Abstract:
A rotary device for a horizontal injection molding machine is configured in the form of a module frame which includes a base plate and a turntable rotatably mounted on the base plate. Drives are provided to move the base plate in longitudinal direction and to rotate the turntable. A fixed mold mounting plate of the injection molding machine can be mounted on a mounting structure of the module frame, whereas a moveable mold mounting plate is received in guides along the sides of the module frame.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS  
         [0001]    This application claims the priority of German Patent Application, Serial No. 101 52 394.7, filed Oct. 24, 2001, pursuant to 35 U.S.C. 119(a)-(d), the disclosure of which is incorporated herein by reference.  
         BACKGROUND OF THE INVENTION  
         [0002]    The present invention relates to a rotary device for a horizontal injection machine for turning mold halves or molded articles between the mold mounting plates about a vertical axis. The invention also relates to an injection mold machine equipped with such a rotary device.  
           [0003]    A rotary device of this type is described, for example, in International patent application no. WO 01/10624 A1 and includes a base plate and a turntable rotatably mounted on the base plate. The base plate with the attached turntable are mounted on a machine bed of a horizontal injection molding machine and can travel in axial direction between a moveable mold mounting plate and a fixed mold mounting plate. The turntable carries in operation a third mold plate, a so-called swivel plate with mold halves, for interaction with respective mold halves of the moving and fixed mold mounting plates. As the rotary device is mounted in the machine bed of the horizontal injection molding machine, a retrofitting of a standard injection molding machine requires a modification of the other components. This is very complicated and cost-intensive.  
           [0004]    It would therefore be desirable and advantageous to provide an improved rotary device for a horizontal injection molding machine to obviate prior art shortcomings and to allow installation in existing machines in an easy and yet reliable manner.  
         SUMMARY OF THE INVENTION  
         [0005]    According to one aspect of the present invention, a rotary device for a horizontal injection molding machine, includes a base plate, a turntable rotatably mounted on the base plate, and a module frame in which the base plate with the turntable are mounted for displacement.  
           [0006]    The present invention resolves prior art problems by the provision of a module frame, which can be mounted as a unit onto the machine bed, whereby the moving and the fixed mold mounting plates are secured to the module frame. The module frame includes hereby a mounting structure for attachment of a fixed mold mounting plate and guides for a moveable mold mounting plate.  
           [0007]    According to another feature of the present invention, the module frame may have integrated therein a drive mechanism for displacement of the base plate with the attached turntable. The drive mechanism may be configured with hydraulic cylinders, spindles or the like. As an alternative, the drive mechanism may be realized by a rack and pinion structure comprised of a fixed rack securely mounted to the module frame, a moving rack securely mounted to the moveable mold mounting plate, and a pinion connected to the base plate and meshing with the fixed and moving racks. A rack and pinion mechanism of this type is described, for example, in International patent application no. WO 01/10624 A1 and operates in a manner that the moveable mold mounting plate moves the base plate about a distance which corresponds to half the movement path of the moveable mold mounting plate. The rack and pinion mechanism is integrated in the module frame, with the module frame having guides for the moving rack.  
           [0008]    The base plate may be configured as massive plate or may be formed with pockets or designed as frame construction (weldment).  
           [0009]    Suitably, the module frame includes a fastening assembly for securement to the machine bed of an injection molding machine.  
           [0010]    According to one aspect of the present invention, a horizontal injection molding machine includes a machine bed, a first mold mounting plate carrying a mold half, a second mold mounting plate adapted for traveling relative to the first mold mounting plate and carrying another mold half, and a rotary device including a modular frame adapted for placement on the machine bed and having a mounting structure for supporting the first mold mounting plate and a guide for supporting the second mold mounting plate, a base plate supported on the modular frame, and a turntable carrying a swivel plate between the first and second mold mounting plates and supported on the base plate for rotation about a vertical axis so as to turn the swivel plate. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWING  
       [0011]    Other features and advantages of the present invention will be more readily apparent upon reading the following description of currently preferred exemplified embodiments of the invention with reference to the accompanying drawing, in which:  
         [0012]    [0012]FIG. 1 is a perspective view of an injection molding machine according to the present invention;  
         [0013]    [0013]FIG. 2 is a perspective view of a module frame of the injection molding machine;  
         [0014]    [0014]FIG. 3 is a sectional view of the modular frame, taken along the line III-III in FIG. 2;  
         [0015]    [0015]FIG. 4 is a bottom perspective view of the module frame;  
         [0016]    [0016]FIG. 5 is a schematic illustration of a drive mechanism for operating a turntable of the module frame;  
         [0017]    [0017]FIG. 6 is a schematic illustration of an exemplified drive for moving a base plate of the modular frame; and  
         [0018]    [0018]FIG. 7 is a schematic illustration of a variation of a base plate of the modular frame. 
     
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0019]    Throughout all the Figures, same or corresponding elements are generally indicated by same reference numerals.  
         [0020]    Turning now to the drawing, and in particular to FIG. 1, there is shown a perspective view of an injection molding machine according to the present invention, including a fixed mold mounting plate  2 , which carries a mold half  3 , and a moveable mold mounting plate  4 , which carries a mold half  5 . Placed between the mold halves  3 ,  5  is a swivel plate  6 . The swivel plate  6  and the mold halves  3 ,  5  are each provided with, not shown, form recesses in confronting relationship to define respective cavities for injection molding plastic articles. Tie bars  8  extend through the fixed mold mounting plate  2  for connection to the moveable mold mounting plate  4  which can thus be moved in the direction of and away from the fixed mold mounting plate  2 . Hydraulic cylinders  10  which form part of a drive mechanism, are shown for movement of the tie bars  8  and thus of the mold mounting plate  4  and injection molding units.  
         [0021]    As shown in FIG. 1, the entire construction of drive mechanism and mold mounting plates is mounted on a module frame  20  which can be secured to a machine bed  35  of the injection molding machine, e.g. via plates  23  and bolts  25 , and will now be described in more detail with reference to FIGS.  2  to  7 .  
         [0022]    Turning to FIG. 2, there is shown a perspective view of the module frame  20 , which includes parallel double-walled side portions  21  in spaced-apart relationship and a base plate  26  which travels in linear or sliding bearings  22  of the side portions  21 . A hydraulic drive system including hydraulic cylinders  24  is provided to implement the displacement of the base plate  26 . Of course, other types of drives are equally applicable for moving the base plate, such as, e.g., a spindle drive. Another alternative of a drive for moving the base plate  26  is shown in FIG. 6. The drive involved here is a rack and pinion mechanism and includes racks  45 ,  46  and a pinion  47 . One of the racks  45 ,  46  is securely mounted to the module frame  20  and the other one of the racks  45 ,  46  is secured to the moveable mold mounting plate  4  and moveably received in a suitable guide. The pinion  47  is connected to the base plate  26  and meshes with the fixed and moving racks  45 ,  46 . A rack and pinion mechanism of this type is described, for example, in International patent application no. WO 01/10624 A1 and operates in a manner that the moveable mold mounting plate  4  moves the base plate  26  about a distance which corresponds to half the movement path of the moveable mold mounting plate.  
         [0023]    The base plate  26  carries a turntable  36 , rotatably supported in suitable bearings  38  (FIG. 3), for attachment to the swivel plate  6 . The turntable  36  has a pivot pin  37  which points downwards through the base plate  26 . On its top surface, the module frame  20  is provided with slideways  28  for guiding the moveable mold mounting plate  4 . A brace  30  extends across between the sidewalls  21  for receiving the fixed mold mounting plate  2 . At the outer axial ends, the sidewalls  21  are interconnected by braces  32 ,  34  to close the module frame  20  to the outside and to provide an option to support a plate of a drive.  
         [0024]    As shown in particular in FIG. 4, the module frame  20  has a substantial hollow construction, whereby the brace  30  for supporting the fixed mold mounting plate  2  is reinforced from underneath by a crosspiece  40 . Suitably, the module frame  20  is configured as cast part.  
         [0025]    Operation of the turntable  36  may be implemented by a suitable drive mechanism, as shown in FIG. 5. The drive mechanism includes a ring gear  43  mounted to the rotary table  36 . The ring gear  43  is in mesh with a pinion  44  which can be driven by a hydraulic motor or electric motor (not shown). A specific construction and manner in which a drive mechanism can be operatively and functionally incorporated into the injection molding machine of the present invention is fully described in International publication WO 01/10624, the entire specification and drawings of which are expressly incorporated herein by reference.  
         [0026]    A standard or conventional injection molding machine can easily be retrofitted with a modular frame  20  simply by detaching the drive, tie bars and the moveable mold mounting plate from the machine bed and placing the module frame  20  according to the present invention upon the machine bed. Subsequently, the drive, tie bars and the moveable mold mounting plate are mounted onto the module frame  20 , without requiring any modifications to these components. Only the structural height of the conventional injection molding machine is affected by the incorporation of the module frame  20 .  
         [0027]    As shown in FIG. 2, the base plate  26  may be configured with recesses  48  so as to allow molded articles, removed from the swivel plate  6 , to drop downwards through the intermediate space between the base plate  26  and the brace  30  or through the intermediate space between the base plate  26  and the brace  34 .  
         [0028]    The base plate  26  may be configured as massive plate. Alternatively, the base plate  26  can have pockets (not shown) or may be configured as a framework construction. An example of a frame construction is shown in FIG. 7 and includes a circumferential frame  49  having struts  50  which extend from the corners of the frame  49  toward a hub  51  in the center of the frame  49 .  
         [0029]    While the invention has been illustrated and described in connection with currently preferred embodiments shown and described in detail, it is not intended to be limited to the details shown since various modifications and structural changes may be made without departing in any way from the spirit of the present invention. The embodiments were chosen and described in order to best explain the principles of the invention and practical application to thereby enable a person skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated.  
         [0030]    What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims and their equivalents: