SLIDER BAG WITH ZIPPER CLOSURE

Abstract

A reclosable fastener assembly comprising a slider having one center leg and two extensions or bumps behind the center leg. The center leg extends downward from the top surface. The top surface does not extend all the way to, but terminates a short distance from, the separator end of the slider. Similarly, the center leg is not at, but terminates a short distance from, the edge of the top surface closest to the separating end of the slider. As a result, the center leg is spaced a short distance from the separator end of the slider.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to a slider bag with a zipper closure, and relates more specifically to a zipper closure with a slider and zipper strips with reciprocal rails for sealing and resealing the slider bag.

2. Related Art

Reclosable fastener assemblies are useful for sealing thermoplastic slider bags. Such reclosable fastener assemblies often include a plastic zipper and a slider. Typically, the plastic zippers include a pair of interlockable fastener elements, or profiles, that form a closure. As the slider moves across the fastener elements, the fastener elements are opened or closed.

The profiles in plastic zippers can take on various configurations. For example, U.S. Pat. No. 5,140,727 describes interlocking rib and groove elements, whereas U.S. Pat. No. 5,007,143 describes a rolling action zipper profile, and U.S. Pat. No. 4,747,702 describes profiles that are U-shaped with interlocking hooks.

The sliders for opening or closing the reclosable fasteners are generally shaped so that the slider straddles the profiles. The sliders often include a separating element that is inserted between the profiles in order to open or separate the fasteners. Such a slider is described in U.S. Pat. No. 5,067,208. In other types of sliders, the separating element does not penetrate between the profiles, but rather slides above the profiles on a specially adapted track located above the profiles, as described in U.S. Pat. No. 5,007,143. The separating elements can have various shapes. For example, U.S. Pat. No. 3,173,184 describes a V-shaped separating element, while U.S. Pat. No. 5,067,208 describes a tapered separating element with a circular end.

A disadvantage of the known fastener assemblies is that thermoplastic bags incorporating the fastener assemblies often leak. Another disadvantage of the known fastener assemblies is that the zippers can be rigid and ineffective while the sliders can be cumbersome, prone to separating from the fastener assembly. Another disadvantage of the known fastener assemblies is that they can be expensive to manufacture. It would be an advance in the art to provide a reclosable fastener assembly that is effective yet simple and inexpensive to manufacture. It is to these needs and others that the present invention is directed.

BRIEF SUMMARY OF THE INVENTION

Briefly, the present invention provides a slider having one center leg and two extensions or bumps behind the center leg. The center leg extends downward from the top surface. The top surface does not extend all the way to, but terminates a short distance from, the separator end of the slider. Similarly, the center leg is not at, but terminates a short distance from, the edge of the top surface closest to the separator end of the slider. As a result, the center leg is spaced a short distance from the separator end of the slider, resulting in an effective slider closure device and mechanism.

One embodiment of the zipper closure and slider of the present invention comprises a short center leg extending between the first and second top hooks (the upper fasteners) and resting on or above the first and second bottom hooks (the bottom fasteners) of the plastic bag. Slider side surfaces are substantially straight and substantially perpendicular to the top surface.

A second embodiment of the zipper closure and slider of the present invention comprises a short center leg extending between the first and second top hooks (the upper fasteners) and resting on or above the first and second bottom hooks (the bottom fasteners) of the plastic bag. The slider side surfaces of the second embodiment are contoured such that each side is concave relative to the center leg. When the slider is in a closed position, the two extensions inside the slider will remain at the welding position holding the sides of the bag together and helping to create a more airtight seal.

A zipper strip comprises four sets of fastener rails at each side: the first and second top hooks, the first and second bottom hooks, top and bottom rails, and first and second lower stabilizing rails. In operation, the first and second top hooks releasably connect to each other and the first and second bottom hooks releasably connect to each other to seal the bag closed after the slider passes in a first direction. Top and bottom rails provide top and bottom walls respectively for the zipper closure, and first and second lower stabilizing rails guide the slider along the zipper closure and to ensure that the slider does not come off of the zipper closure. The four sets of rails are crushed or crimped at each end of the bag so as to provide a stop for the slider at each end of the zipper closure.

A complete understanding of the present invention may be obtained by reference to the accompanying drawings, when considered in conjunction with the subsequent, detailed description of preferred embodiments in which like elements and components bear the same designations and numbering throughout the figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front view of an embodiment of a bag with four sets of rails in accordance with the present invention.

FIG. 2 illustrates a bottom view of an embodiment of a slider in accordance with the present invention.

FIG. 3 is a side view of an embodiment of a slider in accordance with the present invention.

FIG. 4 is a cross-sectional side view of an embodiment of a bag with four sets of rails in a closed position in accordance with the present invention.

FIG. 5 is a cross-sectional side view of an embodiment of a slider in accordance with the present invention.

FIG. 6 is a top perspective view of an alternative embodiment of a slider in accordance with the present invention.

FIG. 7 is a bottom perspective view of an alternative embodiment of a slider in accordance with the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Referring now to FIG. 1, a reclosable thermoplastic slider bag 10 for use in accordance with an embodiment of the present invention comprises a sealed bottom 15 and two opposing sealed edges 20. Bag 10 may be made from any suitable thermoplastic film such as, for example, low density polyethylene, linear low density polyethylene, substantially linear copolymers of ethylene and a C3-C8 alpha-olefin, polypropylene, polyvinylidene chloride, mixtures of two or more of these polymers, or mixtures of one of these polymers with another thermoplastic polymer.

The bag 10 further comprises a pair of flexible plastic sheets 25. The flexible plastic sheets 25 each having top edges 30 with a zipper closure 35 attached thereto. The zipper closure 35 comprises a pair of opposing zipper strips 40. Each opposing zipper strip 40 has an inner surface on the inside of the bag 10 and an outer surface on the outside of the bag 10. In one embodiment, the opposing zipper strips 40 are extruded separately and attached to the respective sides of the bag 10. Alternatively, opposing zipper strips 40 are extruded integrally with the flexible plastic sheets 25 of the bag 10.

The zipper closure 35 further comprises a first pressed end 45a and a second pressed end 45b at the two opposing sealed edges 20 of the bag 10. The opposing zipper strips 40 have sets of rails 50 connected to the inner surfaces of the opposing zipper strips 40 substantially parallel to one another. In a closed position, the sets of rails 50 on each of the inner surfaces of the opposing zipper strips 40 mate and releasably connect to seal the bag 10.

The sets of rails 50 are joined at the first pressed end 45a and the second pressed end 45b to provide a stop for a slider 55 (FIG. 2) at each of the two opposing sealed edges 20 of the bag 10. In one embodiment, the first and second pressed ends 45a and 45b of the zipper closure 35 are welded by ultrasonic wave. In another embodiment, only an end of one or more of the sets of rails 50 is pressed by ultrasonic wave. In a preferred embodiment, the stop formed by the first and second pressed ends 45a and 45b has a smooth or relatively smooth surface rather than a ridged surface to minimize unwanted catching, snagging, and tearing of the slider bag 10.

The slider 55 can be made in multiple parts and welded together or the parts may be constructed to be snapped together. The slider 55 also can be of one piece construction. The slider 55 can be made using any desired method, such as, for example, injection molding or any other method. The slider 55 can be molded from any suitable plastic such, for example, as nylon, polypropylene, polystyrene, acetal, toughened acetal, polyketone, polybutylene terephthalate, high density polyethylene, polycarbonate, or ABS. The slider 55 can be clear, opaque, or colored.

With reference to FIG. 2, an embodiment of a slider 55 in accordance with the present invention comprises separator end 60 with a center leg 65 and a connecting end 70 with a pair of extensions 75a and 75b behind the center leg 65. The center leg 65 extends downward substantially perpendicularly from a top surface 80 of the slider 55. In one embodiment, side walls 85a and 85b extend downward from the edges of the top surface 80 substantially perpendicular to the top surface 80 and substantially parallel to one another. The side walls 85a and 85b each have two arms 90, one at each end, that extend inward. The two arms 90 of side wall 85a extend toward and are congruent with the two arms 90 of side wall 85b. The two arms 90 form approximately a 90 degree angle with each of the side walls 85a and 85b such that the profile of each side wall 85a and 85b forms three sides of a rectangle. In an exemplary embodiment, the side walls 85a and 85b are substantially straight.

In an exemplary embodiment, the top surface 80 does not extend all the way to, but terminates a short distance from, the inner edge of one of the two arms 90 of each of the side walls 85a and 85b at the separator end 60 of the slider 55. In a preferred embodiment, the top surface 80 of the slider 55 terminates between 2.5 mm and 3 mm, and more preferably approximately 2.8 mm, from the inner edge of one of the two arms 90 of each of the side walls 85a and 85b at the separator end 60 of the slider 55. Similarly, the edge of the center leg 65 adjacent the separator end 60 is not at, but terminates a short distance from, the edge of the top surface 80 adjacent to the separator end 60 of the slider 55. In a preferred embodiment, the edge of the center leg 65 adjacent the separator end 60 of the slider 55 terminates between 0.3 mm and 0.5 mm, and more preferably approximately 0.4 mm, from a separator edge 95. As a result, in this exemplary embodiment, the edge of center leg 65 adjacent the separator end 60 is at least approximately 3 mm from the edge of the top surface 80 adjacent the separator end 60.

With reference to FIG. 3, the center leg 65 extends between first top hook 100a and second top hook 100b, but resting on or above first bottom hook 105a and second bottom hook 105b. When the slider 55 is in the closed position, the two extensions 75a and 75b (FIG. 2) inside the slider 55 will remain at the welding position holding the sides of the bag 10 together and helping to create an airtight seal.

The opposing zipper strip 40 (FIG. 1) comprise four sets of rails 50 at each side: the first and second top hooks 100a and 100b, the first and second bottom hooks 105a and 105b, bottom and top rails 110a and 110b, respectively, and first and second lower stabilizing rails 115a and 115b, respectively. The first and second top hooks 100a and 100b and the first and second bottom hooks 105a and 105b extend inward from the opposing zipper strips 40. The first and second top hooks 100a and 100b and the first and second bottom hooks 105a and 105b form an angle of approximately 60 degrees on a first bottom side, and of approximately 120 degrees on a first top side relative to the surface of the opposing zipper strips 40, and forming a vertex at the intersection of the rails 50 with the surface of the opposing zipper strips 40.

With reference to FIG. 4, as the slider 55 passes in a first direction, the first and second top hooks 100a and 100b connect to each other at a free end, and the first and second bottom hooks 105a and 105b connect to each other at a free end so that the rails 50 remain interlocked when the bag 10 to form a seal. The seal advantageously is such that under normal conditions of use, it forms a barrier to liquids.

Bottom and top rails 110a and 110b create a top and bottom wall respectively for the zipper closure for support and in order to maintain the integrity of the seal. First and second lower stabilizing rails 115a and 115b guide the slider 55 along the zipper closure 35 and to ensure that the slider 55 does not come off of the zipper closure 35. When the bag 10 is open, the rails 50 are separated from each other. As shown in FIG. 4, rails 50 have a complimentary hook shape such that they are closed by pressing the flexible plastic sheets 25 of the bag 10 together. The pressing action is accomplished by the extensions 75a and 75b on the slider 55, which straddles both of the opposing zipper strips 40, is adapted to close or open the rails 50 on the opposing zipper strips 40. When the slider 55 moves from an open position to a closed position, the hooks of the rails 50 are interlocked throughout substantially their entire length to close the bag 10. When the slider 55 reaches the open position at the opposite end of the opposing zipper strip 40, the bag 10 is open and the hooks of the rails 50 are disengaged throughout most of their length.

The spacing of the extensions 75a and 75b acts to pinch, or squeeze the opposing zipper strips 40 together, thereby forcing the rails 50 into an interlocked position. Thus, when the slider 55 is moved toward the open position, the extensions 75a and 75b of the slider 55 lead, and the center leg 65 of the slider 55 trails, so that the center leg 65 disengages the rails 50. When the slider 55 is moved toward the closed position, the center leg 65 leads and the extensions 75a and 75b trail, so that the extensions 75a and 75b squeeze the rails 50 together into engagement. The spacing between the first and second top hooks 100a and 100b and the first and second bottom hooks 105a and 105b should be sufficient so that they are pulled open as the center leg 65 forces the rails 50 apart when the slider 55 moves toward the open position.

In construction, the four sets of rails 50 are crushed or crimped the first and second pressed ends 45a and 45b of the bag 10 to provide a stop for the slider 55 at each of the two opposing sealed edges 20 of the bag 10. The rails 50 can be fused by a clamp, an adhesive, pressure, heat, mechanically, ultrasonically, or by any other desired method.

With reference to FIG. 5, a side view of an embodiment of a slider 55 illustrates the center leg 65 positioned centrally relative to the extensions 75a and 75b. The side walls 85a and 85b form angles of approximately 90 degrees with each of the two arms 90. In an exemplary embodiment, one outer corner of one of the two arms 90 of the side walls 85a and 85b is a bevel 120, and in another exemplary embodiment, the plane of each opposing bevel 120 intersects at approximately a 90 degree angle.

