Aesthetically pleasing snap closure for flexible packages with means for facilitating automated application to flexible packages, flexible packages including the same, and apparatus for applying snap closures to flexible packages

A flexible package comprising an integral snap-closure and a method and apparatus for applying the snap closure to the package is disclosed. The snap closure is arranged to enable the repeated opening and closing of a mouth of the package and includes a segmented male closure element and a segmented female closure element that are arranged to snap-fit together. A pair of optional overlay strips may be provided to obscure the male and female closure elements to provide an enhanced aesthetically pleasing package.

BACKGROUND OF THE INVENTION

1. Field of Invention

This invention relates generally to flexible packages, and more particularly to flexible packages for holding products, such as foods, under vacuum therein, and which once opened are arranged to be repeatedly re-opened and re-closed, while keeping the contents fresh.

2. Description of Related Art

Various types of flexible packages for holding particulate materials, e.g., ground or whole bean coffee, chemicals, etc., under vacuum therein have been disclosed in the patent literature and are commercially available today. Examples of such packages are found in the following U.S. Letters patent: U.S. Pat. No. 4,576,285 (Goglio), U.S. Pat. No. 4,705,174 (Goglio), and U.S. Pat. No. 4,913,561 (Beer).

One common type of flexible package for holding goods under vacuum until the package is opened is the so-called “gusseted” package or bag. Typically such a package is formed from a web of flexible stock material, e.g., polyethylene, polyester, polypropylene, metal foil, and combinations thereof in single or multiple plies, into a tubular body, having a face panel, a back panel, and a pair of gusseted sides. Each gusseted side is formed by a pair of gusset sections and a central fold edge interposed between a pair of outer fold edges. The lower end of the bag is commonly permanently sealed, e.g., heat sealed, along a line extending transversely across the width of the bag close to its bottom edge. The top of the bag is commonly sealed transversely across the entire width of the bag in a number of ways to maintain the contents under vacuum until the bag is opened. Such action is frequently accomplished via a readily openable mouth, which when opened provides access to the contents of the bag. For example, in one prior art package the top seal is made peelable by modifying the sealant layer with a peelable coating or incompatible additive. Thus, when the seal is peeled apart the unsealed portions form an open mouth through which the contents of the package may be removed. Another approach to providing an opening or mouth for a flexible package is that of the heretofore identified U.S. Pat. No. 4,705,174 (Goglio). That package includes a peel strip applied to the inner surface of the package below the top edges. The strip provides an air-tight interfacial seal which can be readily peeled apart to provide access to the interior of the package. Another approach to providing an opening or mouth for a flexible package is to score the upper flap of the package by laser or mechanical means through a tear initiation resistant layer(s) of the package structure. In this way the package can be opened by tearing away the scored area to form the package's mouth.

Gusseted bags, particularly those for foods, frequently make use of a plastic coated wire tie to serve as closure for the bag. In particular, the wire tie is designed to close the mouth of the bag after it has been initially opened so that the re-closed bag will keep its contents fresh. Whether or not such wire-tie closures effectively provide a positive means of re-closing a gusseted package is open to debate. Moreover, the effectiveness of such closures is frequently dependent upon the manner in which the wire tie is used. Thus, there is a perception in some quarters of the consuming public that a wire-tie package cannot be re-closed securely enough to maintain product freshness over an extended period of time. Therefore, such packages have not been fully accepted as being truly reclosable.

Non-gusseted flexible packages, such as stand-up pouches, are commercially available and typically include so-called “zipper-type” closures. Examples, of such packages are shown in U.S. Pat. Nos. 5,059,036 (Richison et al.), and 5,147,272 (Richison et al.). These zipper-type closures are generally perceived by the consuming public as providing for a more effective reclosure of the flexible pouch after it has been initially opened than twist or wire tie closures. In fact, zipper-type closures may be more effective than wire-tie closures. At the very least they are easier to use, and not prone to loss or misplacement. Thus, stand-up, flexible pouches with zipper-type closures have gained wide acceptance by the consumer.

While the stand-up, zipper-closure type pouch offers advantages over a gusseted flexible package insofar as actual or perceived reclosability is concerned, its shape does not allow efficient use of case packing and retail shelf space, as does a gusseted package. In addition, the stand-up pouch cannot be stacked readily, if at all.

In U.S. Pat. No. 5,692,837 (Beer), which is assigned to the same assignee as this invention and whose disclosure is incorporated by reference herein there is disclosed a gusseted flexible package having an integrated snap closure for re-closing and resealing the package after it has been initially opened. In particular, that package has an interior for initially holding some product, e.g., whole coffee bean or ground coffee, under vacuum, and which includes a mouth portion arranged to be peeled open to provide access to the contents of the package. The package is formed of a flexible material and includes a front panel, a rear panel, and a pair of opposed side gussets. The panels and gussets each include a top portion, which between them define the package's mouth. A peelable closure is provided within the mouth. A snap closure is provided above the peelable closure. The package is arranged to be sealed under vacuum, with the peelable closure maintaining the vacuum within the package until it is peeled open. The snap closure comprises a pair of snap strip members secured to respective portions of the front and rear panel. The snap strip portions are arranged to be releasably snap fit together with portions of the closure extending through opening in the side gussets, so that the snap strip portions can be opened and reclosed after the peelable closure has been peeled open in order to provide repeated access to the interior of the package, while minimizing the ingress of air into the package when it is closed.

Other references involving closures for packages are found in U.S. Letters patent Nos.: U.S. Pat. No. 4,988,216 (Lyman), and U.S. Pat. No. 5,037,138 (McClintock et al.), and in Japanese Application 6127557 (5/1994), and United Kingdom Patent 1,008,068 (10/1965)

In U.S. Letters Pat. No. 6,082,897 (Galomb) and U.S. Pat. No. 6,132,089 (Galomb et al.), there are disclosed snap closures for a flexible, gusseted package and a flexible gusseted package including the closures. The package includes a mouth portion arranged to be opened to provide access to the contents of the package. The package is formed of a flexible material and includes a front panel, a rear panel, and a pair of opposed side gussets. The panels and gussets each include a top portion, which between them define the package's mouth. The package's mouth is initially sealed but arranged to be opened, e.g., peeled apart. The snap closure enables the resealing of the mouth of the package and is made up of a pair of elongated elements, one of which includes a tongue extending along the length of it. The other element includes an undercut groove extending along the length of it. The elements are arranged to be pressed together, whereupon the tongue of the one element enters the groove of the other element with portions of the panels and side gussets tightly interposed therebetween. The closure elements may be longitudinally rigid or may be segmented to flex in the longitudinal direction to facilitate opening. Moreover, the closure elements may be a part of the package or separate components for use therewith. When the closure is part of the package the closure elements may be secured to the panels via an adhesive covering their entire inner surface. In any case when the closure is utilized it recloses the mouth of the package to preclude or minimize the ingress of air into the package.

While the inventions of the aforementioned prior art are suitable for their intended purposes, a need still exists for snap closures for use on gusseted packages and for gusseted packages which include snap closures which are easy to use, effective and which provide an aesthetically pleasing appearance.

BRIEF SUMMARY OF THE INVENTION

A flexible package having an interior for holding material therein. The package is formed of a flexible material and comprises an integral snap-closure and first and second panels. The panels are connected to each other and each of the panels has an upper end portion, an inner surface and outer surface which conjoin to form a mouth for the package between the inner surfaces of the panels. The package's mouth is openable to provide access to the interior of the package. The snap closure is arranged for reclosing and sealing the mouth and comprises a male closure element and female closure element.

The male closure element is an elongated member comprising a pair of flanges, a pair of walls projecting upward from the flanges and defining a channel therebetween and a bulbous portion interconnecting the pair of walls. The bulbous portion has a plurality of transverse slits extending through it and partially into the walls at longitudinally spaced locations along the male closure element to enable the male member to bend more easily along its length. The male closure element has an outer surface and an inner surface. The inner surface of the male closure element is secured to the outer surface of one of the panels adjacent the mouth, and with portions of the panel extending about the bulbous portion.

The female closure element is an elongated member comprising a generally C-shaped portion having an elongated edge and a flange projecting along the edge. The female closure element has and outer surface, an inner surface and a plurality of slits extending partially through it at longitudinally spaced locations along it. The inner surface of the female closure element is secured to the outer surface of the other of the panels adjacent the mouth of the package. The bulbous portion of the male closure element is arranged to snap-fit into the C-shaped portion of the female closure element, with portions of the panels tightly interposed therebetween to close the mouth of the package to prevent the ingress of air into the package through the mouth.

DETAILED DESCRIPTION OF THE INVENTION

Referring toFIG. 1, there is shown at20inFIG. 1a flexible package constructed in accordance with this invention. The package20basically comprises a gusseted bag22and a re-sealable closure24. The bag20is arranged to hold any material, e.g., coffee beans, ground coffee, chemicals, etc., for dispensing therefrom. The bag or package22is formed of a web of any suitable, flexible material in a manner to be described hereinafter.

Turning now toFIGS. 1–3it can be seen that package22basically comprises a front wall or panel26, a rear wall or panel28, a pair of identical gusseted sides30and32, a top end portion34, and a bottom end portion (not shown). The top end portion34of the package terminates in a top marginal edge36. In a similar manner the bottom end portion has a bottom marginal edge (not shown). If desired, a one-way venting valve (not shown) may be included in any suitable portion of the package to enable gases which may be produced by the material(s), e.g., coffee, contained within the sealed package to vent to the ambient air without air gaining ingress to the package's interior.

The front panel26, rear panel28, and the two gusseted sides30and32of the package are all integral portions of a single sheet or web of the flexible material, of single or multiple plies or layers, which has been folded and seamed to form a tubular body. One exemplary useful flexible material for the package22is a laminated web of flexible packaging material commercially available from Fres-co System USA, Inc., of Telford Pa., the assignee of this invention. That material comprises a 48 gauge polyester layer, ink, an adhesive layer, a 28 gauge aluminum foil layer, another adhesive layer, a 60 gauge nylon layer, another adhesive layer, and a 300 gauge easy open sealant layer. When a web of such material is formed into the tubular body for the package the polyester layer serves as the outer surface of the package, with the easy-open sealant layer being the inner surface of the package. Any other flexible packaging materials can be used in this invention.

As can be seen clearly inFIG. 1, the closure24is located in the top end portion34of the package. The details of the closure24will be described later. Suffice it for now to state that the closure24includes two elements or strips24A and24B (FIG. 2), each of which extends a desired distance across the width of the package's panels24and26, with portions secured on the outer surface thereof in the top portion of the package below its top edge36. As will be seen later the strip24A is a male-like member while the strip24B is a female-like member. The male-like member24A is arranged to releasably snap-fit into the female member to effect the closing and opening of the package, as will be described later.

