Spool for fastener strips and method of winding fastener strips

Abstract

A spool for a fastener strip includes a cylinder comprising a substantially U-shaped recess or protrusion for accommodating a turn in the fastener strip such that an upstream portion and a downstream portion of the fastener strip can point in the same direction. The recess or protrusion allows the strip to be wound onto the spool in such a manner that when the strip is unwound, there is a sufficiently long lead of fastener strip to allow an operator to replace the emptied spool with a new spool and to splice an upstream end of the strip from the emptied spool with a downstream end of the strip from the new spool.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional Application No. 60/684,519, filed on May 26, 2005; the entire content of which is hereby incorporated by reference.

FIELD OF THE INVENTION

The present invention generally relates to a spool for fastener strips and a method of winding a fastener strip.

BACKGROUND

Typically, reclosable bags or pouches are made by joining a pre-made fastener strip or zipper strip with a web of packaging material. The fastener strip is usually flat and wide. The fastener strip is commonly sold and fed in a production line on a spool or roll. When the fastener strip on the spool runs out, the old spool is replaced with a new spool, and ends of the fastener strip from the two spools are spliced together.

However, a drawback occurs when the fastener strip on the spool runs out. In particular, the production line needs to be stopped for the spools to be replaced and the ends of the fastener strip from the old spool and the new spool to be spliced together. This often causes delay and/or disruption in the bag manufacturing process as well as delay and/or disruption in any integrated downstream process steps.

Therefore, there is a need in the art to provide a spool for a fastener strip and a method of winding that strip so as to allow the spool to be replaced and the two ends of the fastener strips to be spliced together without stopping the process line.

SUMMARY

An exemplary spool for fastener strips comprises a cylinder on which to wind a fastener strip. The cylinder includes a substantially U-shaped recess for accommodating a turn in the fastener strip such that an upstream portion and a downstream portion of the fastener strip can point in the same direction.

Another exemplary spool for fastener strips comprises a cylinder on which to wind a fastener strip. The cylinder includes a substantially U-shaped protrusion for accommodating a turn in the fastener strip such that an upstream portion and a downstream portion of the fastener strip can point in the same direction.

An exemplary method of winding a fastener strip comprises providing a spool comprising a substantially U-shaped recess and winding a fastener strip around the substantially U-shaped recess such that an upstream portion and a downstream portion of the fastener strip point in the same direction.

Another exemplary method of winding a fastener strip comprises providing a spool comprising a substantially U-shaped protrusion and winding a fastener strip around the substantially U-shaped protrusion such that an upstream portion and a downstream portion of the fastener strip point in the same direction.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings provide visual representations which will be used to more fully describe the representative embodiments disclosed herein and can be used by those skilled in the art to better understand them and their inherent advantages. In these drawings, like reference numerals identify corresponding elements and:

FIG. 1A shows a side view of an-exemplary embodiment of the spool of the present invention.

FIG. 1B shows a front elevational view of the exemplary embodiment of FIG. 1A.

FIG. 2A shows a side view of another exemplary embodiment of the present invention.

FIG. 2B shows a front elevational view of the exemplary embodiment of FIG. 2B.

FIG. 3 shows a perspective view of the spool of the present invention with a fastener strip attached.

FIG. 4 shows another perspective view of the spool of the present invention with a fastener strip attached.

FIG. 5 shows a perspective view of the correlation between the upstream end of a fastener strip of an emptied spool and the downstream end of a fastener strip of a new spool to be spliced each other.

DETAILED DESCRIPTION

The spool according to the present invention allows a fastener strip to be wound thereon in such a way that a processing line need not be stopped when the spool runs out of fastener strip. In particular, the spool has a cylinder on which the fastener strip is wound. The cylinder is provided with a recess or a protrusion on its circumferential surface to accommodate a U-turn in the fastener strip when the strip is wound onto the spool. The recess or protrusion should have a size and shape such that the strip can rest in or on the recess or protrusion and that additional fastener strip can be wound around and/or on top of the recess or protrusion without permanently deforming the strip in or on the recess or protrusion.

Preferably, the recess or protrusion has a substantially U shape. The term “substantially U shape” or “substantially U-shaped” is used herein to include shapes that can accommodate a change in direction of the fastener strip. Such shapes include semi-circles, semi-ovals, V shapes, and U shapes.

Preferably, the open end of the substantially U-shaped recess or protrusion is pointed in the machine direction or the direction in which the fastener strip is unwound.

When a fastener strip is placed in the recess or around the protrusion, and wound onto the cylinder of the spool, a sufficient amount of strip should be provided on the upstream end such that an operator can have sufficient time to replace the spent spool with a new spool and to splice one end of the strip from the spent spool with a downstream end of the strip from the new spool, without stopping the production line in which the strip is used.

FIGS. 1A and 1B show an exemplary spool 10 according to the present invention. The spool 10 has a cylinder 12 having a circumferential surface 14 onto which a fastener strip can be wound. According to the exemplary embodiment, the outer surface 14 of the cylinder 12 includes recess 30 for receiving a portion of the fastener strip therein. The recess 30 is substantially U-shaped.

