Abstract:
An apparatus molds sheets of thermoplastic material, thermoset plastic material and other similar molding materials into various desired shapes and contours. The apparatus has a molding surface that supports the thermoplastic sheet, thermoset plastic sheet or other similar material to be molded where the molding surface is adjustable vertically to a variety of different shapes and contours enabling the apparatus to form the molding material into panels having different shapes and contours.

Description:
[0001]    This patent application claims the benefit of the filing date of provisional patent application Ser. No. 61/723,082, which was filed on Nov. 6, 2012. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention pertains to an apparatus that molds sheets of thermoplastic material, thermoset plastic material and other similar molding materials into various desired shapes and contours. More specifically, the present invention is an apparatus having a molding surface that supports thermoplastic sheets, thermoset plastic sheets or other similar material sheets to be molded where the molding surface is adjustable to a variety of different shapes and contours enabling the apparatus to form the sheets into panels having various different shapes and contours. 
       BACKGROUND 
       [0003]    Thermoplastic sheets, composite laminate and other similar molding material sheets that can be cured into hardened panels are often used in fabricating contoured body panels of products such as automobiles, boats and other products having bodies with smooth contoured surfaces. In molding sheets of this type, it is common practice to use a tool or solid mold that has a single surface with the desired shape and contours of the body panel to be fabricated. To achieve the desired shape and contours of the body panel, the solid mold surface must have substantially the exact same shape and contour desired for the body panel. It is common practice that a prototype body panel first be produced having the desired shape and contours of the final body panel. From the prototype body panel a solid mold is produced based on the shape and contours of the prototype. The solid mold can be produced by hand crafting or machining the mold surface on a solid material or by other similar known methods. All of these methods typically require substantial amounts of materials and are time consuming and therefore expensive. The mold will then be used to form thermoplastics sheets, composite laminate sheets or other similar molding material sheets into the desired final body panel. 
         [0004]    There are often many difficulties encountered in producing a solid mold having a surface that in turn will form molding material sheets into the desired shape and contours of the final body panel. For example, in drape forming or molding of high temperature thermoplastics on a solid mold surface, there is a large degree of shrinkage of the thermoplastic sheet after the sheet has been molded on the mold surface and the sheet cools. Additionally, in molding the sheets of thermoplastics or composite laminates on a solid mold surface, it is often very difficult to completely engage the sheet material with the mold surface so that the sheet material stays in the desired shape and contour sought for the final molded body panel. As a result, it is often the case that the initial mold produced to achieve the desired final shape and configuration of a body panel may not achieve satisfactory results, requiring a further mold or molds to be produced before the sheet molding process achieves the desired shape and configuration of the body panel product. The need to produce several molds before arriving at the mold that will produce the desired shape and contours of the final body panel product is very time consuming and expensive. 
         [0005]    The current practice of producing solid molds involves cutting the mold surface from a block of material using a computer numerical control (CNC) machine. The cut mold surface would then be finished in order to prepare the surface that will shape the molding material sheets and release the cured sheets properly. Again, this process of forming the molds is time consuming and costly. Many times the mold will have to be reconstructed and modified in order to gain acceptable quality in the shape and contour of the final product. Furthermore, if variations are made to the design of the final product in the development process of the product, the mold for that product must be either modified or completely remade. Again, this is especially difficult when the products to be made are low volume products, as is often the case in the art of forming thermoplastic or plastic composite replacement body panels. 
       SUMMARY OF THE INVENTION 
       [0006]    The disadvantages associated with prior art apparatus and methods for molding sheet material are overcome by the apparatus of the invention that provides a molding surface that can be adjusted into a variety of different shapes and contour configurations whereby thermoplastic sheets, composite laminate sheets or other similar molding material sheets can be molded on the surface to produce a final product panel having a desired shape and contours. The apparatus of the invention is basically comprised of a base, a plurality of rods supported on the base, a molding platform supported on the ends of the rods above the base and a control central processing unit. 
         [0007]    The base includes a housing or frame having opposite top and bottom surfaces and at least one side surface extending around the housing. The housing or frame functions as a support for the apparatus. The housing or frame also contains several of the mechanisms that enable the operation of the apparatus. 
         [0008]    The plurality of rods are supported on the base with the rods projecting upwardly from the housing top surface. The rods are all parallel and are perpendicular to the housing top surface. The rods are arranged in a two dimensional array above the housing top surface and each of the rods contains a mechanism that is operatively connected with mechanisms supported on the housing that are controlled to adjust the length of each of the rods relative to the housing top surface. 
         [0009]    The molding platform is constructed of one or more layers of flexible material. The platform has a top molding surface and an opposite bottom surface. The bottom surface of the platform is connected to the top ends of the plurality of rods. Adjusting the lengths of the rods will cause the molding platform to flex and adjust the top molding surface of the platform to form various different surface configurations and surface contours. 
         [0010]    The apparatus is controlled by a central processing unit (CPU) that communicates with and controls the mechanisms in the base housing and in the plurality of rods. Information is manually input into the CPU and the CPU controls each of the rods to adjust their lengths in response to the input information. The adjustments in the lengths of the rods results in the molding platform moving in response to the rod movements. The movement of the molding platform shapes the top mold surface of the platform to a desired surface configuration where the mold surface will produce a body panel of a desired shape and contour from a thermoplastic material sheet, a composite laminate material sheet or other similar type of molding material sheet that is placed on the mold surface. 
     
    
     
       DESCRIPTION OF THE DRAWINGS 
         [0011]    Further features of the invention are set forth in the following detailed description of the invention and in the drawing figures. 
           [0012]      FIG. 1  is a perspective view of one embodiment of the apparatus of the invention. 
           [0013]      FIG. 2  is a side elevation view of the apparatus. 
           [0014]      FIG. 3  is a top plan view of the apparatus 
           [0015]      FIG. 4  is a side elevation view of the apparatus similar to that of  FIG. 2 , but with the rod lengths adjusted to form the molding platform with a desired molding surface configuration. 
           [0016]      FIG. 5  is a right side perspective view of a further embodiment of the apparatus of the invention. 
           [0017]      FIG. 6  is a left side perspective view of the apparatus shown in  FIG. 5 . 
           [0018]      FIG. 7  is a top plan view of a feature of the apparatus shown in  FIGS. 5 and 6  that supports the drive devices. 
           [0019]      FIG. 8  is a front elevation view of the drive device support feature shown in  FIG. 7 . 
           [0020]      FIG. 9  is a side elevation view of the drive device support feature shown in  FIG. 7 . 
           [0021]      FIG. 10  is a partial view of a universal coupling employed on the apparatus. 
           [0022]      FIG. 11  is a sectioned view of the universal coupling shown in  FIG. 10 . 
           [0023]      FIG. 12  is a partial view of the molding platform of the apparatus. 
           [0024]      FIG. 13  is a side elevation view of the molding platform. 
           [0025]      FIG. 14  is a top plan view of the molding platform. 
           [0026]      FIG. 15  is a side elevation view of the molding platform along the line  15 - 15  shown in  FIG. 14 . 
           [0027]      FIG. 16  is a side elevation view of the molding platform along the line  16 - 16  shown in  FIG. 14 . 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0028]      FIG. 1  is a perspective view of one illustrative embodiment of the apparatus of the invention. A seen in  FIG.1 , the apparatus  12  is basically comprised of a base  14 , a plurality of rods  16  supported on the base, a molding platform  18  supported on the rods, and a controlling central processing unit  22 . With the apparatus  12  being designed to mold sheet material such as thermoplastic sheet, plastic composite sheet or other similar types of molded material sheets, the component parts of the apparatus are constructed of materials having sufficient strength for this intended purpose. 
         [0029]    The base  14  in the embodiment shown in the drawing figures includes a housing having a top surface  24 , an opposite bottom surface  26 , and a side wall  28  extending around the housing. The housing shown has a general rectangular cubic configuration. However, this is only one example of the housing configuration and the housing can have other configurations to suit it for its intended purpose. Although not shown, the housing contains the devices and mechanisms needed for the intended functioning of the apparatus to be described. 
         [0030]    The plurality of rods  16  project upwardly from the housing top surface  24  and are supported by the housing. The rods  16  are substantively identical in their constructions and their function. Each of the rods  16  has a generally cylindrical exterior surface that extends from a bottom end  34  of the rod at the housing top surface  24  to a top end  36  of the rod. The rods  16  are supported by the base  14  with each of the rods being parallel and with the rods arranged in a two dimensional array of the rods on the housing top surface  24 . In the embodiment shown the two dimensional array includes the same number of rods  16  in the rows and columns of the array. In other embodiments of the apparatus the rows and columns of the array of rods  16  could have different numbers of rods, giving the array of rods a different configuration other than the square configuration shown in the drawing figures. Each of the rods  16  contains a linear adjustment mechanism. Each mechanism is operable to adjust the length of the rod  16  projecting from the housing top surface  24  independently of the other rods. 
         [0031]    A plurality of universal couplings  42  are attached to the top ends  36  of the rods  16 . The universal coupling  42  can be any known type of coupling or joint that enables the coupling to move freely in all directions around the length of its attached rod, for example a ball and socket joint. 
         [0032]    The molding platform  18  has a flat rectangular configuration that is shaped and dimensioned to extend the platform over the plurality of couplings  42  on the top ends  36  of the rods  16 . The platform  18  is constructed of one or more layers of flexible material that provide the platform with structural strength, but allow the platform to flex and bend to various different shapes having various different surface contours. The platform  18  has a substantially smooth top surface  44  and an opposite bottom surface  46 . The top surface  44  is prepared as a molding surface that will support thermoplastic sheet, plastic composite sheet or other similar types of molding material sheet that can be cured into hardened panels and then easily removed from the molding surface  44 . The platform bottom surface  46  is secured to each of the plurality of universal couplings  42  at the top ends  36  of the plurality of rods  16 . 
         [0033]    The central processing unit  22  communicates through an electrical connection  52  with the devices and mechanisms contained in the apparatus base  14 . The unit  52  can be any known type of computer controlled device that can receive input information and communicate the information to the devices and mechanisms in the apparatus base  14  to control those mechanisms to adjust the lengths of each of the rods  16 . Information input into the unit  22 , for example through a keyboard of the unit is communicated by the unit to the devices and the mechanisms of the base  14  to control each of the rods to adjust to a specific length in response to the input information. The adjustments in the lengths of the rod  16  results in the molding platform  18  and in particular the molding surface  44  of the platform to move in response to the movement of the rod  16 . The movement of the molding platform  18  forms the platform molding surface  44  into the particular shape and configuration that will produce a body panel of a desired shape and contour from a thermoplastic material sheet, a composite laminate material sheet or other similar type of molding material sheet that has been placed on the mold surface  44 . 
         [0034]      FIGS. 5 and 6  shown respective right and left side perspective views of a further embodiment of the apparatus  56 . The apparatus  56  shown in  FIGS. 5 and 6  is basically comprised of a base or frame  58 , a plurality of rods  62  supported by the frame  58 , a molding platform  64  supported on the rod  62 , and the controlling central processing unit  66 . As with the previously described embodiment, the apparatus  56  shown in  FIGS. 5 and 6  is designed to mold sheet material such as thermoplastic sheet, plastic composite sheet, other similar types of molded material sheets, or other molding materials that can be formed or positioned on a molding surface in the general configuration of a sheet. The component parts of the apparatus are constructed of materials having sufficient strength for this intended purpose. 
         [0035]    The frame  58  of the embodiment shown in  FIGS. 5 and 6  has a generally rectangular cubic configuration defined by a plurality of horizontally oriented frame members or bars, and a plurality of vertically oriented frame members or bars. 
         [0036]    The top of the frame  58  is constructed of four horizontally oriented top frame bars  68  that are connected together in a general rectangular configuration as shown in  FIGS. 5 and 6 . The top frame bars  68  define a top perimeter of the frame  58  and support a top panel  72  within the perimeter. The top panel  72  is provided with a plurality of holes  74  through the panel. The holes  74  are spacially arranged in a two-dimensional array of the holes. Spacially arranged rows of holes extend across the top panel  72  between the opposite sides of the frame and spacially arranged columns of holes extend across the top panel  72  between the front and back of the frame. 
         [0037]    Four vertically oriented posts  76  support the top frame bars  68 . The posts  76  are substantially parallel to each other and have top ends secured at the corners of the intersecting top frame bars  68  and the bottom ends that are secured to casters or rollers  78 . The rollers  78  enable the apparatus  56  to be easily manually moved across a supporting surface. 
         [0038]    Four horizontally oriented upper intermediate frame bars  82  are connected together in a general rectangular configuration between adjacent vertical posts  76 . As shown in  FIGS. 5 and 6 , the upper intermediate bars  82  are parallel to the top bars  68  and are spaced vertically below the top bars. The four upper intermediate bars  82  support an intermediate panel  84  within the perimeter defined by the upper intermediate bars. The intermediate panel  84  has a plurality of holes  86  through the panel that align with the holes  74  through the top panel  72 . 
         [0039]    Four horizontally oriented lower intermediate bars  88  are connected together in a general rectangular configuration between adjacent vertical posts  76 . The lower intermediate bars  88  are parallel with the upper intermediate bars  82  and are spaced vertically below the upper intermediate bars. A plurality of parallel, horizontally oriented support strips  92  extend between the front and rear bars of the lower intermediate bars  88  as shown in  FIGS. 5 and 6 . The strips  92  are spacially arranged between the opposite sides of the frame  58  where each strip  92  is positioned just to the left of but adjacent the aligned columns of holes  86  through the intermediate panel  84  and the columns of holes  74  through the top panel  72 . 
         [0040]    A pair of bottom frame bars  94  extends between the pair of vertical posts  76  at the opposite sides of the frame  58  at the front of the frame and the pair of vertical posts  76  at the opposite sides of the frame at the rear of the frame as seen in  FIGS. 5 and 6 . 
         [0041]    A pair of drive tracks  96  extend between the pairs of vertical posts  76  on the right side of the frame  58  and the left side of the frame as shown in  FIGS. 5 and 6 . The drive tracks  96  have guide features in their top surfaces, for example channels recessed into the top surfaces that extend the lengths of the drive tracks. 
         [0042]    A gantry housing  98  extends beneath the frame  58  between the two drive tracks  96 . Opposite ends of the gantry housing have features that engage in the guide features of the drive tracks  96  and support the gantry housing  98  on top of the drive tracks. A drive mount, for example an internally threaded nut or other equivalent mechanism  102  is provided on the top surface of the gantry housing  98 . A drive shaft  104 , for example an externally threaded screw shaft or other equivalent mechanism extends through the drive mount  102 . As shown in  FIGS. 7-9 , one end of the drive shaft  102  is operatively connected to the output of an electric motor  106 . The electric motor  106  is mounted by a support plate  108  to the rear of the frame  58 . The opposite end of the drive shaft is received in a bearing assembly  112 . The bearing assembly  112  is mounted to a support plate  114  that in turn is connected to the front of the frame  58 . The electric motor  106  communicates with a control device such as a computer numerical control (CNC) or the controlling central processing unit (CPU)  66  of the apparatus that is represented schematically in  FIGS. 7-9 . 
         [0043]    The controlling unit  66 , in response to information input by an operator of the apparatus to the unit, controls the operation of the electric motor  106  to rotate the drive shaft  104  in the clockwise or counterclockwise directions for a controlled number of rotations. The rotations of the drive shaft  104  in the drive mount  102  move the gantry housing  98  over the drive tracks  96  in programmed incremental movements forward and rearward over the drive tracks  96  between the front and rear of the frame  58  and beneath the plurality of rods  62 . 
