Abstract:
front wall, and further comprising a closure mechanism comprising a thin membrane patch bonded to said pouch about a periphery of said opening, a platform bonded to said thin membrane patch, said platform including a window formed therein and a plurality of cutting surfaces adjacent said window, and a pull strip bonded to said thin membrane patch and attached to said platform by a frangible membrane, wherein a removal of the pull strip ruptures said frangible membrane and tears said thin membrane patch at said cutting surfaces.

Description:
BACKGROUND 
       [0001]    The present invention relates generally to flexible containers for liquids and gels, and dry contents, and more particularly to a disposable flexible pouch with a removable strip that can be pulled to gain access to the contents of the pouch. 
         [0002]    Flexible beverage containers are well known in the art, with many shapes and sizes. Common configurations include pouches with straw holes that can be punctured to permit access to the beverage contained therein. Other types of packages include those with spouts, including threaded spouts that employ a twist-off cap. U.S. patent application Ser. No. 11/471,930 filed Jun. 21, 2006 by the present inventor and assigned to the present assignee discloses a method for attaching a spout to a flexible container, and the contents of that application are incorporated fully herein by reference. Another method is a “cut and pour” type of emptying the contents of a stand-up pouch (a pouch with the gusset on the bottom of the pouch). 
         [0003]    While twist-off spouts can be utilized effectively in certain conditions, detachable caps can be misplaced or lost. If a mode of access can be improved to make it easier to open the container, this improved mode will enjoy success in the market place. However, there are many difficulties that arise when working with thin films that form the body of flexible beverage pouches, and it is important to be cognizant of waste and spillage that can arise by poorly constructed opening mechanisms that cause premature puncture or are too difficult to open. There is a need in the art for a pouch with an opening mechanism that is both secure, sterile, and easy to implement in conjunction with thin film pouches. Many stand-up pouches (gusset on the bottom) use a simple method of opening with just a cut and pour feature, although the results of using this method can be messy and not re-closable. However, with a side gusseted pouch, one cannot easily cut the top of this pouch and pour, as cutting the top will jeopardize the structure of the pouch and may cause the contents to spill. The present invention provides a low cost solution for both pouch types, including other pouch shapes as well. 
       SUMMARY OF THE INVENTION 
       [0004]    The present invention is characterized by a thin film pouch with a front wall, and rear wall, and an opening in said front wall, and further comprising a closure mechanism comprising a thin membrane patch bonded to said pouch about a periphery of said opening, a platform bonded to said thin membrane patch, said platform including a window formed therein and a plurality of cutting surfaces adjacent said window, and a pull strip bonded to said thin membrane patch and attached to said platform by a frangible membrane, wherein a removal of the pull strip ruptures said frangible membrane and tears said thin membrane patch at said cutting surfaces. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0005]      FIG. 1   a  is an elevated perspective view of a first preferred embodiment of the present invention prior to release of the pull tab; 
           [0006]      FIG. 1   b  is an elevated perspective view of a first preferred embodiment of the present invention with the pull tab partially released; 
           [0007]      FIG. 1   c  is an elevated perspective view of a first preferred embodiment of the present invention with the pull tab fully released; 
           [0008]      FIG. 2  is an elevated perspective view of the embodiment of  FIG. 1  after release of the pull tab; 
           [0009]      FIG. 3  is an enlarged, lower perspective view of the pull strip and platform of the present invention; 
           [0010]      FIG. 4  is an enlarged, elevated perspective view of the pull strip being lifted off the platform; 
           [0011]      FIG. 5   a  is an enlarged, cross-sectional view of the pull strip and platform prior to actuation of the pull tab; 
           [0012]      FIG. 5   b  is an enlarged, cross-sectional view of the pull strip and platform after actuation of the pull tab; 
           [0013]      FIG. 6   a  is an enlarged, cross-sectional view of a second embodiment of the pull strip and platform prior to actuation of the pull tab; 
           [0014]      FIG. 6   b  is an enlarged, cross-sectional view of the embodiment of  FIG. 6   a  after actuation of the pull tab; 
           [0015]      FIG. 7   a  is an enlarged, cross-sectional view of a re-closable embodiment of  FIG. 5  prior to actuation of the pull tab; and 
           [0016]      FIG. 7   b  is an enlarged, cross-sectional view of the embodiment of  FIG. 7   a  after actuation of the pull tab. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0017]      FIGS. 1   a - 1   c  illustrate a flexible pouch having a pull strip as part of a zip release opening that can be actuated to tear an elongate strip of pouch away from the body of the pouch to gain access to the contents therein. The pouch  10  includes a body having a base  12 , a front surface  14 , a rear surface  16 , side surfaces  18 , and a top  20 . The pouch may have a gable design as shown, or can take the form of a brick, triangular, or pillow-shaped pouch. The pouch  10  may be created by any of the many known techniques for formulating a closed container that incorporates a thin walled member. As further shown in  FIG. 1 , the pouch  10  of the present invention includes a pull strip  22  including a free end  22   a  that can be grasped between a thumb and forefinger to actuate the zip release opening  25 . The free end  22   a  of the pull strip  22  preferably includes a grasping member can take many forms, such as a spherical anchor  24 , annular ring, or flat tab with ridges that can be easily grasped. The pull strip  22  is pulled back to engage the thin wall  32  of the pouch&#39;s outer skin, and then retracted to tear open an elongate aperture  25  on the pouch  10  to expose the pouch&#39;s interior. When the pull strip  22  is fully retracted as shown in  FIG. 1   c , the contents  28  of the pouch  10  can be poured out or otherwise accessed in an expeditious manner as shown in  FIG. 2 . Note that the pouch  10  can be formed with a pouring ledge  30  or other spout structure to prevent fluid from dribbling down the front surface  14  of the pouch during pouring. The coupling of the pull strip  22  to the pouch will now be described in more detail. 
