Abstract:
Apparatus for manufacturing molded products with an EMI/RFI/ESD shield. The apparatus includes shaping apparatus for automatically shaping a mesh blank into a mesh insert on a fixture, and a robot for removing the insert from the fixture and placing it in a molding machine in preparation for molding the insert into a molded product. Also disclosed is a method for manufacturing molded products involving the steps of automatically forming the blank into a mesh insert and automatically transferring the insert to a molding machine using a robot. A holding tool may be provided for the robot to use in transferring the insert to the molding machine.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    This invention relates generally to molded plastic products and, more particularly, to apparatus and methods for making such products with molded-in wire mesh inserts for shielding against electromagnetic interference (EMI), radio frequency interference (RFI) and/or electrostatic discharge (ESD).  
           [0002]    Reference may be made to U.S. Pat. No. 6,054,647 (issued to Ridener, Apr. 25, 2000), which is incorporated by reference herein for all purposes, for background information relating to electromagnetic shielding for plastic parts.  
         SUMMARY OF THE INVENTION  
         [0003]    One embodiment of the present invention is an apparatus for manufacturing plastic products to have EMI/ESD/RFI protection. The apparatus includes a shaping apparatus for shaping a mesh blank into a mesh insert on a fixture. The apparatus also includes a robot for removing the shaped mesh insert from the fixture, transferring the insert to a molding machine, and placing the insert on a mold core of the machine in preparation for a molding operation in which the insert is molded into a molded product.  
           [0004]    Another embodiment of the present invention is a holding tool for use by a robot to transfer mesh inserts to a molding machine and to transfer molded products away from the molding machine. The holding tool includes a base, a mesh insert holder attached to the base, and a molded product holder also attached to the base.  
           [0005]    According to a method of the present invention for manufacturing molded products to have EMI/ESD/RFI protection, a mesh blank is automatically shaped on a fixture into a mesh insert. Then a robot is operated to (1) remove the shaped mesh insert from the fixture, (2) transfer the insert to a molding machine, and (3) place the insert on a mold core of the machine in preparation for a molding operation in which the insert is molded into a molded product. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0006]    [0006]FIG. 1 is a plan view of one embodiment of an apparatus of the present invention alongside a molding machine;  
         [0007]    [0007]FIG. 2 is a side elevation of the apparatus and molding machine shown in FIG. 1;  
         [0008]    [0008]FIG. 3 is an enlarged plan view of a portion of the apparatus shown in FIGS. 1 and 2 showing feeding apparatus, a press, forming apparatus, and shaping apparatus;  
         [0009]    [0009]FIG. 4 is a side elevation of the feeding apparatus, press, forming apparatus, and shaping apparatus shown in FIG. 3;  
         [0010]    [0010]FIG. 5 is an enlarged end view of the press, forming apparatus, and shaping apparatus shown in FIGS. 3 and 4;  
         [0011]    [0011]FIG. 6 is an enlarged plan view of the feeding apparatus shown in FIGS.  1 - 5 ;  
         [0012]    [0012]FIG. 7 is a side elevation of the feeding apparatus shown in FIG. 6;  
         [0013]    [0013]FIG. 8 is an end view of the feeding apparatus shown in FIGS. 6 and 7;  
         [0014]    [0014]FIG. 9 is a horizontal sectional view of the taken in the plane  9 - 9  on FIG. 2 showing the lower platen;  
         [0015]    [0015]FIG. 10 is a sectional view of the upper and lower platens of the press shown in FIG. 9 taken in the plane  10 - 10  on FIG. 9;  
         [0016]    [0016]FIG. 11 is a sectional view of the upper and lower platens of the press taken in the plane  11 - 11  on FIG. 9;  
         [0017]    [0017]FIG. 12 is a plan view of a mesh blank that may be cut by the press shown in FIGS.  9 - 11 ;  
         [0018]    [0018]FIG. 13 is a plan view of a forming apparatus having four spokes;  
         [0019]    [0019]FIG. 14 is an enlarged end view of a portion of the forming apparatus shown in FIG. 13;  