With reference to FIGS. 6 and 7, an alternative embodiment of a slider 155 in accordance with the present invention is shown. In this embodiment, the outer edges of the side walls 185a and 185b of the slider 155 are contoured such that each side wall 185a and 185b is concave relative to the plane of the center leg 165. Side walls 185a and 185b have a plurality of ridges 125 extending away from the top surface 180 of the slider 155. In a preferred embodiment, the ridges 125 are substantially parallel to each other and substantially perpendicular to the top surface 180. The ridges 125 improve a user's grip on the slider 155.

The bag 10 of the present invention can be made using methods well known in the art, such as, for example, by blow or cast extrusion. The slider 55 can be attached to the opposing zipper strips 40 using methods such as causing reciprocal movements of the clasp using a tool, as described in U.S. Pat. No. 4,262,395, through a hinge structure which attaches wings to the body of the slider 55, as described in U.S. Pat. No. 5,067,208, through a rigidizing structure as described in U.S. Pat. No. 5,283,932, or through in-place assembly.

The above detailed description of the embodiments, and the examples, are for illustrative purposes only and are not intended to limit the scope and spirit of the invention, and its equivalents, as defined by the appended claims. One skilled in the art will recognize that many variations can be made to the invention disclosed in this specification without departing from the scope and spirit of the invention.

Claims

1. A slider bag with zipper closure comprising:

A) a zipper closure, wherein said zipper closure comprises: i) a first opposing zipper strip having an inner surface and an outer surface; ii) a second opposing zipper strip having an inner surface and an outer surface; iii) a first set of four rails comprising a top rail at the top of the first opposing zipper strip, a second top hook underneath the top rail, a second bottom hook underneath the second top hook, and a second lower stabilizing rail underneath the second bottom hook, wherein the top rail, the second top hook, and the second bottom hook are positioned along the length of the inner surface of the first opposing zipper strip, and the second lower stabilizing rail is positioned along the length of the outer surface of the first opposing zipper strip; and iv) a second set of four rails comprising a first top hook at the top of the second opposing zipper strip and underneath the top rail, a first bottom hook underneath the first top hook, a first bottom rail underneath the first bottom hook, and a first lower stabilizing rail underneath the first bottom hook, wherein the first top hook, the first bottom hook, and the first bottom rail are positioned along the length of the inner surface of the second opposing zipper strip, and the first lower stabilizing rail is positioned along the length of the outer surface of the second opposing zipper strip; wherein the second top and bottom hooks of the first set of four rails being adapted to engage with the first top and bottom hooks of the second set of four rails, thereby interlocking the first opposing zipper strip with the second opposing zipper strip and creating four points of contact along the zipper closure; and

B) a slider for moving between a closed position and an open position along the first and second opposing zipper strips in straddling relation, the slider having a top surface and first and second side walls extending substantially perpendicularly from opposite sides of the top surface for receiving the first and second sets of four rails therebetween, the first and second side walls extending downward from the top of the first and second opposing zipper strips to a point at or below the first and second lower stabilizing rails, the first and second side walls extending from a separator end of the slider to a connecting end, the first and second side walls being spaced close enough at the connecting end to press the first and second opposing zipper strips into an interlocked relationship as the slider is moved toward the closed position, the slider having a center leg extending substantially perpendicularly from the top surface and between the first and second side walls at the separator end of the slider, the center leg extending between at least the first and second top hooks, wherein: (i) the top surface does not extend all the way to, but terminates a short distance from, an inner edge of one of two arms of each of the side walls at the separator end; and (ii) the edge of the center leg adjacent the separator end is not at, but terminates a short distance from, the edge of the top surface adjacent to the separator end.

2. The slider bag with zipper closure of claim 1 wherein the first and second opposing zipper strips are joined at a first and second pressed end to create a stop for the slider.

3. The slider bag with zipper closure of claim 2 wherein the stop has a substantially smooth surface.

4. The slider bag with zipper closure of claim 1 wherein the center leg extends between at least the first and second bottom hooks and terminates at a point above the bottom rail.

5. The slider bag with zipper closure of claim 4, wherein the first and second top and bottom hooks hold the first and second opposing zipper strips together such that when the slider is in the closed position, the first and second top and bottom hooks are interlocked throughout their entire length.