         [0018]      FIGS. 3 and 4  illustrate the operation of the pull strip  22  from initial deployment to full release. As shown in  FIG. 4 , the pull strip  22  comprises an elongate plastic strip  36  that is affixed to a rectangular platform  38  with an elongate window  44  disposed therein and covered by the plastic strip  36 . On the border  39  of the platform  38  that defines the window  44  are first and second rows of downwardly directed cutting teeth  42  along each longitudinal edge, and a larger cutting tooth  46  at an edge where the free end  22   a  is located. In  FIG. 3   a , the platform  38  is bonded to a thin membrane patch  41  that connects the platform  38  to the edge  32  of the pouch. The plastic strip  36  is also bonded to the thin membrane patch  41   a , where the bonding of the plastic strip  36  to the membrane patch  41   a  is surrounded by the cutting teeth  42 ,  46 . In between the bonding of the patch  41   a and the patch  41  at the perimeter of the platform  38  is a slightly raised surface  37  ( FIG. 3   a ). The cutting teeth  42 ,  46  are fully concealed beneath the raised surface  37  of the membrane patch  41  prior to actuation of the pull strip  22 . As the pull strip  22  is initially lifted as shown in  FIG. 3   b , the plastic strip  36  begins to separate from the platform  38 , and the thin film membrane  41   a  attached to the plastic strip  36  is pulled upward against the cutting teeth  42 . The cutting teeth  42  pierce the thin membrane  41 , beginning with the tooth  46 , as shown in  FIG. 3   b . As the plastic strip  36  is further pulled away from the platform  38  as shown in  FIG. 3   c , the portion of the membrane  41   a  that is bonded to the lower surface of the plastic strip  36  is retained by the plastic strip  36  as the cutting teeth  42  sever the surrounding membrane, creating an aperture  25  in the pouch through the window  44  of the platform  38 .  FIG. 3   d  shows the pouch opening with the plastic strip  36  separated from the platform  38  to fully expose the window  44  and create the pour spout for the pouch. 
         [0019]      FIG. 5   a  shows a cross-sectional view of the closure prior to actuation of the pull strip  22 . The plastic strip  36  carries the pull tab  24  at a proximal end, and rests between edges  39  of the platform  38 . Cutting teeth  42  are disposed along the edges  39  and project below the lower surface of the platform  38 . The patch  41 ,  41   a  are bonded to the bottom surface of the plastic strip  36  and the bottom surface of the platform on opposite sides of the cutting teeth  42 . To enhance ultrasonic bonding of the platform  38  and the plastic strip  36  to the membrane  41 , small raised tabs can preferably extend from those surfaces where said bonding occurs. The plastic strip  36  is attached to the cutting teeth  42 ,  46  by a thin frangible sheet  47  in a septic embodiment shown in  FIG. 5 . The thin sheet  47  is severed when the pull tab  22  is actuated, separating the plastic strip  36  from the cutting teeth  42  as shown in  FIG. 5   b . This embodiment is aseptic because the plastic strip never contacts the contends of the pouch, but rather the pouch is preserved in an aseptic condition until it is opened. In  FIG. 6   a , an alternative embodiment is illustrated (non-septic) where the thin membrane  41   a  is omitted. Here, the platform  38  is bonded to the membrane patch  41 , which in turn is bonded to the outer edge of the pouch  10 . The pull strip  22  is connected to the platform  38  by a thin sheet  47 , but the bottom surface  51  of the plastic strip  36  is exposed to the interior of the pouch  10 . As shown in  FIG. 6   b , when the pull strip  22  is actuated, the sheet  47  is severed and the window  44  of the platform  38  is thereby exposed. In this embodiment, the cutting teeth  42 ,  46  can be minimized or omitted.  FIGS. 7   a  and  7   b  illustrate another embodiment of the closure that can be re-closed after opening. The platform  38  is formed with retaining ledges  55   a,b  that extend slightly over the outer edges of the plastic strip  36 . After the pull tab  22  is actuated and the sheets  47  are ruptured, the contents of the pouch can be accessed. If it is desired to re-close the opening, the plastic strip  36  can be returned to the platform  38  and the retaining ledges  55   a,b  flex to allow the plastic strip to return to the platform  38  where it is held in place by the retaining ledges. Although the aseptic condition has been eradicated by the opening of the plastic strip  36 , for short term usages a simple resealing of the pouch is all that is needed. A non-septic version (see  FIG. 6 ) can also be made with a re-closable closure as just described. 
         [0020]    The closure of the present invention can be made of any sturdy plastic such as polyethylene or polypropylene, as long as economic bonding techniques such as, for example, ultrasonic bonding, will work with the plastic. Because the closure is molded in the closed position, it can be made from a single cavity mold, which is atypical for this type of closure. Using a single cavity mold significantly reduces the costs of manufacturing the closure, making the present invention very economical compared with alterative closure means. 
         [0021]    The foregoing descriptions are intended to be illustrative of various embodiments within the scope of the present invention, and are not intended to be limiting or exclusive. One of ordinary skill in the art would readily appreciate many alternatives and deviations from those embodiments described above, and the invention is intended to include all such alternatives and deviations. Accordingly, the scope of the invention should be construed according to the ordinary meaning of the terms set forth in the appended claims in view of the foregoing descriptions.