Patent Publication Number: US-2011047763-A1

Title: Fastener and device housing using the same

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is related to four co-pending U.S. patent applications, application serial nos. [to be determined], with Attorney Docket No. US28910, US28911 and US28913, and all entitled “DEVICE HOUSING,” application serial no. [to be determined], with Attorney Docket No. US28914, and entitled “METHOD FOR MANUFACTURING DEVICE HOUSING.” The co-pending applications have the same assignee as the present application. 
    
    
     BACKGROUND 
     1. Technical Field 
     The present disclosure relates generally to fasteners and, more particularly, to a fastener for a device housing of electronic devices. 
     2. Description of Related Art 
     With developments in technology, electronic devices such as mobile phones are not only required to perform many functions, but also provide an appearance appealing to the user. 
     A frequently used device housing for a mobile phone includes a plastic frame and a plurality of fasteners engaged with the frame. The fasteners are generally metal pieces, and connected to the plastic frame by injection molding or screws. 
     However, if the device housing is formed by injection molding, combined strength between the plastic frame and the fasteners is minimal because the fasteners are substantially rectangular pieces. The fasteners are easily pulled out of the plastic frame with use. If the fasteners are fixed to the plastic frame by screws, combined strength is improved, but assembly becomes less efficient. 
     Therefore, a fastener and a device housing using the fastener overcoming the described limitations is desirable. 
    
    
     