The package20is arranged to be initially hermetically sealed closed along a transverse seal line38, after it has been filled and vacuumized. The seal line38is located at the situs where the closure strips will be secured and may be permanent or openable (e.g., peelable) and may be formed in any conventional manner. The seal line may be located at any location either above, below, or aligned with the closure24(as shown). In any case the package20can be readily opened by merely grasping portions of the package's panels at the top edges and pulling them apart to cause the peelable seal line to open, thereby forming a mouth for the package to provide access to the interior of the package. If the seal line is permanent it should be located above the closure22with some space between it and the closure24so that the package can be severed along a line between the seal line and the closure to thereby form the package's mouth. In either case, the seal line38extends across the width of the package22and seals the inner surfaces of the abutting front and rear panels to each other between the inner fold lines of the gussets30and32, respectively, while sealing the outer marginal portions of the front panel26to the portions of the gusseted sides contiguous therewith, while also sealing the outer marginal portions of the rear panel28to the portions of the gusseted sides contiguous therewith, as is conventional. Thus, the seal line38serves to isolate the contents of the package from the ambient atmosphere once the package is sealed. If the seal line38is peelable, it may be formed by the appropriate heat sealing of the abutting easy-open sealant layer portions forming the inner surface of the package22. Alternatively, the peelable seal line38can be formed in any other conventional manner, e.g., the use of peelable sealing strips like that disclosed in the aforementioned Goglio patents.

When the package22is filled, vacuumized, and sealed its contents, e.g., whole bean coffee (not shown), will be kept isolated from the ambient air by the seal line38. The closure22is also preferably closed, i.e., its strips24A and24B being interconnected if the closure is located at the seal line. If desired, the top portion34of the package may be folded down to form a flap (not shown). The flap may, if desired, be held in place by a strip of adhesive tape (not shown) or some other adhesive means, so that the package is “brick-like” in shape to facilitate stacking or storage.

In order to gain ingress into the package so that some or all of its contents can be removed, if the package has a peelable seal line38, the portions of the front and rear panels of the package contiguous with the top marginal edges36of the package are grasped and pulled apart. This action peels open the seal line38, while also disconnecting or separating the two strips24A and24B (to be described later) making up the closure24, to open the mouth of the package. The contents of the package can then be poured or otherwise removed through the package's mouth. If the package includes a non-openable seal line, e.g., a permanent heat seal, then the package can be severed below the heat seal line and above the closure24. The newly formed top edge of the front and rear panels of the package which were formed by severing action can then be grasped and pulled apart to separate and disconnect the two strips24A and24B to open the mouth of the package.

The inclusion of the closure24as a part of the package (as in the embodiment ofFIG. 1) enables the mouth of the package to be re-closed or resealed after some of the package's contents have been removed. Thus, the package and closure of the subject invention enable one to keep the remaining contents of the package fresh, i.e., generally isolated from the ambient atmosphere. It should be noted that the closure24can be a separate item not initially secured to the package. In particular a closure can be constructed similar to closure24and arranged to be secured to a conventional gussetted flexible package.

As mentioned above, the closure24comprises the pair of strips24A and24B which are arranged to releasably mate with each other. Each of the strips is an elongated member formed of a plastic material, e.g., high or low density polyethylene or polypropylene or some other material which is slightly flexible to enable it to be bent out of its original shape by the application of force thereto, but which returns to its original shape after removal of that force. Each strip is arranged to be fixedly secured, e.g., welded or permanently adhesively secured to the outer surface of the top portion of a respective one of the panels26and28of the package22and across the full width of the panel.

The construction of the strip24A can best be seen inFIGS. 2–4and basically consists of an elongated tongue-shaped member. In particular, the strip24A includes an elongated planar upper flange section40(FIGS. 3 and 4), an elongated planar lower flange section42that is coplanar with the upper flange and an intermediate projecting bulbous or tongue section44and a pair of intermediate walls46and48. The tongue section includes a generally planar top wall50and a pair of undercut sidewalls52and54which merge with the intermediate flanges46and48, respectively. The intermediate walls46and48are each linear and planar and are spaced from each other to form a channel56. The bulbous tongue section44is hollow and in communication with the channel56. The flanges40and42each include angularly oriented portions58and60which merge with the intermediate walls46and48, respectively, thereby forming a flared entryway to the channel56. The hollow nature of the bulbous tongue section provides several advantages over the closure strips of my aforementioned U.S. patents: U.S. Pat. Nos. 6,082,897 and 6,132,089. First, it makes the wall thickness about the tongue section more consistent with the rest of the male closure strip, making it easier to control the dimensional tolerance of the profile of the supply material used to form the strip more consistent. This results in better and more consistently functioning parts. Second, it reduces the likelihood that a spline used in automated apparatus for applying the closure strip to a bag (such as that to be described later in this application), will meet unwanted resistance.

As best seen inFIGS. 2–4and6a plurality of equidistantly spaced, transverse slits62extend through the bulbous tongue44and partially into the intermediate walls46and48, terminating well short of the flanges40and42. The slits62serve to enable the strip24A to bend or flex longitudinally, i.e., the section of the strip on either side of a slit62may flex with respect to each other to enable the strip24A to be bowed, as will be described later. The flange40of the male strip24A is fixedly secured to the outer surface of the front panel26via any suitable securement means e.g., a hot melt adhesive64. In a similar manner the flange42of the female strip24B is fixedly secured to the outer surface of the front panel26. In order to ensure that the adhesive64does not run out or off of the flanges40and42, thereby detracting from the appearance of the package, the inner surface at the free end of each flange includes an upwardly projecting nub66. The nubs act as barrier walls to the egress of the hot melt adhesive64. The adhesive may extend over the inner surfaces of the flanges40and42, the intermediate sidewalls46and48and the bulbous tongue44thereby securing the front panel26to those portions of the strip24A as shown inFIGS. 3 and 4. Alternatively, the adhesive64may only be located on the flanges40and42and partially on the intermediate sidewalls46and48, as shown inFIG. 5. In either case the front panel is held in tight engagement with the inner surface of the strip24A, although in the embodiment ofFIG. 5, combined thickness of the tongue portion44and the panel26will be less than in the embodiment ofFIG. 3since there will be no adhesive at the interface of the tongue portion44and panel26.

Other types of adhesives can be used to secure the male strip24A to the panel26of the package. For example, an adhesive can be extruded onto the strip24A during the fabrication of the strip. Such action can be accomplished by a co-extrusion process so that the adhesive surface is formed at the same time that the strip is formed. Alternatively, the strip can be formed and the adhesive then extruded on the strip. As should be appreciated by those skilled in the art, if the adhesive is extruded onto the strip the use of the nubs66may be obviated, since the adhesive will be less likely to spill out onto the portions of the package contiguous with the strip, than if a hot melt or other liquid adhesive is used. It should be pointed out that any type of adhesive can be used. In fact the strip24A can be secured to the panel using non-adhesive securement techniques, e.g., thermal welding, ultrasonic welding, etc. While the nubs may be eliminated from the strips as a means of preventing spillage of adhesive off of the strips onto the panels of the package if the strips are provided with an adhesive pre-applied thereto, e.g., an extruded adhesive, the nubs may still be of some value to cooperate with feeding devices (to be described later) for carrying strips through automated application apparatus as will be described later.

The construction of the strip24B will now be described. As can best be seen inFIGS. 2–5the strip24B is an elongated channel or recess-shaped member. In particular, the strip24B includes an elongated planar lower flange section68and a generally C-shaped upper section70defining a groove or recess72therein (FIG. 4). The free edge74of the upper section70is in the form of a rounded bead. The lower flange section68merges with the C-shaped upper section in a bead76. The upper end of the lower flange section is of a reduced thickness to form a hinge78enabling the C-shaped section to flex somewhat with respect to the flange68.

The female strip24B also includes plural equidistantly spaced transverse slits62therein. The slits62of the female member are preferably spaced from each other by the same spacing as the slits62of the male member24A. The slits62of the female member extend partially into the C-shaped upper section70. The slits62of the female member24B serve the same general purpose as the slits62of the male member.

The female strip24B is secured to the outer surface of the bag's rear panel28in a similar manner to the securement of the male strip24A to the panel26. To that end a hot melt adhesive54is applied to the entire inner surface of the strip24as shown inFIGS. 3 and 4. A nub66is located on the inner surface of the flange68at the free edge thereof to act as a stop to prevent leakage or spillage of the hot melt or other liquid adhesive onto the portions of the panel28contiguous with the strip24B.

With the panel28secured to the inner surface of the strip24B, the hollow interior or recess72of the C-shaped section70is arranged to releasably receive the tongue section44and the associated portion of panel26therein. In particular the tongue shaped section44and the panel portion covering it is enabled to snap fit within the recess72as shown clearly inFIG. 3. The size of the recess72in the C-shaped section70of the female member24B is selected so that it is sufficiently large to accommodate the thickness of the panel28and the intermediate adhesive54, yet enable the tongue section44with the adhesive54and the panel26to readily snap in to it to securely close the package's mouth, as shown inFIG. 3, yet enable the tongue section with the adhesive and the panel26to snap out of it to open the package's mouth, as shown inFIG. 4.

If desired the adhesive54of the strip24B can be confined to only the area of the C-shaped section70between the beads74and76as shown in the embodiment ofFIG. 5.

It must be pointed out at this juncture that the strips24A and24B can be mounted and secured to the rear panel28and front panel26, respectively, instead of to the front panel26and rear panel28, respectively, as in the embodiment shown inFIG. 1. Thus, the embodiment of package22shown herein is merely exemplary.

The material forming the strips is in and of itself somewhat elastic and/or flexible so that with the addition of the slits62the tongue portion44of the strip24A can snap-fit into the groove or recess72of the strip24B, and to be locked therein against accidental disconnection, yet which enable the tongue to exit that recess when the strips are pulled apart.

Once the package has been initially opened and a portion of its contents removed, the package can be readily resealed by use of the closure24to prevent or minimize the ingress of air into the interior of the package through its mouth. This action is accomplished by merely bringing the strips24A and22B into a confronting relationship, like shown inFIG. 4. Then the strips can be squeezed together to cause the tongue to snap into the groove carrying with it contiguous portions of the front panel26and side gussets30and32. During this action portions of the front panel26and contiguous side gussets that are bent around the tongue to be carried into engagement with opposed portions of the rear panel28and contiguous side gussets30and32that are within the recess in strip24B. Notwithstanding their flexibility, the strips24A and24B are substantially rigid so that when they are snapped together as just described, the confronting portions of the tongue and groove serve to sandwich the front panel26, rear panel28, and side-gussets30and32tightly therebetween, thereby producing a substantially air-tight seal.

The fact that each of the strips includes flanged portions and other portions projecting from the flanged portions tends to reinforce the strips and keep them linear to further ensure that the mouth of the package is sealed closed when the strips are snap connected to each other. Thus, when the strips24A and24B are snapped together the contents of the bag22are effectively isolated from the ambient surroundings so that it can be kept fresh over an extended period of time.

The package can be readily opened at any time by merely snapping apart (disconnecting) the two strips24A and24B. In order to accomplish that action and since the strips are somewhat flexible and resilient, the user of the package can readily grasp any portion of the front panel of the package contiguous with its top edge between the thumb and forefinger of one hand, and grasp any portion of the rear panel of the package contiguous with its top edge between the thumb and forefinger of the other hand to pull the panels apart and to separate the strips. Alternatively, the user can directly grasp one of the strips between his/her thumb and forefinger of one hand and the other strip between the thumb and forefinger of the other hand to pull the strips apart. In either case this action unsnaps the closure, i.e., causes the tongue of strip24A to snap out of the groove of strip24B, thereby freeing the panels and providing access to the interior of the package through its mouth.