         [0044]    A plurality of small drive devices or electric motors  122  are supported on the gantry housing  98 . As seen in  FIGS. 7 and 8 , the electric motors  122  are spacially arranged along the length of the gantry housing  98  with the output shafts  124  of the motors being oriented vertically upwardly and substantially parallel. Each of the electric motors  122  communicates with the central processing unit  66 . In response to information input into the central processing unit  66  by an operator of the apparatus, the unit controls selectively turning on and turning off each the electric motors  124  for pre-programmed periods of time, and selectively controls each of the electric motors  124  to rotate in a clockwise direction or a counterclockwise direction. 
         [0045]    As in the previously described embodiment, the plurality rods  62  are supported by the frame  58  in substantially parallel, vertical orientations. The rods  62  are supported by the frame  58  with the rods spacially arranged in a two-dimensional array that corresponds to the two-dimensional array of the holes  86  through the intermediate panel  84  and the holes  74  through the top panel  72 . Rows of the rods  62  extend across the frame  58  between the opposite sides of the frame as viewed in  FIGS. 5 and 6 , and columns of rods  62  extend across the frame between the front and back of the frame. Each of the rods  62  is supported at its lower end by one of the strips  92  of the frame  58 . The upper ends of each of the rods extends through one of the holes  86  in the upper intermediate panel  84  and is supported in its vertical orientation by the panel. The top end of each shaft projects above one of the holes  74  in the top panel  72 . 
         [0046]    Each of the rods  62  contains some type of linear actuator. For example, the rods  62  could be constructed with tubular outer housings having internal screw threading inside a hollow bore of the housings and screw threaded shafts extending through the bores of the housings and meshing with the internal screw threading. The tubular outer housings are free to move vertically up and down, but are secured against rotation. The bottom end of each shaft would be provided with a coupling that enables the bottom end of the shaft to be releasably coupled to the output shaft of one of the electric motors  106  when the motor is positioned below the shaft. On selective operation of the electric motor  106  the motor output shaft  108  is rotated either clockwise or counterclockwise and the screw thread shaft is rotated in the internal screw threading of the tubular housing causing the top end of the rod to extend upwardly from the frame top panel  72  or move downwardly toward the frame top panel. Any other equivalent type of linear actuator mechanism that converts opposite directions of rotation of an output shaft of a motor  106  positioned below the rod  62  to upward and downward movements of the top end of the rod could be employed in the rod  62 . 
         [0047]    A plurality of universal couplings  132  are attached to the top ends of the rods  62 . The universal couplings  132  could be any known type of coupling or joint that enables the coupling to move freely in all directions around the length of its attached rod, for example a ball and socket joint. 
         [0048]      FIGS. 10 and 11  show another example of such a universal coupling. The universal coupling  132  shown in  FIGS. 10 and 11  is basically comprised of an acorn nut  134  having a rounded or ball shaped exterior surface  136 . The nut  134  is screw threaded on an externally threaded rod  138  that is secured in a cylindrical insert  142  that in turn is secured in a tube  144  at the top end of a rod  62 . A magnet  146  is attracted to the rounded surface  136  of the acorn nut  134 . The magnet  146  has a concave center depression  148  or socket in the bottom of the magnet. The magnetic attraction of the magnet socket  184  to the ball shaped exterior surface  136  of the acorn nut  134  provides the universal connection between the top end of the rod  62  and the magnet  146 . The magnet  146  is secured in any known manner to the bottom surface of the molding platform  64  in a position above a rod  62 , thereby providing a universal connection between the top of a rod  62  and the bottom surface of the molding surface platform  64 . 
         [0049]    The molding platform  64  has a flat rectangular configuration that is shaped and dimensioned to extend the platform over the plurality of rods  62  supported on the frame  58 . The molding platform  64  has a top, planar surface  152  and an opposite bottom surface  154 . The top surface  152  has mutually perpendicular length and width dimensions. The rectangular peripheral edge  156  of the top surface  152  basically corresponds with the frame periphery defined by the four top frame bars  68 . The top surface  152  is smooth and continuous within the peripheral edge  156 . The molding platform  64  is constructed of several layers of flexible material. A plurality of flexible strands  158  extend through the flexible material between the top surface  152  and bottom surface  154 . The strands  158  can be seen in  FIGS. 12 and 13 . In the preferred embodiment, the strands  158  are arranged in a criss-crossing pattern as represented in  FIG. 12 . Furthermore, in a preferred embodiment the strands  158  are spring steel wire. 
