Abstract:
A closure device for a slider bag with a slider and an end stop operable to releasably latch the slider in the closed position and release the slider with minimal user applied force. The closure device includes first and second interlocking fastening strips arranged to be interlocked over a predetermined length. The slider is slidably disposed on the interlocking fastening strips for facilitating the occlusion and deocclusion of the fastening strips when moved towards first and second ends of the fastening strips. The first and second ends of the fastening strips are secured together and an end stop is provided to the first, closing end of the fastening strips. The end stop is provided with quick release latching structure engagable with cooperating latch-receiving structure provided to the mating or opening end of the slider to secure the slider when it is moved into engagement with the end stop at the closing end of the bag.

Description:
FIELD OF THE INVENTION 
     The present invention relates to improvements in closure devices for plastic storage bags, and more particularly, to plastic reclosable fasteners with sliders for opening and closing the reclosable fasteners on the bag and end stops with engagement means for releasably latching the sliders at the closing end of the bags. 
     BACKGROUND OF THE INVENTION 
     The use of closure devices for fastening storage containers, including plastic bags, is generally known. Furthermore, the manufacture of closure devices made of plastic materials is generally known to those skilled the in the art, as demonstrated by the numerous patents in this area. 
     A particularly well-known use for closure devices is in connection with flexible storage containers, such as plastic bags. In some instances, the closure device and the associated container are formed from thermoplastic materials, and the closure device and the sidewalls of the container are integrally formed by extrusion as a single piece. 
     Alternatively, the closure device and sidewall of the container may be formed as separate pieces and then connected by heat sealing or any other suitable connecting process. In either event, such closure devices are particularly useful in providing closure means for retaining matter within the bag. 
     Conventional closure devices typically utilize mating fastening strips or closure elements, which are used to selectively seal the bag. In addition, sliders may be provided for use in opening and closing the fastening strips. Such reclosable bags equipped with sliders are known in the art as “slider bags.” The slider may include a separator which extends at least partially between the fastening strips. When the slider is moved in the opening direction, the separator divides or deoccludes the fastening strips and opens the bag. When the slider is moved in the closing direction, the slider closes or occludes the fastening strips. 
     It is well known in the art to provide one or both ends of the reclosable fastener of a slider bag with an end stop to prevent movement of the slider past the ends of the bag. The end stop may be formed from the material of the fastening strips as is known from U.S. Pat. No. 5,950,285 to Porchia et al. Alternatively, the end stop may be formed as a separate plastic clip that is fused with the ends of the fastening strips during manufacture of the bag in accordance with the teachings of U.S. Pat. No. 5,448,807 to Herrington. The end stop may also consist of a separate u-shaped plastic clip that straddles the reclosable fastener and wherein individual clamping members of the clip are secured together by a plastic rivet that pierces the film material of the bag below the reclosable fastener. 
     It is desirable to be able to latch or secure the slider in its closed position to prevent the bag from accidentally opening. U.S. Pat. No. 5,301,395 to Richardson et al. discloses an end stop provided with an upward pointing hook member at its bottom forward facing edge. The hook member is adapted to extend into a cooperating recess on the bottom wing of the slider. As stated in the disclosure of this patent, the engagement of the recess by the hook member provides the user with a feel of a definite parking position for the slider when the bag is closed. To open the bag, the user must first disengage the hook member from the recess. This opening procedure requires use of brute force to separate the engaged elements. Repeated uses of the slider may cause the inter-engaging parts to wear or weaken and thus diminish the effectiveness of the positive latching feel of the closure. 
     It would be desirable to releasably latch a slider to an end stop on a bag provided with a reclosable fastener without having to use brute force in order to separate the slider from latching engagement with the end stop. 
     SUMMARY OF THE INVENTION 
     The present invention provides a closure device for a slider bag with a slider and an end stop having quick release latching means operable to releasably latch the slider in the closed position and release the slider with minimal user applied force. The closure device comprises first and second interlocking fastening strips arranged to be interlocked over a predetermined length. The slider is slidably disposed on the interlocking fastening strips for facilitating the occlusion and deocclusion of the fastening strips when moved towards first and second ends of the fastening strips. The first and second ends of the fastening strips are secured together and an end stop is provided to the first, closing end of the fastening strips. The end stop is provided with quick release latching structure engagable with cooperating latch-receiving structure provided to the mating or opening end of the slider to secure the slider when it is moved into engagement with the end stop at the closing end of the bag. 
     In accordance with a preferred embodiment of the invention, the slider is configured as an inverted u-shaped member having an upper portion disposed above the fastening strips and a pair of downwardly extending side walls disposed adjacent to the respective first and second fastening strips of the fastener. The quick release latching structure of the end stop includes a pair of tangs or latch members, disposed spaced apart and adjacent to the first and second fastening strips. Each latch member extends lengthwise away from the closing end of the bag and towards the opening end of the slider and has an outward extending ridge member or projection adapted to be receivingly engaged by a corresponding recess provided to the respective inside side wall surfaces of the opening end of the slider. The tangs or latch members are bendable or deflectable at their free ends, much like a diving board, and are designed to be “grandmother friendly” so that they require only a moderate inward pinching force by a user&#39;s thumb and finger to release engagement of the slider. 
     In accordance with an alternate embodiment of the invention, the quick release latching means comprise a single latch member disposed along one sidewall of the end stop. The procedure for unlatching the slider is essentially the same as above whereby the user applies inward pressure to one side of the end stop to initiate disengagement with the slider. 
     In accordance with another alternate embodiment of the invention, the quick release latching means comprise a single latch member disposed along the top portion of the end stop. The single top-mounted latch member includes an upstanding ridge member or projection adapted to engage a corresponding recess provided to inner wall of the slider top portion. To initiate unlatching of the slider from the end stop, the user pushes downwardly on the top-mounted latch member of the end stop to move the ridge member or projection out of engagement with the recess in the slider while moving the slider in the opening direction. 
     In accordance with yet another alternate embodiment of the invention, the engagement and receiving structural parts are reversed whereby the end stop is provided with one ore more recesses and the slider is provided with one or more latch members, each having a ridge or projection adapted to be receivingly engaged within the corresponding recess in the end stop. 
     Methods and apparatus which incorporate the features described above and which are effective to function as described above constitute further, specific objects of the invention. Other objects and advantages of the invention will become apparent upon reading the following description and upon reference to the drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     For a more complete understanding of this invention reference should now be had to the embodiments illustrated in greater detail in the accompanying drawings and described below by ways of examples of the invention. In the drawings: 
     FIG. 1 is a perspective view of a container in the form of a plastic bag having a slider and an end stop provided with means for quick release latching engagement of the slider in accordance with one embodiment of the present invention; 
     FIG. 2 is an enlarged perspective view of the slider of FIG. 1; 
     FIG. 3 is an enlarged perspective view of the end stop of FIG. 1; 
     FIG. 4 is an enlarged fragmentary side elevation view of the container of FIG. 1; 
     FIG. 5 is a partial cross-sectional view through the end stop and slider taken along the line and in the direction of arrows  5 — 5  of FIG. 4 (note the reclosable fastener has been omitted for clarity); 
     FIG. 6 is a partial cross-sectional view similar to FIG. 5 showing the slider disengaged from the end stop; 
     FIG. 7 is a perspective view of an end stop with quick release engagement means in accordance with an alternate embodiment of the present invention; 
     FIG. 8 is a perspective view of another embodiment of the present invention; and 
     FIG. 9 is a perspective view of another embodiment of the present invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     A container constructed in accordance with a preferred embodiment of the present invention is generally designated by reference numeral  100  in FIG.  1 . The container  100  is in the form of a plastic food bag  120  having a reclosable fastener device  121  at the open top of the bag  120 . The bag  120  includes a first sidewall  122  and a second sidewall  123  joined at seams  125 ,  126  to define a compartment accessible through the open top but sealable by means of the closure device  121 . The closure device  121  includes first and second fastening strips  130 ,  131  and a slider  132 . The fastening strips  130 ,  131  are adapted to be interlocked between a first end  127  and a second end  128 . The fastening strips  130 ,  131  are secured together at the first and second ends  127 ,  128  to form end seals. As shown in the figures, the first and second ends  127 ,  128  include melted portions  135 ,  137 , in which the fastening strips  130 ,  131  are melted together by heat sealing, ultrasonic sealing or other operation to form the end seals. In other embodiments, the first and second ends  127  and  128  may be secured together by plastic clamps, or by other means. The closure device  121  further includes an end stop  134  disposed proximate the first end  127 . 
     The fastening strips  130 ,  131 , slider  132  and end stop  134  have a longitudinal X-axis  102 , a transverse Y-axis  104  and a vertical Z-axis  106 . The transverse Y axis  104 , the longitudinal X axis  102  and the vertical Z axis  106  are mutually perpendicular to one another and define a three axis coordinate system. The fastening strips  130 ,  131  each have a bottom edge  115  and a top edge  117 . The closure device  121  may include a tape portion  118  that extends downward a distance from the bottom edge  115  of the fastening strips  130 ,  131  for attachment to the respective first and second sidewalls  122 ,  123 . Alternately, tape portion may be omitted and the sidewalls  122 ,  123  may be attached directly to the respective first and second fastening strips  130 ,  131 . 
     The slider  132  straddles the fastening strips  130 ,  131  and is mounted so that the slider  132  is restrained from being inadvertently pulled off of the fastening strips  130 ,  131  along the vertical Z axis  106  but is free to slide back and forth along the longitudinal X axis  102 . The slider  132  engages the fastening strips  130 ,  131  so that when the slider moves in the occlusion direction  114 , the fastening strips  130 ,  131  interlock and the bag  120  is sealed, and when the slider  132  moves in a deocclusion direction  116 , the fastening strips  130 ,  131  separate and the bag is open. 
     FIG. 2 is a perspective view looking into the opening end of the slider  132 . The slider  132  includes a top portion  140 , a first side portion  142  and a second side portion  144 . The first side portion  142  has an inner side wall  146  and an outer side wall  148 , and an inwardly directed bottom tab  150 . Similarly, the second side portion  144  has an inner side wall  152  and an outer side wall  154 , and an inwardly directed bottom tab  156 . As best seen in FIGS. 4 and 5, the outer side walls  148  and  154  are bowed outward. 
     The first and second side portions  142 ,  144  straddle the respective first and second fastening strips  130 ,  131  and the inwardly directed tabs  150 ,  156  mate with the respective bottom edges  115  of the fastening strips  130 ,  131 . The slider  132  is prevented from being accidentally pulled off of the reclosable fastener  121  by the engagement between the upper surfaces of the inwardly directed bottom tabs  150 ,  156  and the bottom edge  115  of the respective first and second fastening strips  130 ,  131 . 
     As best seen in FIG. 2, inner sidewall  152  of the second side portion  144  is provided with a recess  158 , the purpose of which will be described in greater detail below. Although not visible in FIG. 2, the inner sidewall  146  of the first side portion  142  is similarly provided with a recess  159 . In accordance with an alternate embodiment, only one of the first and second side walls is provided with a recess. Each of the outer sidewalls  142  and  154  is provided with upraised ridges  160  which provide gripping areas for the user&#39;s fingers when moving the slider  132  back and forth along the reclosable fastener  121 . As best seen in FIGS. 2,  4  and  5 , the ridges  160  sit within a shallow well  162  provided to the respective outer sidewalls  148 ,  154  of the first and second side portions  142 ,  144  so as to maintain the bowed outward contour of the outer sidewalls  148 ,  154 . 
     Referring to FIGS. 3 and 4, the end stop  134  includes a top portion  170 , a first side portion  172  and a second side portion  174 . The first side portion  172  includes a latch member  176  having a base end  176   a  connected to the first side portion  172  and a free end  176   b  that extends in the longitudinal x-axis  102 . The free end  176   b  includes an end face  178  that is tapered inwardly in the direction of the longitudinal x-axis  102 . The free end  176   b  further includes a ridge member or projection  180  that extends outwardly in the direction of the transverse y-axis  104 . In similar fashion, the second side portion  174  includes a latch member  182  having a base end  182   a  connected to the second side portion  174  and a free end  182   b  that extends in the longitudinal x-axis  102 . 
     The free end  182   b  includes an end face  184  that is tapered inwardly in the direction of the longitudinal x-axis  102 . The free end  182   b  further includes a ridge member or projection  186  that extends outwardly in the direction of the transverse y-axis  104 . 
     The end stop  134  straddles the fastening strips  130 ,  131  at the first end  127  of the bag. End stop side portion  172  includes a bottom portion  188  having an inwardly projecting tab  198  adapted to engage against the bottom edge  115  of fastening strip  130 . Similarly, end stop side portion  174  includes a bottom portion  200  having an inwardly projecting tab  202  adapted to engage against the bottom edge  115  of fastening strip  131 . The lower inside comers of each tab  198 ,  202  are provided with upwardly and inwardly tapered surfaces  204  and  206 , respectively. The tapered surfaces  204 ,  206  facilitate snap fit insertion of the end stop  134  onto the reclosable fastener  121 . The end stop  134  is secured in straddling position over the reclosable fastener  121  by heat sealing, ultrasonic sealing or other operation to form seals between the bottom portions  188 ,  200  and the respective adjacent sides of the bag  120 . 
     As best seen in FIG. 4, the slider  132  and the end stop  132  are conformingly contoured in outer appearance so as to provide an aesthetic blend of the two parts and so that they interfacially fit together when the slider  132  is positioned against the end stop  134  at the closing end  127  of the bag  120 . The respective top portions  140  and  170  of the slider  132  and end stop  134  slope upward to form a common peak at the point of interfacial engagement between the respective mutually facing end faces  155  and  196  of the slider  132  and end stop  134 . Each of the end stop side portions  172  and  174  further include upstanding longitudinally oriented ribs  190  having end faces  192  adapted to conform with and abut against the respective leading edges  194  of the first and second side portions  142 ,  144  of the slider  132  when the slider is moved into to the fully closed position on the bag  120 . 
     In accordance with the present invention there is provided means for the quick release latching engagement of the slider  132  to the end stop  134 . Referring now to FIGS. 5 and 6, a positive latching of the slider  132  to the end stop  143  is effectuated by the cooperating receiving engagement of the outward projections  180 ,  186  on the latch members  176 ,  184  of the end stop  134  within the corresponding recesses  158 ,  159  of the slider  132 . The inward tapered faces  178 ,  184  on the respective free ends of latch members  176 ,  182  help guide the interfacial latching engagement between the slider  132  and end stop  134 . The latch members  176 ,  182  of the end stop  134  are inwardly bendable or deflectable in the direction of the transverse y-axis  104  as shown in FIG.  6 . The inward deflection of the latch members  176 ,  182  moves the respective outward projections  180 ,  186  out of engagement with the recesses  158 ,  159  thereby permitting the slider  132  to be moved in the opening direction of the bag. While, a dual latch member arrangement has been shown and described, it is understood that a single latch member arrangement may also be used with equally good results. In other words, the end stop  134  described herein may have only one side portion equipped with a deflectable latch member that is receivingly engagable within a recess provided to an inner sidewall of the slider  132 . 
     FIG. 7 illustrates a perspective view of another embodiment of an end stop  300  in accordance with the present invention. The end stop  300  includes a top portion  302 , a first side portion  304  and a second side portion  306 . The first side portion  304  includes a latch member  308  having a base end  308   a  connected to the first side portion  304  and a free end  308   b  that extends in the longitudinal x-axis  102 . The free end  308   b  includes a projection  310  that extends outwardly in the direction of the horizontal y-axis  104 . In similar fashion, the second side portion  306  includes a latch member  312  having a base end  312   a  (not visible in the figure) connected to the second side portion  306  and a free end  312   b  that extends in the longitudinal x-axis  102 . The free end  312   b  includes a projection  314  (not visible in the figure) that extends outwardly in the direction of the horizontal y-axis  104 . 
     The end stop  300  includes clamp means for clamping together the respective lower pad regions  316 ,  318  of side portions  304 ,  306 . In accordance with this embodiment, the clamp means comprise a hasp-type fastener including a rivet  320  which holds together the lower pad regions  316 ,  318 . In use, the end stop  300  straddles the reclosable fastener  121  and the lower pad regions  316 ,  318  act as a pair of clamps on opposite sides of the reclosable fastener  121 . 
     FIG. 8 illustrates a perspective view of another embodiment of a flexible food bag-type container  400  with quick release latching structure in accordance with the present invention. The container  400  comprises a closure device  402  including first and second fastening strips  404 ,  406  and a slider  408 . As described above in connection with the prior embodiments, the fastening strips  404 ,  406  are adapted to be interlocked between a first end  409  and a second end (not shown). The closure device  402  further includes an end stop  410  disposed proximate the first end  409 . 
     The slider  408  is configured as an inverted, generally u-shaped piece that straddles the fastening strips  404 ,  406  and is mounted to slide back and forth along the longitudinal x-axis  102 . Although not shown, the slider  408  may include inwardly directed bottom tab structure that is effective to prevent the slider from being inadvertently pulled off the fastening strips  404 ,  406 . The slider  408  includes a top portion  412 , a first side portion  414  and a second side portion  416 . The top portion  412  extends a distance above the fastening strips  404 ,  406 . The slider  408  further includes a latch member  418  that extends longitudinally in the direction of the end stop  410  and is elevated a distance above the fastening strips  404 ,  406 . The latch member  418  is provided with a recess  420  along its top surface. 
     The end stop  410  is also configured as an inverted, generally u-shaped piece including a top portion  422 , a first side portion  424  and a second side portion  426 . The lower ends of first and second side portions  424 ,  426  are connected to the sides of the bag either by ultrasonic sealing, heat sealing or by use of a rivet or like mechanical fastening means. The upper ends of the first and second side portions  424 ,  426  extend a distance above the fastening strips  404 ,  406 , which in combination with the top surface  422  defme a cavity  428  sized to receive the insertion of the latch member  418  as the slider  408  is moved into the closed position on the bag. The upper inside wall of the cavity  428  is provided with a downward extending projection  430  adapted to engage within recess  420  of the latch member  418 . The first and second sidewalls  414  and  416  of the slide are cutaway at region  432  adjacent and below the latch member. The cut away portions  432  permit the end stop-facing end of the slider top portion  412  to bend downward upon the application of finger pressure applied to the top portion  412  just aft of the latch member as indicated by the directional arrow A. The downward deflection of the latch member  418  frees the recess  420  from latching engagement with the projection  430  thereby allowing the slider  408  to be freely moved in the opening direction of the bag. As shown, the latch member  418  may further include a locator member in the form of a longitudinally projecting member  440 , which is cooperably received within a corresponding recess  442  provided to the back wall of cavity  428 . 
     FIG. 9 illustrates a perspective view of another embodiment of a flexible food bag-type container  500  with quick release latching structure in accordance with the present invention. The container  500  comprises a closure device  502  including first and second fastening strips  504 ,  506  and a slider  508 . As described above in connection with the prior embodiments, the fastening strips  504 ,  506  are adapted to be interlocked between a first end  509  and a second end (not shown). The closure device  502  further includes an end stop  510  disposed proximate the first end  509 . 
     The slider  508  is configured as an inverted, generally u-shaped piece that straddles the fastening strips  504 ,  506  and is mounted to slide back and forth along the longitudinal x-axis  102 . Although not shown, the slider  508  may include inwardly directed bottom tab structure that is effective to prevent the slider from being inadvertently pulled off the fastening strips  504 ,  506 . The slider  508  includes a top portion  512 , a first side portion  514  and a second side portion  516 . The first side portion  514  includes a latch member  518  having a base end  518   a  connected to the first side portion  514  and a free end  518   b  that extends in the longitudinal x-axis  102 . The latch member free end  518   b  includes a ridge member or projection  520  that extends outwardly in the direction of the transverse y-axis  104 . In similar fashion, the second side portion  516  includes a latch member  519  having a base end  519   a  (not visible in the Figure) connected to the second side portion  516  and a free end  519   b  that extends in the longitudinal x-axis  102 . The second latch free end  519   b  includes a ridge member or projection  521  (not visible in the Figure) that extends outwardly in the direction of the transverse y-axis  104 . 
     The end stop  510  is also configured as an inverted, generally u-shaped piece including a top portion  522 , a first side portion  524  and a second side portion  526 . The lower ends of first and second side portions  524 ,  526  are connected to the sides of the bag either by ultrasonic sealing, heat sealing or by use of a rivet or like mechanical fastening means. The first end stop side portion  524  includes recess structure, in this example hole  528 , sized to receivingly engage the projection  520  of latch member  518  of the slider first side portion  514 . Similarly, the second end stop side portion  526  includes a hole  530  sized to receivingly engage the projection provided to the latch member  519  of the slider second side portion  516 . The latch members  518 ,  519  of the slider  508  are inwardly bendable or deflectable in the direction of the transverse y-axis. 
     The inward deflection of the latch members  518 ,  519  moves the respective outward projections  520 ,  521  out of engagement with the holes  528 ,  530  thereby permitting the slider  508  to be moved in the opening direction of the bag. This embodiment is substantially a reversal of parts of the embodiment shown and described above in connection with FIGS. 2-6. 
     Although several interlocking fastening strip embodiments have been specifically described and illustrated herein, it will be readily appreciated by those skilled in the art that other kinds, types, or forms of fastening strips can alternatively be used without departing from the scope or spirit of the present invention. 
     The interlocking fastening strips may be manufactured by extrusion through a die and may be formed from any suitable thermoplastic material including, for example, polyethylene, polypropylene, nylon, or the like, or from a combination thereof. Thus, resins or mixtures of resins such as high-density polyethylene, medium-density polyethylene, and low-density polyethylene may be employed to prepare the interlocking fastening strips. 
     When the fastening strips are used in a sealable bag, the fastening strips and the films that form the body of the bag may be conveniently manufactured from heat sealable material. In this way, the bag may be economically formed by using an aforementioned thermoplastic material and by heat sealing the fastening strips to the bag. For example, the bag may be made from a mixture of high pressure, low-density polyethylene and linear, low-density polyethylene. 
     The fastening strips may be manufactured by extrusion or other known methods. For example, the closure device may be manufactured as individual fastening strips for later attachment to the bag or may be manufactured integrally with the bag. In addition, the fastening strips may be manufactured with or without flange portions on one or both of the fastening strips depending upon the intended use of the fastening strips or expected additional manufacturing operations. The slits may be cut during the manufacturing of the fastening strips using rollers which contain an appropriately placed knife edge. 
     Generally, the fastening strips can be manufactured in a variety of forms to suit the intended use. The fastening strips may be integrally formed on the opposing sidewalls of the container or bag, or connected to the container by the use of any of several known methods. For example, a thermoelectric device may be applied to a film in contact with the flange portion of the fastening strips or the base portion of fastening strips having no flange portion, to cause a transfer of heat through the film to produce melting at the interface of the film and a flange portion or base portion of the fastening strips. Suitable thermoelectric devices include heated rotary discs, traveling heater bands, resistance-heated slide wires, and the like. The connection between the film and the fastening strips may also be established by the use of hot melt adhesives, hot jets of air to the interface, ultrasonic heating, or other known methods. The bonding of the fastening strips to the film stock may be carried out either before or after the film is U-folded to form the bag. In any event, such bonding may be done prior to side sealing the bag at the edges by conventional thermal cutting. In addition, the first and second fastening strips may be positioned on opposite sides of the film. Such an embodiment would be suited for wrapping an object or a collection of objects such as wires. The first and second fastening strips should usually be positioned on the film in a generally parallel relationship with respect to each other, although this will depend on the intended use. 
     The slider may be multiple parts and snapped together. In addition, the slider may be made from multiple parts and fused or welded together. The slider may also be a one-piece construction. The slider can be colored, opaque, translucent or transparent. The slider may be injection molded or made by any other method. The slider may be molded from any suitable plastic material, such as high-density polyethylene, polypropylene, nylon, acetal, toughened acetal, polyketone, polybutylene terrephthalate, polycarbonate or ABS (acrylonitrile-butadiene-styrene) 
     From the foregoing it will be understood that modifications and variations may be effectuated to the disclosed structures—particularly in light of the foregoing teachings—without departing from the scope or spirit of the present invention. As such, no limitation with respect to the specific embodiments described and illustrated herein is intended or should be inferred. On the contrary, it is intended to cover all alternatives, modifications and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims.