Abstract:
A reclosable pouch includes a closure assembly secured to pouch walls and a slider disposed on the closure assembly and movable between open and closed positions. The pouch further includes an end stop disposed at an end of the closure assembly and including a first portion secured to the pouch adjacent the closure assembly and a second portion extending from the first portion and deflected into secure engagement with the pouch.

Description:
TECHNICAL FIELD  
       [0001]     The present invention relates to reclosable pouches, and more particularly, to end stops for such pouches.  
       BACKGROUND ART  
       [0002]     A reclosable pouch may include a closure mechanism comprising male and female closure elements or profiles attached to pouch walls. In addition, a pouch may have a slider disposed upon the closure elements and movable between open and closed positions. Various arrangements have been used to prevent the slider from sliding off of the bag. In one such arrangement, an end stop is disposed at the end of the closure elements to prevent the slider from being unintentionally removed from the bag.  
         [0003]     Herrington et al. U.S. Pat. No. 5,189,764 discloses latching means for retaining a plastic slider in a closed position along a pair of interlocking plastic strips. The latching means comprises a detent on the plastic slider, which engages a protrusion on the plastic strips proximate an end of the bag.  
         [0004]     Richardson et al U.S. Pat. No. 5,301,394 discloses a slider having two detent elements located on opposite sides of a separator finger within the slider. When the slider is at any location along a zipper other than a fully closed position, the detent elements ride against the outside surfaces of flanges of the zipper. When the slider reaches the closed position just past the zipper flanges, the detents spring inward against the sides of the separator finger to lock the slider in the closed position.  
         [0005]     Richardson et al. U.S. Pat. No. 5,405,478 discloses a method for applying end stops as bags are being manufactured before the bags are separated from one another. The end stops on adjacent bags are formed from a single length of plastic tubing that is secured to zipper tape carried by a plastic web forming bag walls.  
         [0006]     Morgan U.S. Pat. No. 5,442,837 discloses a thermoplastic bag having a zipper secured to a plastic web. The zipper includes flanges at ends of the bag having an increased height, thereby providing for adequate plastic material to form integrated end stop seals that interfere with removal of a slider from the zipper. The end stop seals are sufficiently strong such that additional end clips or clamps are not required.  
         [0007]     Dobreski et al. U.S. Pat. No. 5,924,173 discloses end stops in the form of plastic pins or posts having enlarged heads and wherein the pins further include linear portions that extend through ends of first and second closure strips. The enlarged heads retain the end stops on the closure strips and interfere with removal of a slider therefrom.  
       SUMMARY OF THE INVENTION  
       [0008]     According to one aspect of the present invention, a reclosable pouch comprises a closure assembly secured to pouch walls. A slider is placed on the closure assembly and is movable between open and closed positions. An end stop is disposed at an end of the closure assembly. The end stop includes a first portion secured to the pouch adjacent the closure assembly and a second portion extending from the first portion and deflected into secure engagement with the pouch.  
         [0009]     According to another aspect of the present invention, a method of producing an end stop for a reclosable pouch includes the steps of applying a first portion of a plastic member to a surface of the pouch proximate a closure assembly and forming an end stop by attaching a second portion of the plastic member to the pouch at a position proximate a side portion thereof.  
         [0010]     Other aspects and advantages of the present invention will become apparent upon consideration of the following detailed description and the attached drawings, in which like elements are assigned like reference numerals.  
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]      FIG. 1  comprises a side elevational view of a reclosable thermoplastic storage pouch according incorporating an embodiment of the present invention;  
         [0012]      FIGS. 2 and 3  comprise sectional views taken generally along the lines  2 - 2  and  3 - 3 , respectively, of  FIG. 1 ;  
         [0013]      FIG. 4  comprises a fragmentary plan view of the storage pouch of  FIG. 1 ; and  
         [0014]      FIGS. 5A and 5B  are sectional diagrammatic views of a clamping apparatus during the process of forming end stops according to the present invention. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0015]     Referring to  FIGS. 1 and 2 , a reclosable pouch in the form of a thermoplastic storage bag  20  comprises a first body portion  22  and a second body portion  24  adjacent the first body portion  22 . The first body portion  22  and the second body portion  24  are joined to one another at first and second side edges  26 ,  28  and may be integral with one another at a bottom, folded edge  30 . Alternatively, the body portions  22  and  24  may not be integral with one another and may be joined to each other at the side edges  26 ,  28  and bottom edge  30  by any suitable means and/or process. An opening  32  ( FIGS. 1 and 2 ) is disposed at a top portion  34  of the bag  20 . A closure assembly  36 , comprising first and second closure elements  38  and  40 , respectively, is also disposed at the top portion  34  of the bag  20 . A slider  50  straddles the first and second closure elements  38  and  40  and is prevented from being pulled upwardly off of the bag  20  across the closure assembly  36  by slider retention rails  52  and  54 . End stops  56   a ,  56   b  and  58   a ,  58   b  are disposed at ends  60  and  62  of the closure assembly  36  as noted in greater detail hereinafter and prevent the slider  50  from being pulled sideways off of the bag  20  at side edges  26 ,  28 .  
