Abstract:
A sheet retainer for keeping a sheet affixed to a solid structure: The retainer consists of two pieces, one of them is attached rigidly to the solid structure, while the other can engage or disengage with the 1 st  piece. When engaged with each other, the two pieces of the retainer capture a portion of the sheet and affixing it to the solid structure.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    (Not Applicable) 
       STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH/DEVELOPMENT 
       [0002]    (Not Applicable) 
       BACKGROUND OF THE INVENTION 
       [0003]    As is often desired, one needs to attach a sheet to a solid structure so that the sheet, or a portion of it, does not move with respect to the solid structure. An example is the attachment of a trash bag to a trash can. To keep a trash can clean and for easy trash removal, a trash bag is typically used inside a trash can. Trash bags are notoriously known for easily falling into a trash can when material is placed inside of them. As a result, the material may fall outside of the trash bag and into the space between the trash bag and the trash can, which makes it difficult to pick the material up. When the material is trash, it can also make the trash can dirty. 
         [0004]    Many trash bag and retainer designs have been introduced in the past in order to solve the problem of a trash bag falling into a trash can. Prior arts include many different designs to hold the trash bag in place, for example, tabs inside a trash can (U.S. Pat. No. 3,825,150); an elastic band (U.S. Pat. No. 4,338,979); elastic band with protruding structures (U.S. Pat. No. 7,055,224); handles on a trash bag attached to holders on a trash can (U.S. Pat. No. 4,437,634); a wire frame (U.S. Pat. No. 4,623,111); side bars for supporting handled trash bags (U.S. Pat. No. 5,054,724); interlocked rings (U.S. Pat. No. 5,062,533); clips (U.S. Pat. No. 5,645,186); two handles (U.S. Pat. No. 5,671,861); clamps designed into a trashcan (U.S. Pat. No. 6,484,374). These inventions and others have advanced the art, but are still not convenient enough. The object of the invention is to device a design so that the attachment of a sheet to a solid structure, such as the attachment of a trash bag to a trash can, can be easily made. 
       BRIEF SUMMARY OF THE INVENTION 
       [0005]    The present invention relates to the usage of a retainer or a set of retainers for the attachment of a sheets or a bag to a solid structure. An example is the attachment of a trash bag to a trash can. For simplicity sake and unless otherwise stated, we use trash bags and trash cans for the general discussion of this invention. 
         [0006]    The aforementioned retainer consists of two pieces: One of them is attached rigidly to the trash can, while the other can engage or disengage with the 1 st  piece. When engaged with each other, with a portion of the trash bag sandwiched in between, the two pieces prevent the trash bag from slipping into the trash can. In the present invention, the engagement of the two pieces may be by means of magnetism. The present invention can be operated easily with a single hand, making it very convenient to use. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]      FIG. 1  is a three dimensional and front view of the 1 st  piece ( 10 ) of the holding device. 
           [0008]      FIG. 2  is a three dimensional and front view of the 2 nd  piece ( 20 ) of the holding device. 
           [0009]      FIG. 3  is a three dimensional and front view of the 1 st  and 2 nd  piece ( 10  &amp;  20 ) of the holding device engaged with each other. 
           [0010]      FIG. 4  illustrates how the holding device works. 
           [0011]      FIG. 5  is a front and bottom view of one embodiment of the 1 st  piece ( 10 ) of the holding device. 
           [0012]      FIG. 6  is a front and side view of one embodiment of the 2nd piece ( 20 ) of the holding device. 
           [0013]      FIG. 7  is a front and side view of another embodiment of the 2nd piece ( 20 ) of the holding device. 
           [0014]      FIG. 8  has three drawings located at the top, bottom and bottom-right, corresponding to the top, front and side view of a trash can with four of the 1 st  piece ( 10 ) of the holding device attached. 
           [0015]      FIG. 8   a  is the enlargement of a corner of the trash can in  FIG. 8  with a 1 st  piece ( 10 ) of the holding device attached. 
           [0016]      FIG. 9  is the three dimensional view of part of the top portion of a trash can with the 1 st  piece ( 10 ) of the holding device attached to the outside wall ( 302 ). 
           [0017]      FIG. 10  is an enlarged front view (view A in  FIG. 9 ) after a portion of the trash can is cut open along the broken line in  FIG. 9 . 