6. The slider bag with zipper closure of claim 2, wherein the first and second pressed ends create a stop and hold the first and second top and bottom hooks together such that when the slider is in the closed position, the first and second top and bottom hooks are interlocked throughout their entire length.

7. The slider bag with zipper closure of claim 1, wherein the first and second lower stabilizing rails maintain the slider in straddling relation with the first and second opposing zipper strips.

8. The slider bag with zipper closure of claim 7, wherein the two arms extend from each end of the first and second side walls toward and are congruent with the two arms of the second side wall and form approximately a 90 degree angle relative to the first and second side walls whereby the profile of each of the first and second side walls forms three sides of a rectangle.

9. The slider bag with zipper closure of claim 8, wherein the first and second side walls are substantially straight.

10. The slider bag with zipper closure of claim 8, wherein the two arms of the first and second side walls further maintain the slider in straddling relation to the first and second opposing zipper strips, and wherein the lower stabilizing rails form a track along the length of the zipper closure such that the two arms at each end of the first and second side walls grasp the slider bag below the ridge.

11. The slider bag with zipper closure of claim 1, the slider further comprising a pair of extensions having a connected end and a free end extending substantially perpendicularly from the top surface and substantially perpendicular to and between the first and second side walls behind the center leg, wherein the free ends of each of the extensions are spaced apart, and wherein the space between the free ends of each of the extensions is equal to or greater than the width of the center leg, and wherein the extensions straddle both of the first and second opposing zipper strips.

12. The slider bag with zipper closure of claim 11, wherein the space between the free ends of the extensions acts to pinch the first and second opposing zipper strips together and force the first and second top and bottom hooks into an interlocked position when the slider is moved to the closed position, and wherein the center leg disengages the first and second top and bottom hooks into a separated position when the slider is moved to the closed position.

13. The slider bag with zipper closure of claim 8, wherein the edge of the top surface does not extend all the way to, but terminates a short distance from, an inner edge of an arm of the first and second side walls at the separator end.

14. The slider bag with zipper closure of claim 8, wherein the edge of the top surface terminates between 2.5 mm and 3.0 mm from an inner edge of an arm of the first and second side walls at the separator end and the edge of the center leg adjacent to the separator end terminates between 0.3 mm and 0.5 mm from a separator edge.

15. The slider bag with zipper closure of claim 8, wherein the edge of the center leg adjacent to the separator end terminates a short distance from the edge of the top surface adjacent to the separator end.

16. The slider bag with zipper closure of claim 8, wherein the edge of the top surface terminates approximately 2.8 mm from an inner edge of an arm of the first and second side walls at the separator end and the edge of the center leg adjacent to the separator end terminates approximately 0.4 mm from a separator edge.

17. The slider bag with zipper closure of claim 16, wherein the edge of the center leg adjacent the separator end is at least 3 mm from the edge of the top surface adjacent the separator end.

18. The slider bag with zipper closure of claim 1, wherein he first and second top and bottom hooks extend inward from the first and second opposing zipper strips, form an angle of approximately 60 degrees on a first bottom side and of approximately 120 degrees on a first top side relative to the inner surfaces of the opposing zipper strips, and form a vertex at the intersection of the first and second top and bottom hooks with the inner surfaces of the first and second opposing zipper strips.

19. A slider bag with zipper closure comprising:

A) a zipper closure, wherein said zipper closure comprises: i) a first opposing zipper strip having an inner surface and an outer surface; ii) a second opposing zipper strip having an inner surface and an outer surface; iii) a first set of four rails comprising a top rail at the top of the first opposing zipper strip, a second top hook underneath the top rail, a second bottom hook underneath the second top hook, and a second lower stabilizing rail underneath the second bottom hook, wherein the top rail, the second top hook, and the second bottom hook are positioned along the length of the inner surface of the first opposing zipper strip, and the second lower stabilizing rail is positioned along the length of the outer surface of the first opposing zipper strip; and iv) a second set of four rails comprising a first top hook at the top of the second opposing zipper strip and underneath the top rail, a first bottom hook underneath the first top hook, a first bottom rail underneath the first bottom hook, and a first lower stabilizing rail underneath the first bottom hook, wherein the first top hook, the first bottom hook, and the first bottom rail are positioned along the length of the inner surface of the second opposing zipper strip, and the first lower stabilizing rail is positioned along the length of the outer surface of the second opposing zipper strip, wherein the second top and bottom hooks of the first set of four rails being adapted to engage with the first top and bottom hooks of the second set of four rails, thereby interlocking the first opposing zipper strip with the second opposing zipper strip and creating four points of contact along the zipper closure, and wherein the first and second top and bottom hooks extending inwardly from the first and second opposing zipper strips, and forming an angle of approximately 60 degrees on a first bottom side and of approximately 120 degrees on a first top side relative to the inner surfaces of the opposing zipper strips, and forming a vertex at the intersection of the first and second top and bottom hooks with the inner surfaces of the first and second opposing zipper strips; and

