Patent Publication Number: US-2011059200-A1

Title: Double Mold Locking Apparatus

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a locking apparatus and, more particularly, to a double mold locking apparatus. 
     2. Description of the Related Art 
     A conventional double mold locking apparatus in accordance with the prior art shown in  FIGS. 13-17  comprises a fixed mold  50 , a first die  52  mounted on the fixed mold  50 , a movable mold  51  movable relative to the fixed mold  50 , a second die  53  mounted on the movable mold  51  and movable relative to the first die  52 , a plurality of support rods  54  extending through and movable relative to the fixed mold  50  and the movable mold  51 , a plurality of hydraulic cylinders  55  mounted on the fixed mold  50  and connected with the support rods  54  to drive the support rods  54  to move relative to the fixed mold  50  and the movable mold  51 , a drive member  56  connected with the hydraulic cylinders  55  to drive the hydraulic cylinders  55 , and a plurality of locking members  57  movably mounted on the movable mold  51  and movable relative to the support rods  54 . Each of the support rods  54  is provided with a locking groove  58 . In operation, when the movable mold  51  is moved toward the fixed mold  50 , the second die  53  is moved to press the first die  52  as shown in  FIG. 13  so that the first die  52  and the second die  53  are closed. Then, the hydraulic cylinders  55  are driven by the drive member  56  to move the support rods  54  backward until the locking groove  58  of each of the support rods  54  is aligned with each of the locking members  57  as shown in  FIG. 14 . Then, each of the locking members  57  is moved toward each of the support rods  54  and is inserted into the locking groove  58  of each of the support rods  54 . Then, the support rods  54  are driven by the hydraulic cylinders  55  to move forward and to press the locking members  57  toward the movable mold  51  as shown in  FIG. 15  so that the locking members  57  transmits a high pressure to the movable mold  51  so as to press the movable mold  51  toward the fixed mold  50  and to lock the first die  52  and the second die  53 . After the molding process is accomplished, the support rods  54  are driven by the hydraulic cylinders  55  to move backward and to release the locking members  57  as shown in  FIG. 16  so that the high pressure applied by the locking members  57  is released. Finally, the support rods  54  are driven by the hydraulic cylinders  55  to move backward successively and to move the locking members  57  backward as shown in  FIG. 17  so that the second die  53  is moved to space from the first die  52  so that the first die  52  and the second die  53  are opened. However, the double mold locking apparatus comprises many hydraulic cylinders  55  that will elongate the calibration time of the first die  52  and the second die  53  so that the working efficiency of the molding process is decreased. 
     BRIEF SUMMARY OF THE INVENTION 
     In accordance with the present invention, there is provided a double mold locking apparatus, comprising a mold unit and a plurality of positioning devices. The mold unit includes a fixed mold for mounting a first die, a movable mold movable relative to the fixed mold to drive a second die to move relative to the first die, a plurality of support rods extending through the fixed mold and the movable mold, and a plurality of driving cylinders mounted between the fixed mold and the movable mold to drive the movable mold to move relative to the fixed mold reciprocally. Each of the positioning devices includes a high pressure locking cylinder to transmit a locking force to the movable mold of the mold unit so as to apply a high pressure to the first die and the second die when the first die and the second die are closed, two opposite semi-nuts movable relative to each other to clamp a respective one of the support rods of the mold unit between the two semi-nuts, and a position finder to find a position of the respective support rod of the mold unit. 
     The primary objective of the present invention is to provide a double mold locking apparatus that only needs to calibrate the distance of two dies once during the molding process. 
     According to the primary objective of the present invention, the position of the outer threaded portion of each of the support rods relative to the semi-nuts of the respective positioning device is micro-adjusted when the first die and the second die are opened and when the first die and the second die are closed, so that a user only needs to calibrate the position of each of the support rods at the first time when the first die and the second die are opened and closed without having to adjust and calibrate the position of each of the support rods at each cycle when the first die and the second die are opened and closed reciprocally so as to save the working time during the molding process and to facilitate the molding operation. 
     According to another objective of the present invention, the high pressure locking cylinder of each of the positioning devices is positioned in place by operation of the positioning cylinder so as to lock the first die and the second die exactly and closely. 
     According to a further objective of the present invention, the support rods are locked onto the fixed mold by the driven gears of the regulating unit so as to provide a support to the fixed mold. 
     Further benefits and advantages of the present invention will become apparent after a careful reading of the detailed description with appropriate reference to the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING(S) 
         FIG. 1  is a front cross-sectional view of a double mold locking apparatus in accordance with the preferred embodiment of the present invention. 
         FIG. 2  is a side view of the double mold locking apparatus as shown in  FIG. 1 . 
         FIG. 3  is a schematic operational view of the double mold locking apparatus as shown in  FIG. 2 . 
         FIG. 4  is a schematic operational view of the double mold locking apparatus as shown in  FIG. 1 . 
         FIG. 5  is a schematic operational view of the double mold locking apparatus as shown in  FIG. 4 . 
         FIG. 6  is a locally enlarged view of the double mold locking apparatus taken along circle “A” as shown in  FIG. 5 . 
         FIG. 7  is a schematic operational view of the double mold locking apparatus as shown in  FIG. 5 . 
         FIG. 8  is a locally enlarged view of the double mold locking apparatus taken along circle “B” as shown in  FIG. 7 . 
         FIG. 9  is a schematic operational view of the double mold locking apparatus as shown in  FIG. 7 . 
         FIG. 10  is a locally enlarged view of the double mold locking apparatus taken along circle “C” as shown in  FIG. 9 . 
         FIG. 11  is a schematic operational view of the double mold locking apparatus as shown in  FIG. 9 . 
         FIG. 12  is a schematic operational view of the double mold locking apparatus as shown in  FIG. 11 . 
         FIG. 13  is a front cross-sectional view of a conventional double mold locking apparatus in accordance with the prior art. 
         FIG. 14  is a schematic operational view of the conventional double mold locking apparatus as shown in  FIG. 13 . 
         FIG. 15  is a schematic operational view of the conventional double mold locking apparatus as shown in  FIG. 14 . 
         FIG. 16  is a schematic operational view of the conventional double mold locking apparatus as shown in  FIG. 15 . 
         FIG. 17  is a schematic operational view of the conventional double mold locking apparatus as shown in  FIG. 16 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to the drawings and initially to  FIGS. 1-3 , a double mold locking apparatus in accordance with the preferred embodiment of the present invention comprises a mold unit  1 , a plurality of positioning devices  2  and a regulating unit  3 . 
     The mold unit  1  includes a fixed mold  12  for mounting a first die  42 , a movable mold  11  movable relative to the fixed mold  12  to drive a second die  41  to move relative to the first die  42 , a plurality of (preferably four) support rods  13  extending through the fixed mold  12  and the movable mold  11 , and a plurality of (preferably four) driving cylinders  14  mounted between the fixed mold  12  and the movable mold  11  to drive the movable mold  11  to move relative to the fixed mold  12  reciprocally. 
     The movable mold  11  of the mold unit  1  is movable on the support rods  13 . The support rods  13  of the mold unit  1  extend through four corners of each of the fixed mold  12  and the movable mold  11  and are movable in the fixed mold  12  and the movable mold  11 . The support rods  13  of the mold unit  1  are positioned in place temporarily by a positioning mold (not shown) which is spaced from the movable mold  11 . Each of the support rods  13  of the mold unit  1  is provided with an outer threaded portion  130  and an outer threaded section  132 . 
     Each of the positioning devices  2  is mounted on a first side of the mold unit  1  and includes a high pressure locking cylinder  21  to transmit a locking force to the movable mold  11  of the mold unit  1  so as to apply a high pressure to the first die  42  and the second die  41  when the first die  42  and the second die  41  are closed, two opposite semi-nuts  22  movable relative to each other to clamp a respective one of the support rods  13  of the mold unit  1  between the two semi-nuts  22 , and a position finder  23  to find a position of the respective support rod  13  of the mold unit  1 . 
     The high pressure locking cylinder  21  of each of the positioning devices  2  is mounted on the movable mold  11  of the mold unit  1 . The two semi-nuts  22  of each of the positioning devices  2  are mounted beside the high pressure locking cylinder  21 . The two semi-nuts  22  of each of the positioning devices  2  are movable toward the respective support rod  13  of the mold unit  1  to mesh with the outer threaded portion  130  of the respective support rod  13  so as to lock the respective support rod  13 . The position finder  23  of each of the positioning devices  2  is mounted beside the semi-nuts  22 . The position finder  23  of each of the positioning devices  2  has a detector (not shown) to detect the threading position of the outer threaded portion  130  of the respective support rod  13  when the first die  42  and the second die  41  are opened or closed to align the semi-nuts  22  of each of the positioning devices  2  with the outer threaded portion  130  of the respective support rod  13 . 
     Each of the positioning devices  2  further includes two opposite actuating cylinders  221  mounted beside the high pressure locking cylinder  21  and connected with the two semi-nuts  22  to move the two semi-nuts  22  relative to the respective support rod  13  of the mold unit  1  and a positioning cylinder  222  mounted between the two semi-nuts  22  and the movable mold  11  of the mold unit  1  and connected with the high pressure locking cylinder  21  to regulate and locate the position of the high pressure locking cylinder  21 . 
     The regulating unit  3  is mounted on a second side of the mold unit  1  and includes a plurality of (preferably four) driven gears  33  each provided with an inner threaded section  332  screwed onto the outer threaded section  132  of the respective support rod  13  to releasably lock the respective support rod  13  onto the fixed mold  12  of the mold unit  1 , a drive gear  32  intermeshing with the driven gears  33  to drive each of the driven gears  33  to rotate relative to the respective support rod  13  of the mold unit  1  respectively, and a drive motor  31  connected with the drive gear  32  to rotate the drive gear  32 . 
     The drive gear  32  of the regulating unit  3  is located between the driven gears  33  and abuts the fixed mold  12  of the mold unit  1 . The drive gear  32  of the regulating unit  3  has a diameter greater than that of each of the driven gears  33 . Each of the driven gears  33  of the regulating unit  3  surrounds the respective support rod  13  of the mold unit  1  and is movable to abut the fixed mold  12  of the mold unit  1 . 
     In practice, the support rods  13  of the mold unit  1  are positioned in place temporarily by the positioning mold. In such a manner, when the drive motor  31  is operated in the positive direction, the drive gear  32  is rotated counterclockwise as shown in  FIG. 2  to rotate the driven gears  33  clockwise so that the inner threaded section  332  of the driven gears  33  is screwed onto the outer threaded section  132  of the respective support rod  13  to lock the respective support rod  13  onto the fixed mold  12  of the mold unit  1 . On the contrary, when the drive motor  31  is operated in the negative direction, the drive gear  32  is rotated clockwise as shown in  FIG. 3  to rotate the driven gears  33  counterclockwise so that the inner threaded section  332  of the driven gears  33  is unscrewed from the outer threaded section  132  of the respective support rod  13  to unlock the respective support rod  13  from the fixed mold  12  of the mold unit  1 . Then, the support rods  13  of the mold unit  1  are loosened from the positioning mold so that each of the support rods  13  of the mold unit  1  is movable freely relative to the fixed mold  12  as shown in  FIG. 4  to micro-adjust the position of each of the support rods  13  relative to the two semi-nuts  22  of the respective positioning device  2 . After adjustment of the position of each of the support rods  13  is accomplished, the support rods  13  of the mold unit  1  are positioned in place by the positioning mold. Then, the drive gear  32  is rotated counterclockwise as shown in  FIG. 2  to rotate the driven gears  33  clockwise so that the inner threaded section  332  of the driven gears  33  is screwed onto the outer threaded section  132  of the respective support rod  13  to lock the respective support rod  13  onto the fixed mold  12  of the mold unit  1 . 
     In operation, referring to Figs.  FIGS. 1-12 , the driving cylinders  14  are operated to drive the movable mold  11  to space from the fixed mold  12  as shown in  FIG. 1 . Then, the first die  42  is mounted on the fixed mold  12 , and the second die  41  is mounted on the movable mold  11 . At this time, the regulating unit  3  is operated to unlock the support rods  13  so that each of the support rods  13  of the mold unit  1  is movable freely relative to the fixed mold  12  as shown in  FIG. 4  to micro-adjust the position of each of the support rods  13  relative to the two semi-nuts  22  of the respective positioning device  2 . Then, the driving cylinders  14  are operated to drive the movable mold  11  to move toward the fixed mold  12  as shown in  FIG. 5  until the second die  41  abuts the first die  42  so as to close the first die  42  and the second die  41 . At the same time, the position finder  23  of each of the positioning devices  2  detects the position of the outer threaded portion  130  of the respective support rod  13  as shown in  FIG. 6  when the first die  42  and the second die  41  are closed. Then, the regulating unit  3  is operated to unlock the support rods  13  so that each of the support rods  13  of the mold unit  1  is movable freely relative to the fixed mold  12  as shown in  FIG. 7  to micro-adjust the position of each of the support rods  13  relative to the two semi-nuts  22  of the respective positioning device  2 , and the position finder  23  of each of the positioning devices  2  detects the position of the outer threaded portion  130  of the respective support rod  13  as shown in  FIG. 8 . At this time, each of the support rods  13  has a determined micro-adjustment range “c” that is limited between the minimum position “a” and the maximum position “b” as shown in  FIG. 7 . After the position finder  23  of each of the positioning devices  2  confirms the exact position of the outer threaded portion  130  of the respective support rod  13  as shown in  FIG. 8 , adjustment of the position of each of the support rods  13  is accomplished as shown in  FIG. 7 . Subsequently, the actuating cylinders  221  of each of the positioning devices  2  are operated to move the two semi-nuts  22  toward the respective support rod  13  of the mold unit  1  so as to clamp and position the respective support rod  13  of the mold unit  1  as shown in  FIG. 9 . At this time, the two semi-nuts  22  of each of the positioning devices  2  mesh with the outer threaded portion  130  of the respective support rod  13  as shown in  FIG. 10  so as to lock the respective support rod  13 . Then, the high pressure locking cylinder  21  of each of the positioning devices  2  transmits a locking force to the movable mold  11  of the mold unit  1  to apply a high pressure to the first die  42  and the second die  41  so as to compress and lock the first die  42  and the second die  41  closely. At this time, the high pressure locking cylinder  21  of each of the positioning devices  2  is located at an expanded position “e” when the locking force is applied by the high pressure locking cylinder  21  of each of the positioning devices  2 . After the molding process is accomplished, the locking force applied by the high pressure locking cylinder  21  of each of the positioning devices  2  is released so as to release the high pressure applied on the first die  42  and the second die  41 . At this time, the high pressure locking cylinder  21  of each of the positioning devices  2  is located at a retracted position “d” when the locking force applied by the high pressure locking cylinder  21  of each of the positioning devices  2  is released. In such a manner, the high pressure locking cylinder  21  of each of the positioning devices  2  is movable between the expanded position “e” and the retracted position “d” as shown in  FIG. 11  by operation of the positioning cylinder  222 . Finally, the driving cylinders  14  of the mold unit  1  are operated to drive the movable mold  11  to move outwardly relative to the fixed mold  12  as shown in  FIG. 12  until the second die  41  is spaced from the first die  42  so as to open the first die  42  and the second die  41 . 
     Accordingly, the position of the outer threaded portion  130  of each of the support rods  13  relative to the semi-nuts  22  of the respective positioning device  2  is micro-adjusted when the first die  42  and the second die  41  are opened as shown in  FIGS. 1 and 4  and when the first die  42  and the second die  41  are closed as shown in  FIGS. 5 and 7 , so that a user only needs to calibrate the position of each of the support rods  13  at the first time when the first die  42  and the second die  41  are opened and closed without having to adjust and calibrate the position of each of the support rods  13  at each cycle when the first die  42  and the second die  41  are opened and closed reciprocally so as to save the working time during the molding process and to facilitate the molding operation. In addition, the high pressure locking cylinder  21  of each of the positioning devices  2  is positioned in place by operation of the positioning cylinder  222  so as to lock the first die  42  and the second die  41  exactly and closely. Further, the support rods  13  are locked onto the fixed mold  12  by the driven gears  33  of the regulating unit  3  so as to provide a support to the fixed mold  12 . 
     Although the invention has been explained in relation to its preferred embodiment(s) as mentioned above, it is to be understood that many other possible modifications and variations can be made without departing from the scope of the present invention. It is, therefore, contemplated that the appended claim or claims will cover such modifications and variations that fall within the true scope of the invention.