           [0018]      FIGS. 11-14  illustrate a sequence for engaging the 1 st  ( 10 ) and the 2 nd  piece ( 20 ) of the holding device so that they hold a portion of a trash bag in between them to prevent the said bag from slipping. 
           [0019]      FIGS. 15-17  illustrate three of the alternative embodiments of the 1 st  piece ( 10 ) of the holding device. 
           [0020]      FIG. 17   a  is an enlargement of piece  11  in  FIG. 17 . 
           [0021]      FIG. 18  is the corresponding embodiment of the 2 nd  piece ( 20 ) of the holding device with respect to  FIG. 17 . 
           [0022]      FIG. 18   a  is an enlargement of the top portion of  FIG. 18 . 
           [0023]      FIGS. 19-26  illustrate some of the alternative designs of the present embodiment. 
           [0024]      FIG. 27  shows different views of the piece  10  in  FIG. 1 . 
           [0025]      FIG. 28  illustrates an alternative embodiment of the 1st piece ( 10 ) of the holding device. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0026]    Drawings herein are for purposes of illustrating the preferred embodiments of the present invention only, not to limit the present invention. There are no dimensional specifications in these drawings so that the dimensions may be altered to fit with specific applications.  FIGS. 1&amp;2  are a three dimensional and front view of the 1 st  ( 10 ) and 2 nd  ( 20 ) piece of the holding device. The inside top surface ( 101 ) of the 1 st  piece ( 10 ) attracts the 2 nd  piece ( 20 ) magnetically. The details of how this works will be discussed later.  FIG. 3  shows the engagement of the 1 st  ( 10 ) and 2 nd  ( 20 ) piece of the holding device. They are held together by the magnetic force between them. As shown in  FIG. 4 , when pieces  10  and  20  are engaged with each other, they may capture a portion of a trash bag ( 40 ) in between. The magnetic force between the inside top surface ( 101 ) of the 1 st  piece ( 10 ) and the 2 nd  piece ( 20 ) holds the trash bag ( 40 ) in place and prevents it from slipping away when the trash bag ( 40 ) is pulled at its end ( 401 ). The strength of magnetic force between the two pieces of the holding device should be such that they hold the trash bag in place while allowing for easy separation of the two pieces when needed. 
         [0027]    In one embodiment ( FIG. 5 ), piece  10  consists of two portions: one ( 11 ) is made of a magnet or a piece of magnetic material and the other ( 12 ) is made of a non-magnetic material. Piece  11  is attached to the underside of piece  12 . The upper portion of  FIG. 5  is the front view of the piece  10 , while the lower portion of  FIG. 5  is the bottom view of the piece  10 . In this embodiment, piece  20  ( FIG. 2 ) is made of a magnet or a piece of magnetic material so that the top of piece  20  ( 201  in  FIG. 2 ) is attracted to piece  11  of piece  10  in  FIG. 5 . As shown in  FIG. 5 , length a and b do not have to be the same. 
         [0028]    In another embodiment ( FIG. 6 ), piece  20  consists of a top piece ( 21 ) and bottom piece ( 22 ). Piece  22  is made of none magnetic material. Piece  21  is made of a magnet or a magnetic material so that piece  21  is attracted to piece  11  of  10  in  FIG. 5 . Length a and b in  FIG. 6  do not have to be the same; neither do width c and d in  FIG. 6 . Piece  21  may also be recessed partly into piece  22  as shown in  FIG. 7 , where the top portion of  FIG. 7  is the top view and the bottom portion is the front view. 
         [0029]      FIG. 8  consists of three separate drawings located at the top, bottom and bottom-right, corresponding to the top, front and side view of a trash can with four of the 1 st  piece ( 10 ) of the holding device attached. 
         [0030]      FIG. 8   a  is the enlargement of a corner of the trash can in  FIG. 8  with a 1 st  piece ( 10 ) of the holding device attached to the outside wall of the trash can. 
         [0031]      FIG. 9  is the three dimensional view of part of the top portion of a trash can with the 1 st  piece ( 10 ) of the holding device mounted on the outside of the trash can wall ( 302 ).  301  is top rim of the trash can.  FIG. 10  is an enlarged front view (view A in  FIG. 9 ) after a portion of the trash can is cut open along the broken line in  FIG. 9 , showing the cross section of part of the trash can wall ( 302 ) and the top rim of the trash can ( 301 ) together with the head on view of piece  10 . 
