Patent Document

CROSS-REFERENCE TO RELATED APPLICATIONS 
     This Non-provisional application claims priority under 35 U.S.C. §119(a) on Patent Application No(s). 098135172 filed in Taiwan, Republic of China on Oct. 16, 2009, the entire contents of which are hereby incorporated by reference. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to a fastening assembly and a method for manufacturing a fastening assembly and, more particularly, to a method in which a fastening assembly is first manufactured and then the fastening assembly is manufactured at a case. 
     2. Description of the Related Art 
     A case of an electronic apparatus is usually made of plastic, and fasteners such as screws are usually used for assembling a plastic assembly.  FIG. 1  is a schematic diagram showing a plurality of fastening assemblies  10  for fastening a second case  30  to a first case  20  in the prior art. The fastening assembly  10  includes a seat  101 , a boss  103 , and a screw  105 , and the boss  103  has a screwed hole (not shown) at an inner side. The second case  30  includes a plurality of fastening holes  301 , and the position of the fastening hole  301  on the second case  30  corresponds to the position of the corresponding boss  103  on the first case  20 . 
       FIG. 2  is a partial enlarged schematic diagram showing a connection place of the fastening assembly  10  and the first case  20  in  FIG. 1 . Generally speaking, the seats  101  at the first case  20  are integrally injected and molded with the first case  20 . Then, the boss  103  is embedded into the corresponding seat  101  by hot melting. When the second case  30  needs to be fastened to the first case  20 , the screw  105  can be screwed into the corresponding boss  103  via the corresponding fastening hole  301  of the second case  30 . After the screws  105  are screwed into the boss  103  via the fastening holes  301 , the second case  30  can be fastened to the first case  20 . In  FIG. 2 , an angle or depth of the boss  103  hot melted into the corresponding seat  101  needs to be very accurate, or else the screw  105  may fail to be accurately screwed into the corresponding boss  103  further to cause the second case  30  to fail to be accurately fastened to the first case  20 . 
       FIG. 3A  and  FIG. 3B  are side views of the fastening assembly  10 . An embedding surface of the seat  101  where the boss  103  is hot melted can be parallel to a bottom surface of the seat  101 . That is, the embedding surface can be a flat surface. Otherwise, the embedding surface may not be parallel to the bottom surface of the seat  101 . That is, the embedding surface can be an inclined plane. In addition, when one boss  103  is hot melted into one seat  101 , although the yield of the fastening assembly  10  as the embedding surface of the seat  101  is a flat surface is better than that as the embedding surface is an inclined plane, the yield of the fastening assembly  10  is mostly only 95%. However, the yield mentioned above is for facilitating elaboration of the objective of the invention, and the practical yield is obtained by manufacture statistics. 
     According to the above, the yield of the whole group of the fastening assembly  10  may decrease to about 60% (i.e., about 0.95 to the tenth power) while supposing that the first case  20  includes ten fastening assemblies  10  and the yield of each fastening assembly  10  is about 95%. That is, since the ten seats  101  are simultaneously injected and molded with the first case  20  first, once one of the boss  103  fails to be accurately embedded into the corresponding seat  101  by hot melting, the first case  20  including the ten seats  101  and the boss  103  embedded into the seats  101  by hot melting may be all scrapped. Thus, the cost of the electronic apparatus will increase. 
     Since the seat  101  of the conventional fastening assembly  10  is simultaneously injected and molded with the first case  20  first, once the first case  20  includes a plurality of seats  101  and any one of the boss  103  fails to be accurately embedded into the corresponding seat  101  by hot melting, the whole first case  20  may be scrapped and fail to be reused. 
     BRIEF SUMMARY OF THE INVENTION 
     One objective of this invention is to provide a fastening assembly and a method for manufacturing a fastening assembly to improve yield of manufacturing the fastening assembly and to avoid problems of higher developing cost and unnecessary expense of electronic apparatus in the prior art. 
     This invention provides a method for manufacturing a fastening assembly for an electronic apparatus. The electronic apparatus includes a first case. The method at least includes the following steps. A boss is embedded into a seat by hot melting to allow the boss and the seat to form a first fastening element, and the boss has a screwed hole. The first fastening element is then disposed at the first case by hot melting. 
     This invention also provides a fastening assembly for fastening a first case and a second case of an electronic apparatus. The fastening assembly includes a first fastening element and a second fastening element. The first fastening element is disposed at the first case by hot melting, and the first fastening element has a boss and a seat. The boss is embedded into the seat by hot melting and the boss has a screwed hole. The second fastening element passes through a fastening hole of the second case and is screwed into the boss of the first fastening element to fasten the first case and the second case. After the boss is embedded into the seat by hot melting, the first fastening element is disposed at the first case by hot melting. 
     In the invention, the seat of the fastening assembly is not injected and molded with the first case simultaneously, that is, the seat is disposed at the first case by hot melting after the boss is embedded into the seat by hot melting. Therefore, according to the method in the invention, the yield of the first fastening element can be greatly improved further to improve the assembling yield of fastening the second case to the first case. 
     These and other features, aspects, and advantages of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic diagram showing a plurality of fastening assemblies for fastening a second case to a first case in the prior art; 
         FIG. 2  is a partial enlarged schematic diagram showing a connection place of the fastening assembly and the first case in  FIG. 1 ; 
         FIG. 3A  is a side view of a fastening assembly, wherein an embedding surface of a seat where a boss is hot melted is a flat surface; 
         FIG. 3B  is a side view of a fastening assembly, wherein an embedding surface of a seat where the boss is hot melted is an inclined plane; 
         FIG. 4A  to  FIG. 4C  are schematic diagrams showing manufacturing a fastening assembly according to one embodiment of the invention; and 
         FIG. 5  is a schematic diagram showing fastening assemblies for fastening a second case to a first case according to one embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 4A  to  FIG. 4C  are schematic diagrams showing manufacturing a first fastening element  41  according to one embodiment of the invention. In  FIG. 4A  to  FIG. 4C , a fastening assembly  40  includes a first fastening element  41  and a second fastening element  42 . The first fastening element  41  is disposed at a first case  50  by hot melting and has a seat  411  and a boss  413 . The boss  413  is embedded into the seat  411  by hot melting and has a screwed hole (not shown). The second fastening element  42  can pass through a second case  60  (refer to  FIG. 5 ) and be screwed into the boss  413  of the first fastening element  41  to fasten the first case  50  and the second case  60 . The first fastening element  41  is disposed at the first case  50  by hot melting after the boss  413  is embedded into the seat  411  by hot melting. That is, the seat  411  and the first case  50  are injected and molded separately. Further, in one preferred embodiment, the first fastening element  41  will be inspected after the boss  413  is embedded into the seat  411  by hot melting to ensure the quality of the first fastening element  41 . The qualified first fastening element  41  is then disposed at the first case  50  by hot melting, thus to greatly improve the manufacturing yield of the fastening assembly  40 . 
     According to  FIG. 4A  to  FIG. 4C , the method for manufacturing a fastening assembly in one embodiment of the invention is further described below. Referring to  FIG. 4A , the seat  411  is injected and molded first, and the boss  413  is then embedded into the seat  411  by hot melting. An embedding surface of the seat  411  where the boss  413  is hot melted is an inclined plane, and the seat  411  further has a plurality of hot melting points  4111 . The first fastening element  41  is then inspected after the boss  13  is embedded into the seat  411  by hot melting. If the first fastening element  41  is qualified, the first fastening element  41  passes through a fastening hole  501  of the first case  50  and is hot melted at the first case  50  via the hot melting points  4111  of the seat  411  as shown in  FIG. 4B . When the qualified first fastening elements  41  are all hot melted at the first case  50 , the second case  60  can be fastened to the first case  50  after the second fastening elements  42 , i.e. screws, are screwed into the corresponding bosses  413  by passing through fastening holes  601  of the corresponding second case  60  as shown in  FIG. 4C . In view of structural strength, the embedding surface of the seat  411  is fitted to an inner wall of the second case  60 , which is not shown. 
       FIG. 5  is a schematic diagram showing the fastening assembly  40  for fastening the second case  60  to the first case  50  according to one embodiment of the invention. In  FIG. 5 , the seat  411  is hot melted at the first case  50  via the hot melting points  4111  thereon after the first fastening element  41  passes the inspection. After all of the qualified first fastening element  41  are hot melted at the first case  50 , and the second fastening elements  42 , i.e. screws, are screwed into the corresponding bosses  413  via the fastening holes  601  of the corresponding second case  60 , the second case  60  can be fastened to the first case  50 . In view of the structural strength, the embedding surface of the seat  411  can be fitted to the inner wall of the second case  60 , which is not shown. 
     To sum up, the seat  411  is not simultaneously injected and molded with the first case  50 , and the seat  411  and the first case  50  are injected and molded separately. That is, the seat  411  is disposed at the first case  50  by hot melting after the boss  413  is embedded into the seat  411  by hot melting. In addition, the first fastening elements  41  are all inspected thus to ensure that the first fastening elements  41  hot melted at the first case  50  are all qualified, further to improve the assembling yield of fastening the second case  60  to the first case  50 . 
     Furthermore, If the seat  411  is inspected to be unqualified, only the single unqualified first fastening element  41  is scrapped since the seat  411  is still not disposed at the first case  50  by hot melting at that moment, and it is different from the conventional manufacture of the fastening assembly  10 . During the conventional manufacture, all of the seats  101  simultaneously injected and molded with the first case  20  and the bosses  103  hot melted into the seats  101  are all scrapped. Compared with the prior art, according to the method for manufacturing a fastening assembly in the invention, manufacturing cost of the apparatus can be effectively reduced. 
     According to one preferred embodiment, the first case  50  and the second case  60  are made of plastic. However, the invention is not limited thereto. 
     Furthermore, in the embodiment of the invention, the fastening assembly  40  used for fastening the first case  50  and the second case  60  of the electronic apparatus is taken for example. However, the invention is not limited thereto. The fastening assembly  40  in the invention can also be used for fastening cases of any apparatus. 
     Although the present invention has been described in considerable detail with reference to certain preferred embodiments thereof, the disclosure is not for limiting the scope of the invention. Persons having ordinary skill in the art may make various modifications and changes without departing from the scope and spirit of the invention. Therefore, the scope of the appended claims should not be limited to the description of the preferred embodiments described above.

Technology Category: 7