         [0020]    [0020]FIG. 15 is an enlarged side view of the shaping apparatus shown in FIGS.  1 - 5 ;  
         [0021]    [0021]FIG. 16 is an end view of the shaping apparatus shown in FIG. 15;  
         [0022]    [0022]FIG. 17 is a perspective view of a mesh insert that may be formed by folding or bending the mesh blank shown in FIG. 12;  
         [0023]    [0023]FIG. 18 is a perspective view of a holding tool for the robot arm;  
         [0024]    [0024]FIG. 19 is a rear view of the holding tool shown in FIG. 18;  
         [0025]    [0025]FIG. 20 is a plan view of the holding tool shown in FIG. 18;  
         [0026]    [0026]FIG. 21 is a side elevation of a robot arm in the process of transporting a mesh insert from the apparatus shown in FIGS.  1 - 5  to the molding machine;  
         [0027]    [0027]FIG. 22 is a side elevation of a robot arm in the process of placing the mesh insert into the molding machine;  
         [0028]    [0028]FIG. 23 is an enlarged perspective view of a portion of the forming apparatus and a portion of a shaping apparatus about to begin forming a mesh blank into a mesh insert;  
         [0029]    [0029]FIG. 24 is an enlarged perspective view of the portion of the forming apparatus and the portion of the shaping apparatus shown in FIG. 23 just after the hold down plate has moved down to hold the mesh blank in place;  
         [0030]    [0030]FIG. 25 is an enlarged perspective view of the portion of the forming apparatus and the portion of the shaping apparatus shown in FIG. 23 just after the end swipes have bent the end flaps over the fixture;  
         [0031]    [0031]FIG. 26 is an enlarged perspective view of the portion of the forming apparatus and the portion of the shaping apparatus shown in FIG. 23 just after the lower assembly has moved into position in preparation for forming tabs;  
         [0032]    [0032]FIG. 27 is an enlarged perspective view of the portion of the forming apparatus and the portion of the shaping apparatus shown in FIG. 23 just after the tab shaping members have formed the tabs;  
         [0033]    [0033]FIG. 28 is an enlarged perspective view of the portion of the forming apparatus and the portion of the shaping apparatus shown in FIG. 23 just after the tab forming members have returned to their original position after forming the tabs;  
         [0034]    [0034]FIG. 29 is an enlarged perspective view of the portion of the forming apparatus and the portion of the shaping apparatus shown in FIG. 23 just after the side swipes have bent the side flaps to form side walls;  
         [0035]    [0035]FIG. 30 is an enlarged perspective view of the portion of the forming apparatus and the portion of the shaping apparatus shown in FIG. 23 with a completely formed mesh insert on the fixture;  
         [0036]    [0036]FIG. 31 is an enlarged plan view of a robot arm ready to remove a molded product from a mold core;  
         [0037]    [0037]FIG. 32 is an enlarged plan view of a robot arm removing a molded product from a mold core;  
         [0038]    [0038]FIG. 33 is an enlarged plan view of a robot arm placing a mesh insert on a mold core;  
         [0039]    [0039]FIG. 34 is a perspective view of a molded product made according to the present invention;  
         [0040]    [0040]FIG. 35 is a cross sectional view of the molded product shown in FIG. 34 taken through the plane  35 — 35  shown on FIG. 34; and  
         [0041]    [0041]FIG. 36 is a schematic diagram of a pneumatic circuit that may be used to supply compressed air to pneumatic actuators that may be used in an apparatus of the present invention.  
         [0042]    Corresponding reference numbers are used to identify corresponding parts throughout the drawings. 
     
    
     DETAILED DESCRIPTION  
       [0043]    Generally, as will be described, an apparatus of the present invention is operable to automatically form mesh inserts of electrically conductive material (e.g., copper), and to robotically load the inserts into the mold of a molding machine which forms plastic products with the mesh inserts molded into the products for shielding against electromagnetic interference (EMI), radio frequency interference (RFI) and/or electrostatic discharge (ESD). The molded products may be robotically unloaded from the molding machine for inspection or other processing.  