B) a slider for moving between a closed position and an open position along the first and second opposing zipper strips in straddling relation, the slider having a top surface and first and second side walls extending substantially perpendicularly from opposite sides of the top surface for receiving the first and second sets of four rails therebetween, the first and second side walls extending downward from the top of the first and second opposing zipper strips to a point at or below the first and second lower stabilizing rails, the first and second side walls extending from a separator end of the slider to a connecting end, the first and second side walls being spaced close enough at the connecting end to press the first and second opposing zipper strips into an interlocked relationship as the slider is moved toward the closed position, the slider having a center leg extending substantially perpendicularly from the top surface and between the first and second side walls at the separator end of the slider, the center leg extending between at least the first and second top hook, wherein: (i) the top surface does not extend all the way to, but terminates a short distance from, an inner edge of one of two arms of each of the side walls at the separator end; and (ii) the edge of the center leg adjacent the separator end is not at, but terminates a short distance from, the edge of the top surface adjacent to the separator end.

20. A slider bag with a zipper closure comprising:

A) a zipper closure, wherein said zipper closure comprises: i) a first opposing zipper strip having an inner surface and an outer surface;

ii) a second opposing zipper strip having an inner surface and an outer surface; iii) a first set of four rails comprising a top rail at the top of the first opposing zipper strip, a second top hook underneath the top rail, a second bottom hook underneath the second top hook, and a second lower stabilizing rail underneath the second bottom hook, wherein the top rail, the second top hook, and the second bottom hook are positioned along the length of the inner surface of the first opposing zipper strip, and the second lower stabilizing rail is positioned along the length of the outer surface of the first opposing zipper strip; and iv) a second set of four rails comprising a first top hook at the top of the second opposing zipper strip and underneath the top rail, a first bottom hook underneath the first top hook, a first bottom rail underneath the first bottom hook, and a first lower stabilizing rail underneath the first bottom hook, wherein the first top hook, the first bottom hook, and the first bottom rail are positioned along the length of the inner surface of the second opposing zipper strip, and the first lower stabilizing rail is positioned along the length of the outer surface of the second opposing zipper strip; wherein the second top and bottom hooks of the first set of four rails being adapted to engage with the first top and bottom hooks of the second set of four rails, thereby interlocking the first opposing zipper strip with the second opposing zipper strip and creating four points of contact along the zipper closure;

B) a slider for moving between a closed position and an open position along the first and second opposing zipper strips in straddling relation, the slider having a top surface and first and second side walls extending substantially perpendicularly from opposite sides of the top surface for receiving the first and second sets of four rails therebetween, the first and second side walls extending downward from the top of the first and second opposing zipper strips to a point at or below the first and second lower stabilizing rails, the first and second side walls extending from a separator end of the slider to a connecting end, the first and second side walls being spaced close enough at the connecting end to press the first and second opposing zipper strips into an interlocked relationship as the slider is moved toward the closed position, the slider having a center leg extending substantially perpendicularly from the top surface and between the first and second side walls at the separator end of the slider, the center leg extending between at least the first and second top hooks;

C) two arms extending from each end of the first and second side walls, wherein the two arms of the first side wall extend toward and are congruent with the two arms of the second side wall and form approximately a 90 degree angle relative to the first and second side walls whereby the profile of each of the first and second side walls forms three sides of a rectangle; and

D) a pair of extensions having a connected end and a free end extending substantially perpendicularly from the top surface and substantially perpendicular to and between the first and second side walls behind the center leg, wherein the free ends of each of the extensions are spaced apart;

wherein the edge of the top surface terminates approximately 2.8 mm from an inner edge of an arm of the first and second side walls at the separator end; the edge of the center leg adjacent to the separator end terminates approximately 0.4 mm from a separator edge; and the edge of the center leg adjacent the separator end is at least 3 mm from the edge of the top surface adjacent the separator end.