Abstract:
A method of molding a container closure providing selective fluid communication between an interior of a fluid container and an exterior environment, the method comprising: (i) configuring and closing a mold having a first cavity negatively defining a base of a container closure that includes a spout and a container mount, where the spout and container mount cooperate to define a conduit therethrough in fluid communication with an outlet orifice of the spout; (ii) injecting a first material into the first cavity to mold the base; (iii) cooling the first material in the mold to impart at least minimal rigidity to the base; (iv) reconfiguring at least a portion of the mold to define a second cavity adjacent to the first material, the second cavity negatively defining a cap covering the outlet orifice of the spout; (v) injecting a second material into the second cavity to mold the cap over the outlet orifice; (vi) cooling the second material in the mold to impart at least minimal rigidity to the cap; and (vii) removing the base and integrally formed cap from the mold.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
       [0001]     This application claims priority to and benefit from U.S. provisional patent application 60/745,560, filed on Apr. 25, 2006, under 35 U.S.C. §119(e). 
     
    
     RELATED ART  
       [0002]     1. Field of the Invention  
         [0003]     The present application is related to closures for fluid containers utilizing overmolded components; and, more specifically, to closures where the spout and base component of the closure is molded in a first molding step and a repositionable or removable cap is molded over at least the spout of the closure in a second molding step.  
         [0004]     2. Brief Discussion of Related Art  
         [0005]     Container closures for certain beverage and condiment dispensers include a cylindrical base portion and a spout portion extending from the base portion. The base portion is typically threaded to be mounted to a mount of the dispenser. In this manner, fluid product from the interior of the dispenser is generally withdrawn through the spout portion, and when product is no longer desired to be withdrawn, the spout portion is closed by a removable or repositionable cap. The spout may be closed by a removable overcap or a retained cap repositionably mounted to the spout.  
         [0006]     Certain container closures include base and spout portions that are molded with circumferential grooves or channels that are adapted to accept a circumferential ring of the retained cap. With such closures, the base and spout portion and the retained cap are individually molded apart from one another in separate processes. In other words, the base and spout portion is completely molded and the retained cap is completely molded, only thereafter to have the circumferential ring of the retained cap be frictionally fit within the groove of the base and spout portion to allow the cap to be mounted to the base and spout portion even when the cap does not close the orifice in the spout portion. It should be understood that the friction fit is the primary prior art means used to mount the cap to the spout portion.  
       SUMMARY  
       [0007]     The present application is related to closures for fluid containers utilizing overmolded components; and, more specifically, to closures where the spout and base component of the closure is molded in a first molding step and a repositionable or removable cap is molded over at least the spout of the closure in a second molding step.  
         [0008]     Accordingly, it is a first aspect of the invention to provide a method of molding a container closure providing selective fluid communication between an interior of a fluid container and an exterior environment, the method comprising: (i) configuring and closing a mold having a first cavity negatively defining a base of a container closure that includes a spout and a container mount, where the spout and container mount cooperate to define a conduit therethrough in fluid communication with an outlet orifice of the spout; (ii) injecting a first material into the first cavity to mold the base; (iii) cooling the first material in the mold to impart at least minimal rigidity to the base; (iv) reconfiguring at least a portion of the mold to define a second cavity adjacent to the first material, the second cavity negatively defining a cap covering the outlet orifice of the spout; (v) injecting a second material into the second cavity to mold the cap over the outlet orifice; (vi) cooling the second material in the mold to impart at least minimal rigidity to the cap; and (vii) removing the base and integrally formed cap from the mold.  
         [0009]     It is a second aspect of the present invention to provide a method of overmolding a repositionable cap onto a container closure, the method comprising the steps of: (i) configuring and closing a mold housing a container closure base to at least partially define a mold cavity approximate a spout of the container closure base; (ii) injecting a first material into the mold cavity to overmold a cap over the spout that closes an outlet orifice of the spout; (iii) cooling the second material to impart at least minimal rigidity to the cap; and (iv) removing the base and overmolded cap from the mold.  
         [0010]     It is a third aspect of the present invention to provide a method of imparting a tamper evident indicia to an injection molded product, the method comprising: (i) molding a first component of a product; and (ii) molding a second component of the produce over the first component to create a bond between the first component and the second component, where the second component includes at least one of a transparent property and a translucent property so that bonded portions of the first and second components exhibit a color that is a combination of colors of the overmolded portions of the first and second components, where breaking of the bond substantially removes the combination color in the areas where the bond has been broken.  