         [0044]    FIGS.  1 - 5  show one embodiment of apparatus of the present invention. The apparatus (sometimes referred to as a “cell”), generally designated  1 , comprises a feeding apparatus  3  at a feeding station  5  for pulling a continuous web of wire mesh  7  from a supply roll  9  and feeding the web  7  to a stamping station  11 . As is known to those skilled in the art, a conventional alignment mechanism (not shown) may be provided for helping to keep the web of wire mesh  7  aligned as the feeding apparatus  3  pulls it from the supply roll  9 . The wire mesh  7  may be made of any suitable conductor (e.g., copper). The size of the holes in the mesh  7  may vary. One exemplary wire mesh is made of 0.065 inch diameter wires and has between about 30 and 40 wires per inch running in one direction cross-linked with a roughly equal number wires per inch running in a cross (e.g., perpendicular) direction. However, it is possible to use a much finer or courser wire mesh if desired.  
         [0045]    A press  15  at the stamping station  11  stamps flat mesh blanks  17  from the web  7 . The blanks  17  are automatically placed on a forming apparatus  21  having a forming fixture  19  and delivered to a shaping apparatus  23  which shapes the mesh blanks  17  over the forming fixture  19  to form mesh inserts  25 . The cell  1  also includes a robot  27  for picking up the shaped inserts  25 , for transferring them to a molding machine  29  (e.g., an injection molding machine), and for unloading molded products from the molding machine. A control system  35  (e.g., computer) controls the operation of the cell  1 , the robot  27 , and the molding machine  29 . A table  13  or similar support may be used to provide a level surface for the various parts of the apparatus.  
         [0046]    As shown in FIGS.  6 - 8 , the feeding apparatus  3  may comprise, in one embodiment, a pair of jaws  41  or grippers mounted at the forward ends  45  of two arms  43  extending along opposite sides  223  of the web  7 , and a mechanism  47  (e.g., pneumatic cylinders) for opening and closing the jaws  41 . The arms  43  are mounted on a carriage  49  which is capable of moving the arms in X  51 , Y  53  and Z  55  directions relative to the web  7 , that is, X being back and forth in a direction generally parallel to the web  7 , Y being up and down, and Z being in and out in a direction generally transverse to the web  7 . The movements of the carriage  49  and arms  43  are effected by suitable power actuators  57  (e.g., pneumatic cylinders).  
         [0047]    Referring to FIGS.  9 - 11 , the press comprises upper and lower platens  65 ,  67  (“shoes”) and conventional cutting tooling  71  (e.g., one or more dies) for cutting blanks  17  of appropriate size and shape from the web  7 . FIG. 12, for example, shows the outline of a mesh blank  17  that may be cut by the cutting tooling  71  shown in FIG. 9. The mesh blank  17  has two end flaps  251  and two side flaps  265 . The mesh blank may include holes  97  (e.g., two holes) for receiving locator pins, as will be described later. Additional holes  101  may be cut in the blank  17  if desired. The mesh blank  17  also has a forward end  243  and a trailing end  241 . For reasons that will become apparent, a gap  73  (FIG. 9) is provided in the cutting tooling  71  so that the trailing end  241  of the mesh blank  17  is not severed from the web  7  while the blank  17  is still on the press  15 . Instead, as will be described later in more detail, the tooling  71  includes a blank-severing portion  83 , which is operable to sever the trailing end  241  of the blank  17  from the web  7  as the next blank  17  is being cut. In one embodiment, the lower platen  67 , on which the web  7  has been placed, is stationary and the upper platen  65  is movable in a vertical direction toward and away from the lower platen  67 . An actuator  69  (e.g., pneumatic cylinder) may be provided to power movement of the upper platen  65 .  
