PRIORITY CLAIM 
       [0001]    Applicant claims priority based on U.S. Provisional Application Ser. No. 61/065,945, filed Feb. 15, 2008, titled “Self-Sealing Container” by inventor Michael T. Fusco. 
     
    
     FIELD OF INVENTION 
       [0002]    This invention concerns flexible plastic containers or bags that can be sealed without heat seals, welding, adhesives or interlocking sealing members. 
       BACKGROUND 
       [0003]    Bags or containers made from sheets of flexible hydrocarbon polymers, such as low and very low density polyethylene, are well-known and widely used. Such bags frequently are heat sealed or welded on three sides during manufacture, leaving most or all of the fourth side open to permit filling of the bag or container. 
         [0004]    Once filled, a user typically wants to seal the bag to prevent the contents from escaping from the bag or container. Ties made of wire, plastic, or paper strips have been twisted or tied to seal plastic bags, but such sealing methods are unsatisfactory for holding liquids, and require an additional step for the user. 
         [0005]    Heat seal devices are used where the layers of plastic forming the bag walls are heat sealed to each other by melting the plastic. This method generally provides a satisfactory seal, but requires an expensive heat sealing device, produces surfaces of sufficiently high temperature that can burn the user, and requires an additional step after filling. 
         [0006]    Another well-known method of sealing plastic bags or containers uses interlocking ridges of thicker plastic on the interior opposing faces of the opening. The user lines up the ridges and presses the ridges together to seal the bag or container. This seal also is satisfactory for most purposes when sealed properly, but is more expensive than similar plastic bags without the locking seals. Additionally, the ridges frequently are difficult to line up, and frustrate the user, and may not completely seal. These locking ridges require an additional step after filling the bag or container 
         [0007]    Other closure means use adhesive between the plastic sheets of the opening, or use mechanical clamps or closures, all of which are more expensive than the bags without such devices, and all of which require an additional step beyond filling the bag or container. 
         [0008]    What is needed is an inexpensive plastic bag or container that can be filled and will seal itself without clamps, adhesive or similar known methods of sealing. 
         [0009]    What is needed is such a plastic bag or container that can be filled with a fluid and pressurized, and will not leak, even if the bag or container containing fluid is frozen. 
         [0010]    What is needed is such a bag or container that can be used without expensive or dangerous equipment. 
       SUMMARY OF INVENTION 
       [0011]    The self-sealing bag comprises a thin, flexible polyethylene bag having a tapered neck. The bag may include indents in the neck to help hold a filling nozzle. A tapered nozzle is inserted into the tapered neck to fill the bag. An alternative tapered nozzle can have two conduits to permit simultaneous filling and air bleeding. As the bag is filled, the sides expand, and the expanded sides exert pressure on the bag sides at the tapered neck to force the bag sides together and thereby seal the bag. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]      FIG. 1  shows a plan view of the bag; 
           [0013]      FIG. 2  shows a perspective view of a tapered nozzle; and 
           [0014]      FIG. 3  shows a perspective view of an alternative tapered nozzle. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0015]    The self-sealing bag  10  shown in  FIG. 1  is made of polyethylene using well-known methods to form the bag. Specifically, a rectangular sheet of polyethylene approximately 31.8 millimeters (hereafter “mm”) wide and 439 mm long is folded along a line approximately 223 mm from one end to create the rectangle shown in  FIG. 1 . The rectangle is then sealed by well-known means along the two sealing lines  11  shown in  FIG. 1 . 
         [0016]    When the rectangle is folded as described, a short tab  12  and a long tab  13  remain above the top sealing flanges  14 . The short tab  12  extends approximately 7 mm above the top sealing flanges  14  and the long tab  13  extends approximately 14 mm above the top sealing flanges  14 . This difference permits the user to open the bag  10  at the top  15  more easily, since the user can easily separate the short tab  12  and the long tab  13  to reach the tapered neck  24 . 
         [0017]    The bag  10  has a tapered neck  24  between the top sealing flanges  14  and the body  18 . Approximately 13 mm from the top sealing flanges  14 , in the direction of the bottom  16 , the bag has a pair of indents  19  formed by the sealing lines  11 . The indents  19  are v-shaped, and the angle of the ‘v’ as measured from a line  20  perpendicular to the length  21  of the bag  10  towards the top  15  of the bag  10  is approximately 54.6° (the top angle  22 , shown in  FIG. 1 ). The bottom angle  23 , shown in  FIG. 1 , measures approximately 48.1°. 
         [0018]    The tapered neck  24  extends from the top sealing flanges  14  to the body opening  25 . The tapered neck  24  is approximately 12.27 mm wide  26  at the top  15 . 
         [0019]    The bag  10  also may have holes  27  near the tapered neck  24  which extend through the bag to provide a convenient way to hold the bag  10  in place as it is being filled. The bag  10  can be mounted on posts (not shown) by putting the posts through the holes  27 . 
         [0020]    The bag  10  is filled using a tapered nozzle  28 , sized to match the tapered neck  24 , so that the tapered neck  24  is pushed onto the tapered nozzle  28 , and so the tapered neck fits snuggly and will not allow the filling material  34  to leak out of the tapered neck in the direction of the top  15  of the bag  10 . The fit between the tapered neck  24  and the tapered nozzle  28  is improved if the tapered nozzle  28  includes a ridge  29  sized to fit the indents  19 . As the ridge  29  is pushed into the indents  19 , a seal similar to an “o” ring is formed. The length of the tapered nozzle relative to the tapered neck is very important. If the tapered nozzle is too short, it will cause the tapered neck to seal off between the end of the tapered nozzle  28  and the body opening  25 . If the tapered nozzle is too long, it will enter the body opening  25  and the tapered neck  24  will not seal when the tapered nozzle  28  is removed. It is preferable if the tapered nozzle  28  is inserted into the tapered neck  24  approximately 85% of the length of the tapered neck  24 . 
         [0021]    In an alternative embodiment shown in  FIG. 3 , the tapered nozzle  28  preferably has two conduits, a filling conduit  30  and a bleeding conduit  31 , as shown in  FIG. 2 . This alternative is not necessary for most bags, since they contain very little air when first filled. The filling conduit  30  allows liquid or fluid or other material (collectively “filling material”  34 ) used to fill the bag to flow into and fill the body  18 . As the filling material  34  flows into the bag, air bleeds from the bag through the bleeding conduit  31 , and out of the bleeding conduit through an air bleeder vent  32 . The bleeding conduit  31  is not in fluid communication with the filling material reservoir  33 , but the filling conduit  30  is in fluid communication with the filling material reservoir  33  to permit filling material  34  to flow from the filling material reservoir  33 , through the filling conduit  30  and into the body  18 . 
         [0022]    The bag  10  shown in  FIG. 2  lacks a short tab  12  and a long tab  13  to show the filling and vent features more clearly. 
         [0023]    As the filling material  34  is placed in the bag  10  through the filling conduit  30 , and air bleeds from the body  18  through the bleeding conduit  31 , the bag expands. When the body  18  is full, the user removes the bag  10  from the tapered nozzle  28 . The expanded body  18  exerts a pressure on the bag  10  in the region of the tapered neck  24  between the body opening  25  and the sealing lines  11 . This pressure is sufficient to retain the filling material  34  in the body  18 , even while the filling material is being frozen. 
         [0024]    The method of filling the bag  10  comprises the steps of opening the bag  10  at the top  15 ; inserting the tapered nozzle  28  into the tapered neck  24 ; filling the body  18  with filling material  34  and removing the bag  10  from the tapered nozzle  28 . If the tapered nozzle  28  includes a ridge  29 , and the bag  10  includes indents  19 , the tapered nozzle  28  is inserted into the tapered neck  24  until the ridge  29  seats in the indents  19 . 
         [0025]    The tapered nozzle  28  can be placed in the tapered neck  24  by moving the tapered nozzle  28  relative to the tapered neck  24 , or vice versa. 
         [0026]    The bag  10  can be filled using a pressurized filling material reservoir  33 . The pressurizing could arise from something as simple as a flexible bottle that is squeezed by the user, or from hand or electrically operated pumps. 
         [0027]    In one application of the bag, a sweet syrup is placed in the filling material reservoir  33 , a bag  10  is placed on a fixed tapered nozzle  28 , and a hand pump is pumped to force the syrup into the bag. After filling, the bag  10  is frozen to create a frozen treat for human consumption. 
         [0028]    Although the present invention has been described in terms of certain preferred embodiments, other embodiments will become apparent to those of skill in the art with reference to the disclosure contained herein. Accordingly, the scope of the present invention is intended not to be limited by the disclosed embodiments, but to be coextensive with the full scope of the attached claims.
The self-sealing bag comprises a thin, flexible polyethylene bag having a tapered neck. The bag may include indents in the neck to help hold a filling nozzle. A tapered nozzle is inserted into the tapered neck to fill the bag. An alternative tapered nozzle can have two conduits to permit simultaneous filling and air bleeding. As the bag is filled, the sides expand, and the expanded sides exert pressure on the bag sides at the tapered neck to force the bag sides together and thereby seal the bag.