Patent Description:
Manufacturers of household products have increasingly replaced rigid packages with recloseable flexible packages due to the advantages offered by these flexible packages that include: less packaging material, lower package cost, reduced storage space, and lower shipping costs. The addition of slider devices to flexible closures has made bags easier to open and close. Packages using recloseable closures with slider devices will have end stops on each end of the closure to prevent the slider device from falling off of the end of the closure. <CIT> and <CIT> disclose examples of known reclosable closure devices with slider devices.

One problem with recloseable closures is a resulting restricted open mouth width available to access the contents of the package due to the space occupied by the two end stops and the slider. The mouth width needs to be sufficiently large for the hand or fingers of an adult to enter the small package and remove the contents. Thus, there is a need to reduce the space occupied by the two end stops and the slider device to increase the open mouth width.

In one aspect, a slider device for selectively interlocking and unlocking complementary profiles of opposing tracks of a plastic zipper closure is provided. The slider device includes a top member with an opening end and an opposite closing end; and a pair of spaced legs depending from the top member; the spaced legs defining an open volume therebetween to allow for passage of the tracks therethrough and with the legs having terminal ends straddling the tracks. The top member has an internal surface within the open volume between the legs; the internal surface including at least a first region and a second region; the first region extending from the closing end partially along the internal surface of the top member; and the second region being between the first region and the opening end; the first region extending at a greater distance from the terminal ends of the spaced legs than the second region. Internal surfaces are spaced sufficiently close together to press the profiles into interlocking relationship as the slider is moved in a closing direction along the zipper closure leading with the opening end and trailing with the closing end. A separator plow extends from the second region of the top member into the open volume between the legs; the separator plow being positioned to wedge between opposing tracks and unlock the profiles as the slider device is moved in an opening direction along the zipper closure leading with the closing end and trailing with the opening end. The second region of the top member includes an engagement surface positioned to strike an end stop on at least one end of the zipper closure.

In some examples, the engagement surface is located between the separator plow and the first region.

In example embodiments, the legs each have internal facing hooks at their respective terminal ends.

The hooks can extend an entire length of the slider between the opening end and closing end.

Some embodiments included the engagement surface being a portion of the separator plow.

In one or more examples, there is a leg engagement surface extending from an internal surface of each of the legs.

For some embodiments, the hooks extend from the opening end only a partial length of the slider toward the closing end.

In some embodiments, the hooks extend only along the portions of the legs that are along the second region of the top member.

The second region extends from the opening end, in some embodiments.

In one or more example embodiments, a first pointed projection extends from the engagement surface partially toward the closing end.

In examples, the internal surface of the top member further includes a third region; the third region extending from the opening end, with the second region being between the third region and the first region; and the third region extends at a greater distance from the terminal ends of the spaced legs than the second region.

In one or more embodiments, the third region and the first region extend a same distance from the terminal ends of the spaced legs.

In some examples, there is further including a second pointed projection extending from the second region partially toward the opening end.

In another aspect, a slider zipper closure system is provided including: a recloseable zipper closure with complementary profiles of opposing tracks for interlocking and unlocking; the closure having a first end and an opposite second end; a first end stop positioned at the first end of the closure; a second end stop positioned at the second end of the closure; and a slider device having a closing end and an opposite opening end; the slider device slidably positioned on the zipper closure between and engaging the first end stop and second end stop to selectively: (i) unlock the complementary profiles as the slider device is moved along the tracks in an opening direction leading with the closing end and trailing with the opening end; and (ii) interlock the complementary profiles as the slider device is moved along the tracks in a closing direction leading with the opening end and trailing with the closing end; and the slider device having a first end stop engagement surface positioned inboard from the closing end and adapted to strike the first end stop.

In one or more example embodiments, the slider device includes a top member; a pair of spaced legs depending from the top member; the spaced legs defining an open volume therebetween with passage of the tracks therethrough and with the legs having terminal ends straddling the tracks; the top member having an internal surface within the open volume between the legs; the internal surface including at least a first region and a second region; the first region extending from the closing end partially along the internal surface of the top member; the second region being between the first region and the opening end; the first region extending at a greater distance from the terminal ends of the spaced legs than the second region. The slider device further includes internal surfaces spaced sufficiently close together to move the profiles into interlocking relationship as the slider is moved in the closing direction; a separator plow extending from the second region of the top member into the open volume between the legs; the separator plow adapted to wedge between opposing tracks and unlock the profiles as the slider device is moved in the opening direction along the zipper closure leading with the closing end and trailing with the opening end; and the second region of the top member including the first end stop engagement surface positioned to strike the first end stop, when the zipper closure has been unlocked.

In example embodiments, the first end stop and the second end stop are each an inverted U-clip.

The first end stop engagement surface is a portion of the separator plow, in some embodiments.

In some examples, the first end stop engagement surface is between the separator plow and the closing end.

The opening end of the slider device engages against the second end stop, when the zipper closure has been interlocked, in example embodiments.

In some implementations, the first end stop and second end stop are each formed fins projecting above a top of the tracks.