         [0048]    [0048]FIGS. 13 and 14 show a forming apparatus  21 , which comprises a central hub  75  rotatable about a vertical axis  77 , and a plurality of arms or spokes  79  radiating out from the hub  75 . For example, four spokes  79  may be provided at 90° intervals. A fixture  19  having a shape corresponding to the shape of the mesh insert  25  to be formed is mounted toward the outer end  81  of each spoke  79  (FIG. 14). For example, the fixture  19  may have a flat rectangular base  85  and a rectangular block  87  on the base  85 . The fixture block  87  has an upper surface  89 , two opposing side surfaces  91 , and two opposing end surfaces  93 . Locator pins  95  (e.g., two pins) extend up from the fixture block  87  for reception in holes  97  in the mesh blank  17  to properly locate the mesh blank  17  on the fixture  19 . Magnets  99  (e.g., two electro-magnets in FIG. 13) are provided on one or more of the fixture surfaces  89 ,  91 ,  93  to hold the blank  17  in place. A suitable drive mechanism  107  (e.g., an electric motor), is provided for indexing the spokes  79  between four positions or stations, namely, a first blank-receiving station  111  adjacent the press  15 , a second insert shaping station  113 , a third insert loading station  115 , and a fourth idle station  117 . One or more sensors  105  (e.g., magnetic proximity sensors) are provided for sensing the correct position of the mesh blank  17  and mesh inset  25  on the fixture  19 . The sensors  105  are just one example of a plurality of sensors (not shown) that may be stationed at various locations on or in the apparatus  1  to provide feedback to the control system  35  regarding the operation of the apparatus  1 .  
         [0049]    Referring to FIGS. 15 and 16, a shaping apparatus  23  is provided at the second (shaping) station  113  for shaping each blank  17  into a mesh insert  25 . The shaping apparatus  23  may include an upper assembly  127  comprising, in one embodiment, a horizontal hold-down plate  129  movable up and down by a power cylinder  131  (shown in FIG. 23), two opposing end shaping members  133  (“end swipes”) at opposite ends of the hold-down plate  129  movable up and down by power cylinders  135 , and two opposing side shaping members  137  (“side swipes”) at opposite sides of the hold-down plate  129  movable up and down by power cylinders  139 . The shaping apparatus  23  also includes a lower frame  145  (sometimes referred to as a “tab unit”) movable up and down by one or more power actuators  147 , and two opposing pairs of tab shaping members  149  on the lower frame  145  movable toward and away from one another by power actuators  151 . Two push rods  155  are also fixed to the lower frame  145 . Position sensors (e.g., magnetic proximity sensors, not shown) are provided for sensing the positions of the various shaping members  133 ,  137 ,  149 . Position sensors are also provided for sensing the position of each fixture  19  as it moves from station to station. The shaping apparatus  23  is operable, in a manner to be described below, to form the exemplary mesh blank  17  into the exemplary mesh inset  25  shown in FIG. 17. The mesh insert  25  has a top wall  275 , two end walls  253 , and two side walls. End wall flanges  257  are provided at the lower edges of the end walls  253 . Similarly, side wall flanges  273  are provided at the lower edges of the side walls  271 . The end walls  253  also have flanges (“tabs”)  269  along their edges  267  which tuck inside the side walls  271  to provide corners  277  which are completely sealed against EMI/RFI/ESD.  
         [0050]    The robot  27  is positioned within reach of the loading station  115  of the forming apparatus  21 . The robot  27  includes an arm  165  carrying a holding tool  167 , which is shown in FIGS.  18 - 20 . The holding tool  167  comprises a base  175  for attachment to the arm  165 , an insert holder  177  and a molded product holder  179 , the two holders  177 ,  179  being positioned side by side on the base  175 . The insert holder  177  comprises an array of magnets  181  (e.g., six) on magnet supports  183  attached to the base  175 . The magnets  181  are preferably electro-magnets arranged to define a cavity  185  for holding a mesh insert  25 . For example, if the mesh insert  25  is going to have a generally rectangular shape, a first group  189  of opposing magnets  181  may be operable to contact the end walls  253  of the insert  25  and a second group  193  of opposing magnets  181  may operable to contact the side walls  271  of the insert  25  (e.g., two magnets on each side wall and one on each end wall). The product holder  179  comprises a pair of parallel plates  197  extending from the base  175  and spaced for receiving a molded product  33  therebetween, and vacuum devices  201  on the base  175  between the plates  197 . The robot  27  also includes a conventional frame  169  and mechanism (not shown) for moving the arm  165  between the insert loading station  115  and the molding machine  29 .  
