Abstract:
A push-on pull-off and screw-on screw-off closure assembly  20  is provided comprising a spout  30  adapted to be attached to a container  10,  the spout  30  having a wall  36  defining a flow path and having an outer surface  40  having a spiral-shaped spout thread  44  thereon. The assembly also comprises a cap  50  having a base  52  with an outer annular wall  54  extending from the base  52  having an inner surface  58.  The inner surface  58  having a cap thread  60  thereon, wherein the cap thread  60  substantially engages the spout thread  44  and the cap  50  and spout  30  are adapted to close the flow path when the cap  50  is pushed onto the spout  30.

Description:
TECHNICAL FIELD  
         [0001]    The present invention relates to a closure assembly for a container and, more particularly, to a cap assembly that can be pushed on or pulled off, or screwed on or screwed off the container spout.  
         BACKGROUND OF THE INVENTION  
         [0002]    Containers such as collapsible plastic bags are often used to store liquid products such as chemicals, soft drink syrup, fruit juices and food condiments. The plastic bags are typically housed in a corrugated paperboard box to aid in the transporting, handling and dispensing of the product. The paperboard box provides structural support to the flexible plastic bag filled with liquid product. Such packaging systems are commonly referred to as “bag-in-box” packaging systems.  
           [0003]    The plastic bags typically have sidewalls sealed along a peripheral seam to define a fluid containing chamber. A spout or a fitment provides access to the fluid chamber for filling and dispensing the product within the bag. A closure assembly is provided in the form of a cap assembly that fits over the spout to close the plastic bag. Vacuum pump systems are sometimes connected to the spout to assist in draining fluid from the bag.  
           [0004]    The bag-in-box assemblies are typically filled by a filler at a plant location using an automated filler apparatus. The filler apparatus is designed to utilize a friction-fit or interference-fit cap that is pulled-off the container spout just before product is injected into the container. The cap is then pushed back onto the spout after filling forming an interference fit between the cap and spout to therefore close the container. The filler apparatus is not available in a configuration to manipulate a screw-on/screw-off cap assembly because this type of configuration would slow down the filling process. In addition, a threaded cap/spout assembly would add complexity to the container. Certain container applications cannot accommodate this cap complexity. For example, sometimes the bag-in-box assemblies require aseptic filling wherein the cap/spout define an aseptic zone that must be kept free from contamination. A complex screw mechanism in this application is unacceptable as it would be impractical to keep the cap and spout clean and sterile.  
           [0005]    The end user of the bag-in-box assembly, however, often desires a screw-on/screw-off cap so it can screw-off the cap and screw onto the spout a pump assembly to dispense the liquid from the container. This is true even for end users utilizing the bag-in-box assemblies in aseptic processes. Thus, it is desirable to have a cap for the plastic bags that can be pulled-off and pushed-on by the filler but can be screwed off and on by the end user.  
           [0006]    The present invention is provided to solve these and other problems.  
         SUMMARY OF THE INVENTION  
         [0007]    The present invention provides a closure assembly for a container. The closure assembly comprises a cap assembly that is adapted to be pulled-off and pushed-on a container spout assembly during a filling process and screwed-off, or twisted-off, and screwed-on or twisted-on for removal from and attachment to the container spout by an end user.  
           [0008]    According to one aspect of the present invention, a closure assembly is provided. The assembly comprises a spout adapted to be attached to a container. The spout has a cylindrical wall defining a flow path and an outer surface having a spiral-shaped spout thread thereon. The assembly further comprises a cap having a base, an outer annular wall extending from the base having an inner surface, and the inner surface having a cap thread thereon, wherein the cap thread is adapted to substantially engage the spout thread and the cap and spout are adapted to seal the flow path when the cap is pushed onto the spout.  
           [0009]    Other features and advantages of the invention will be apparent from the following specification taken in conjunction with the following drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]    To understand the present invention, it will now be described by way of example, with reference to the accompanying drawings in which:  
         [0011]    [0011]FIG. 1 is an isometric view of a flexible container with the closure assembly of the present invention attached thereto;  
         [0012]    [0012]FIG. 2 is an isometric exploded view of a closure assembly of the present invention with a portion of the cap shown in phantom;  
         [0013]    [0013]FIG. 3 is a top plan view of a closure assembly of the present invention in an assembled state;  
         [0014]    [0014]FIG. 4 is an isometric view of the cap of FIG. 3;  
         [0015]    [0015]FIG. 5 is a top plan view of the cap of FIG. 4;  
         [0016]    [0016]FIG. 6 is a side sectional view taken along the line  6 - 6  of FIG. 5;  
         [0017]    [0017]FIG. 7 is an isometric view of the spout of FIG. 2;  
         [0018]    [0018]FIG. 8 is a top plan view of the spout of FIG. 7;  
         [0019]    [0019]FIG. 9 is a side sectional view of the spout taken along the line  9 - 9  shown in FIG. 8;  
         [0020]    [0020]FIG. 10 is a side elevation section of the closure assembly taken along the line  10 - 10  as shown in FIG. 3;  
         [0021]    [0021]FIG. 11 is a side elevation section of the closure assembly taken along the line  11 - 11  as shown in FIG. 3;  
         [0022]    [0022]FIG. 12 is a side elevation section of the closure assembly taken along the line  12 - 12  as shown in FIG. 3;  
         [0023]    [0023]FIG. 13 is a side elevation section of the closure assembly taken along the line  13 - 13  as shown in FIG. 3; and  
         [0024]    [0024]FIG. 14 is a top plan view of the assembled closure assembly of the present invention wherein the cap has been rotated in a counterclockwise position from that shown in FIG. 3. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0025]    While this invention is susceptible of embodiments in many different forms, there is shown in the drawings and will herein be described in detail preferred embodiments of the invention with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the broad aspect of the invention to the embodiments illustrated.  
         [0026]    Referring now in detail to the Figures, FIG. 1 shows a flexible container generally designated with the reference numeral  10 . The container can be any type of container. In one preferred embodiment the container  10  is flexible collapsible bag used to store liquid products. Attached to the flexible container  10  is a closure assembly  20  of the present invention. As can be seen in FIG. 2, the closure assembly  20  includes a spout or spout assembly  30  and a cap or cap assembly  50 .  
         [0027]    FIGS.  7 - 9  generally depict the spout assembly  30 . The spout  30  has a cylindrical wall  36  with a flange  32  at a base end  34  thereof. The flange  32  facilitates attachment of the spout  30  to the container  10 , said attachment generally shown in FIG. 1. The cylindrical wall  36  defines a flow path in line with the axis X. The cylindrical wall  36  has an outer spout surface  40  and an inner spout surface  42 . A top end  38  of the cylindrical wall  36  is generally sized and adapted to be received by the cap  50 . Near the vicinity of the top end  38 , a spout-thread  44  is located on the outer spout surface  40 . The spout-thread  44  extends for approximately one full revolution of the spout  30  or for approximately  360  degrees. The spout-thread  44  has an upper spout thread surface  45 . The spout thread  44  also has spout thread beginning point  31  and a spout thread ending point  33 .  
         [0028]    Also located on the outer spout surface  40  is an outer spout ring or annular spout protrusion  46 . The outer spout ring  46  is depicted in the FIGS. as being located at the top end  38  of the cylindrical wall  36 . The outer spout ring  46  has a ring height  47  in the direction of axis X. An inner annular seal ring or annular spout projection  48  projects from the inner spout surface  42 .  
         [0029]    Located on the outer spout surface  40  and extending radially therefrom is an intermediate flange or handling ring  49 . The handling ring  49  is located between the flanged base  32  and the spout thread  44 . The handling ring  49  facilitates the handling of the spout by an automated filler (not shown).  
         [0030]    Referring to FIGS.  4 - 6 , the cap  50  has a base  52 , an outer annular wall or thread skirt  54  and an inner annular wall or plug ring  64 . The base  52  has a locator or orienting notch  53 . The base also has a series of gripping grooves  51  about its periphery.  
         [0031]    The thread skirt  54  has an outer surface  56  and an inner surface  58 . The thread skirt  54  has an end surface  55  distal from the cap base  52 . The thread skirt  54  extends generally perpendicularly from the base  52 . However, as presently preferred and shown in FIG. 6, the thread skirt extends from the base  52  such that a diameter of the thread skirt  54  near the base  52 , is smaller than a diameter of the thread skirt  54  near the end surface  55 .  
         [0032]    Extending from the inner surface  58  of the thread skirt  54  is a single helical or spiral cap-thread  60 . The cap-thread  60  has an upper cap thread surface  61  and a lower cap thread surface  62 . Both the upper cap thread surface  61  and the lower cap thread surface  62  are at approximately a 45 degree angle to the thread skirt inner surface  58 . The cap-thread  60  extends approximately 360 degrees about the inner surface  58  of the thread skirt  54 . The cap thread  60  has a cap thread beginning point  72  and a cap thread ending point  74 . The cap-thread  60  both begins and ends in the vicinity of the orienting notch  54 .  
         [0033]    A recess or annular groove  63  is located on the inner surface  58  of the thread skirt  54 . The annular groove  63  is positioned between the cap thread  60  and the base  52 . The annular groove  63  has a groove height  65  with an upper surface  67  and lower surface  69 . The groove height  65  is greater than the ring height  47 .  
         [0034]    The plug ring  64  extends from the base generally perpendicularly and has an outer sealing surface  66  and a plug ring end surface  68 . As shown in FIG. 6, the intersection of the outer sealing surface  66  and the end surface  68  is rounded off to form a rounded guide surface or edge  70 .  
         [0035]    In operation, the cap  60  may be affixed to the spout  30  by pushing it or snapping it onto the spout  30 . To push the cap  60  onto the spout  30 , the cap  60  must first be properly oriented with respect to the spout  30 . The cap  60  should be positioned such that the thread skirt  54  is extending from the base  52  towards the spout  60  in a manner to receive the top end  38  of the cylindrical wall  36 , as can be seen in FIG. 2. Also, the cap  60  must be rotationally oriented with respect to the spout  30  prior to being pushed onto the spout  30 . The orienting notch  53  on the cap  60  must be oriented to coincide with a starting position on the spout  30 . The starting position of the spout  30  will be that point along its outer surface  40  that substantially simultaneously allows the cap thread beginning point  72  to pass over the spout thread  44 ; allows the outer sealing surface  66  of the plug ring  64  to form an effective seal with the inner seal ring  48 ; and allows the outer spout ring  46  to be received by the annular groove  63  forming an interference fit; as the cap  50  is pushed onto the spout  30 . In one preferred embodiment shown in the figures and described herein, the starting position is located approximately 90 degrees counterclockwise from that point on the cylindrical wall  36  where the spout thread  44  begins and ends. Although not shown in the FIGS., it is understood that a starting point indicator or marker may be included on the spout to identify the starting point.  
         [0036]    Once this particular orientation of the cap  50  and spout  30  is achieved, the cap  60  may be pushed or snapped onto the spout  30  through the application of a force to the cap  60  generally perpendicular to the base  52  and in the direction of the spout  30 .  
         [0037]    As the cap  60  initially moves towards the spout  30  in this orientation, the rounded guide surface  70  assists in the mating of the plug ring  64  with the cylindrical wall  36  and in positioning the cap  60 . Also, as the cap thread  60  and the spout thread  44  are of the same or a matching pitch, a substantial portion of the cap thread lower surface  62  comes into contact with a substantial portion of the spout thread upper surface  45 . Because the cap thread lower surface  62  and the spout thread upper surface  45  are at roughly a forty five degree angle to the line of force being applied, a radial force is exerted on the cap thread  60 . Because the thread skirt  54  is made from a material to be sufficiently resilient, the thread skirt  54  deflects outward and allows the cap thread  60  to pass over the spout thread  44 .  
         [0038]    Once the cap thread  60  has passed over the spout thread  44 , the outer sealing surface  66  of the plug ring  64  frictionally engages the inner seal ring  48  of the cylindrical wall  36 , forming a seal and closing off the flow path through the spout  30 . Also, the outer annular spout ring  46  cooperates with the annular groove  63  to form an interference fit that holds and maintain the cap  50  on the spout  30 . In this initial orientation of the cap  50  and spout  30 , the spout ring  46  is adjacent the upper surface  67  of the annular groove  63 .  
         [0039]    Referring to FIGS.  10 - 14 , when the cap  50  and spout  30  are in the assembled state shown therein, an annular space is formed between thread skirt inner surface  58  and the outer spout surface  40 . An annular passage is formed by the end surface  55  of the thread skirt  54  and the handling ring  49 . The annular passage is in flow communication with the annular space. This allows a steam sterilization solution to be utilized to sterilize inner surface  58  and outer spout surface  40 , after the cap  50  has been pushed on or screwed on to the spout  30 .  
         [0040]    The cap  50  can also be pulled off of the spout  30  by applying a sufficient force perpendicular to the base  52  and away from the spout  30 . Similar to pushing the cap  50  onto the spout  30 , in pulling it off, a radial force is exerted between the spout thread  44  and the cap thread  60 . This causes the thread skirt  54  to deflect outward and allows the cap thread  60  to pass over the spout thread  44 . At substantially the same time, the interference fit between the annular groove  63  and the outer spout ring  46  is over come and the plug ring outer sealing surface  66  frictionally disengages the inner seal ring  48  to open the flow path through the spout  30 .  
         [0041]    The cap  50  can also be screwed off the spout  30 . To remove the cap  50  from the spout  30  in this way, one merely needs to rotate the cap  50  in a counterclockwise direction relative to the spout  30 . In doing so, the lower cap thread surface  62  cooperates with the upper spout thread surface  45  to create an axial force tending to separate the cap  50  from the spout  30 .  
         [0042]    Subsequent to the initial rotation, an intermediate orientation is reached as depicted in FIG. 14. In this intermediate position, the outer spout ring  46  abuts the lower surface  69  of the annular groove  63 . Continued rotation of the cap  50  results in the axial force becoming greater than that required to break or overcome the interference fit between the outer annular spout ring  46  and the annular groove  63 . As this interference fit is being overcome, the outer sealing surface  66  of the plug ring  64  separates or frictionally disengages from the inner seal ring  48  breaking the seal created therebetween and opening the flow path through the spout  30 . The thread skirt  54  is sufficiently rigid to prevent the cap thread  60  from passing over the spout thread  44  while rotating the cap relative to the base. In one preferred embodiment depicted in the figures, a rotation of the cap  50  of approximately 270 degrees from the initial orientation is required to separate the cap  50  from the spout  30 . However, the amount of required rotation may be varied depending upon the configuration and pitch of the particular threads and the configuration of the interference or friction fitting used in any particular embodiment.  
         [0043]    The cap  50  may also be screwed onto the spout  30 . In doing so, one would move the cap  50  towards the spout  30  such that the spout  30  begins to be received by the thread skirt  54 . The cap  50  is then rotated in a clockwise direction as looking at the assembly from the perspective shown in FIG. 3. In doing so, the cap thread  60  will begin to engage the spout thread  44 , both of which will generally cooperate to advance the cap  50  towards the spout  30 . As the cap  50  so advances, the annular groove  63  receives the outer spout ring  46  forming an interference fit holding the cap  50  on the spout  30 , and the inner seal ring  48  frictionally engages the outer sealing surface  66  of the plug ring  64 , sealing the flow path through the spout  30 .  
         [0044]    While the specific embodiments have been illustrated and described, numerous modifications come to mind without significantly departing from the spirit of the invention, and the scope of protection is only limited by the scope of the accompanying Claims.