In example embodiments, the slider device may further include a first pointed projection extending from the first end stop engagement surface partially toward the closing end and capable of digging into the first end stop.

In some embodiments, the internal surface of the top member further includes a third region; the third region extends from the opening end, with the second region being between the third region and the first region; and the third region extends at a greater distance from the terminal ends of the spaced legs than the second region.

The third region and the first region extend a same distance from the terminal ends of the spaced legs, in many example embodiments.

In one or more embodiments, there further includes a second pointed projection extending from the second region partially toward the opening end and digging into the second end stop.

In another aspect, a method of operating a zippered flexible package having an openable and recloseable mouth is provided. The method includes providing a zippered flexible package having a recloseable zipper closure at the mouth including opposing tracks with complementary profiles for interlocking and unlocking; the complementary profiles interlocking to close the mouth and unlocking to open the mouth; first and second end stops on opposite ends of the zipper closure; a slider device located on the zipper closure; the slider device having a closing end and an opposite opening end and a first end stop engagement surface positioned inboard from the closing end; and opening the mouth by moving the slider device along the tracks leading with the closing end and trailing with the opening end to unlock the complementary profiles until the first end stop engagement surface strikes the first end stop.

In example methods, the step of striking the first end stop includes striking an inverted U-clip forming the first end stop.

Some implementations further include a step of closing the mouth by moving the slider device along the tracks leading with the opening end and trailing with the closing end to interlock the complementary profiles until the opening end of the slider device strikes an inverted U-clip forming the second end stop.

The step of striking the first end stop can include digging a first pointed projection extending from the first end stop engagement surface partially toward the closing end into a fin forming the first end stop.

Some example methods further include closing the mouth by moving the slider device along the tracks leading with the opening end and trailing with the closing end to interlock the complementary profiles until a second pointed projection positioned inboard from the opening end digs into a fin forming the second end stop.

A variety of examples of desirable product features or methods are set forth in the description that follows, and in part, will be apparent from the description, or maybe learned by practicing various aspects of this disclosure. The aspects of this disclosure may relate to individual features as well as combinations of features. It is to be understood that both the foregoing general description and the following detailed description are explanatory only, and are not restrictive of the claimed invention.

Referring first to <FIG>, there is illustrated one non-limiting example embodiment of a flexible package <NUM>. The package <NUM> can be a plastic bag <NUM> made of, for example, a polymeric material. The package <NUM> has a mouth <NUM> that provides access to a package interior <NUM>. The mouth <NUM> is repeatedly openable and recloseable with a zipper closure <NUM>.

In the example embodiment, and in reference now to <FIG> and <FIG>, the bag <NUM> is formed from a single flexible plastic sheet folded upon itself, although many variations are possible. The bag <NUM> has first and second opposing body panels <NUM>, <NUM>. Body panels <NUM>, <NUM> are fixedly connected to each other along a pair of side edges <NUM>, <NUM> and a bottom <NUM>. The side edges <NUM>, <NUM> are often formed by heat sealing together the opposed body panels. The bottom <NUM> extends between the pair of side edges <NUM>, <NUM> and is often embodied as a fold in the plastic sheet. In other embodiments, the bottom <NUM> can also be a heat sealed edge, if, for example, two separate pieces of a plastic sheet are used and then attached to each other. The flexible package <NUM> can include many variations such as: side gussets, bottom gussets, stand-up pouch, etc..

The zipper closure <NUM> is illustrated as extending along the mouth <NUM> at the opposite of the bottom <NUM> of the bag <NUM>, but many other arrangements are possible. The body panels <NUM>, <NUM> and bottom <NUM> form a surrounding wall <NUM> of the bag <NUM>.

The zipper closure <NUM> includes complementary profiles of opposing tracks <NUM>, <NUM>, which can interlock together to close the mouth <NUM>; or, unlock from each other to open the mouth <NUM>. Many different embodiments are possible for the opposing tracks <NUM>, <NUM>. In the example shown, the track <NUM> has a male profile <NUM>, and the track <NUM> has a female profile <NUM>. The cross-sectional shapes of the interlocking male and female profiles <NUM>, <NUM> are described in <CIT>, which is incorporated herein by reference. The male and female profiles <NUM>, <NUM> have complementary cross-sectional shapes and are closed by pressing a bottom of the elements together first and then rolling the elements to a closed position toward the top thereof. Many alternatives can be used.

While many different embodiments are possible, in the example shown in <FIG>, the tracks <NUM>, <NUM> are made by an extrusion process, each having a fin <NUM>, <NUM> and attached (typically by a heat seal, but adhesive or other ways are possible) to the respective body panels <NUM>, <NUM> on opposite sides of the bag mouth <NUM>.

The zipper closure <NUM> is openable and recloseable with a slider device <NUM> (<FIG>). The slider device <NUM> selectively interlocks and unlocks the complementary profiles of opposing tracks <NUM>, <NUM>, by moving the slider device <NUM> relative to the zipper closure <NUM>. Various example embodiments of slider devices <NUM> are described herein. Typically, the slider devices <NUM> described are molded as a single piece of plastic, although alternatives are possible.

The zipper closure <NUM> has at opposite ends, terminations or end stops <NUM>, <NUM> (<FIG>). The termination <NUM> is also along the side edge <NUM>, while the termination <NUM> is along the side edge <NUM>, although the end terminations <NUM>, <NUM> do not necessarily need to be at the side edges <NUM>, <NUM>. End terminations <NUM>, <NUM> can have various purposes such as (a) preventing or inhibiting the slider device <NUM> from going past the ends of the closure <NUM>; (b) interacting with the slider device <NUM> to give a tactile indication of being closed; (c) assisting in inhibiting or preventing leakage from the package <NUM>; and (d) holding the opposing tracks <NUM>, <NUM> together to provide additional strength in resisting stresses applied to the tracks <NUM>, <NUM> during normal use of the package <NUM>.

Many different types of end stops <NUM>, <NUM> are possible including flexible clips <NUM>, <NUM> (<FIG>) that can be mounted on the closure tracks <NUM>, <NUM> automatically with suitable insertion equipment, or manually. The clips <NUM>, <NUM> can be in the form of plastic, molded U-clips that are wrapped around the tracks <NUM>, <NUM> and fused thereon using many example methods, such as ultrasonically, with adhesive, or with heat. Further description of useable clips <NUM>, <NUM> may be obtained from <CIT>, incorporated herein by reference.

Other types of end stops <NUM>, <NUM> include terminations made from ultrasonic crushing or welding that results in ultrasonic fins <NUM>, <NUM> (<FIG>, <FIG>, <FIG>). Further description of techniques that can be used to make ultrasonic fins for end stops can be obtained from <CIT>, incorporated herein by reference.

In the embodiment of <FIG>, the package <NUM> has a slider zipper closure system <NUM>. The slider zipper closure system <NUM> includes the zipper closure <NUM> and the slider device <NUM> slidably positioned on the zipper closure <NUM>. The slider device <NUM> is slidably movable between the end stop <NUM> (<FIG>) and the end stop <NUM>. When the slider device <NUM> is moved in an opening direction <NUM>, the complementary profiles <NUM>, <NUM> are disengaged or unlocked to provide access to the interior <NUM> of the bag <NUM> through the mouth <NUM>. When the slider device <NUM> is moved in a closing direction <NUM>, the complementary profiles <NUM>, <NUM> are interlocked to close the mouth <NUM> and prevent access to the interior <NUM>.

In <FIG> and <FIG>, the slider device <NUM> is shown in a position after the closure <NUM> has been opened. The slider device <NUM> is straddling the end clip <NUM> (<FIG>) and, in the example embodiment shown, is parked overhanging the side edge <NUM> of the bag <NUM>, although in other embodiments there may be no overhang. This results in advantages. The overlap of the end clip <NUM> by the slider device <NUM> increases the opening width of the mouth <NUM> beyond what is obtainable by a slider device that uses an end of the slider device abutting the end clip <NUM> as a stopping surface.

When the closure <NUM> is closed, the slider device <NUM> is positioned with an end face <NUM> against an end surface <NUM> of the clip <NUM>.

Various embodiments of slider devices <NUM> can be used with the package <NUM> of <FIG> and <FIG>. A first embodiment of the slider device <NUM> is shown in <FIG>. The slider device <NUM> includes a closing end <NUM> and an opposite opening end <NUM>. The closing end <NUM> of the slider device <NUM> is the portion of the slider, which when being the trailing end while moving along the closure <NUM>, will interlock the opposing tracks <NUM>, <NUM>. The opening end <NUM> is the portion of the slider device <NUM>, which when trailing while moving along the closure <NUM>, will unlock the interlocked tracks <NUM>, <NUM> to open the mouth <NUM>.

The slider device <NUM> includes a first end stop engagement surface <NUM> (<FIG>). The first end stop engagement surface <NUM> is positioned inboard, or away from, the closing end <NUM> and is adapted to strike the first end stop <NUM>. In <FIG>, a leg engagement surface <NUM> (described further below) is within a same plane as the first end stop engagement surface <NUM>, and is located at a distance "d" from the closing end <NUM>. Example useable distances d can be many distances and range from <NUM> inch-<NUM> inch, and can be between <NUM>-<NUM>% of an overall length of the slider device <NUM>.

In general, a user wishing to open the zipper closure <NUM> moves the slider device <NUM> along the tracks <NUM>, <NUM> in the opening direction <NUM> with the closing end <NUM> leading, and the opening end <NUM> trailing. This separates the interlocked tracks <NUM>, <NUM> and opens the mouth <NUM>. The movement in the opening direction <NUM> continues until the slider device <NUM> is stopped by engagement between the first end stop engagement surface <NUM> and surface <NUM> of the clip <NUM>. In some non-limiting examples, the movement in the opening direction <NUM> continues past the side edge <NUM> of the bag <NUM>. It should be noted in <FIG> that the respective end surfaces <NUM> of the clip <NUM> and end surface <NUM> of the clip <NUM> face each other and the zipper closure <NUM>. Opposite end surfaces <NUM> for clip <NUM> and <NUM> for clip <NUM> face away from the remainder of the zipper closure <NUM>, and in this embodiment, are shown to be even with, or very close to even with, the side edges <NUM>, <NUM>, but do not necessarily need to be.

When the end stop engagement surface <NUM> of the slider device <NUM> hits the end surface <NUM> of the clip <NUM>, the slider device <NUM> is prevented from further motion in the opening direction <NUM>, and the mouth <NUM> is open to allow access to the interior <NUM>.

The slider device <NUM> usable with the zipper closure system of <FIG> and <FIG> can have many embodiments. Reference is now made to <FIG> and <FIG>, which show various embodiments of slider devices <NUM> that are usable with the slider zipper closure system <NUM> of <FIG> and <FIG>.

The slider device <NUM> includes a top member <NUM>. The top member <NUM> extends between the opening end <NUM> and the closing end <NUM>. In the examples shown in <FIG> and <FIG>, the top member <NUM> is a solid wall <NUM>. Although in the examples shown, the wall <NUM> is a flat, planar surface, there can be many variations including contours or handles or finger-grasp areas.

The top member <NUM> has an externally directed outer surface <NUM> and an opposite internal surface <NUM>. The internal surface <NUM> faces the zipper closure <NUM>, when the slider device <NUM> is slidably mounted on the zipper closure <NUM>.

The slider device <NUM> includes a pair of spaced legs <NUM>, <NUM>. The legs <NUM>, <NUM> depend from the top member <NUM>. The spaced legs <NUM>, <NUM> define an open volume <NUM> therebetween, to allow for passage of the tracks <NUM>, <NUM> therethrough. The legs <NUM>, <NUM> have terminal ends <NUM>, <NUM> straddling the tracks <NUM>, <NUM>, when the slider device <NUM> is positioned on the zipper closure <NUM>.

The internal surface <NUM> of the top member <NUM> is located within the open volume <NUM> between the legs <NUM>, <NUM>. As can be seen in the views of <FIG>, the internal surface <NUM> includes at least a first region <NUM> and a second region <NUM>. The first region <NUM> extends from the closing end <NUM> partially along the internal surface <NUM> of the top member <NUM>. The second region <NUM> is between the first region <NUM> and the opening end <NUM>. The first region <NUM> extends at a greater distance from the terminal ends <NUM>, <NUM> of the spaced legs <NUM>, <NUM> than the second region <NUM>. The resulting effect is that the volume <NUM> between the legs <NUM>, <NUM> between the closing end <NUM> and where the first region <NUM> ends along the internal surface <NUM> creates a recess <NUM>. The recess <NUM> forms a first overlap chamber <NUM> to allow the slider device <NUM> to straddle the end stop <NUM> and move beyond the plane of end surface <NUM>; in some non-limiting examples, this is moving beyond the side edge <NUM> of the bag <NUM> in the open position. The first end stop engagement surface <NUM> in the recess <NUM> strikes the end surface <NUM> of the clip <NUM> of the end stop <NUM> and prevents the slider device <NUM> from coming off of the zipper closure <NUM>.

In the example embodiments of <FIG> and <FIG>, the first end stop engagement surface <NUM> is part of the second region <NUM> of the top member <NUM>. For example, as shown in the depicted embodiments, the first end stop engagement surface <NUM> is an end face <NUM> of the second region <NUM>. The end face <NUM> is contained within a plane that is generally orthogonal to a plane containing the wall <NUM> of the top member <NUM>.

The slider device <NUM> further includes internal surfaces <NUM>, <NUM> within the legs <NUM>, <NUM> that are spaced sufficiently close together to press the profiles <NUM>, <NUM> into interlocking relationship, as the slider device <NUM> is moved in the closing direction <NUM> along the zipper closure <NUM> leading with the opening end <NUM> and trailing with the closing end <NUM>.

The slider device <NUM> further includes a separator plow <NUM>. The separator plow <NUM> extends from the second region <NUM> of the top member <NUM> into the open volume <NUM> between the legs <NUM>, <NUM>. The separator plow <NUM> is positioned to wedge between the opposing tracks <NUM>, <NUM> and disengage the profiles <NUM>, <NUM>, as the slider device <NUM> is moved in the opening direction <NUM> along the zipper closure <NUM> leading with the closing end <NUM> and trailing with the opening end <NUM>. Many different embodiments for the plow <NUM> are possible. In the example shown, the plow <NUM> has the shape of a triangle, with a base of the triangle being at or adjacent to the opening end <NUM>, and an apex of the triangle pointing toward the closing end <NUM>.

In the embodiments of <FIG>, the first end stop engaging surface <NUM> is located between the separator plow <NUM> and the first region <NUM>. As will be described in connection with further embodiments (for example, <FIG>) the first end stop engagement surface <NUM> can also be a portion of the separator plow <NUM>.

