Patent Publication Number: US-2009236769-A1

Title: Injection mold and method for making a housing using the injection mold

Description:
RELATED APPLICATIONS 
     This application is related to U.S. Pat. No. 18,915, filed concurrently with this application and assigned to the same entity as this application. 
    
    
     BACKGROUND 
     1. Field of the Invention 
     The present invention relates to an injection mold and a method for making a housing using the injection mold and especially relates to a rotating injection mold and a method for making a housing with soft layer using the rotating injection mold. 
     2. Description of Related Art 
     The housing is one of the main components of electronic devices, such as telephones, computers and etc. Because molded articles have advantages of being light, low cost and anti-corrosion, housings for electronic devices are often made by injection molding. 
     To enable the housings to have a good touch feel, in the prior art, a soft layer, such as leather or fabric is formed on the housings. When making such housings, the soft layer is firstly positioned into the mold. After injecting plastic material into the mold, the plastic material is cooled and attaches to the soft layer to form a semi-finished product. The semi-finished product is then removed from the mold and superfluous edges of the soft layer cut. However, the cutting process can be complicated, and the processing efficiency is low. 
     Therefore, there is room for improvement within the art. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a schematic view of an exemplary embodiment of the present injection mold; 
         FIG. 2  shows a cross-sectional view of a housing making by the injection mold; 
         FIG. 3  shows a schematic view of a first soft layer of the housing put in the injection mold; 
         FIG. 4  shows a schematic view of closing the injection mold to injecting; 
         FIG. 5  shows a schematic view of rotated the injection mold; 
         FIG. 6  shows a schematic view of the injection mold rotating injection and opening after cutting; and 
         FIG. 7  shows a schematic view of another exemplary embodiment of the injection mold. 
     
    
    
     DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS 
       FIG. 1  shows an exemplary embodiment of an injection mold  100  used to make a housing  90  ( FIG. 2 ) including a main body  92  and a soft layer  94  formed on the main body  92 . 
     The injection mold  100  is a rotating injection mold including a first female mold  10 , a second female mold  20 , a first male mold  30  and a second male mold  40  connected to the first male mold  30 . 
     The first female mold  10  defines a first cavity  102 . The second female mold  20  includes a joining surface  202  facing to one of the first male mold  30  and the second male mold  40 , a second cavity  203  defined therein and two cutting portions  204  formed on the joining surface  202 . The cutting portion  204  may be a cutting mold with blades for cutting the soft layer  94  on a semi-finished product of the housing  90 . 
     The first male mold  30  has a first protruding portion  32  and a first runner  34  extending through the first male mold  30 . The second male mold  40  has a similar structure as the first male mold  30 . The second male mold  40  has a second protruding portion  42 , and a second runner  44  extending through the second male mold  40 . The first male mold  30  and the second male mold  40  are mounted on a rotating platform  70 . The rotating platform  70  drives the first male mold  30  and the second male mold  40  to rotate to respectively match with the first female mold  10  and second female mold  20 . 
     The method for making the housing  90  by using the injection mold  100  includes following steps: 
     Referring to  FIG. 3 , the injection mold  100  is opened, with the two male molds separated from the two female molds. At this moment, the first male mold  30  aligns with the first female mold  10 , and the second male mold  40  aligns with the second female mold  20 . 
     A preformed soft layer  94  is then placed on the first female mold  10  to enclose the first cavity  102 . 
     In  FIG. 4 , the injection mold  100  is closed. The first male mold  30  and the first female mold  10  define a first chamber  103  therebetween. The first protruding portion  32  of the first male mold  30  pushes the preformed soft layer  94  into the cavity  102  of the first female mold  10 . 
     A melted material (e.g., plastic and/or silicone) is injected into the first chamber  103  through the first runner  34  to combine with the soft layer  94 . As such, a first semi-finished product  96  of the housing  90  is formed. 
     After the first semi-finished product  96  is cooled, the injection mold  100  is opened ( FIG. 5 ). The first semi-finished product  96  is attached to the first protruding portion  32  of the first male mold  30 . The rotating platform  70  rotates the first male mold  30  and the second male mold  40  to make the first male mold  30  with the first semi-finished product  96  align with the second female mold  20 . 
     The injection mold  100  is closed again. The first male mold  30  moves towards the second female mold  20 , and superfluous edges of the preformed soft layer  94  are then cut by the cutting portion  204 . The housing  90  is complete. 
     Finally, the injection mold  100  is opened. The housing  90  is removed from the injection mold  100 . 
     It is to be understood, in the sixth step, before the injection mold  100  is closed, another preformed soft layer  940  can be put onto the first female mold  10  to cover the first cavity  102 . At the same times, a second chamber (not shown) is formed by the second male mold  40  and the first female mold  10 . Then, melted material is injected into the second chamber through the second runner  44 . The melted material combines with another preformed soft layer  940  to form a second semi-finished product  960  of the housing  90 . 
     Referring to  FIG. 6 , the injection mold  100  is cooled down, so the melted material is cooled to become a main body  920 . The rotating platform  70  of the injection mold  100  is rotated 180 degrees and the above processing steps repeated. 
     Referring to  FIG. 7 , in a further embodiment, the injection mold  100  may include two receiving slots  3002 ,  4002 . The receiving slots  3002 ,  4002  are defined between the first male mold  300  and the second male mold  400  corresponding to the cutting portions  2040  of the second female mold  200 . During a cutting process, the two cutting portions  2040  are inserted into the receiving slots  3002 ,  4002  to achieve a more precise cutting effect. 
     It is to be understood, however, that even through numerous characteristics and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and function of the invention, 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.