The printed circuit board is then fixed to a support (such as a flat plate of a computer enclosure) by screws for supporting the electronic components. However, besides the typical flat shape of many supports, some supports have an irregular shape. For example, the support may include two flat plates inclined relative to each other. It is difficult to firmly and reliably fix the printed circuit board on the two inclined plates just by screws, and this can make the process of assembling the printed circuit board to the support problematic. 
         [0005]    What is needed, therefore, is a means which can address the limitations described. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]    Many aspects of the present embodiments can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale, the emphasis instead being placed upon clearly illustrating the principles of the present embodiments. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the various views. 
           [0007]      FIG. 1  is an isometric view of a plate assembly in accordance with an eclectic embodiment of the present disclosure 
           [0008]      FIG. 2  is an exploded view of the plate assembly of  FIG. 1 . 
           [0009]      FIG. 3  is an enlarged view of a fixing device of the plate assembly of  FIG. 2 . 
           [0010]      FIG. 4  is a top plan view of a first plate of the plate assembly of  FIG. 2 . 
           [0011]      FIG. 5  is a cross section of the plate assembly of  FIG. 1 , taken along line V-V thereof. 
           [0012]      FIG. 6  is an enlarged view of a circled part VI of  FIG. 5 . 
           [0013]      FIG. 7  is an enlarged, side plan view of a sleeve of the fixing device of  FIG. 2 , but showing the sleeve in a free (undeformed) state. 
       
    
    
     DETAILED DESCRIPTION 
       [0014]    Referring to  FIG. 1 , a plate assembly  10  in accordance with an eclectic embodiment of the present disclosure is shown. The plate assembly  10  includes an panel  30 , a first plate  20  disposed on the panel  30 , and three fixing devices  60  fixing the first plate  20  on the panel  30 . For simplicity, only one fixing device  60  is shown in the drawings and described herein. Furthermore, in the following description, unless the context indicates otherwise, references to “top,” “bottom,” “upper,” “lower,” “left” and “right” refer to positions and/or orientations as viewed in the drawings. 
         [0015]    Also referring to  FIGS. 2 and 5 , the panel  30  includes a second plate  40  and a third plate  50  connected to the second plate  40 . The second plate  40  is orientated horizontally, and defines a plurality of holes  42  therein. Three first posts  44  protrude upwardly from a top face of the second plate  40 . The first posts  44  are located adjacent to a boundary of the second plate  40  and the third plate  50 . For simplicity, unless the context indicates otherwise, only one of the first posts  44  will be described hereinafter. The first post  44  has a threaded hole  440  defined in a top face thereof. The third plate  50  is inclined relative to the second plate  40 . In this embodiment, an angle between a top face of the third plate  50  and the top face of the second plate  40  is larger than 180 degrees and less than 270 degrees. The third plate  50  defines a window  52  in a central area thereof. A plurality of second posts  54  are formed on the top face of the third plate  50 . 
         [0016]    Also referring to  FIG. 4 , the first plate  20  is parallel to the third plate  50  and inclined relative to the second plate  40 . In this embodiment, the first plate  20  is a printed circuit board. The first plate  20  has three fixing holes  22 ,  22   a ,  22   b  defined along one side thereof, corresponding to the first posts  44  of the second plate  40 . The fixing hole  22  is defined in a side edge of the first plate  20  adjacent to the side of the first plate  20  having the three fixing holes  22 ,  22   a ,  22   b . The fixing hole  22  includes a first portion  220 , and a second portion  222  communicating with the first portion  220 . The first portion  220  has a width gradually decreasing from the edge of the first plate  20  towards the second portion  222 . The second portion  222  has a substantially circular shape. A width of the fixing hole  22  at a boundary of the first portion  220  and the second portion  222  is less than that at the other positions of the fixing hole  220 . The first plate  20  further defines a plurality of mounting holes  24  near a periphery thereof. The mounting holes  24  correspond to the second posts  54  of the third plate  50 . Screws (not shown) extend through the mounting holes  24  into the second posts  54  to fix the first plate  20  to the third plate  50 . 
         [0017]    Also referring to  FIGS. 3 and 7 , the fixing device  60  includes a sleeve  70  and a screw  80  extending through the sleeve  70 . The sleeve  70  may be made of soft and elastically deformable material such as rubber. The sleeve  70  includes a hollow column  72 , and a plurality of flanges  74  formed on an outer circumferential face of the column  72 . The column  72  defines a through hole  720  from a top face of the sleeve  70  to a bottom face of the sleeve  70 , for receiving the screw  80 . The column  70  has a smallest outer diameter at a middle portion along a height direction thereof. The flanges  74  are parallel to each other, with intervals between every two adjacent flanges  74  (see  FIG. 7 ). In this embodiment, the flanges  74  are annular. There are three upper flanges  74  located above the middle portion of the column  72 , and three lower flanges  74  located below the middle portion of the column  72 . The middle portion of the column  72  has an outer diameter less than a diameter of the second portion  222  of the fixing hole  22 . Each flange  74  has an outer diameter larger than the diameter of the second portion  222  of the fixing hole  22 . The sleeve  70  is retained in the first plate  20  by way of the middle portion of the column  72  being pushed from the first portion  220  into the second portion  222  of the fixing hole  22 . The first plate  20  is thus sandwiched between two flanges  74  adjacent to the middle portion of the column  72 . 
