Patent Publication Number: US-2006016837-A1

Title: Twist-off container plug

Description:
BACKGROUND OF THE INVENTION  
      1. Field of the Invention  
      The present invention relates generally to a tab or plug, and more particularly to twist tab or plug for a container.  
      2. Related Art  
      Existing container caps and the like require the use of scissors or a knife in order to access the contents of the container. Often there is no mechanism for resealing, so the entire contents must be used, leading to unnecessary waste. Caps that do allow for resealing often do not seal effectively, leading to drying out and rapid deterioration of tube contents. Caps or plugs that do seal tightly are difficult to remove.  
      Plugs or caps are often separate components that are sometimes lost during shipping, display, or storage before use. U.S. Pat. No. 5,295,601 to Bostelman discloses a cap with a tether so that the cap does not separate from the container during use. However, this requires the separate purchase of a cap, resulting in added cost. The separate purchase of a cap also means the cap is not specifically made to fit the container for which it is used to seal. Thus there is no guarantee that the seal will be as effective as desired.  
      Another disadvantage of currently existing separate caps and plugs is that they may need to be separately molded.  
      Container tips are composed of sturdy plastic, making cutting difficult, and potentially dangerous. Further, it may take several attempts before achieving a hole of the appropriate size. For example, cutting too close to the tip edge may create an opening that is not large enough for the contents to easily flow through, leading to clogging. A cut that is too large results in too much material flowing out of the tube. There is no remedy for this, except to start over with a another tube. Finally, a hole that is too large or too small may preclude use of the resealing cap that is provided. All of these scenarios can lead to unnecessary waste and expense.  
      Another disadvantage in the prior art is that caps, by design, may not be properly fitted for sealing the tip hole that results from cutting. Again, this leads to degradation of tube contents. However, plugs that seal tightly can then be difficult to remove.  
      What is needed then is an improved tab, cap or plug that overcomes shortcomings of conventional solutions.  
     BRIEF SUMMARY OF THE INVENTION  
      The present invention is for a container having a tubular, tapered tip and a tab. The tab is removable and can be used to seal the tip. A tubular receptacle sits at the end of the tip opposite to the end at which the tab sits. The receptacle may be designed to contain a viscous substance or a suspension of a solid in a fluid matrix, such as, for example, caulk, icing, sauces, gels, lotions, soaps, a wood filler, and the like.  
      The tab has lateral projections which are substantially perpendicular to the axis of the tip prior to removal of the tab. Removal of the tab creates a dispensing opening in the tip. By rotating the tab 90° so that the axis of the projections is substantially parallel to the axis of the tip, the opening may be resealed using the lateral projections of the tab.  
      The tab also contains a joining piece. This portion of the tab is connected to the tip prior to removal of the tab. The joining piece facilitates removal of the tab once the tip has already been sealed by allowing the user to grip the piece and remove the tab.  
      The container and tab can be manufactured as one unit. There are several advantages to this invention where the tab is manufactured/sold as part of the container. A first advantage is that the tab is molded to fit the tip to which it is attached, resulting in an effective seal. Another advantage is that the purchase of a separate cap or tab is not required. Further, there is no danger of the plug or cap being separated from the tip and lost prior to use.  
      The invention is also drawn to a method of using the container and its easily removable tab to create an dispensing opening, dispense the contents of the container, and re-seal the opening.  
      The invention is additionally drawn to a method of manufacturing the container of the present invention by compression molding and extrusion blow molding.  
      Further objectives and advantages, as well as the structure and function of preferred embodiments will become apparent from a consideration of the description, drawings, and examples. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      The foregoing and other features and advantages of the invention will be apparent from the following, more particular description of an exemplary embodiment of the invention, as illustrated in the accompanying drawings wherein like reference numbers generally indicate identical, functionally similar, and/or structurally similar elements.  
       FIG. 1  depicts an exemplary embodiment of a twist container according to the present invention, prior to opening;  
       FIG. 2  depicts the removable tab and top end of the tip prior to opening of the container, according to the present invention;  
       FIG. 3  depicts the top end of the tip and the tab when the tab has been removed, creating a dispensing opening, according to the present invention.  
       FIG. 4  depicts the twist tab and top end of the tip as in the present invention, once the tip has been resealed. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION  
      Embodiments of the invention are discussed in detail below. In describing embodiments, specific terminology is employed for the sake of clarity. However, the invention is not intended to be limited to the specific terminology so selected. While specific exemplary embodiments are discussed, it should be understood that this is done for illustration purposes only. A person skilled in the relevant art will recognize that other components and configurations can be used without parting from the spirit and scope of the invention. All references cited herein are incorporated by reference as if each had been individually incorporated.  
       FIG. 1  illustrates the container of the present invention. The container  100  is a one-piece construction that is compression/blow molded and is made of a plastic material such as a polyester, including polyethylene terephthalate (PET) and polyethylene naphthalate (PEN); polyolefins such as polyethylenes, and polypropylenes; and polyamides such as nylon. High density polyethylene (HDPE) is a particular example of a plastic material useful in practicing the invention. The container can be used to package a wide variety of materials, including viscous materials and suspensions such as caulk, wood filler compositions, icing, gels, sauces, lotions, soaps, and others.  
      The container  100  has a tubular receptacle  101  for containing the material, having a bottom end  102 , a tubular sidewall  103  and a top end  104 . The tubular sidewall  103  of the illustrated embodiment is circular in cross-section, such that the receptacle  101  is cylindrical. Other cross-sectional shapes can be similarly used and manufactured. Extending from the top end  104  of the tubular receptacle  101  is the tip  106 , which is connected to the top end  104  of the receptacle  101  by the tip&#39;s bottom end  108 . The tip  106  has a tubular sidewall  110 , and a top end  112 , to which the removable twist tab  114  is attached. The twist tab contains a wider joining piece  111  which is connected to the top end of the tube  112 . The top end  112  of the tip is narrower than the bottom end of the tip  108  such that at least a portion of the tip between the receptacle  101  and the twist tab  114  is tapered. In the illustrated embodiment, the tip sidewall  110  is also cylindrical in shape, but other shapes can be used.  
      The twist tab  114  has tapered lateral projections  116 . (See  FIG. 2 ). Prior to opening, the tab  114  is connected to and seals the tip  106 . In this position, the lateral projections  116  are substantially perpendicular to the tip sidewall  110 . By firmly holding the lateral projections  116 , a user can twist the tab  114  and remove it from the tip  106 . This creates a dispensing opening  118  at the position where the joining piece  111  was attached to the hollow part of the tip  106 . (See  FIG. 3 .) After use, the tip  106  can be resealed with the same tab  114 . By turning the tab 90°, such that the lateral projections  116  are substantially parallel to the axis of the tip sidewall  110 , the dispensing opening  118  can be sealed with lateral projection  116 . (See  FIG. 4 .)  
      At least one of the lateral projections  116  of the tab  114  are tapered at the end  120  to create an effective seal when inserted into the opening. In the embodiment pictured, the projections are symmetrical. However, the invention also includes asymmetrical projections. It is also possible for the tab to have only one lateral projection.  
      The cross-sectional area of the tab  114  at the widest point, i.e. where the lateral projection  116  meets central portion of the tab, C 1 , is greater than the cross-sectional area C 2  of the dispensing opening  118  at the tip  106 . (See  FIG. 3 .) The tapered ends  120  of the lateral projections  116  easily slide into the tip  106  until the point where the cross-sectional area of the tab is equivalent to the cross-sectional area of the dispensing opening, C 2 . At this point the tab  114  cannot move any further into the tip  106 . (See  FIG. 4 .) The result is an effective seal that minimizes exposure of the container contents to air.  
      Another advantage of the tapered tab  114  is that the tapered end  120  of the lateral projection  116  that first slides into the tip  106  is narrow and pointed enough to help dislodge any tube contents that are stuck in the tip  106 . This prevents blockage of the opening  118 , resulting in greater ease in dispensing. This will also prevent contents from adhering to the sides of the tip and drying up.  
      When re-use of the container  100  is desired, tab  114  can be easily grasped by the joining piece  111  and pulled. The joining piece is a solid piece of material that makes up a portion of the tab  114  and provides a grip for removal of the tab  114  from the tip opening  118 . Once removed, the tab  114  can be set aside or stored elsewhere until it is needed to re-seal the tip. This facilitates reuse of the container  100  by allowing repeated unsealing and resealing of the tip  106 .  
      Thus, the present invention is a tab/plug  114  that can be easily removed by twisting the tab  114 . Projections  116  on the side of the tab allow for an easy grip-and-twist removal. These projections  116  are then used to seal the tip  106  when the tab  114  is turned on its side. No scissors are required, and the tab  114  allows for a tight seal so that the container contents may be stored for later use. The elimination of the cutting requirement saves time, frustration, and possible injury. Subsequent removal of the tab  114  is easily accomplished. The joining piece  111  of the tab  114  allows a user to grip the tab  114  for removal from the opening  118 .  
      The container  100  of the present invention can be unitarily manufactured by a compression/blow molding process. A parison is placed between the two halves of a mold cavity and as the mold halves clamp together over the parison, a portion of the parison is compressed to create the tab. The remainder of the container is subsequently blow molded to form the tip  106  and the tubular receptacle  101 . Alternatively, the tab  114  with tip  106  can be integrally molded and then assembled together with a preexisting tubular receptable  101 .  
      The container  100  can then be filled with the material to be dispensed. For example, at a filling station, the tubular receptacle  101  of the container is filled with the desired contents from the bottom end  102  of the receptacle  101 . Once the contents are in the tubular receptable  101 , the bottom end  102  can be flattened and heat welded. This creates a flat seal on the bottom end  102  of the receptacle  101 , and allows a user to squeeze out container contents in the amount desired. Alternatively, a movable piston can be placed at the bottom of the receptacle, similar to a known caulk tube used with a caulk gun. In the latter embodiment, the bottom end  102  of the receptacle  101  would remain cylindrical in shape and open.  
      The embodiments illustrated and discussed in this specification are intended only to teach those skilled in the art the best way known to the inventors to make and use the invention. Nothing in this specification should be considered as limiting the scope of the present invention. All examples presented are representative and non-limiting. The above-described embodiments of the invention may be modified or varied, without departing from the invention, as appreciated by those skilled in the art in light of the above teachings. It is therefore to be understood that, within the scope of the claims and their equivalents, the invention may be practiced otherwise than as specifically described.