Patent Document

FIELD OF THE INVENTION  
       [0001]     This invention relates to injection molded closures, particularly of the “flip-top” type. More specifically, the present invention relates to a component of a molding apparatus which closes the closure prior to part ejection.  
       BACKGROUND OF THE INVENTION  
       [0002]     A typical injection molded closure of the “flip-top” type has a closure body hingedly connected to a cap. The cap is swingable about the hinged connection over the closure body. The cap and closure body are provided with mutual inter-locking means such as a protrusion which engages a lip to secure the cap to the closure body in a closed configuration. The cap and closure body are generally molded simultaneously in an open configuration with the cap adjacent the closure body.  
         [0003]     In-mold closing devices are used for molding such closures. In order to provide a good seal and fit between the protrusion and the cap and the lip and the closure body, it is desirable to engage the respective sides of these components immediately after molding for optimizing shrinkage during cooling. The closing of the cap also simplifies handling after molding and part ejection, as this alleviates concern that the parts will interlock with each other, or damage the hinge. As well, by flexing the hinge while it is still warm, the hinge has a tendency to withstand more open and close cycles of the cap.  
         [0004]     A device for effecting closure of a cap over a closure body is described in U.S. Pat. No. 4,351,630 (Hayberg et al) which discloses the use of a push pin mounted within one of the mold halves to push a cap into an upright position in order for a slide finger having a roller to roll over and snap shut the cap in its closed configuration. This apparatus requires synchronized movement between the pin and the slide finger which is problematic as the components have independent actuation. Accordingly, there remains the possibility of collision between the two components. Furthermore, the pin is problematic in mold design, as the pin and a piston assembly behind the pin which actuates the pin need to be directly located behind the cap. This restriction may reduce the cooling accessible to the cap and as well complicates mold design.  
         [0005]     U.S. Pat. No. 4,741,088 (Ramella) teaches forming a cap over a closing mechanism. Closing is effected by having the mechanism move away from and then along the closure.  
         [0006]     U.S. Pat. Nos. 4,812,116 and 4,783,056 (both of which issued to Abrams) teach the use of a flipper arm mounted to a mold cavity plate to flip a lid over a vial. As with the Hayberg and Ramella structures, Abrams has an in-mold component and accordingly doesn&#39;t avoid the problems associated with accommodating a closing unit as part of a mold.  
         [0007]     An object of the present invention is to eliminate having a synchronized pin and slide finger arrangement to avoid the possibility of in-mold collisions. A further object of the present invention is to provide a closing device for closing a cap over an injection molded closure body without requiring an in-mold component for initial lifting of the cap.  
       SUMMARY OF THE INVENTION  
       [0008]     In general terms, the present invention provides a laterally movable lifting arm and follower which may be mounted adjacent a mold. The lifting arm is movable from a cap engaging position wherein it initially moves the cap away from the mold into the path of the follower. The cap is initially moved across the lid by lateral movement of the lifting arm. The follower is subsequently passed across the cap to lockingly engage the closure.  
         [0009]     More specifically, a closing device is provided for closing a molded closure while the closure is in a mold and wherein the closure has a body hingedly connected to a cap. The cap is swingable about the hinge over the closure body and the cap and enclosure body are provided with mutual interlocking means for securing the cap to the closure in a closed configuration. The closing device has a head movable across the cap and the closure in a lateral direction while the cap and closure are in the mold. The device further has a lifting arm with a base end movably connected to the head and a forward end extending away from the head for contacting the cap. A follower is connected to the head adjacent the base end of the lifting arm. A lifting arm actuator is provided which acts between the head and the lifting arm for moving at least the forward end of the lifting arm to contact the cap and to move the cap from an open molded configuration toward the closed configuration. A head actuator is provided for moving the head in conjunction with the arm and the follower across the cap and the closure for the follower to urge the cap toward the closure to engage the interlocking means and secure the closure in the closed configuration.  
         [0010]     The head actuator may be a fluid pressure responsive drive or a screw drive.  
         [0011]     The head may be mounted on a carrier plate on which the head actuator acts.  
         [0012]     The carrier plate may be slidably secured to a mounting plate, the mounting plate securing the closing device to a mold assembly and the actuator acting between the carrier plate and the mounting plate.  
         [0013]     The lifting arm may be hingedly affixed to the head for rotational movement about a hinge axis transverse to the lateral direction. The lifting arm actuator may have a first member movable relative to the lifting arm parallel to the lateral direction and a translating coupling extending between the lifting arm and the first member to translate relative movement between the first member and the lifting arm into the rotational movement.  
         [0014]     The translating coupling may be a rack carried by the first member which acts on a pinion connected to the lifting arm.  
         [0015]     Alternatively, the translating coupling may be a cam carried by the first member which acts against a cam follower connected to the lifting arm.  
         [0016]     As a further alternative, the translating device may be a link pivotally coupled as a first end to the first member and at a second end to the lifting arm.  
         [0017]     In a further embodiment, the closing device may be a fluid pressure actuated rod and cylinder assembly connected to act between a lifting arm and the head.  
         [0018]     The closing device may have a coupler coupling the first member to the carrier plate and to the mounting plate for moving the first member relative to the lifting arm in response to relative movement between the carrier plate and the mounting plate.  
         [0019]     The coupler may have a first stop connected to the first member for acting on the carrier plate to limit movement of the first member toward the lifting arm. A second stop may be connected to the carrier plate for acting against the mounting plate to limit movement of the carrier plate away from the mounting plate. A first biasing means may be connected to the first member and to the carrier plate for urging the first member toward the lifting arm.  
         [0020]     The lifting arm actuator may include an actuator plate on an opposite side of the mounting plate from the carrier plate and an intermediate plate between the actuator plate and the mounting plate. The actuator plate and the carrier plate may be movable toward and away from the mounting plate. An intermediate stop may be connected to the mounting plate for acting against the intermediate plate to limit movement of the intermediate plate away from the mounting plate. A second biasing means may be connected to the mounting plate and the intermediate plate to urge the intermediate plate and in turn the actuator plate away from the mounting plate. The first biasing means may exert a biasing force greater than that of the second biasing means by an amount sufficient to avoid movement of the first member toward to the lifting arm until the intermediate plate abuts against the carrier plate and the carrier plate abuts against the mounting plate.  
         [0021]     The first and second biasing means may be resilient members.  
         [0022]     The first and second biasing means may be springs.  
         [0023]     The invention also provides a method for closing a cap over a closure in a mold cavity with the method comprising the following steps: 
        (i) providing a laterally movable lifting arm and follower adjacent the mold cavity;     (ii) engaging the cap with the lifting arm;     (iii) rotating the lifting arm to lift the cap away from a corresponding recess in the mold cavity;     (iv) moving the lifting arm across the closure body by laterally moving the lifting arm; and     (v) passing the follower across the cap to urge the cap toward the closure body to lockingly engage the cap with the closure body.       
 
     
    
     DESCRIPTION OF DRAWINGS  
       [0029]     The invention is described in detail below with reference to the accompanying drawings in which:  
         [0030]      FIG. 1A  is a front elevation illustrating a closing device according to the present invention in a parked position;  
         [0031]      FIG. 1B  is a schematic view from above corresponding to  FIG. 1A ;  
         [0032]      FIG. 2A  is a view corresponding to  FIG. 1A  but illustrating the closing device in a ready to flip position;  
         [0033]      FIG. 2B  is a schematic view from above corresponding to  FIG. 2A ;  
         [0034]      FIG. 3A  is a front elevation of a closing device according to the present invention in a finished flip position;  
         [0035]      FIG. 3B  is a schematic view from above corresponding to  FIG. 3A ;  
         [0036]      FIG. 4A  is a front elevation of a closing device according to the present invention in a closed lid position;  
         [0037]      FIG. 4   b  is a schematic view from above corresponding to  FIG. 4A ;  
         [0038]      FIG. 5A  is a schematic representation of an alternate embodiment of a lifting arm actuator to that illustrated in  FIG. 1A through 4B  in actuating configuration;  
         [0039]      FIG. 5B  is a schematic representation of the lifting arm actuator of  FIG. 5A  in its non-actuating configuration.  
         [0040]      FIG. 6A  is a schematic representation of a further alternate embodiment of a lifting arm actuator in an actuated configuration;  
         [0041]      FIG. 6B  is a schematic representation of the lifting arm actuator of  FIG. 6A  in its non-actuating configuration;  
         [0042]      FIG. 7A  is a schematic representation of an alternate lifting arm actuator in its actuating configuration; and,  
         [0043]      FIG. 7B  is a schematic representation of the lifting arm actuator of  FIG. 7A  in its non-actuating configuration. 
