Patent Publication Number: US-2009230281-A1

Title: Mold with unloading mechanism

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention generally relates to a mold, and more particularly to a mold with unloading mechanism. 
     2. The Related Art 
     Traditionally, some products, such as a product  100  shown in  FIG. 1 , are unloaded by twice ejecting after injection molding. Referring to  FIG. 2 , a traditional mold with unloading mechanism used to mold and unload the product  100  is shown. The mold with unloading mechanism includes a lower plate  51 , a lower insert  52 , a padding plate  53 , a bottom clamping plate  54  and an unloading mechanism. The lower insert  52  is embedded in the lower plate  51  and matches with an upper insert  61  embedded in an upper plate  62  to define a cavity (not shown) therebetween for molding the product  100 . The padding plate  53  is located under the lower plate  51  and defines a space  531  penetrating from top to bottom. The padding plate  53  further defines a preventing portion  532  stretching into the space  531  at the top. The bottom clamping plate  54  is fixed under the padding plate  53 . The unloading mechanism comprises an ejector plate assembly  55 , a stroke plate  56  located under the ejector plate assembly  55 , a pusher  57 , a stroke pin  58 , two unloading pins  59  and a connecting part  50  connecting with the ejector plate assembly  55  and the stroke plate  56 . The bottom of the connecting part  50  is fixed in the stroke plate  56  and the top thereof can freely open and close and is inserted in the ejector plate assembly  55 . The ejector plate assembly  55  and the stroke plate  56  are movably received in the space  531  and the stroke plate  56  is restricted by the preventing portion  532 . The top of the pusher  57  penetrates through the stroke plate  56  to push the ejector plate assembly  55 . The bottom of the pusher  57  passes through the bottom clamping plate  54  to stretch out of the bottom of the bottom clamping plate  54 . The bottom of the unloading pin  59  is fixed in the ejector plate assembly  55  and the top thereof penetrates through the lower plate  51  and the lower insert  52  to push the product  100 . The bottom of the stroke pin  58  is fixed in the stroke plate  56  and the top thereof protrudes upward to form a shaping section  581 . The shaping section  581  penetrates through the ejector plate assembly  55 , the lower plate  51  and the lower insert  52  to stretch into the cavity for molding a corresponding region of the product  100 . 
     When the mold with unloading mechanism is opened after injection molding, the pusher  57  pushes the ejector plate assembly  55  to move upward and further drives the stroke plate  56  to move upward by the connecting part  50 . The ejector plate assembly  55  and the stroke plate  56  respectively drive the unloading pin  59  and the stroke pin  58  to move upward. When the stroke plate  56  abuts against the preventing portion  532 , the stroke plate  56  stops moving upward. At this moment, the product  100  and the shaping section  581  stretch out of the cavity. When the pusher  57  continues pushing the ejector plate assembly  55  to move upward, because the stroke plate  56  stops moving upward, the top of the connecting part  50  is opened by the thrust of the pusher  57  to make the ejector plate assembly  55  isolated from the stroke plate  56 . Then, the ejector plate assembly  55  continues moving upward and further drives the unloading pin  59  to move upward to further push the product  100 . At this moment, the region of the product  100  in accordance with the shaping section  581  of the stroke pin  58  is actuated by the thrust of the unloading pin  59  to open under the self-elasticity so as to strip off the shaping section  581 . So far, the product  100  is completely unloaded from the mold with unloading mechanism. When the mold with unloading mechanism is closed, the pusher  57  moves downward to pull the ejector plate assembly  55  and the unloading pin  59  to move downward. In the process of the ejector plate assembly  55  moving downward, the top of the connecting part  50  is gradually closed to make the stroke plate  56  connected with the ejector plate assembly  55  to move downward together. The stroke plate  56  further drives the stroke pin  58  to reposition. 
     The above-mentioned mold with unloading mechanism utilizes the cooperation of the stroke plate  56 , the connecting part  50  and the preventing portion  532  to twice eject the product  100 . However, the stroke plate  56 , the connecting part  50  and the preventing portion  532  have a complicated structure to be processed difficultly and occupy a large space so that it is unsuitable to process a smaller product. 
     SUMMARY OF THE INVENTION 
     An object of the present invention is to provide a mold with unloading mechanism, which has a simpler structure and occupies a smaller space. 