         [0051]    The injection molding machine  29  is positioned within reach of the robot arm  165  as shown in FIGS. 21 and 22, for example. The molding machine  29  comprises a mold core  203  and a mold cavity  205  for receiving the core  203 , as will be understood by those skilled in the art. The mold core  203  has an external shape generally corresponding to the shape of the fixtures  19  on the spokes  79  of the forming apparatus  21  and the inside contour of each shaped mesh insert  25 . The mold core  203  has magnets  211  (e.g., electromagnets) on it for holding a shaped insert  25  in place on the core  203 , as explained below. The construction of the molding machine  29  is otherwise conventional and will not be described in detail. Suffice it to say that as plastic is injected into the mold cavity  205 , the plastic flows through the mesh insert  25  so that it becomes an integral “molded-in” part of the finished product to provide effective and reliable protection against EMI/ESD/RFI. As shown in FIGS. 1 and 2, a product conveyance chute  221  may be provided adjacent the loading station  115  (or at another convenient location) for receiving molded products from the robot  27  and for transferring the products to a suitable location (not shown) for inspection and, if necessary, further processing.  
         [0052]    The operation of the apparatus  1  will now be described. With the arms  43  of the feeding apparatus  3  positioned immediately adjacent opposite side edges  223  (FIGS.  1 - 5 ) of the web  7 , the grippers  41  are actuated to close on the mesh web  7 . The press  15  closes to die cut a blank  17  from the web  7  and opens upon completion of the cutting. The carriage  49  and arms  43  of the feeding apparatus  3  (FIGS.  6 - 8 ) are then raised to lift a partially cut blank  17  from the press  15 , and the carriage  49  advances in a forward direction  51  to move the partially cut blank  17  to a position above a fixture  19  at the first station  111  (FIGS.  1 - 5 ). At this point, the blank  17  (FIG. 12) cut from the web is still connected to the web  7  at its trailing (back) end  241  because of the gap  73  in the tooling  71  (FIG. 9). Thus, forward movement of the arms  43  functions to pull more web  7  from the supply roll  9  and to advance a section of raw uncut web  7  into the press  15  over the lower platen  67  of the press  15 . The carriage  49  and arms  43  are then lowered to place the blank  17  on the locating pins  95  of the fixture block  87  at the first station  111  and to place the raw web  7  on the lower platen  67 , following which the grippers  41  are opened and the arms  43  move away from one another to release the web  7 . The carriage  43  is then raised and moved in a rearward direction  51  to a position where the grippers  41  are at their home position adjacent the press  15  (FIG. 2), at which point the arms  43  move toward one another and the grippers  41  close to grip the web  7  in preparation for the next blank  17  to be cut. As the next blank is cut, the connection between the trailing end  241  of the mesh blank  17  and the web  7  is severed by the severing portion  83  of the tooling  71  (FIG. 9) and the cycle repeats. Those skilled in the art will understand that one feed mechanism may be used to feed raw web to the press  15  and a second mechanism used to move the mesh blank  17  to the forming station  21  without departing from the scope of this invention. However, it will also be recognized that certain advantages may be achieved by providing a single feed mechanism to perform both tasks, as described above.  
         [0053]    After the blank  17  at the first station  111  has been severed from the mesh web  7 , the hub  75  of the forming apparatus  21  (FIGS. 13 and 14) is rotated to index the blank  17  from the first (blank-receiving) station  111  to the second (forming) station  113 . The shaping apparatus  23  (FIGS. 15 and 16) then forms the mesh blank  17  into a mesh insert  25 . In order to form the exemplary mesh insert  25 , the hold-down plate  129  is lowered as shown in FIG. 24 to hold the mesh blank  17  securely against the upper surface  89  of the fixture  19 , as confirmed by the sensor  105  in the fixture  19 . The locating pins  95  may retract into the fixture block  87  to provide a space for the hold-down plate  129 .  