         [0016]     Referring next to  FIG. 3 , during production of bags, at least one, and preferably two flanges  64 ,  66  are extruded or otherwise suitably formed and secured on lower (as seen in  FIG. 3 ) portions of the closure elements  38 ,  40  below the rails  52 ,  54 , respectively. The flanges  64 ,  66  are preferably made of a suitable thermoplastic, such as an olefin including homopolymers or copolymers of polyethylene or polypropylene. Also preferably (although not necessarily) the flanges  64 ,  66  extend continuously from the end  60  to the end  62  across the full width of the bag  20 . Alternatively, one or both of the flanges  64 ,  66  may by preformed and post-applied by adhesive or any other securing means to any portion of the bag and/or one or both flanges  64 ,  66  may be discontinuous across the width of the bag. In the latter case, the discontinuous flange(s)  64  and/or  66  are preferably positioned at the ends  60 ,  62 . In any event, base portions  70 ,  72  of each flange  64 ,  66  are secured as noted above either intermittently or continuously to the closure elements  38 ,  40  or other portion(s) of the bag. In the illustrated embodiment, free ends  74 ,  76  of the flanges  64 ,  66  are disposed opposite the base portions  70 ,  72  and comprise enlarged or bulbous head portions. Referring also to  FIGS. 5A and 5B , the end stops  56  and  58  are each created by deflecting the free ends  74 ,  76  into secure engagement with portions of the closure elements  38 ,  40  or other bag portions at the ends  60 ,  62 . This is preferably accomplished during bag production by bringing heated clamping tools  80 ,  82  into simultaneous contact with the free ends  74 ,  76  and advancing the heated clamping tools  80 ,  82  toward each other until the bulbous heads of the free ends  74 ,  76  are heat staked or otherwise fused to the closure elements  38 ,  40  or other bag portions at the ends  60 ,  62 , as seen in  FIG. 2 . This fusing may be accomplished by simple transfer of heat from the heated clamping tools to the free ends  74 ,  76  and/or by otherwise securing the free ends  74 ,  76 , such as by adhesive, melted thermoplastic, or the like.  
         [0017]     The fusing or other attachment of the free ends  74 ,  76  preferably is undertaken over a limited span at the ends  60 ,  62  so that travel of the slider  50  is only inhibited at such ends. More particularly, the slider  50  includes feet  90 ,  92  (visible in  FIGS. 2 and 3 ) that are interfered with by the bulbous ends of the flanges  64 ,  66  (see  FIG. 2 ). This interference prevents the slider  50  from being easily removed from the bag  20 . Referring to  FIG. 3 , at locations away from the ends  60 ,  62 , the free ends  74 ,  76  are disposed out of interfering relationship with the feet  90 ,  92  so that the slider  50  is free to move along a slider travel path at locations intermediate the ends  60 ,  62 .  
       Industrial Applicability  
       [0018]     The pouch described herein advantageously includes reinforced end stops created by attaching a plastic member, comprising a first portion and a second portion, to pouch walls. The first portion of the plastic member is secured to the pouch adjacent a closure assembly and the second portion of the plastic member is deflected into secure engagement with the pouch at a position proximate an end thereof. The first portion is joined to the second portion by an intermediate portion that may be (but need not be) narrowed as compared to the first and second portion  
         [0019]     It should be noted that the flange(s)  64 ,  66  may be replaced by flange(s) of different cross-sectional shape and/or material, if desired. Further, a single flange may be provided having a first portion secured to only one side of the bag  20 , and may further have a second portion deflected into secure engagement with a portion of the bag at ends of the bag to provide end stops. Still further, the first and/or second portions may continuously extend across an entire width of the bag  20 , or either may be discontinuous in the sense that the first and/or second portion may be of limited length relative to the bag width dimension.  
         [0020]     Numerous modifications will be apparent to those skilled in the art in view of the foregoing description. Accordingly, this description is to be construed as illustrative only and is presented for the purpose of enabling those skilled in the art to make and use the invention and to teach the best mode of carrying out same. The exclusive rights to all modifications that come within the scope of the appended claims are reserved.