     
    
     DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0044]     A closing device according to the present invention is generally indicated by reference numeral  10  in the accompanying illustrations.  FIGS. 2A, 3A  and  4 A illustrate a representative closure  20  having a closure body  22  hingedly connected to a cap  24  by an integral hinge  26 . The cap  24  and closure body  22  are provided with mutual interlocking means for securing the cap  24  to the closure body  22 . The interlocking means illustrated include a protrusion  28  extending from the cap  24  which registers with and is received by a lip  30  extending about a passage through the closure body  22 .  
         [0045]     The closing device  10  has a head  40  movable across the cap  24  and the closure body  22  in a “lateral” direction illustrated by arrow  42  while the closure is in the mold. “Lateral” should be interpreted in a general rather than a specific sense to include but not be restricted to having the head  40  move parallel to the mold. For example, as illustrated in  FIGS. 1A, 2A ,  3 A and  4 A, the closing device  10  may be titled slightly toward the closure  20  for the head  40  to move non-parallel to (i.e. at an angle to) a face of the mold or the cap  24 . A lifting arm  44  having a base end  46  is movably connected to the head  40 . The lifting arm  44  further has a forward end extending away from the head for contacting the cap  24  as illustrated for example in  FIG. 2A .  
         [0046]     A follower  50  such as the roller illustrated is connected to the head  40  adjacent the base end  46  of the lifting arm  44 .  
         [0047]     A lifting arm actuator  60  acts between the head  40  and the lifting arm  44  for moving at least the forward end  48  of the lifting arm  44  to contact the cap  24  and to move the cap  24  from an open molded configuration as illustrated in  FIG. 2A  initially toward a partially closed configuration as illustrated in  FIG. 3A  and eventually toward a fully closed position as illustrated in  FIG. 4A . Various configurations for the lifting arm actuator may be utilized as discussed in more detail below. Generally, the lifting arm actuator  60  is arranged to move the lifting arm  44  for its forward end  48  to raise the cap away from a corresponding recess in a mold cavity (not illustrated). Illustrative examples are discussed in more detail below.  
         [0048]     A head actuator generally indicated by reference  70  is provided for moving the head  40  in conjunction with the lifting arm  44  and the follower  50  across the cap  24  and the closure body  22  for the follower  50  to urge the cap  24  toward the closure body  22  to engage the interlocking means  28  and  30  and secure the closure  20  in its closed configuration.  
         [0049]     The head actuator  70  illustrated is a fluid pressure responsive drive comprising a piston  72  within a cylinder  74  of the type commonly referred to as a “pneumatic cylinder” or “hydraulic cylinder”, depending on the nature of the fluid. Other head actuator arrangements may be apparent to those skilled in such devices, such as a screw drive, a rack and pinion arrangement or a chain and sprocket assembly.  
         [0050]     The head  40  may be mounted on a carrier plate  80  on which the head actuator  70  acts by virtue of the carrier plate  80  being connected to the piston  72  by a connector  76 . As illustrated, the carrier plate  80  may be slidably secured to a mounting plate  90  which is connected to a mold assembly represented by reference  100  to secure the closing device  10  to the mold assembly  100 . The cylinder  74  of the head actuator  70  is also secured to the mounting plate  90  for the head actuator  70  to act between the mounting plate  90  and the carrier plate  80  to cause movement of the carrier plate and in turn the head  40  in the lateral direction  42 . Guidance may be provided by having pins  82  extending from the carrier plate  80  received by bushings  92  in the mounting plate  90 .  
         [0051]     The mounting plate  90  may be attached to the side of the mold, on a cavity plate or a stripper plate (which is not shown). Generally as long as the closing device  10  is in a repeatable position from which the lifting arm  44  can access the caps  24  during actuation, any of the foregoing attachment points may be used.  
         [0052]     The lifting arm  44  is illustrated as being hingedly affixed to the head  40  for rotational movement about a hinge axis  52  transverse to the lateral direction  40 . If a roller is used for the follower  50 , the hinge axis may correspond with the rotational axis of the roller.  