         [0054]    Forming of the mesh insert  25  begins when two end shaping members  133  are actuated to move down as shown in FIG. 25 to bend or fold the two end flaps  251  of the mesh blank  17  down against the end surfaces  93  of the fixture  19  to form opposing end walls  253  of the shaped mesh insert  25 . Preferably, the two end flaps  251  are somewhat longer than the height H of the fixture block  87  (FIG. 14), so that as the end shaping members  133  reach the bottom of their strokes, they press the lower edge margins of the end flaps  251  against the base  85  of the fixture to form 90° flanges  257  at the lower ends of the insert end walls  253 . As shown in FIG. 26, the lower frame  145  (“tab unit”) then rises to an elevated position adjacent the fixture  19 . As the frame  145  rises, the push rods  155  on the frame  145  contact the two side flaps  265  of the blank  17  and push them up a short distance and out of the way for the next step to be performed. With the side flaps  265  pushed up, the two pairs of tab shaping members  149  are actuated to move inwardly toward one another and the fixture  19  to bend or fold edge portions  267  of the mesh end walls  253  against the side surfaces  91  of the fixture  19  to form corner tabs  269  or flanges along the mesh end walls  253 , as shown in FIG. 27. Upon completion of their respective strokes, the tab shaping members  149  retract to their home position as shown in FIG. 28. Then the lower frame  145  returns to its lowered position. Upon arrival of the frame  145  at its lowered position, as sensed by a sensor, the two side shaping members  137  are actuated to move down as shown in FIG. 29 to bend or fold the two side flaps  265  of the mesh blank  17  down against the side surfaces  91  of the fixture  19  and over the corner tabs  269  to form opposing side walls  271  of the shaped mesh insert  25 . Preferably, the two side flaps  265  are also somewhat longer than the height H of the fixture block  87 , so that as the side shaping members  137  reach the bottom of their strokes, they press the lower edge margins of the side flaps  265  against the base  85  of the fixture  19  to form 90° flanges  273  at the lower ends of the insert side walls  271 . A sensor signals the bottom of each stroke, after which the side shaping members  137 , end shaping members  133 , and hold-down plate  129  are all raised back to their home positions, as sensed by a sensor, to complete the forming cycle.  
         [0055]    After the mesh insert  25  is formed, the hub  75  of the forming apparatus  21  (FIGS. 13 and 14) rotates to index the formed mesh  25  insert from the second (forming) station  113  to the third (loading) station  115  for pick-up by the robot  27 . The robot arm  165  is activated to move the holding tool  167  to the loading station  115  to a position in which the shaped mesh insert  25  on the fixture  19  is received in the cavity  185  of the insert holder  177  and held by the magnets  181  on the tool  167 . The magnets  99  on the fixture  19  are then de-energized and the arm  165  is manipulated to remove the mesh insert  25  from the fixture  25 , as sensed by a sensor  105 . After a predetermined interval of time sufficient to insure removal of the insert  25  from the fixture  19 , a signal is sent to the control system  35  indicating that the forming apparatus  21  can continue its operation of making shaped inserts  25  from the stamped blanks  17 . Assuming the molding machine  29  is ready to mold a part, as sensed by appropriate sensors and the control system  35 , the robot arm  165  is maneuvered to move the holding tool  167  to a position in which the molded product holder  179  is immediately adjacent the mold core  203  which holds a freshly molded product  33 , as shown in FIG. 31. Referring to FIG. 32, ejector pins  279  are then actuated to help the robot arm  165  slide the product  33  off the core  203 . The molded product  33  is held by the holding tool  167  between the two holding plates  197  by the vacuum cups  201 . As shown in FIG. 33, the robot arm  165  is then manipulated to shift the holding tool  167  over to a position in which the shaped mesh insert  25  is aligned with the core  203 , and then advanced to place the insert  25  on the core  203 , after which the magnets  181  of the holding tool  167  are de-energized and the robot arm  165  is retracted to leave the insert  25  on the core  203 . The robot arm  165  then carries the molded product  33  to the product conveyance chute  221  and de-activates the vacuum cups  201  to allow the product  33  to fall into the chute  221 . To complete the cycle, the robot arm  165  returns to the loading station  115  for pick-up of the next shaped mesh insert  25 .  