In the embodiments of <NUM>-<NUM>, the second region <NUM> extends from the opening end <NUM> of the slider device <NUM>. In other embodiments (for example, <FIG>), the second region <NUM> is spaced from the opening end <NUM>.

In many embodiments, the internal surface <NUM>, as extending between the closing end <NUM> and opening end <NUM>, is not in a single plane. In some example embodiments, the internal surface <NUM> has at least two planes, and they can be parallel to each other. For example, the first region <NUM> is contained in a first plane, and the second region <NUM> is contained in a second plane parallel to the first plane, with the plow <NUM> extending from the second plane.

Each the legs <NUM>, <NUM> can further include a leg engagement surface <NUM>, <NUM>. The leg engagement surface <NUM>, <NUM> extends from an internal surface of each of the legs <NUM>, <NUM> and can be a portion of the first end stop engagement surface <NUM>. For example, in the embodiment of <FIG>, it can be seen how the first end stop engagement surface <NUM>, <NUM> extends orthogonally from the internal surface <NUM> of the top member <NUM> and is within the same plane as the first end stop engagement surface <NUM>.

For the slider devices <NUM> shown in <FIG>, each of the legs <NUM>, <NUM> has an internal facing hook <NUM>, <NUM> at their respective terminal ends <NUM>, <NUM>. The hooks <NUM>, <NUM> help to hold the slider device <NUM> in place on the zipper closure <NUM> by having the hooks <NUM>, <NUM> engage under the profiles <NUM>, <NUM>. Many embodiments are possible.

For example, in the embodiment of <FIG>, the hooks <NUM>, <NUM> extend an entire length of the slider device <NUM> between the opening end <NUM> and the closing end <NUM>.

In another example embodiment of <FIG>, the hooks <NUM>, <NUM> extend only along the portions of the legs <NUM>, <NUM> that extend from the opening end <NUM> to the engagement surface <NUM>. In a non-limiting example, the hooks <NUM>, <NUM> are along the second region <NUM> of the top member <NUM>. As shown in <FIG>, the legs <NUM>, <NUM> that are along the first region <NUM> do not have hooks.

In the embodiment of <FIG>, the hooks <NUM>, <NUM> extend from the opening end <NUM> only a partial length of the slider device <NUM> toward the closing end <NUM>. This embodiment is similar to that shown in <FIG>, in that the hooks <NUM>, <NUM> extend from the opening end <NUM> only along portions of the legs <NUM>, <NUM> that are along the second region <NUM> of the top member <NUM>. However, in the embodiment of <FIG>, the length of the second region <NUM> is longer than the length of region <NUM>. Compare this to the embodiment of <FIG>, in which the length of the second region <NUM> is shorter than the length of the first region <NUM>. As such, in the embodiment of <FIG>, the recess <NUM> is greater, resulting in a longer (or deeper) first overlap chamber <NUM>. This results in allowing the slider device <NUM> to move further in the opening direction <NUM> and create a greater opening in the mouth <NUM>.

In the embodiment of <FIG> and <FIG>, the package <NUM> includes slider zipper closure system <NUM>. The slider zipper closure system <NUM> is the same as the system previously described with respect to <FIG> and <FIG>, but in this case, the end stops <NUM>, <NUM> are formed fins <NUM> (shown in hidden lines in <FIG>), <NUM>, instead of clips <NUM>, <NUM>. The formed fins <NUM> can be made by, for example, ultrasonically forming. The slider device <NUM> also has different internal structure, as described further below. General operation of the slider zipper closure system <NUM> of <FIG> and <FIG> is the same, in that when the slider device <NUM> is moved in the opening direction <NUM>, the complementary profiles <NUM>, <NUM> are disengaged or unlocked to provide access to the interior <NUM> of the bag <NUM> through the mouth <NUM>. When the slider device <NUM> is moved in the closing direction <NUM>, the complementary profiles <NUM>, <NUM> are interlocked to close the mouth <NUM> and contain the contents in the interior <NUM>.

One example embodiment of slider device <NUM> usable with the closure system <NUM> of <FIG> and <FIG> is shown in <FIG>. <FIG> and <FIG> are an end view of the slider device <NUM>, as viewed from the opening end <NUM>. <FIG> is a cross-sectional view of the slider device <NUM>, taken along the line A-A of <FIG>.

In <FIG>, the slider device <NUM> illustrates the first region <NUM> extending from the closing end <NUM> partially along the internal surface <NUM> of the top member <NUM>. The second region <NUM> having the first end stop engagement surface <NUM> is also visible. In this embodiment, the slider device <NUM> includes a first pointed projection <NUM> extending from the first end stop engagement surface <NUM> partially toward the closing end <NUM>. The pointed projection <NUM> is sized and shaped to dig into the ultrasonic fin <NUM> of the first end stop <NUM>. The dimensions of the pointed projection <NUM> can be adjusted, per the needs of the closure <NUM>. In general, the pointed projection <NUM> is sharp, but not so long or deep that it would cut off the ultrasonically formed fin <NUM>. The pointed projection <NUM> is long enough to dig in, but the slider device <NUM> will jam up against the ultrasonic fin <NUM>, once the pointed projection <NUM> begins cutting in. In some example embodiments, the length of the pointed projection shown at extension L in <FIG> is at least <NUM> inch and no greater than <NUM> inch.

Still in reference to <FIG>, the slider device <NUM> further includes a third region <NUM> that is part of the internal surface <NUM> of the top member <NUM>. The third region <NUM> extends from the opening end <NUM>, with the second region <NUM> being between the third region <NUM> and the first region <NUM>. As can be seen in <FIG>, the third region <NUM> extends at a greater distance from the terminal ends <NUM>, <NUM> of the legs <NUM>, <NUM> than the second region <NUM>. This defines a recess <NUM> defining a second overlap chamber <NUM> at the opening end <NUM>.

While many different embodiments are possible, in the one shown, the third region <NUM> and the first region <NUM> extend at a same distance "D" (<FIG>) from the terminal ends <NUM>, <NUM> of the legs <NUM>, <NUM>. The second overlap chamber <NUM> allows the slider device <NUM> to capture the ultrasonic fin <NUM>. The second overlap chamber <NUM> also helps to prevent the fin <NUM> from being pushed out of the way when the slider device <NUM> is positioned in the closed position on the zipper closure <NUM>.

In many embodiments, the internal surface <NUM>, as extending between the closing end <NUM> and opening end <NUM>, is in two or more planes, which can be parallel to each other. For example, the first region <NUM> is contained in a first plane, and the second region <NUM> is contained in a second plane parallel to the first plane, with the plow <NUM> extending from the second plane, and the third region <NUM> is contained in either the first plane or in a third plane.

With reference again to <FIG>, the slider device <NUM> can further include a second pointed projection <NUM> extending from the second region <NUM> partially toward the opening end <NUM>. The second pointed projection <NUM> is sized to dig into the ultrasonic fin <NUM>, but it is sized such that it is not long or deep enough to cut off the ultrasonically formed fin <NUM>. The second pointed projection <NUM> can be sized with about the same dimensions as the first pointed projection <NUM>. As can be seen in <FIG>, the second pointed projection <NUM> points toward the opening end <NUM> and into the second overlap chamber <NUM>.

In <FIG>, the slider zipper closure system <NUM> is illustrated with the slider device <NUM> removed for a better illustration of the end stops <NUM>, <NUM>. The ultrasonic fins <NUM>, <NUM> are shown along with indents <NUM>, <NUM>. The indents <NUM>, <NUM> are created after the slider device <NUM> has been pushed against the end stops <NUM>, <NUM> and the pointed projections <NUM>, <NUM> have dug into the fins <NUM>, <NUM>. The indent <NUM> is shown enlarged, and has the same appearance as the indent <NUM>. As can be seen from reviewing <FIG>, the indents <NUM>, <NUM> are small relative to the overall length of the base of the fins <NUM>, <NUM>. For example, the indents <NUM>, <NUM> extend less than <NUM>. 01inch into the respective fins <NUM>, <NUM>. As a percent of the overall length of the base of the fins <NUM>, <NUM>, the length of the indents <NUM>, <NUM> is no greater than <NUM>%.

<FIG> is a variation on the slider device <NUM> shown in <FIG>. In <FIG>, the slider device <NUM> is shown schematically in cross-section engaging the fin <NUM>, which is omitted for clarity. In this embodiment, the first end stop engagement surface <NUM> is a portion of the separator plow <NUM>. The plow <NUM> includes the first pointed projection <NUM> extending from the apex of the plow <NUM>. The second region <NUM> extends from the opening end <NUM> to the end of the plow <NUM> at the first pointed projection <NUM>. The first region <NUM> extends from the closing end <NUM> completely to the pointed projection <NUM> of the plow <NUM>.

In operation, the system <NUM> of <FIG> and <FIG> can be used by opening the mouth <NUM> by moving the slider device <NUM> in the opening direction <NUM>, which separates the profiles <NUM>, <NUM>. The movement of the slider device in the opening direction <NUM> continues and overlaps the start of the end stop <NUM>, which in some non-limiting examples can include moving past the side edge <NUM> of the bag <NUM>, until the slider device <NUM> is stopped by the first pointed projection <NUM> hitting or engaging the ultrasonic fin <NUM>. The first pointed projection <NUM> rides just above the tracks <NUM>, <NUM> prior to contact with the ultrasonic fin <NUM>. After the closure <NUM> is opened, the contents of the package <NUM> can be accessed. Thereafter, the slider device <NUM> is moved in the closing direction <NUM> to engage the profiles <NUM>, <NUM> and close the mouth <NUM>. The overlap feature <NUM> will receive the fin <NUM>, and the second pointed projection <NUM> will dig into the fin <NUM>.