         [0011]     It is a fourth aspect of the present invention to provide a closure for a fluid container comprising: (i) a container fitting including: (a) a distal container receiver adapted to couple the container fitting to a container, thereby providing a fluidic seal between the container fitting and the container; (b) a proximal spout including a conduit therethrough that is in communication with a proximal orifice of the spout through which material flowing through the conduit is adapted to egress from the container fitting; and (c) a lid that is repositionable between a closed position closing off the proximal orifice of the spout, and an open position opening the proximal orifice of the spout, where the lid is molded in the closed position over the proximal spout to provide a sealed fluidic interface between the lid and the spout. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]      FIG. 1  is a cross-sectional view of an additional exemplary closure in accordance with the present invention;  
         [0013]      FIG. 2  is a cross-sectional view of the closure of  FIG. 1  offset 90 degrees;  
         [0014]      FIG. 3  is a rear perspective view of the closure of  FIG. 1 ;  
         [0015]      FIG. 4  is an elevated perspective view of the closure of  FIG. 1 , where the lid is in the open and closed position;  
         [0016]      FIG. 5  is a cross-sectional view of an exemplary mold to fabricate a first aspect of the closure of  FIG. 1 ;  
         [0017]      FIG. 6  is a cross-sectional view of an exemplary mold to fabricate a second aspect of the closure of  FIG. 1 , thereby finishing the molding of the closure as shown in  FIG. 1 ;  
         [0018]      FIG. 7  is an overhead, cut-away view of the mold of  FIG. 6  showing the flow of the polymer to form the second aspect of the closure; and  
         [0019]      FIG. 8  is rear view of an alternate exemplary hinge structure for the closure of  FIG. 1 . 
     
    
     DETAILED DESCRIPTION  
       [0020]     The exemplary embodiments of the present invention are described and illustrated below to encompass methods of fabricating container closure and the closures produced utilizing such methods. Of course, it will be apparent to those of ordinary skill in the art that the preferred embodiments discussed below are exemplary in nature and may be reconfigured without departing from the scope and spirit of the present invention. However, for clarity and precision, the exemplary embodiments as discussed below may include optional steps, methods, and features that one of ordinary skill should recognize as not being a requisite to fall within the scope of the present invention.  
         [0021]     Referring to  FIGS. 1-4 , an exemplary closure  400  includes a base  402  and an overmolded repositionable cap  404  that are adapted to cooperate to retain the contents of a container (not shown) when the closure  400  is mounted to the container. The base  402  includes a circumferential wall  406  that forms a conduit through which fluid flows from the interior of the container and out an outlet orifice  408  in the proximal end  410  of the wall. The circumferential wall  406  includes a tamper-evident band  412  connected to a threaded, cylindrical container mating portion  414  that are adapted to be mounted to the throat of the container. The tamper-evident band  412  includes a plurality of projections  416  circumferentially spaced along an interior surface  418  thereof Each projection  416  includes a contoured leading edge  420  having an arcuate wall  422  that extends radially inward and intersects with a topside ledge  424  and a backside wall  426  that each extend perpendicularly inward from the interior surface  418 . A plurality of bridges  428  extend between and connect the tamper-evident band  412  to the container mating portion  414 . These bridges  428  are adapted to be broken when the closure  400  is first removed from the container, thereby separating the tamper-evident band  412  from the container mating portion  414 . The bridges  428  are broken when either or both of the topside ledge  424  and the backside wall  426  catch one or more corresponding projections from the throat of the container so that continued upward movement of the closure  400  tensions the bridges  428  beyond their breaking points.  
         [0022]     The container mating portion  414  includes a cylindrical wall  430  that intersects with a radially inwardly extending wall  432  that transitions concurrently into a circumferential, axially, extending flange  434  and an opposed frustoconical wall  436 . The cylindrical wall  430  includes an interior surface  438  having helical threads  440  extending radially inward that are adapted to interact with a corresponding helical projection on the throat of the container to allow the closure  400  to be rotationally mounted and dismounted from the container. An exterior surface  442  of the cylindrical wall  430  includes a plurality of vertically oriented and spaced apart ribs  444  adapted to enable a user to more easily grip and rotate the closure  400  with respect to the container.  
         [0023]     The cylindrical wall  430 , the radially inwardly extending wall  432 , and the circumferential flange  434  cooperate to define a circumferential inverted U-shaped profile that is adapted to be seated upon the top wall of the mouth of the container. A circumferential projection  446  extends from an interior surface  448  of the radially inwardly extending wall  432  and cooperates with the flange  434  to guide a top wall of the mouth of the container into contact with a sealing ring  450  also extending from the radially inwardly extending wall  432 . The sealing ring  450  is adapted to compress and seal against the top wall of the mouth of the container when the closure  400  is mounted to the container.  