As should be appreciated by those skilled in the art the tongue portion44of the male closure strip24A, i.e., the portion including the transversely extending slits62, is completely covered by the panel26when the strip24A is secured to that panel. Thus, the only visible portions of the male closure member are the two coplanar flanges40and42. Accordingly the presence of the male closure element does not detract from the aesthetics of the package.

In the event that it is desired to hide the closure24from view, a pair of overlay or cover strips can be used to hide the respective strips or elements of the closure. In particular, two optional elongated strip80and82may be provided. These optional overlay strips are shown by the phantom lines inFIG. 1and by the solid lines inFIG. 2. As can be seen the overlay strip80is used to obscure either closure strip24A, while the other overlay strip82is used to obscure the closure strip24B. It should be clear that the overlay strip82can be used to obscure the closure strip24A, while the overlay strip80is used to obscure the closure strip24B. To achieve that end, both of the strips are of the same construction. In particular, each of the strips is formed of a flexible sheet material and each is of a sufficient width and height to cover the entire length of its associated closure strip. Each overlay strip is adhesively secured by an adhesive layer84to the portions of the panel contiguous with the associated closure strip. If desired the overlay strips can be formed of the same material as that making up the panels of the package, and may also be of the same color, surface texture, and bear the same indicia (if any) as the material of the panels. By so doing, the package's panels will appear uninterrupted visually, i.e., the package will appear as if it didn't include any closure members. The adhesive84can be a hot melt adhesive or any other suitable type of adhesive. The overlay strips can be secured so that they closely conform to the closure strips over which they are placed or can be secured so that they merely bridge those strips. For example, with respect to the male closure strip24A, the overlay strip80may be in intimate engagement with the flanges40and42and wall portions58and60of the strip24A so that a portion of the overlay strip extends to the channel56as shown by the phantom lines inFIGS. 3 and 4. Alternatively, the overlay strip80may merely be secured to the portions of the bag panel26contiguous with the strip24A and engaging the flanges40and42, but not engaging the wall portions58and60forming the entryway to the channel56. In so doing the overlay strip will remain generally planar, with a generally planar portion bridging over the tapered entryway to the channel56. This latter arrangement not only obscures the male closure strip24A from being seen, but also has the effect of obscuring its very existence, since the shape of the underlying closure strip24will not be visible. With respect to the female closure strip24B, the overlay strip82may be in intimate engagement with the entire outer surface of the C-shaped portion70and with the entire outer surface of the flange68as shown by the phantom lines inFIGS. 3 and 4. Alternatively, the overlay80strip may merely be secured to the portions of the bag panel28contiguous with the strip24B and engaging only a portion of the C-shaped portion70so that the overlay strip82appears to be bowed gently, simulating a generally planar appearance, thereby obscuring not only the closure strip24B, but the shape of the closure strip.

As should be appreciated by those skilled in the art the use of overlay strip provides advantages in addition to concealment of the closure strips and aesthetics of the finished bag. In particular, the overlay strips help to secure the closure strips to the bag. They also serve to protect the bag's panels from puncture or other damage in the event that the corners or edges of the closure may be sharp. In addition, the cover strip would also serve to protect the user in such an event. As should be appreciated by those skilled in the art to achieve these advantages the overlay strips need not be opaque. Thus, it is contemplated that the overlay strips be formed of transparent or translucent materials, if obscuring the closure strip is not a concern.

The male closure strip24A and the female closure strip24B are preferably both formed of the same material, e.g., extruded plastic, and are preferably provided in indeterminate lengths, e.g., reels or linear sections, to apparatus for applying the strips to a filled and sealed bag22. To that end, as will be described in detail in the portion of this specification to follow, the indeterminate length of material making up the male closure strip24A and the indeterminate length of material making up the female closure strips24B are each severed into the appropriate length for use on the package, with the length of the severed pieces depending upon the width of the mouth of the package. Moreover, in accordance with one preferred aspect of this invention the strips24A and24B are applied to a series of filled and sealed packages22by automated equipment. One exemplary embodiment of such automated equipment is the applicator apparatus designated by the reference number100and shown inFIGS. 7–9. The apparatus100is arranged to make use of a supply of extruded plastic for the male closure strip24A and a supply of extruded plastic for the female closure strip24B. The apparatus100includes a pair of feeder devices102and104(to be described later) for carrying the indeterminate length strips to respective cutters106and108(also to be described later) to sever the indeterminate length strips into respective closure strips24A and24B. The apparatus also includes respective adhesive applicator devices110and112to apply an adhesive on the desired portions of the respective closure strips24A and24B. The apparatus also comprises a pair of respective carrier heads114and116, including respective track sections118and120, for receiving the closure strips24A and24B, respectively, which now have adhesive thereon, and for carrying those strips into engagement with the panels26and28, respectively, of a filled and sealed bag22. The coordination of all of the operations of the apparatus is effected by any suitable controller (not shown), such as a microprocessor. That controller provides electrical signals to various motors, actuators, etc., making up the device so that a series of bags22that have been filled and sealed may be carried by a conveyor (not shown) to the apparatus100, whereupon snap-closures24constructed in accordance with this invention can be applied to each of those bags.