         [0018]    The screw  80  includes a head  82 , and a pole  84  extending downwardly from the head  82 . The head  82  has a diameter larger than that of the through hole  720  of the sleeve  70 , and the pole  84  has a diameter less than that of the through hole  720  of the sleeve  70 . The pole  84  extends through the through hole  720  of the sleeve  70  into the first post  44  of the second plate  40 , thereby fixing the first plate  20  to the second plate  40 . 
         [0019]    Also referring to  FIG. 6 , in assembly of the plate assembly  10 , the sleeve  70  is retained in the fixing hole  22  of the first plate  20  beforehand. The first plate  20  is then disposed on the third plate  50 . The mounting holes  24  of the first plate  20  are respectively aligned with the second posts  54  of the third plate  50 , and the sleeve  70  is located just above the corresponding first post  44  of the second plate  40 . The screws (not shown) are extended through the mounting holes  24  of the first plate  20  into the second posts  54  of the third plate  50  to fix the first plate  20  to the third plate  50 . The screw  80  is extended downwardly through the sleeve  70  into the threaded hole  440  of the first post  44  of the second plate  40 . The upper flanges  74  are pressed by the head  82  of the screw  80  and deform. Right ends of the deformed upper flanges  74  abut against each other, and resiliently press against a top face of the first plate  20  in a direction towards the second plate  40 . Left ends of the deformed upper flanges  74  remain spaced from each other. The lower flanges  74  are pressed by a bottom face of the first plate  20  and deform. Left ends of the deformed lower flanges  74  abut against each other, and resiliently press against the bottom face of the first plate  20  in an upward direction. Right ends of the deformed lower flanges  74  remain spaced from each other. Thus, the first plate  20  is fixed to the second plate  40  by the sleeve  70  and the screw  80 . 
         [0020]    In order to reinforce the sleeve  70 , two latches  90  are provided on the sleeve  70 . Each latch  90  includes a wire  92 , and a plurality of hooks  94  formed on the wire  92 . The wire  92  of an upper one of the latches  90  connects the top face of the sleeve  70 , and the wire  92  of a lower one of the latches  90  connects the bottom face of the sleeve  70 . The hooks  94  of the upper latch  90  extend upwardly and inclinedly from an outer circumferential face of the wire  92 , and the hooks  94  of the lower latch  90  extend downwardly and inclinedly from an outer circumferential face of the wire  92 . The upper latch  90  extends through apertures  740  defined in the left ends of the upper flanges  74 , and the lower latch  90  extends through apertures  740  defined in the right ends of the lower flanges  74 . The hooks  94  of the upper latch  90  press upwardly against bottom faces of the left ends of the upper flanges  74 , and the hooks  94  of the lower latch  90  press downwardly against top faces of the right ends of the lower flanges  74 . Thereby, the sleeve  70  is reinforced by the two latches  90  to achieve more reliable engagement of the first plate  20  with the second plate  40 . 
         [0021]      FIG. 4  also shows two alternative types of fixing holes, namely the fixing holes  22   a ,  22   b . The first alternative type of fixing hole  22   a  includes a first portion  220   a , and a second portion  222   a  communicating with the first portion  220   a . The first portion  220   a  is substantially circular, and has a diameter larger than that of the flange  74 . The second portion  222   a  has a diameter less than that of the flange  74 , and larger than that of the middle portion of the column  72 . The sleeve  70  can be mounted in the fixing hole  22   a  by inserting the sleeve  70  into the first portion  220   a , and then moving the sleeve  70  into the second portion  222   a  from the first portion  220   a . The second alternative type of fixing hole  22   b  includes a first portion  220   b , and a second portion  222   b  communicating with the first portion  220   b . The first portion  220   b  and the second portion  222   b  are symmetrical with each other. Each of the first portion  220   b  and the second portion  222   b  has a maximum diameter less than that of the flange  74 , and a minimum diameter larger than that of the middle portion of the column  72 . The sleeve  70  can be mounted into the second portion  222   b  of the fixing hole  22   b  by directly inserting the sleeve  70  into the second portion  222   b . During this process, the lower flanges  74  (or alternatively the upper flanges  74 ) of the sleeve  70  are squeezed by edges of the first plate  20  surrounding the second portion  222   b , and thereby deform such that the lower flanges  74  can pass through the second portion  222   b . Then when the lower flanges  74  extend below the second portion  222   b , the lower flanges  74  elastically recover to their original shapes. The first plate  20  is thus sandwiched between the two flanges  74  adjacent to the middle portion of the column  72 . 
         [0022]    It is to be understood, however, that even though numerous characteristics and advantages of the present embodiments have been set forth in the foregoing description, together with details of the structures and functions of the embodiments, the disclosure is illustrative only; and changes may be made in detail, especially in matters of shape, size, and arrangement of parts within the principles of the invention to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.