         [0056]    After the robot arm  165  is clear of the molding machine  29 , the molding machine brings the mold core  203  and mold cavity  205  together and injects material (e.g., plastic) into the mold. Generally, the material flows into the mold and surrounds the mesh insert. FIGS. 34 and 35 show an exemplary molded product  33  that may be made using the exemplary mesh insert  25 . As shown in FIG. 35, the mesh insert  25  is embedded within the molded product. Those skilled in the art will recognize that the apparatus  1  could be modified to produce any of a wide variety of mesh inserts and molded products without departing from the scope of the invention. For example, the tooling  71  at the press  15  may be altered to cut a differently-shaped blank, the fixture  19  can be shaped differently, and/or the shaping apparatus  23  can be adapted to bend the parts of the blank  17  in a different order or along different bend lines to create a mesh insert having a different shape. Also the molding machine may be adapted to change the molded product without changing the mesh insert. The apparatus  1  can shape and mold mesh inserts into practically any molded product, including automotive radio cases, computer housings, cell phones, instrument panels, housings for electric motors, and hand-held bar code scanners to name just a few.  
         [0057]    All movements of the apparatus  1  may be powered by pneumatic cylinders. FIG. 36 is a schematic representation of one suitable pneumatic circuit  301  for control of the various pneumatic cylinders that may be used to power apparatus movements. The circuit  301  itself is conventional and need not be discussed in great detail. The pneumatic circuit  301  comprises a source of compressed air  303 , a lock out  305 , a filter  313 , a pressure regulator  307 , air supply lines  309 , and a plurality of operating valves  311  for supplying compressed air to the various pneumatic actuators (e.g., cylinders). Small pneumatic pistons  321 , which may be activated by solenoids  323  controlled by the control system  35 , can be provided to shift the spools in the operating valves  311 . In this way, the control system  35  can control operation of the apparatus  1  by selectively activating and deactivating the solenoids  323 , thereby directing movement of the apparatus  1  according to a programmed sequence. Those skilled in the art will recognize that the apparatus  1  could be moved by a variety of alternative mechanisms without departing from the scope of the invention.  
         [0058]    The control system  35  (FIGS.  1 - 5 ) can also be used to selectively energize and de-energize the electromagnets  99 ,  181 ,  211  according to a programmed sequence. The previously mentioned sensors may signal the control system  35  at each step of the operational cycle to confirm that the apparatus  1  is performing properly. Alternatively, if the apparatus is not performing properly, such as if blank  17  or mesh insert  25  falls off the apparatus, the control system  35  will detect the problem based on the signals it receives from the sensors and shut the apparatus  1  down. The control system  35  may further sound an alarm to notify a person of the problem. The control system  35  also facilitates adaptation of the apparatus  1  to form a differently-shaped mesh insert  25  because the programmed sequence of apparatus  1  movements can be modified to accommodate a different bending sequence that may be used to form a mesh blank  17  into a different shape at the forming station  21 . Initial and terminal sequences can also be programmed into the control system  35  to account for the absence of blanks  17 , inserts  25  or molded products  33  at various phases of start-up or shut-down. Preferably, the control system  35  will have a keypad and display panel (or other user interface) to allow a person to supervise or direct operation of the apparatus  1 . The control system  35  may also allow manual control of the apparatus  1 , which may be desirable from time to time for user-controlled movement of the apparatus  1 .  
         [0059]    When introducing elements of the present invention or the preferred embodiment(s) thereof, the articles “a”, “an”, “the” and “said” are intended to mean that there are one or more of the elements. The terms “comprising”, “including” and “having” are intended to be inclusive and mean that there may be additional elements other than the listed elements.  
         [0060]    In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained.  
         [0061]    As various changes could be made in the above constructions and methods without departing from the scope of the invention, it is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.