The recess 30 allows for the fastener strip to be wound on top of the U turn in the strip without permanently deforming it. Preferably, the recess 30 is deepest and narrowest at its center portion 32, and shallows and widens towards the sides 34 (not shown). At the deepest point, the fastener strip is substantially perpendicular to the outer surface of the cylinder 12, and mostly or completely held within the recess 30. The width of the recess 30 at the center portion 32 should be at least equal to the thickness of the fastener strip so that the strip can fit into and fall easily out of the recess 30 when the spool is unwound. As the fastener strip moves to the sides 34 as shown in FIGS. 3 and 4, it becomes substantially flat so that it can be wound onto the cylinder 12.

Preferably, the distance L between the ends 36 of the recess is less than or equal to the width W of the cylinder 12 minus two times the width of the fastener strip. In addition, the radius of curvature R of the recess should be sufficiently large so that the fastener strip does not become permanently deformed when it is bent to conform to the U shape.

FIGS. 2A and 2B show another exemplary spool 50 according to the present invention. The spool 50 has a cylinder 52 having a circumferential surface 54 onto which a fastener strip can be wound. According to the exemplary embodiment, the outer surface 54 of the cylinder 52 includes a protrusion 56 for supporting a portion of the fastener strip thereon. The protrusion 56 is substantially U-shaped.

The protrusion 56 allows for the fastener strip to be wound on top of the U turn in the strip without permanently deforming it. Preferably, the protrusion is highest at its center 72, and tapers down towards the sides 74 (not shown). At the highest point, the fastener strip is substantially perpendicular to the outer surface of the cylinder 52, and the height of the center 72 is about the width of the fastener strip. As the fastener strip moves to the sides 74 as shown in FIGS. 3 and 4, it becomes substantially flat so that it can be wound onto the cylinder 52.

Preferably, the distance L between the ends 76 of the protrusion is less than or equal to the width W of the cylinder 52 minus two times the width of the fastener strip. In addition, the radius of curvature R of the protrusion should be sufficiently large so that the fastener strip does not become permanently deformed when it is bent to conform to the U shape.

FIGS. 3 and 4 depict a method of winding the fastener strip according to the invention. For illustration purposes, a fastener strip 20 is shown with the spool 10 from FIGS. 1A and 1B. In FIG. 3, the fastener strip 20 is placed or wound in the recess (not shown) of the spool 10 such that an upstream end 22 and a downstream end 24 of the fastener strip 20 can point in the same direction. The downstream end 24 of the fastener strip is rolled onto the cylinder 12 in the normal fashion as shown in FIG. 4. The upstream end 22 is provided with a length Ls of the strip to be wound onto the cylinder 12. This length of strip should be sufficiently long in order to provide an operator with enough time to exchange the emptied spool 10 with a new spool 10′ as depicted in FIG. 5 and to splice the downstream end 24′ of the new spool 10′ with an upstream end 22 of the emptied spool 10.

The fastener strip of the present invention is of the type used for reclosable bags or pouches. The fastener strip may be a zipper-type fastener, or may be a press-to-close device. However, it should be understood that the present invention may apply to other types of fastener strips or securing devices for packages that are applied in a process line.

The presently disclosed embodiments are considered in all respects to be illustrative and not restrictive. The scope is indicated by the appended claims, rather than the foregoing description, and all changes that come within the meaning and range of equivalents thereof are intended to be embraced.

Claims

1. A spool for holding a fastener strip, comprising:

a cylinder on which to wind a fastener strip, said cylinder comprising a substantially U-shaped recess for accommodating a turn in said fastener strip such that an upstream portion and a downstream portion of said fastener strip can point in the same direction.

2. The spool of claim 1, wherein at least a portion of said recess has a depth at least equal to the width of said fastener strip.

3. The spool of claim 1, wherein said recess has a radius of curvature at least equal to the radius of curvature that said fastener strip can be bent without permanently deforming the fastener strip.

4. A spool for holding a fastener strip, comprising:

a cylinder on which to wind a fastener strip, said cylinder comprising a substantially U-shaped protrusion for accommodating a turn in said fastener strip such that an upstream portion and a downstream portion of said fastener strip can point in the same direction.

5. The spool of claim 4, wherein at least a portion of said protrusion has a height at least equal to the width of said fastener strip.

6. The spool of claim 4, wherein said protrusion has a radius of curvature at least equal to the radius of curvature that said fastener strip can be bent without permanently deforming the fastener strip.

7. A method of winding a fastener strip, comprising:

providing a spool according to claim 1;

winding a fastener strip around the substantially U-shaped recess such that an upstream portion and a downstream portion of said fastener strip point in the same direction.

8. The method of claim 7, wherein the upstream portion of said fastener strip is sufficiently long to allow an operator to replace a spool depleted in fastener strip with a new spool and to splice an upstream end of the fastener strip from the depleted spool with a downstream end of a fastener strip from the new spool without stopping a production line employing said fastener strip.

9. A method of winding a fastener strip, comprising:

providing a spool according to claim 4;

winding said fastener strip around the substantially U-shaped protrusion such that an upstream portion and a downstream portion of said fastener strip point in the same direction.

10. The method of claim 9, wherein the upstream portion of said fastener strip is sufficiently long to allow an operator to replace a spool depleted in fastener strip with a new spool and to splice an upstream end of the fastener strip from the depleted spool with a downstream end of a fastener strip from the new spool without stopping a production line employing said fastener strip.