The above structures can be used as part of a method of operating a zippered flexbile package having an openable and reclosable mouth. In one example, the method includes providing a zippered package <NUM>, such as bag <NUM> having surrounding wall <NUM> formed from first and second panels <NUM>, <NUM> each having a top forming the mouth <NUM>. The surrounding wall <NUM> has closed bottom <NUM> at an end that is opposite of the mouth <NUM> and side edges <NUM>, <NUM> along opposite sides. Reclosable zipper closure <NUM> includes opposing tracks <NUM>, <NUM> with complementary profiles <NUM>, <NUM> for interlocking and unlocking. One profile <NUM> is in proximity to the top of the first panel <NUM>, while the other profile <NUM> is in proximity to the top of the panel <NUM>. The complementary profiles <NUM>, <NUM> interlock to close the mouth <NUM> and unlock to open the mouth <NUM>. First and second end stops <NUM>, <NUM> are on opposite ends of the zipper closure <NUM>. Slider device <NUM> is slidably or operable mounted on the zipper closure <NUM>. The slider device <NUM> has a closing end <NUM> and an opposite opening end <NUM>. The slider device <NUM> also has a first end stop engagement surface <NUM> positioned inboard from the closing end <NUM>. The method includes opening the mouth <NUM> by moving the slider device <NUM> along the tracks <NUM>, <NUM> leading with the closing end <NUM> and trailing with the opening end <NUM> to unlock the complementary profiles <NUM>, <NUM> until the first end stop engagement surface <NUM> strikes the first end stop <NUM>.

In one example method, the step of striking the first end stop <NUM> includes striking inverted U-clip <NUM> forming the first ends stop <NUM>.

In another variation, the step of striking the first end stop <NUM> includes digging first pointed projection <NUM> extending from the first end stop engagement surface <NUM> partially toward the closing end <NUM> into ultrasonically formed fin <NUM> forming the first end stop <NUM>.

The method can further include the step of closing the mouth <NUM>. The step of closing the mouth <NUM> includes moving the slider device <NUM> along the tracks <NUM>, <NUM> leading with the opening end <NUM> and trailing with the closing end <NUM> to interlock the complementary profiles <NUM>, <NUM> until the opening end <NUM> strikes inverted U-clip <NUM> forming the second end stop <NUM>.

In another variation, the step of closing the mouth <NUM> includes moving the slider device <NUM> along the tracks leading with the opening end <NUM> and trailing with the closing end <NUM> to interlock the complementary profiles <NUM>, <NUM> until the second pointed projection <NUM> positioned in board from the opening end <NUM> digs into the ultrasonic fin <NUM> forming the second end stop <NUM>.

A variety of embodiments for the slider device <NUM> are usable, and the relative dimensions of the various features can be modified, per the system requirements. For example, the length of the recess <NUM> can vary from the closing end <NUM> until the plow <NUM> becomes a first end stop engagement surface <NUM>, as shown in <FIG>. The dimensions of the plow <NUM> and the length of the recess <NUM> can be related in that the length of the plow <NUM> added to the length of the recess <NUM> can equal the total length of the slider device <NUM>, assuming that the plow <NUM> is located at the opening end <NUM> of the slider device <NUM>. The dimensions of the plow <NUM> are driven by the geometry required to open and close a specific zipper closure <NUM>, and the recess <NUM> dimensions are driven by the dimensions of the plow <NUM>.

The overlap chambers <NUM>, <NUM> can be helpful in increasing usable opening of the package and/or improving end retention by helping to capture the end stop. When the slider device <NUM> includes second overlap chamber <NUM> on the opening end <NUM> of the slider device <NUM>, the purpose is to improve retention of the end stop <NUM>. When the chamber <NUM> is on the closing end <NUM>, it has a dual purpose of increasing the size of the opening of the mouth <NUM> and of improving retention of the end stop <NUM>.

Some helpful dimensions to the overlap chamber <NUM> include the overlap length (the length from end of slider device <NUM> to where the overlap stops); overlap width <NUM> (<FIG>); and overlap height (from internal surface <NUM> of top member <NUM> to terminal ends <NUM>, <NUM>).

(<NUM>) Overlap length: the length of the overlap chamber <NUM>, <NUM> depends on the purpose of the overlap, the size of the slider <NUM>, and the dimensions of the end stop <NUM>, <NUM> with which it is intended to interact. If the purpose of the overlap chamber <NUM>, <NUM> is only for end retention, it need only be deep enough to capture the fin <NUM>, <NUM>, such that when a force is applied the fin <NUM>, <NUM> is not allowed to fold under or out of the way of the slider <NUM> and allow the slider <NUM> to become free of the closure <NUM>. If the purpose of the overlap chamber <NUM> is to maximize usable opening space, the overlap chamber <NUM> should be as long as possible. Constraints that might limit the length include the overall length of the slider <NUM>, location of the plow <NUM> within the slider <NUM>, and the distance from the contact point of the end stop <NUM>, <NUM> to the edge <NUM>, <NUM> of the closure <NUM>, if desirable for the slider <NUM> not to exceed the edge of the closure <NUM>.

(<NUM>) Overlap width: the width <NUM> of the overlap chamber <NUM>, <NUM> depends to some degree on the purpose. If the purpose is end retention, it may be desirable for the overlap chamber <NUM>, <NUM> to be relatively narrow, close to the width of the fin <NUM>, <NUM>. If the purpose of the overlap chamber <NUM> is to increase usable opening space, it may be desirable to provide plenty of clearance to make sure the slider <NUM> can easily overlap the end stop <NUM>, <NUM>. A dimension of <NUM>" to <NUM>" clearance vs. the target width of the slider <NUM> is sufficient in most cases.

(<NUM>) Overlap height: The height of the overlap chamber <NUM>, <NUM> is basically a one-side specification, it needs to be tall enough to provide clearance over the end stop <NUM>, <NUM>. There is a trade-off between the amount of clearance provided and the height of the slider <NUM>. The taller the overlap chamber <NUM>, <NUM>, the less risk there is for interference between the top of the chamber <NUM>, <NUM> and the end stop <NUM>, <NUM>, but the taller the overall slider <NUM> will have to be, which may be undesirable in terms of cost, packaging, customer preference, etc. In some embodiments, the overlap chamber <NUM>, <NUM> can extends through the top of the slider <NUM> making it more of a slot than a chamber.

Side-to-side location: It is possible that the end stop <NUM>, <NUM> could be offset to one side of the track. In this case, the overlap chamber <NUM>, <NUM> may also need to be offset. The overlap chamber <NUM>, <NUM> should be located according to the target end stop <NUM>, <NUM> location across the width of track profile.

Other factors: The pointed projections <NUM>, <NUM> should be sharp enough to cut into the fins <NUM>, <NUM>. The length of the projections cannot be too short or too long. If too short, it may not develop enough interference to increase end retention significantly - it could slip out of the indents <NUM>, <NUM> it makes in the end stop <NUM>, <NUM> too easily, or it could fail to form any indents at all. If too long, there is a risk that the projections <NUM>, <NUM> could cut so far into the end stop <NUM>, <NUM> that it would be weakened, or even continue to cut all the way through the end stop <NUM>, <NUM> and off the closure <NUM>.

It is desirable for the width of the pointed projections <NUM>, <NUM> to be at least as wide as the end stop <NUM>, <NUM>, and lined up with the end stop <NUM>, <NUM>. If the pointed projections <NUM>, <NUM> are too narrow, non-cutting surfaces of the slider <NUM> may contact the end stop <NUM>, <NUM> first and not dig in. This risk is higher given that there can be some uncertainty in the location and thickness of the end stop <NUM>, <NUM> due to manufacturing process variation. The pointed projections <NUM>, <NUM> are inside of an overlap chamber <NUM>, <NUM> and should be across the full width of the overall chamber <NUM>, <NUM>. The width of the overlap chamber <NUM>, <NUM> is driven by other factors unrelated to the pointed projections <NUM>, <NUM>.

The pointed projections <NUM>, <NUM> can ride right on the top of the tracks <NUM>, <NUM>, or can be elevated off of the tracks <NUM>, <NUM> some amount. The pointed projections <NUM>, <NUM> can be elevated off of the track to "almost" the height of the end stop <NUM>, <NUM> and still be effective at improving end retention. If the pointed projections <NUM>, <NUM> are above the height of the top of the end stop <NUM>, <NUM>, it would be rendered ineffective. It is most effective when closer to the top of the tracks <NUM>, <NUM> (effectively the bottom of the fins <NUM>, <NUM>), where the fins <NUM>, <NUM> are thick, thus providing more material to create force and making it less likely that the fin <NUM>, <NUM> may bend out of the way when the pointed projections <NUM>, <NUM> is not paired with an overlap chamber <NUM>, <NUM>; or, they are relatively shallow due to other constraints.

Claim 1:
A slider device (<NUM>) for selectively interlocking and unlocking complementary profiles of opposing tracks of a plastic zipper closure; the slider device comprising:
(a) a top member (<NUM>) with an opening end (<NUM>) and an opposite closing end (<NUM>);
(b) pair of spaced legs (<NUM>, <NUM>) depending from the top member; the spaced legs defining an open volume (<NUM>) therebetween to allow for passage of the tracks therethrough and with the legs having terminal ends (<NUM>, <NUM>) straddling the tracks;
(c) the top member having an internal surface (<NUM>) within the open volume between the legs; the internal surface including at least a first region (<NUM>) and a second region (<NUM>);
(i) the first region extending from the closing end partially along the internal surface of the top member; and
(ii) the second region being between the first region and the opening end;
(iii) the first region extending at a greater distance from the terminal ends of the spaced legs than the second region;
(d) internal surfaces (<NUM>, <NUM>) spaced sufficiently close together to press the profiles into interlocking relationship as the slider is moved in a closing direction (<NUM>) along the zipper closure leading with the opening end and trailing with the closing end;
(e) a separator plow (<NUM>) extending from the second region of the top member into the open volume between the legs; the separator plow being positioned to wedge between opposing tracks and unlock the profiles as the slider device is moved in an opening direction along the zipper closure leading with the closing end and trailing with the opening end; and
(f) the second region of the top member including an engagement surface (<NUM>) positioned to strike an end stop on at least one end of the zipper closure.