     The mold with unloading mechanism adapted for molding a product whose unloading from the mold needs to be ejected twice includes an upper plate with an upper insert embedded therein, a lower plate, a lower insert, a padding plate under the lower plate, a bottom clamping plate and an unloading mechanism. The lower plate matches with the upper plate and defines at least one preventing hole and at least one first perforation therethrough. The lower insert is embedded in the lower plate and matches with the upper insert to define a cavity therebetween for molding the product. The lower insert defines at least one insert hole and at least one second perforation respectively matching with the preventing hole and the first perforation. The bottom clamping plate is located under the padding plate and defines an aperture therethrough. The unloading mechanism includes an ejector plate assembly, a pusher, at least one unloading pin, at least one stroke pin and an elastic element. The ejector plate assembly is movably received in the padding plate and defines a stroke hole at the top thereof and a receiving groove connecting the stroke hole at the bottom thereof. A shoulder is formed at the junction of the stroke hole and the receiving groove. The top of the pusher passes through the aperture of the bottom clamping plate for pushing the ejector plate assembly. The bottom of the unloading pin is fixed in the ejector plate assembly and the top of the unloading pin passes through the first perforation of the lower plate and the second perforation of the lower insert for pushing the product. The stroke pin has a restricting section received in the receiving groove and restricted by the shoulder. A preventing section extends upward from the restricting section and is movably received in the stroke hole and restricted by the preventing hole of the lower plate. The preventing section extends upward to form an ejector section. The top of the ejector section passes through the preventing hole of the lower plate and the insert hole of the lower insert for pushing the product. One end of the elastic element is received in the receiving groove and abuts against the restricting section. The other end of the elastic element stretches out of the receiving groove and is against the bottom clamping plate. 
     As described above, the mold with unloading mechanism of the present invention utilizes the elastic element, the preventing section and the restricting section which have a simpler structure and occupy a smaller space instead of a stroke plate, a connecting part and a preventing portion of a traditional mold with unloading mechanism which have a complicated structure and occupy a large space. Therefore, the mold with unloading mechanism of the present invention has a simpler structure to be processed easily and occupies a smaller space so that a smaller product can be processed therein. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention will be apparent to those skilled in the art by reading the following description of a preferred embodiment thereof, with reference to the attached drawings, in which: 
         FIG. 1  is a partially cutaway perspective view of a product, whose unloading needs to be ejected twice; 
         FIG. 2  is a cross-sectional view of a traditional mold with unloading mechanism which is closed; 
         FIG. 3  is a cross-sectional view of a mold with unloading mechanism in accordance with the present invention, wherein the mold with unloading mechanism is closed; 
         FIG. 4  is a cross-sectional view of the mold with unloading mechanism of  FIG. 3  without unloading pins, a stroke pin, a spring, a locating bar and a screw; 
         FIG. 5  is a cross-sectional view of the mold with unloading mechanism of  FIG. 3 , which is lying in the state of the first ejecting; and 
         FIG. 6  is a cross-sectional view of the mold with unloading mechanism of  FIG. 3 , which is lying in the state of the second ejecting. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     With reference to  FIG. 3  and  FIG. 4 , a mold with unloading mechanism in accordance with the present invention is adapted for molding a product  100  shown in  FIG. 1 . The mold with unloading mechanism includes an upper assembly  10 , a lower assembly  20  located under the upper assembly  10  and an unloading mechanism configured in the lower assembly  20 . 
     Referring to  FIG. 4 , the upper assembly  10  includes an upper plate  11 , an upper insert  12  embedded in the bottom of the upper plate  11  and a top clamping plate  13  fixed on the top of the upper plate  11 . The lower assembly  20  includes a lower plate  21 , a lower insert  22 , a padding plate  23  and a bottom clamping plate  24 . The lower insert  22  is embedded in the top of the lower plate  21  and matches with the upper insert  12  to define a cavity therebetween (not shown). The lower insert  22  vertically defines two cylindrical second perforations  221  and a cylindrical insert hole  222  located between the two second perforations  221 . The top of the second perforation  221  and the insert hole  222  communicates with the cavity and the bottom thereof penetrates through the bottom of the lower insert  22 . The lower plate  21  vertically defines two first perforations  211  and a preventing hole  212  respectively matching and connecting the corresponding second perforations  221  and the insert hole  222 . The padding plate  23  is located under the lower plate  21  and defines a space  231  penetrating from top to bottom. The bottom of the first perforations  211  and the preventing hole  212  communicates with the space  231 . The bottom clamping plate  24  is fixed under the padding plate  23  and vertically defines an aperture  241  penetrating from top to bottom and communicating with the space  231 . The top of the bottom clamping plate  24  defines a cylindrical fillister  242  facing to the preventing hole  212  of the lower plate  21 . The diameter of the fillister  242  is greater than the diameter of the preventing hole  212 . The bottom of the bottom clamping plate  24  defines a cylindrical screw hole  244  connected with the bottom of the fillister  242  via a smaller cylindrical channel  243 . 
     Referring to  FIGS. 3 and 4 , the unloading mechanism includes a pusher  31  extending vertically, an ejector plate assembly  32 , two unloading pins  35 , a stroke pin  36 , a spring  37 , a locating bar  38  and a screw  39 . The ejector plate assembly  32  is received in the space  231  of the padding plate  23  and can move upward or downward. The ejector plate assembly  32  comprises a bottom ejector plate  33  and a top ejector plate  34  fixed on the top of the bottom ejector plate  33 . The bottom of the bottom ejector plate  33  defines a cylindrical receiving groove  331  matching with the fillister  242  of the bottom clamping plate  24 . The top ejector plate  34  defines a cylindrical stroke hole  341  connecting the top of the receiving groove  331  and facing to the preventing hole  212  of the lower plate  21 . The diameter of the stroke hole  341  is greater than the diameter of the preventing hole  212  and smaller than the diameter of the receiving groove  331 . A shoulder  332  is formed at the junction of the stroke hole  341  and the receiving groove  331 . The bottom of the top ejector plate  34  defines two fixing grooves  343  respectively located at two sides of the stroke hole  341 . The middle of the top of the fixing groove  343  extends upward to penetrate through the top ejector plate  34  for forming a connecting hole  342  matching with the corresponding first perforation  211  of the lower plate  21 . The top of the pusher  31  is fixed on the bottom of the bottom ejector plate  33  and the bottom of the pusher  31  stretches out of the aperture  241  of the bottom clamping plate  24 . 
     The unloading pin  35  has a cylindrical ejector body  351  extending vertically. The bottom of the ejector body  351  protrudes outward to form a fixing block  352  fixed in the fixing groove  343 . The top of the ejector body  351  passes through the connecting hole  342 , the first perforation  211  and the second perforation  221  to abut against the bottom of the product  100  molded in the cavity. The stroke pin  36  has a cylindrical restricting section  364  movably received in the receiving groove  331  and restricted by the shoulder  332 . The middle of the top of the restricting section  364  extends upward to form a cylindrical preventing section  361  passing through the stroke hole  341  to stretch into the space  231 . The middle of the top of the preventing section  361  extends upward to form a cylindrical ejector section  362  movably received in the preventing hole  212  and the insert hole  222 . The top of the ejector section  362  protrudes upward to form a shaping section  363  stretching into the cavity to mold a corresponding region of the product  100 . The spring  37  is compressed and configured in the receiving groove  331  and the fillister  242 . The top of the spring  37  abuts against the restricting section  364 . The locating bar  38  has a locking block  382  received in the screw hole  244 . The top of the locking block  382  extends upward to form a locating portion  381  passing through the channel  243  to insert into the spring  37  for preventing the spring  37  slanting. The screw  39  is configured in the screw hole  244  to abut against the locking block  382  for fixing the locating bar  38 . 
     Referring to  FIG. 5 , when the mold with unloading mechanism is opened after injection molding, the upper assembly  10  moves upward. The pusher  31  pushes the ejector plate assembly  32  to move upward in the space  231  and further drives the unloading pin  35  to move upward. At the same time, the stroke pin  36  is driven by the elasticity of the spring  37  to move upward with the ejector plate assembly  32 . When the top of the preventing section  361  of the stroke pin  36  abuts against the bottom of the lower plate  21 , the stroke pin  36  stops moving upward. At this moment, the shaping section  363  and the product  100  stretch out of the cavity. 
     Referring to  FIG. 6 , when the stroke pin  36  stops moving upward, the pusher  31  continues pushing the ejector plate assembly  32  to move upward and further driving the unloading pin  35  to continue moving upward to further push the product  100 . At this moment, because the stroke pin  36  stops moving, the region of the product  100  in accordance with the shaping section  363  is actuated by the thrust of the unloading pin  35  to open under the self-elasticity so as to strip off the shaping section  363 . So far, the product  100  is completely unloaded from the mold with unloading mechanism. 
     When the mold with unloading mechanism is closed, the pusher  31  moves downward to pull the ejector plate assembly  32  and the unloading pin  35  to moving downward. When the shoulder  332  of the bottom ejector plate  33  abuts against the restricting section  364  of the stroke pin  36 , the shoulder  332  pushes the restricting section  364  downward to drive the stroke pin  36  to move downward with the ejector plate assembly  32 . At the same time, the restricting section  364  compresses the spring  37  along the locating portion  381  of the locating bar  38  to make the spring  37  in the state of being compressed again. At last, the upper assembly  10  moves downward to abut against the top of the lower assembly  20 . 
     As described above, the mold with unloading mechanism of the present invention utilizes the spring  37 , the preventing section  361  and the restricting section  364  which have a simpler structure and occupy a smaller space instead of a stroke plate  56 , a connecting part  50  and a preventing portion  531  (as shown in  FIG. 2 ) which have a complicated structure and occupy a large space. Therefore, the mold with unloading mechanism of the present invention has a simpler structure to be processed easily and occupies a smaller space so that a smaller product can be processed therein.