         [0024]     An exterior surface  452  of the radially inwardly extending wall  432  includes a circumferential lip  454  that separates complementary circumferential grooves  456 ,  458 . Each groove  456 ,  458  receives part of a retaining ring  460  molded thereover to mount the repositionable cap  404  to the base  402 . As will be discussed in more detail below, the lip  454  increases the surface area for bonding between the retaining ring  460  and the base  402 , thereby providing a more secure connection. Two legs  462  that are bonded to an exterior surface  464  of the frustoconical wall  436  extend from the retaining ring  460 . The legs  462  converge to form a backbone  466  that extends parallel to exterior surface  464  of the frustoconical wall  436 , where the proximal segment of the backbone  466  includes rigidity ribs  467  that transition into a lid  468  that is removably bonded to the proximal end  410  of the circumferential wall  406  to close the outlet orifice  408  of the spout formed by the frustoconical wall  436  and completely cover the entire exposed surface of the proximal end  410 . The lid  468  includes a downwardly extending circumferential plug  470  that is adapted to be frictionally received by the outlet orifice  408  to seal the outlet orifice. A tapered lip  472  of the lid  468  overhangs the exterior surface  464  of the frustoconical wall  436  and is adapted to receive an upward manual force. When manual force is applied upwardly against the lip to force the lid off of the spout and the plug  470  from the outlet orifice  408 , the reduced thickness of the legs  462  to provide a living hinge  474  about which the backbone  466  and lid  468  pivot with respect to the retaining ring  460  and the base  402 . The backbone  466  includes an outwardly extending prong  474  that is adapted to be pivoted inwardly and be received by a corresponding depression  476  within the exterior surface  464  of the frustoconical wall  436 , thereby retaining the hinge in the open position. When the backbone  466  and lid  468  pivot approximately 90° or more, the prong  474  continues to extend outward from the backbone  466  and is wedged against the exterior surface  464  of the frustoconical wall  436  to retain the backbone  466  and lid  468  in the pivoted position. A force applied to one or more of the top of the lid  468  and the back side of the backbone  466  is operative to deform the prong  474  out from the depression  476  allowing the backbone  466  and lid  468  to pivot to the closed position.  
         [0025]     U.S. Pat. No. 6,478,184, entitled “Two-Piece Hinged Closure”, discloses retention structure for a hinged closure that is similar to that disclosed herein. The &#39;184 patent describes a two-piece closure that incorporates a cam tab similar to the extending prong  474  of the instant invention to retain the cap in the open position. U.S. Pat. No. 6,478,184 is herein incorporated by reference.  
         [0026]     Referencing  FIGS. 4-7 , the exemplary closure  400  is fabricated in a two-shot injection molding process. In the first shot, the first and second blocks  500 ,  502  of the mold  504  are brought together to provide an internal cavity having negative dimensions and features representative of the base  402  discussed above. A polymer, such as polypropylene, is injected into the cavity to form the base  402 . The polymer is allowed to sufficiently harden so that the mold  504  may be opened without substantially deforming the base  402 . The first block  500  of the mold  504  is thereafter withdrawn from the second block  502  to remove the base  402  from the second block  502  and expose the exterior surface  452  of the radially inwardly extending wall  432  and the exterior surface  464  of the frustoconical wall. A third block  508  of the mold  504  is then brought into contact with the first aspect  500  to provide an internal cavity having dimensions and features representative of the repositionable cap  404  discussed above, adjacent to the exposed portions of the base  402 . A second polymer, such as polyethylene, is injected into the cavity to form the repositionable cap  404  in a second shot over the exposed portions of the base  402 . The polymer forming the repositionable cap  404  is allowed to sufficiently harden so that the mold  504  may be opened without substantially deforming the cap  404 . Thereafter, the third block  506  is separated from the first block  500  and a finished closure  400  is removed from the first block  500 .  
         [0027]     Referring to  FIGS. 1-7 , the two-shot process discussed above molds the repositionable cap  404  to the base  402  so as to form a band and a seal at the interface between the two components. This is particularly advantageous where, as here, the molding process molds the cap  404  in not only a closed position, but with a fluidic seal with respect to the outlet orifice  408  in the proximal end  410  of the base  402  and the lid  468 .  
         [0028]      FIG. 7  provides an exemplary injection point  510  where the second polymer is first introduced to fill those aspects of the circumferential grooves  456 ,  458  farthest from the legs  462 . It is important to understand that injection molded polymers flow like streams of viscous fluids. As more polymer is introduced, the pressure and additional polymer force the initially injected polymer outward and around the frustoconical wall  436  in two arcuate polymer streams. As further polymer is introduced, the polymer at the lead end of each stream begins to cool and becomes more resistant to flow. The polymer material continues to flow in these two streams to form the legs  462 , until the two polymer streams converge to form the backbone  466  and lid  468 , thereby completely covering and sealing the outlet orifice  408  in the proximal end  410  of the base  402 . The mold  504  is designed so that the molding of the lid  468  and the backbone  466  coincide with the lead end polymer becoming increasingly viscous so much so that the injection molding equipment can no longer inject polymer to force the lead end material further into the mold.  
         [0029]     In a further exemplary application of the two-shot molding process, the repositionable cap  404  and the base  402  include a tamper evident indicia visually apparent when the seal between the cap  404  and base  402  has not been compromised. For example, the base may be fabricated from a blue polyethylene material and the cap may be fabricated from a yellow polyethylene material that is substantially transparent and/or translucent. Thus, the overmolded portions of the cap will exhibit a green color combination of blue and yellow materials being bonded to one another. In this example, the yellow polyethylene material is transparent so that an overhead view of the closure  400  after molding would reveal a dark green ring around a yellow circle, evidencing that the seal was intact between the cap  404  and base  402 , particularly with respect to the seal between the outlet orifice  408  and the circumferential plug  470 . When a user of the closure  400  first peels the lid  468  back to displace the circumferential plug  470  from the outlet orifice  408 , thereby discontinuing the seal therebetween, the overhead view of the closure  400  would reveal a very faint green ring around a yellow circle (or no green color at all), evidencing that the seal was no longer intact between the cap  404  and base  402 , particularly with respect to the seal between the outlet orifice  408  and the circumferential plug  470 . The absence of the dark green ring would alert a potential user than the lid has been previously been opened.  
         [0030]     Simply put, the visual indicia is the difference in appearance when the cap and base continue to have a bond or a seal therebetween and the appearance when no bond/seal is present between the cap and base. In other words, the absence of presence of a visual cue alerts the user of the sealed or unsealed state. Along these same lines, it is also within the scope of the invention that the dominant visual cue be apparent after the cap has been initially repositioned from the base, thereby discontinuing the bond/seal therebetween. Those of ordinary skill will readily understand that various color combinations can be utilized to provide a color change once a molded seal is discontinued, such as, without limitation, a red base  402  and a yellow cap  404 , and a blue base  402  and a red cap  404 .  
         [0031]     Referring to  FIG. 8 , an alternate exemplary hinge structure  600  is shown. This exemplary hinge  600  is analogous to the living hinge  474  of  FIG. 1  and may be used in lieu of the living hinge  474  of  FIG. 1 . The hinge line is shown with a dotted line and is vertically elevated with respect to the living hinge  474  of  FIG. 1 . It should be noted that his hinge structure  600  provides for a continuous ring  602  around the circumference of the base  604  to inhibit rotation of the cap  606  about the base.  
         [0032]     An alternate exemplary closure  700  in accordance with the present invention includes a tear-away tamper evident feature  702  as shown in  FIG. 9 . The closure  700  is similar in structure to that of the first exemplary closure  400  by including a base  702  and an overmolded repositionable cap  704 . The base  702  for purposes of explanation includes the same structural features as the base  402  discussed in the first exemplary embodiment. The cap  704 , however, is different in that the entire cap may be molded and a subsequent cutter operation is applied to the cap to define the tear away portion. This cutting action may tear off a tab, or the tab may be torn off after the cap is pivoted rearward away from the spout.  
         [0033]     Following from the above description and invention summaries, it should be apparent to those of ordinary skill in the art that, while the apparatuses herein described and illustrated constitute exemplary embodiments of the present inventions, it is understood that the inventions are not limited to these precise embodiments and that changes may be made therein without departing from the scope of the inventions as defined by the claims. Additionally, it is to be understood that the inventions are defined by the claims and it is not intended that any limitations or elements describing the exemplary embodiments set forth herein are to be incorporated into the meanings of the claims unless explicitly recited in the claims themselves. Likewise, it is to be understood that it is not necessary to meet any or all of the recited advantages or objects of the inventions disclosed herein in order to fall within the scope of any claim, since the inventions are defined by the claims and since inherent and/or unforeseen advantages of the present inventions may exist even though they may not have been explicitly discussed herein.