As will be appreciated from the discussion to follow each closure strip24A and24B includes at least one portion that facilitates the automated movement of it through the apparatus100for securement to the bag22. Those portions constitute the flange40and the channel56of the male closure strip24A and the flange68of the female closure strip24B. Before describing those portions and their interaction with components of the apparatus100, a discussion of the components making up the apparatus100is in order. To that end, as best seen inFIG. 7an indeterminate length124A of material for forming the closure strip24A is provided from a supply (not shown). The source can comprise a reel of material that is extruded to the shape of the male closure element or can be plural strips of such extrusions. The extrusions may be pre-slit with the equidistantly spaced transverse slits62or may be unslit for slitting by the apparatus100. An advantage of pre-slitting the source material is that it can be readily reeled up into a supply reel for ready use with the apparatus. In the exemplary embodiment shown the extrusions of source material for forming both the male and female closure strips are not pre-slit (i.e., are unslit) and are arranged to be slit by the apparatus100and in particular a pair of slicing heads122and150to be described later. If the source material is pre-slit, the apparatus100need not make use of slicing heads122and150to form the transverse slits62in the male and female extrusions, since such slits will already be present.

In the exemplary embodiment shown, the source material for the male closure strip is of the identical cross-sectional shape of the strip24A, but does not include the transverse slits62cut therein. The source material124A may be provided from a reel or a reservoir of long sections to the feeder device102. The feeder device102basically comprises a block (to be described later) through which a channel (not shown) passes. The source material is arranged to be introduced into this channel and then fed to downstream components for severing to form the male closure strip24A and subsequent application to the panel26of the bag.

Located immediately adjacent the upstream end of the feeder device102is a slicing head122. The head basically comprises a block126holding a linear blade128. The head is arranged to be reciprocated towards and away from the source material124A by means (not shown). This action has the effect of forming a transverse cut or slit in the source material. That slit forms one of the heretofore described transverse slits62. The operation of the slicing head is coordinated with the feeder device102, to form plural equidistantly spaced transverse slits62in the source material. It should be pointed out at this juncture, that other types of slicing heads, e.g., a rotary blade, may be used to form the slits62.

The movement of the source material through the apparatus so that it can have the slits62cut therein and so that the resulting material can be severed to form the male closure strip24A is accomplished by the heretofore identified feeder device102. To that end, the leading end of the source material124A for forming the strip24A, and which has just been severed by the blade128, is introduced into a feeder device102. The feeder device102basically comprises a block130through which a channel (not shown) passes. The channel has a cross-sectional shape to accommodate the source material124A. The block130also includes a notch132that is in communication with the channel passing through the block and is located so that a portion of the underside of the source material124A is exposed. A drive roller134is located at the notch132to frictionally engage the underside of the source material124A, e.g., the underside of its flange40. The drive roller134is driven by means (not shown) to cause it to rotate in the clockwise direction as shown inFIG. 7. The rotation of the drive roller134thus carries the supply material124A through the feeder device102. If desired the drive roller may be located so that it engages a different portion of the supply material, e.g., it may be located and arranged to engage the nub66on one of the flanges.

Disposed immediately adjacent the downstream end of the feeder device block130is the heretofore identified cutter106. The cutter106basically comprises a block136holding a linear blade138. The cutter106is arranged to be reciprocated towards and away from the source material124A by means (not shown). This action has the effect of severing an upstream portion of the supply124A from the remainder of the supply to form the strip24A. The length of the supply material that is fed upstream of the cutter106is determined by the width of the mouth of the package22onto which the male closure strip24A is to be applied. That length of supply material is introduced into the heretofore identified track118of the carrier head114. To that end the carrier head is located immediately upstream of the cutter106. The details of the track118and the carrier head114will be described later. Suffice it for now to state that the feeder device102feeds a desired length of the supply material124A into the track118and is coordinated with the cutter106so that when that track is filled (as shown inFIG. 7) the closure strip24A will be of the desired length and can be severed from the remaining supply material124A.

Located immediately upstream of the cutter head106and above the downstream end of the track118is the heretofore identified adhesive applicator110. The adhesive applicator can be any type of device, e.g., a pair of glue guns, for applying a hot melt adhesive64onto the flanges40and42of the now cut male closure strip24A. It should be noted that other types of adhesives can be used. If so, any type of adhesive applicator suitable for use with such alternative adhesives can be used and located immediately upstream of the cutter106in lieu of the applicator110. In fact, it is contemplated that the apparatus100can be used with supply material124A having an adhesive pre-applied to its flanges. For example, it is contemplated that the flanges40and42of the supply material124A include an adhesive that has been extruded thereon so that no adhesive applicator is required of the apparatus100. In such alternative embodiments, the adhesive can be applied as a co-extrusion when the supply material124A is made, or can be extruded onto its flanges after the extrusion of the material124A. As will be appreciated by those skilled in the art the use of an extruded adhesive on the flanges of the supply material124A has the advantage of eliminating or at least minimizing the chances that the adhesive will spill off of the strip's flanges onto the contiguous portion of the bag panel26to which it is secured, thereby resulting in a more consistently aesthetically pleasing appearance for the bag22. Moreover, if an extruded adhesive is used the nubs66on the flanges40and42(provided to prevent the hot melt adhesive from spilling off the flanges) may be eliminated.

