Patent Publication Number: US-2009230590-A1

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

Description:
RELATED APPLICATIONS 
     This application is related to US18914, 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 an injection mold and a method for making a housing with soft layer using the 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, for example, leather or fabric is formed on the housing. When making such housing, 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 cross-sectional view of an exemplary embodiment of the present injection mold in an opening state; 
         FIG. 2  shows a cross-sectional view of a housing making by the injection mold; 
         FIG. 3  shows a schematic view of a soft layer put in the injection mold; 
         FIG. 4  shows a schematic view of the soft layer sticking inside the injection mold; 
         FIG. 5  shows a schematic view of closing the injection mold to cut the soft layer; and 
         FIG. 6  shows a schematic view of the injection mold injecting plastic material. 
     
    
    
     DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS 
     Referring to  FIGS. 1 and 2 , in an exemplary embodiment, an injection mold  10  is used to make a housing  90 . The housing  90  includes a main body  92  and a soft layer  94  formed on the main body  92 . 
     The injection mold  10  includes a female mold  20  and a male mold  40  corresponding to the female mold  20 . 
     The female mold  20  includes a first joining surface  22  facing the male mold  40 , a concave cavity  24  defined in the female mold  20  facing the male mold  40 , a plurality of air suction holes  26  extending through the female mold  20 , and a receiving slot  28  defined around the concave cavity  24 . Each air suction hole  26  communicates with the concave cavity  24 . 
     The male mold  40  includes a second joining surface  42  facing the female mold  20 , a protruding portion  44  formed on the second joining surface  42 , at least a runner  46  extending through the male mold  40 , and at least a cutting portion  48  separately defined around the protruding portion  44 . The cutting portion  48  may be a cutting mold with blades. The cutting portion  48  is smaller than the receiving slot  28 , enabling the receiving slot  28  to accommodate the cutting portion  48 . When the male mold  40  engages the female mold  20 , the cutting portion  48  engages closely with a sidewall within the receiving slot  28 . 
     A method for making the housing  90  by using the injection mold  10  may include following steps: 
     Referring to  FIGS. 3 and 4 , the soft layer  94  is put on the first joining surface  22  and encloses the concave cavity  24 . Then, the soft layer  94  is drawn against the concave cavity  24  by vacuuming the concave cavity  24  through a plurality of air suction holes  26  using a vacuum generator (not shown), thereby making the soft layer  94  sticking to inside of the concave cavity  24 . Meanwhile, the soft layer  94  covers the receiving slot  28 . 
     Referring to  FIG. 5 , the injection mold  10  is closed, and the cutting portion  48  of the male mold  40  engages into the receiving slot  28  for cutting superfluous edges of the soft layer  94 . The male mold  40  and the female mold  20  define together a die chamber  50  therebetween. 
     Referring to  FIG. 6 , melted material (e.g., plastic and/or silicone) is injected into the die chamber  50  through the runner  46  and attached to the soft layer  94 . The housing  90  with the soft layer  94  is complete. 
     After the housing  90  is cooled, the housing  90  is removed from the injection mold  10 . 
     In a further embodiment, the cutting portion  48  can be positioned on the female mold  20 , and a receiving slot  28  can be defined in the male mold  40  and configured for accommodating the cutting portion  48  on the female mold  20 . 
     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.