         [0053]     The lifting arm actuator  60  has a first member  62  which is movable relative to the lifting arm  48  in a direction parallel to the lateral direction  42 . Different embodiments of the first member  62  are described below.  
         [0054]     A translating coupling, also described in more detail below may be provided which extends between the lifting arm  44  and the first member  62  to translate relative movement between the first member  62  and the lifting arm  44  into the aforementioned rotational movement.  
         [0055]     The translating coupling may, as illustrated in  FIGS. 1A through 4B  comprise a rack  64  extending along the first member  62  which engages a pinion  66  connected to the lifting arm  44 . Alternate embodiments are illustrated in  FIGS. 5A through 7B .  
         [0056]      FIG. 5A  illustrates a cam  110  secured to the first member  62  and a cam follower  112  which acts against the cam  110 . The cam follower  112  is secured to the lifting arm  44  to pivot about a pivot  114  corresponding to the hinge axis  52  of the lifting arm  44 . As can be seen by comparing  FIGS. 5A and 5B , relative lateral movement of the first member  62  and the cam follower  112  will cause rotation of the lifting arm  44  about the pivot  114  between an actuating configuration illustrated in  FIG. 5A  and a non-actuating configuration illustrated in  FIG. 5B .  
         [0057]      FIGS. 6A and 6B  illustrate the use of a linkage arm in a lifting arm actuator  60 . As illustrated in  FIGS. 6A and 6B , a link  120  is pivotably coupled at a first end  122  to the first member  62  and at a second end  124  to the lifting arm  44 . As can be seen by comparing  FIGS. 6A and 6B , movement of the first member  62  to the left (as illustrated) causes downward movement of the forward end  48  of the lifting arm  44 . Conversely, movement of the first member  62  to the right causes upward movement of the forward end  44  about the pivot  114 .  
         [0058]      FIGS. 7A and 7B  illustrated an alternative arrangement for a lifting arm actuator  60 . According to the  FIGS. 7A and 7B  embodiment, the lifting arm actuator  60  does not rely upon relative movement between a first member and the lifting arm  44 . Instead, a piston  130  slidably movable in a cylinder  132  is mounted to the head  40 . A connecting rod  134  extends between the piston  130  and the lifting arm  44 , being pivotably connected by pivotal coupling  136  to the lifting arm  44 . Movement of the piston along the bore of the cylinder  132  from right to left (as illustrated) causes anti-clockwise rotation of the forward end  48  of the lifting arm  44  from the actuated configuration of  FIG. 7A  to the non-actuated configuration of  FIG. 7B . Movement of the piston along the cylinder  132  may be effected by introducing a pressurized fluid between the piston  130  and the cylinder  132  on either side of the piston  130 .  
         [0059]     A coupler, generally indicated by reference  200  may be provided for coupling the first member  62  to the carrier plate  80  and to the mounting plate  90  for moving the first member  62  relative to the lifting arm  44  in response to relative movement between the carrier plate  80  and the mounting plate  90 . The coupler  200  includes a first stop  210  connected to the first member  62  through an actuator plate  220 . The actuator plate  220  is on an opposite side of the mounting plate  90  from the carrier plate  80 . The first stop  210  has a first end  212  which abuts against the carrier plate  80  to limit movement of the first member  62  toward the lifting arm  44 .  
         [0060]     A second stop  230  is connected to the carrier plate  80  by a connector rod  232 . The second stop acts against the mounting plate  90  to limit movement of the carrier plate  80  away from the mounting plate  90 . The action of the second stop  230  may, as illustrated, be through an intermediate plate  240  located between the mounting plate  90  and the actuator plate  220 .  
         [0061]     A first biasing means, such as the spring  250  is connected to the first member  62  through a first spring cup  250  secured to the actuator plate  220 . The first biasing means  250  is also connected to the carrier plate  80  by a rod  254  for the first biasing means  250  to urge the first member  62  toward the lifting arm  44 .  
         [0062]     As can be seen by comparing  FIGS. 1   a  through  4   b , the actuator plate  220  and intermediate plate  240  are movable toward and away from the mounting plate  90  in the lateral direction  42 .  
         [0063]     An intermediate stop  242  is connected by a rod  244  to the mounting plate  90 . The intermediate stop limits movement of the intermediate plate  240  away from the mounting plate  90 . A second biasing means  246  abuts against the mounting plate  90  and is connected to the intermediate plate  240  through a second spring cup  248 . As illustrated, the second biasing means may be a resilient member such as a spring. The second biasing means acts between the mounting plate  90  and the intermediate plate  24   b  to urge the intermediate plate  240  away from the mounting plate  90 .  
         [0064]     The first biasing means  250  is selected to have a greater force than the second biasing means  246 . Accordingly, movement of the piston  72  and in turn the carrier plate  80  to the left as illustrated will initially result in movement of the actuator plate  220  toward the intermediate plate  240  without any relative movement between the actuator plate  220  (and in turn the first member  62 ) and the lifting arm  44 . Once the actuator plate  220  abuts against the intermediate plate  240 , as illustrated in  FIGS. 2A and 2B , the lifting arm  44  is in a “ready to flip” position in which it extends downwardly to engage the cap  24 .  
         [0065]     Further movement of the piston  72  to the left as illustrated will over come the force exerted by the first biasing means  250  allowing relative movement between the lifting arm  44  and the first member  62 . This causes rotation of the lifting arm upwardly, as illustrated in  FIGS. 3A and 3B  which aligns the cap for further closing.  
         [0066]     Continued movement of the piston  70  to the left as illustrated initially causes the lifting arm  44  to urge the cap  24  over the closure body  22 . Still further movement to the left causes the follower  50  to roll across the cap  24  to complete interlocking between the cap  24  and the closure body  22 .  
         [0067]     It will be appreciated that the coupling arrangement illustrated is but one manner in which the lifting arm  44  may be rotated to “lip” the cap  24 . For example, if the piston and cylinder arrangement illustrated in  FIGS. 7A and 7B  is utilized for the lifting arm actuator  60 , the coupler arrangement of  FIGS. 1A through 4B  would not be required. Instead, pressurized fluid would be introduced as required into the cylinder  132  to effect the movement of the lifting arm  44 . Other variants may be apparent to persons skilled in such devices. For example, it may be possible to mount the first member  62  for lateral movement relative to the lifting arm  44  utilizing a more direct linkage such as a pressurized fluid operated cylinder or solenoid acting directly along the first member  62 . With such an arrangement, it may also be possible to mount the first member  62  for transverse rather than longitudinal movement relative to the lateral direction  42 .  
         [0068]     The spring arrangement could also be replaced with other technology such as pistons, solenoids, motors etc. In general, anything that provides the back and forth movement in a controllable manner is a potential candidate for substitution.  
         [0069]     Although the above description describes how the lifting arm  44  and follower close a single cap, the design is applicable to multiple columns of parts. In multiple column arrangements, the lifting arm  44  would pivot up and down over each part and the roller  50  could be on springs to roll over each column. It may also be possible to couple the lifting arm  44  to the roller  50  utilizing a connecting rod in a “locomotive-type” arrangement wherein rotation of the roller effects up and down movement of the lifting arm  44 .  
         [0070]     The above description is intended in an illustrative rather than a restrictive sense. Variations, such as those described above and others may be apparent to persons skilled in such structures without departing from the spirit and scope of the present invention as defined by the claims set below.  
         [0071]     Parts List  
                                       10   closing device       20   closure       22   closure body       24   cap       26   hinge       28   protrusion       30   lip       40   head       42   lateral direction       44   lifting arm       46   base end (lifting arm)       48   forward end (lifting arm)       50   follower       52   hinge axis (lifting arm)       60   lifting arm actuator       62   first member       64   rack       66   pinion       70   head actuator       72   piston       74   cylinder       76   connector (piston to carrier plate)       80   carrier plate (head)       82   pins       90   mounting plate       92   bushing       100   mold assembly       110   cam       112   cam follower       114   pivot       120   link       122   first end link       124   second end link       130   piston       132   cylinder       134   connecting rod       136   pivotable coupling (rod to lifting arm)       200   coupler       210   first stop       212   end (of first stop)       220   actuator plate       230   second stop       232   connector rod (second stop to carrier plate)       240   intermediate plate       242   intermediate stop       244   rod (intermediate stop)       246   second biasing means       248   second spring cup       250   first biasing means       252   first spring cup (first biasing means)       254   rod (first biasing means)

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