       BRIEF DESCRIPTION OF THE 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 disclosure. Moreover, in the drawings, like reference numerals designate corresponding parts throughout the several views. 
         FIG. 1  is an isometric view of a first embodiment of a fastener. 
         FIG. 2  is an isometric view of a second embodiment of a fastener. 
         FIG. 3  is an isometric view of a third embodiment of a fastener. 
         FIG. 4  is an isometric view of a fourth embodiment of a fastener. 
         FIG. 5  is an isometric view of a fifth embodiment of a fastener. 
         FIG. 6  is an isometric view of a sixth embodiment of a fastener. 
         FIG. 7  is an isometric view of a seventh embodiment of a device housing. 
         FIG. 8  is an exploded, isometric view of the device housing of  FIG. 7 . 
         FIG. 9  is a partial, side view of the device housing of  FIG. 7 . 
         FIG. 10  is a cross-section of the device housing of  FIG. 7  taken along line X-X. 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIG. 1 , a first embodiment of a fastener  30  includes a main body  31  and a hook portion  33  extending from an end of the main body  31 . The main body  31  defines a connecting hole  35  in an end adjacent to the hook portion  33 . The connecting hole  35  is configured to allow molten material to flow therethrough during injection molding. In the illustrated embodiment, the main body  31  is substantially rectangular. The fastener  30  is made of metal. The connecting hole  35  is an isosceles trapezoid hole, and a width of the connecting hole  35  decreases from a first end to a second end, along a direction towards the hook portion  33 . Two flat engaging surfaces  351  opposite to each other are formed on a sidewall defining the connecting hole  35 . 
     Referring to  FIG. 2 , a second embodiment of a fastener  40  differs from the fastener  30  of the first embodiment. The fastener  40  includes a main body  41  and a hook portion  43  extending from an end of the main body  41 . The main body  41  defines a connecting hole  45  in an end adjacent to the hook portion  33 , and an assembly hole  46  in another end away from the hook portion  43 . Two flat engaging surfaces  451  opposite to each other are formed on a sidewall defining the connecting hole  45 . In the illustrated embodiment, the engaging surfaces  451  are angled. 
     Referring to  FIG. 3 , a third embodiment of a fastener  50  differs from the fastener  30  of the first embodiment in that a main body  51  defines two connecting holes  55  arranged side by side in an end adjacent to a hook portion  53 . Two flat engaging surfaces  551  opposite to each other are formed on a sidewall defining each connecting hole  55 . It should be pointed out that the fastener  50  may define more than two connecting holes  55 . 
     Referring to  FIG. 4 , a fourth embodiment of a fastener  60  differs from the fastener  30  of the first embodiment only in that a connecting hole  65  of the fastener  60  is hemispherical, with a width decreasing from a first end to the second end, towards a hook portion  63 . Two curved engaging surfaces  651  opposite to each other are formed on a sidewall defining the connecting hole  65 . 
     Referring to  FIG. 5 , a fifth embodiment of a fastener  70  differs from the fastener  40  of the second embodiment only in that a connecting hole  75  of the fastener  70  is substantially rectangular. Two rough engaging surfaces  751  opposite to each other are formed on a sidewall defining the connecting hole  75 . Each rough engaging surface  751  is composed of a plurality of slight sloping surfaces. 
     Referring to  FIG. 6 , a sixth embodiment of a fastener  80  differs from the fastener  40  of the second embodiment, except that a connecting hole  85  of the fastener  80  is parallelogrammic. An engaging surface  851  is formed on a sidewall defining the connecting hole  85 . In the illustrated embodiment, the engaging surfaces  851  is angled. 
     Referring to  FIGS. 7 through 10 , a seventh embodiment of a device housing  90  is integrally formed by a plastic frame  91  and a plurality of fasteners  30 ,  40  and  50 . The plastic frame  91  includes a side frame  911  and an annular positioning portion  912  formed on an inner surface of the side frame  911 . A plurality of engaging portions  913 , corresponding to the connecting holes  35 ,  45  and  55  of the fasteners  30 ,  40  and  50 , are formed on a bottom end of the side frame  911 . In the illustrated embodiment, the side frame  911  is substantially rectangular. The plastic frame  91  is comprised of nylon and fiberglass. A cross-section of the engaging portions  913  parallel to the fasteners  30 ,  40  and  50  is substantially an isosceles trapezoid. In alternative embodiments, the device housing  90  can be integrally formed by a plastic frame  91  and with more than one of the fasteners  30 ,  40 ,  50 ,  60 ,  70  and  80 . 
     The device housing  90  can be integrally formed by positioning the fasteners  30 ,  40  and  50  in an injection mold (not shown) and injecting molten material towards the fasteners  30 ,  40  and  50 , such that the molten material flows through and fills in the connecting holes  35 ,  45  and  55  of the fasteners  30 ,  40  and  50  to form the plastic frame  91  when the molten material cools. 
     After the device housing  90  is formed, the hook portions  33 ,  43  and  53  of the fasteners  30 ,  40  and  50  are hooked on the plastic frame  91 , thus preventing the fasteners  30 ,  40  and  50  from disengaging from the plastic frame  91 . Moreover, the plastic frame  91  has engaging portions  913  with a cross-section of an isosceles trapezoid. Thus, when the engaging portions  913  are engaged in the connecting holes  35 ,  45  and  55  of the fasteners  30 ,  40  and  50 , the engaging portions  913  resist the engaging surface  351 ,  451  and  551 . When fasteners  30 ,  40  and  50  are pulled, a force is generated between the engaging portions  913  and the engaging surface  351 ,  451  and  551  to prevent the fasteners  30 ,  40  and  50  from disengaging from the plastic frame  91 . Therefore, a combined strength of the fasteners  30 ,  40  and  50  and the plastic frame  91  is further improved. 
     It should be pointed out that the connecting holes  35 ,  45  and  55  of the fasteners  30 ,  40  and  50  may be other shapes, such as a triangle, but a width of the connecting holes  35 ,  45  and  55  should still decrease along a direction towards the hook portions  33 ,  43  and  53 . In addition, since the fastener  60  has the curved engaging surfaces  651 , and the fastener  70  has the rough engaging surfaces  751 , the plastic frame  91  can form the engaging portion  913  resisting or engaging with the engaging surfaces  651 ,  751 , so as to enhance a combined strength of the fasteners  60 ,  70  and the plastic frame  91 . 
     It is believed that the present embodiments and their advantages will be understood from the foregoing description, and it will be apparent that various changes may be made thereto without departing from the spirit and scope of the disclosure or sacrificing all of its material advantages.