         [0032]    As shown in  FIG. 11 , to hold a trash bag, the bottom portion ( 401 ) of the trash bag ( 40 ) needs to be placed in the trash can and the top portion of the trash bag ( 402 ) should extend beyond the top rim of the trash can ( 301 ). The trash bag outside of the trash can is then folded down covering piece  10  and extents beyond it, by at least an 1″, for example ( FIG. 12 ). As shown in  FIGS. 13 and 14 , the top of piece  20  ( 201 ) is brought into contact with the inside top of piece  10  ( 101 ) with part of the trash bag sandwiched between  101  and  201 . The magnetic force between pieces  10  and  20  holds the sandwiched portion of the trash bag in place and prevents the said trash bag from falling into the trash can. 
         [0033]    The placement of a magnet or a magnetic material ( 11 ) in piece  10  can be at different locations from that shown in  FIG. 5 . It can be, e.g., on the inward sides of piece  10  as shown in  FIGS. 15 and 16 . Also, the outside surface of  11  in  FIG. 5  may have groves for improved holding capabilities as shown in  FIGS. 17 and 17   a . In this case, the top surface  201  of piece  20  in  FIG. 2  should have matching groves as shown in  FIGS. 18 and 18   a.    
         [0034]    There are numerous variations of the present embodiment. Variations in dimension and structure may be implemented by one skilled in the art of this disclosure. Some exemplary variations are shown in  FIGS. 19 ,  20 . 
         [0035]      FIG. 21  is still another exemplary variation of the present embodiment. In this example, the top of the cross section of the trash can (top of the shaded area in  FIG. 20 ) is not just a straight angle, but is n-shaped as shown by the top of the shaded area in  FIG. 21 . A magnet or a magnetic material ( 11 ) can be attached to the underside of the n-shaped portion. Piece  20  engages with piece  11  with a portion of the trash bag sandwiched in-between as shown in  FIG. 21 . 
         [0036]      FIG. 22  is still another exemplary variation of the present embodiment. It can be used with piece  10  in  FIG. 1 , where the inside top of  10  ( 101  in  FIG. 1 ) is attracted magnetically to the top of  50  ( 501 ) in  FIG. 22 . The bottom of  50  ( 502  in  FIG. 22 ) is attached to the outside wall of a trash can ( FIG. 23 ). Piece  10  engages with piece  50  with a portion of the trash bag ( 40 ) sandwiched in between as shown in  FIG. 23 , so as to prevent the said trash bag from falling off. 
         [0037]      FIG. 24  and  FIG. 25  are still other exemplary variations of the present embodiment. Piece  60  in  FIG. 24  essentially consists of two units of piece  10  in  FIG. 1 . The corresponding piece  70  ( FIG. 25 ) has two ridges ( 701  and  702 ) which are magnetically attracted to the top undersides of piece  60  ( 601 ,  603  of  FIG. 24 ). Furthermore, if it is desired, one can make the inside top of piece  70  ( 703  of  FIG. 25 ) to magnetically attract to ridge  604  of piece  60  ( FIG. 24 ).  FIG. 26  shows that piece  60  is attached to the outside wall of a trash can and piece  60  is attracted to piece  70  with a portion of the trash bag ( 40 ) sandwiched in between, so as to prevent the said trash bag from falling off. 
         [0038]      FIG. 27  is a different 3 dimensional and front view of piece  10  in  FIG. 1 .  FIG. 28  (piece  10 A) is an illustration of an exemplary variation of piece  10  where the front and back ends ( 103  and  104 ) of piece  10  in  FIG. 27  are capped off. Piece  20  of  FIG. 2  can fit into the cavity in piece  10 A. The side caps on piece  10 A keep piece  20  properly positioned with respect to piece  10 A. 
         [0039]    Illustrations above provide exemplary embodiments of the present invention. The scope of the present invention is not limited by these illustrations. The number of variations, some of which are shown in this presentation, is too many to list. These variations may be implemented by one skilled in the art in view of this disclosure.