The track118with the adhesive bearing male closure strip24A located therein basically comprises a pair of elongated flanged jaws140and142which are disposed adjacent one another on the carrier head114. The jaws are movable with respect to each other (by means, not shown) and form a channel therebetween having a cross-sectional shape to accommodate the male closure strip24A therein. The jaws forming the track118are arranged to be opened slightly to enable the strip24A of material to be slid down the channel between them by the operation of the feeder device102. Once the strip24A is in place in the track, the jaws are brought closer together so that the male closure strip24A is held therein. A slot or entry-way144to the strip-holding channel is provided between the jaws140and142. A spline146(FIG. 8) forming a portion of the carrier head114extends through the slot144so that it can extend into the channel56of the supply material124A as that material is fed down the track118to be severed to form the male closure strip24A. The disposition of the spline in the channel56facilitates the movement of the supply material124A down the track and prevents any deformation thereof. To that end the spline is a thin member mounted on the carrier head114and having a thickness that is slightly less than the width of the channel56in the supply material124A. A stop148is located at the upstream end of the jaws140and142to ensure that the length of supply material introduced into the track118is precisely the desired length of the male closure strip24A, i.e., it bridges the upstream end of the channel to prevent the upstream end of the supply material124A from exiting the track118.

Once the male closure strip has been severed from the supply material124A and has the adhesive64applied thereto it is ready to be carried into engagement with the panel26of the bag22. This action will occur at the same time that the female closure strip24B is carried into engagement with the panel28of the bag. However, before describing these operations, a description of the formation of the female closure strip24B is in order.

The female closure strip24B is formed at the same time as the male closure strip by similar portions of the apparatus100as that described heretofore with respect to the male closure strip. To that end as best seen inFIG. 7an indeterminate length124B of material for forming the closure strip24B is provided from a supply (not shown). That source material is of the identical cross-sectional shape of the strip24B, and in this exemplary embodiment does not include the transverse slits62cut therein. The source material124B may be provided from a reel or a reservoir of long sections to the feeder device104. The feeder device104is similar to the feeder device102and includes a channel into which the source material124B is arranged to be introduced and then fed to downstream components for severing to form the female closure strip24B and subsequent application to the panel28of the bag.

Located immediately adjacent the upstream end of the feeder device104and below the incoming supply material124B is a slicing head150. The slicing head150is constructed similar to slicing head122and includes a block152holding a linear blade154. The slicing head150is arranged to be reciprocated towards and away from the source material124B by means (not shown) to form a transverse cut or slit in that source material. That slit forms one of the heretofore described transverse slits62. The operation of the slicing head106is also coordinated with the feeder device104, to form plural equidistantly spaced transverse slits62in the source material124B. As discussed above, other types of slicing heads, e.g., a rotary blade, may be used to form the slits62.

The movement of the source material124B through the apparatus for slitting and cutting to form the female closure strip24B is accomplished by the heretofore identified feeder device104. In particular, the leading end of the source material124B for forming the strip24B, and which has just been sliced by the blade154, is introduced into a feeder device104. The feeder device104is similar to feeder device102and basically comprises a block156through which a channel (not shown) passes. The channel is of a cross-sectional shape to accommodate the source material124B. The block156also includes a notch158that is in communication with the channel passing through the block and is located so that a portion of the underside of the incoming source material124B is exposed. A drive roller160is located at the notch158to frictionally engage the underside (inside surface) of the flange68of the source material124B. The roller160is driven by means (not shown) to cause it to rotate in the clockwise direction, whereupon the roller carries the material124B through the feeder device104. If desired, the drive roller may be located so that it engages a different portion of the supply material, e.g., it may be located and arranged to engage the nub66on the flange68. Disposed immediately adjacent the upstream end of the feeder device block156is the heretofore identified cutter108. The cutter108is similar to cutter106and basically comprises a block162holding a linear blade164. The cutter108is arranged to be reciprocated towards and away from the supply material124B by means (not shown) to sever the upstream portion of the supply material124B from the remainder of it to form the female closure strip24B. The length of the supply material124B that is fed upstream of the cutter108is determined by the width of the mouth of the package22and is introduced into the heretofore identified track120of the carrier head116. The track120is similar to the track118described above. The feeder device104feeds a desired length of the supply material124B into the track120and is coordinated with the cutter108so that when that track is filled (as shown inFIG. 7) the female closure strip24B will be of the desired length and can be severed from the remaining supply material124B.

Located immediately upstream of the cutter head108is the heretofore identified adhesive applicator110. That device is similar to applicator110(except that there is only one) to apply a hot melt adhesive64onto the inner surface of the C-shaped portion70and the associated flange68of the now cut female closure strip24B. Other types of adhesives can be used for the female closure strip, if desired. If so, any type of adhesive applicator suitable for use with such alternative adhesives can be used and located immediately upstream of the cutter108. In fact, as discussed with reference to the male closure strip24A, it is contemplated that the apparatus100can be used with supply material124B having an adhesive pre-applied to its interior surface. For example, it is contemplated that the interior surface of the C-shaped portion of the supply material124B and the flange portion68of that supply material include an adhesive that has been extruded thereon so that no adhesive applicator is required of the apparatus100. In such alternative embodiments, the adhesive can be applied as a co-extrusion when the supply material124B is made, or can be extruded onto the supply material after it has been extruded into shape. The extrusion of the adhesive onto the supply material124B offers the same advantages as discussed above with respect to extruding an adhesive on the supply material124A.

The track120basically comprises a pair of elongated jaws166and168which are disposed adjacent one another on the carrier head116. The jaws form a channel therebetween having a cross-sectional shape to accommodate the female closure strip24B therein as shown inFIG. 7. The jaws are arranged to be opened slightly to enable the supply material124B to be slid therealong to form the female closure strip24B. A stop170is located at the upstream end of the jaws166and168to make sure that the length of supply material124B introduced into the track120is precisely the desired length of the female closure strip24B. The jaws are arranged to be closed to hold the female closure strip therein so that it can be applied to the bag. As mentioned above, this action occurs at the same time that the male closure strip24A is carried into engagement with the panel26of the bag.

In the exemplary embodiment of apparatus100shown herein the two tracks118and120into which the male and female closure strips24A and24B, respectively, are introduced are disposed horizontally. The bag22to which those closure strips has already been filled and its mouth sealed by filling and sealing apparatus (not shown). Such filling and sealing apparatus may be any conventional machine. The filled and sealed bags exiting from the filling and sealing machinery are typically disposed on a conveyor and are oriented so that their front and rear panels26and28are disposed vertically. Accordingly, the carrier heads114and116of the applicator apparatus100are arranged to pivot the tracks118and120holding the closure strips from the horizontal orientation shown inFIG. 7to a vertical orientation shown inFIG. 8, whereupon the male closure strip24A is disposed in a confronting relationship to the bag panel26adjacent the location of the bag's mouth, while the female closure strip is disposed in a confronting relationship to the bag panel28adjacent the location of the bag's mouth.

The two carrier heads are of similar construction. In particular, the carrier head114basically comprises an arcuate guide track172(FIG. 8) through which a pivotable piston actuator174extends. The track172is in the form of a 90 sector of a circular arc. The upper end of the track is oriented in a horizontal plane and the lower end of the track is oriented in a vertical plane. The piston actuator174is an elongated member from which a an elongated piston shaft176is arranged to be pneumatically extended under the control of the apparatus controller. The top end of the piston shaft176is fixedly secured to a guide block178. The guide block178is arranged to slide along the arcuate track172. A plate180is fixedly secured to the guide block and supports the two jaws140and142forming the track118thereon. A pivot pin182extends through a middle portion of the piston actuator. The piston actuator is arranged to be pivoted by means (not shown) about the pin182from a vertical orientation shown by full lines inFIG. 7to a horizontal orientation shown by phantom lines in that figure. When the piston actuator is in the vertical orientation the track118is oriented horizontally and is ready to receive the male closure strip24A. In order to secure the male closure strip onto the panel26of the bag22once the closure strip has been formed and had its adhesive applied thereto, the carrier head114of the apparatus100operates, whereupon the piston actuator174is pivoted under control of the apparatus controller to bring the track118bearing the male closure strip24A to the vertical orientation shown by the phantom lines inFIG. 8. At the same time that this occurs the carrier head116is operated to bring the track120bearing the female closure strip124B into its vertical orientation to secure it to the bag panel28. As mentioned above, the carrier head116is constructed similarly to the carrier head114. Thus, in the interest of drawing simplicity and brevity the various components making up the carrier head116will be given the same reference numbers as those components making up the carrier head114and the details of their construction and operation will not be reiterated.

As best seen inFIGS. 7 and 8the lower end of the track172of the each carrier head114and116includes an elongated transversely extending cavity184. When the piston actuator172carrying the track118is pivoted to the horizontal orientation shown in phantom lines inFIG. 8the guide block178is located in that transversely extending cavity. In a similar manner when the piston actuator172carrying the track120is pivoted to the horizontal orientation, the guide block178of the carrier head114is located in its transversely extending cavity184. The applicator apparatus100is now ready to bring the male and female closure strips24A and24B, respectively, into engagement with the bag's panels26and28, respectively. This action is shown inFIG. 9. To that end the controller of the apparatus causes the piston actuators174of the two carrier heads114and116to extend their associated piston rods176from the actuators. This action moves the guide block178out of the cavity184of the carrier head114and brings the male closure member24A located in the track118into tight engagement with the outer surface of the bag panel26, whereupon the adhesive64on the male closure strip secures it in place. At the same time the guide block178of the carrier head116is moved out of the cavity184by the extension of its piston rod176to bring the female closure member24B located in the track120into tight engagement with the outer surface of the bag panel28, whereupon the adhesive64on the female closure strip secures it in place. This completes the application of the closure24to the bag22. The piston rods are then automatically retracted to bring the guide blocks178into their respective cavities184of their respective carrier heads. Once this has occurred the piston actuators are pivoted to their vertical orientation, thereby carrying the tracks118and120back to their horizontal orientation so that the tracks may be filled with the next succeeding portions of the supply materials124A and124B, respectively, to form the next set of closures24A and24B and to apply the adhesive to such closure strips. Once this has occurred the apparatus automatically operates to apply those closure strips to the bag.

If it is desired to utilize optional overlay strips, such as those described above, the applicator apparatus100can be modified to include carriers for carrying the overlay strips into engagement with the package over the closure strips24A and24B.

It should be pointed out at this juncture that the apparatus100is merely exemplary of various types of apparatus that can be used to apply closure components constructed in accordance with this invention to flexible bags. Thus, the apparatus can be arranged to sever the strips from supply material before applying the hot melt or other adhesive. Moreover, the supply material and/or the formed strips could be fed through applicator guide tracks in a vertical orientation to avoid the need to pivot them into a horizontal plane for application to the panels of the bag. In such an arrangement the adhesive can be applied to the supply material or the formed strips while in the vertical orientation. Further still, the formed closure strips can be held in the carrier or other applicator heads by means other than retractable gripping jaws. As will also be appreciated by those skilled in the art, the closures of this invention can be modified insofar as its construction and/or material composition is concerned in order to accommodate the preferred degree of opening and/or closing pressure required to operate it. Moreover, a closure in accordance with this invention need not extend across the full width of the bag or package to which it is secured. Thus, a closure may only extend across a portion of the width of the package or bag, e.g., if the mouth of the bag only extends a portion of the width of the bag, the closure need only extend the portion of the bag encompassed by the mouth. Further still, the adhesive for securing each closure strip to its associate panel of the bag may be located on other surface(s) of the strip than shown and described above. Further yet, the closure strips may include an adhesive extruded on their outer surface to secure overlay strip thereon, if such overlay strips are desired.