         [0050]    The top surface  152  is prepared as a molding surface that will support thermoplastic sheet, plastic composite sheet or other similar types of molding material sheet, or materials that could be poured or spread on the top surface and that can be cured into hardened panels and then easily removed from the molding surface  152 . 
         [0051]    The platform bottom surface  154  is secured to each of the plurality of universal couplings that secure the bottom surface to the top ends of the rods  162 . For example, in the embodiment described earlier the plurality of magnets  164  at the tops of each of the universal couplings are secured to the platform bottom surface  154  in a spacial arrangement that corresponds to the two-dimensional array of rods  162  supported by the frame  58 . The magnets  146  can be secured to the bottom surface  154  by adhesives or in any other equivalent manner Each of the magnets  146  is positioned with its socket  148  over one of the ball shaped surfaces  136  of the acorn nuts  134  at the tops of each of the rods  62 . This secures the platform bottom surface  154  to each of the plurality of universal couplings at the top ends of the rods  62 . 
         [0052]    In operation of the embodiment of the apparatus shown in  FIGS. 5-16 , an operator of the apparatus inputs information into the central processing unit  66  based on the desired shape and configuration of a sheet of molding material placed on the top surface  152  of the molding platform. The information input into the central processing unit  66  is communicated to the motor  106  controlling movements of the gantry housing  98  to cause the gantry to move beneath the first row of rods  62  supported at the front of the frame  58 . The central processing unit  66  then controls the plurality of motors  122  on the gantry housing  98  to adjust the lengths of each of the rods  62  in the row and thereby cause the molding platform to move vertically along its length and width dimensions whereby separate portions of the top surface  152  move vertically relative to other adjacent portions of the top surface. This procedure is repeated for each of the rows of rods  62  whereby the vertical adjustment in the length of the rods  62  controlled by the CPU  66  causes separate portions of the top surface  152  along the length and width dimensions to move vertically relative to adjacent portions of the top surface and move the sheet of molding material supported on the top surface vertically to a desired configuration of the sheet of molding material. The adjusted top surface  152  holds the sheet of molding material in its desired configuration until the sheet of molding material cures and solidifies. The movement of the molding platform  64  forms the platform top surface  152  and the sheet of molding material supported on the top surface into the particular shape and configuration desired that will produce a body panel of a desired shape and contour from the molding material sheet. 
         [0053]    The apparatus of the invention enables an individual to use a single apparatus to accurately replicate surfaces or shapes available in three dimensional electronic geometry by way of a simple entry of numerical data into the control unit of the apparatus, thereby providing information on a “real” surface to the control unit for the purposes of molding various materials within minutes into the replicated surface, as well as consuming a minimal amount of materials and without requiring any other equipment. 
         [0054]    The apparatus replicates three dimensional geometry of a known shape having known three dimensional locations of points on the shape by inputting information into the apparatus control unit to control the plurality of rods to position their top ends in identical positions to the three dimensional array of known points and thereby produce a “point cloud” at the adjusted top ends of the apparatus rods. The top surface of the molding platform overlaying the point cloud created by the rod top ends provides a smooth molding surface between adjacent rod top ends and provides an accurate molding surface to replicate the desired three dimensional geometry. 
         [0055]    As various modifications could be made in the construction of the apparatus and its method of use herein described and illustrated without departing from the scope of the invention, it is intended that all matter contained in the foregoing description or shown in the accompanying drawings shall be interpreted as illustrative rather than limiting. Thus, the breadth and scope of the present invention should not be limited by any of the above described exemplary embodiments, but should be defined only in accordance with the following claims appended hereto and their equivalents.