WO2008005976A9

WO2008005976A9 - Carton

Info

Publication number: WO2008005976A9
Application number: PCT/US2007/072724
Authority: WO
Inventors: Tamio Ikeda
Original assignee: Meadwestvaco Packaging Systems; Tamio Ikeda
Priority date: 2006-07-05
Filing date: 2007-07-03
Publication date: 2009-06-25
Also published as: JP2008013200A; EP2035298A1; WO2008005976A1

Abstract

A carton for holding a plurality of articles comprises a panel having a zipper. The opposed sides of the zipper are defined by a pair of severance lines respectively. Each severance lines has at least one row of a plurality of shaped short slits. At least some of the short slits adjacent to one end of the zipper are disposed in an opposite orientation to at least some of said short slits adjacent to the other end of said zipper so that severance of the zipper from the carton may be initiated from either end of the zipper.

Description

Carton

TECHNICAL FIELD

The present invention relates to a carton that contains multiple articles such as cans. More specifically, the present invention relates to an arrangement for facilitating opening of a carton.

Background of the Invention

Various types of cartons have been provided for consumers and distribution that store multiple articles such as cans and bottles for beverage (e.g., soft drink). In general, well-known types of cartons for storing articles are as follows: a box-shaped carton comprising a top wall panel, a bottom wall panel, and sidewall panels (left, right, front and back); a box-shaped carton, part of which is cut off to form a window so that the content can be confirmed; and a roundup carton of a cylindrical structure comprising a top wall panel, a bottom wall panel, and a pair of sidewall panels (front and back sides are open so that the content can be confirmed). There are also many other types of cartons including a roundup carton having partially closed structures (sidewall panels) on the open sections so as to prevent articles from dropping and a carton covering and holding only the top portion of articles. Some cartons have a holding section on one end or part of the top wall panel for the convenience of carrying and arranging articles.

Consumers who purchased a carton of articles carries it by holding a holding means formed on the top portion of the carton. Articles can be removed, for example, by breaking the carton by pulling a cut-off panel (zipper) formed on the top portion of the carton.

With a zipper as an opening means, a carton is usually opened by breaking it by pulling a band-shaped cut-off panel (zipper), that is, a severance line such as a perforated line punched out from starting points of breaking to its end points. However, the pulling direction of a zipper (i.e., the starting points and end points of breaking) is usually determined depending on the shape of the zipper or severance line. Therefore, a severance line, which is supposed to break by pulling, fails to do so if a zipper is inversely pulled from end points of breaking to its starting points. Instead, the severance line is ruptured toward the center of the band-shaped zipper.

To solve these problems, various types of cartons have been proposed that have no definite starting points or end points of breaking and therefore can be opened from either direction. As this type of cartons, the following cartons have been disclosed: a carton blank with a breaking tape buried therein that can be broken along the breaking tape by pulling it (see patent literature 1 below); and a carton having a zipper formed by continuously arranging severance lines such as perforated lines, the zipper having starting points of breaking at its both ends (see patent literatures 2 ~ 4 below). Conventional zippers are shown, for example, in US Patent No. 3,167,237, US patent No. 3,368,737, US patent No. 5,542,598 and US patent No. 3,865,366.

However, the carton such as is described in patent literature 1 has problems that an additional process is required for placing breaking tapes in addition to punching out of a carton blank, resulting in higher costs. The carton such as is described iα-patent literatures 2 - 4 had another problem that it is difficult to continuously break adjacent perforated lines once a rupture occurs off course, because the severance lines such as perforated lines are arranged linearly. As a result, a rupture occurs in places that are not supposed to be broken. The level of liability that severance lines are broken must be high in order to assure that breaking occurs surely along severance lines, resulting in lower strength of the carton. On the other hand, the level of liability that severance lines are broken must be low in order to increase the strength of the carton, resulting in the difficulty of breaking the severance lines. SUMMARY OF THE INVENTION

The present invention is related to a carton for holding a plurality of articles such as cans that has a cylindrical structure comprising a plurality of panels including a bottom wall panel, sidewall panels, and a top wall panel. The top wall panel has a zipper separated by a pair of severance lines on both sides breakable at the time of opening a carton. Each severance line has at least one row of a plurality of Z-shaped and inverse Z-shaped short slits. Of three Z-shaped and inverse Z-shaped sides, two sides on both ends extend in the same direction that each severance line extends. Severance lines consists of a pair of diverging sections that extend from the starting points of breaking, a pair of parallel sections that extend from the vicinity of the end points of the diverging sections, and a pair of converging sections that converge to the end points of breaking starting from the vicinity of the end points of the parallel sections. The starting points and the end points of breaking have a mirror-image association. So are the diverging sections and the converging sections. The zipper can be opened from both ends of the severance lines.

In the carton having the above constitution, breaking occurs along the severance lines because two sides out of three sides of a short slit constituting the severance lines extend in the same direction that the severance lines extend. Moreover, the remaining one side of those three sides extends at a certain angle to the direction of the severance lines (i.e., said one side is arranged such that it resists breaking). Therefore, if a rupture occurs off course, said remaining side resists it and brings the breaking back to the original direction.

Furthermore, a zipper can be broken from either side (i.e., either the starting points of breaking or their end points) because the starting points of breaking and its end points are formed symmetrical.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a plan view of a carton blank for forming a carton according to an embodiment the present invention.

Fig. 2 is a perspecitive view of the carton formed from the blank of Fig. 1.

Fig. 3 is a perspective view of the carton of Fig. 2, showing a method of opening the carton.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

A description of the embodiment of the present invention is given below by referring to drawings.

Fig. 1 is a carton blank made of bendable sheet material such as cardboard that is used for making a carton for storing multiple articles such as cans. In Fig. 1 , a carton blank 10a comprises the first bottom wall panel 11 , the first sidewall panel 12, the top wall panel 13, the second sidewall panel 14, and the second bottom wall panel 15 that are connected sequentially and bendably by pleat lines 21 , 22, 23, and 24. These panels 11 ~ 15 forms a rectangle-shaped cylindrical body. On the edges of those panels 11 ~ 15 are formed various panels and flaps as described below.

On the front side (left side in the drawing) and the rear side (right side in the drawing) of the first sidewall panel 12 and the second sidewall panel 14 are formed multiple folding panels 32 bendably by pleat lines 25. On the front and rear sides of the panels 11 ~ 15 are formed article support panels 33 bendably by pleat lines on both sides of pleat lines 21 , 22, 23, and 24. These article support panels 33 hold articles such as cans by hooking their upper and lower ends at a time when a carton is assembled, so that those articles do not fall off the carton.

On the first bottom wall panel 11 are punched out multiple joining flaps 31 that serve as joining sections at the time of assembling a carton. It is connected to the first bottom wall panel 11 (sic) bendably by a pleat line. On the second bottom wall panel 15 are formed multiple joining flap receptacles 41 that receive the joining flaps 31.

On the top wall panel 13 is formed a cut-off panel (zipper) 16 made of severance lines on both sides that comprises the starting points of breaking 51 , a plurality of Z- shaped or inverse Z-shaped short slits 52, and intermediate slits 53 at the center. These slits constitute a pair of diverging sections A that extend from the starting points of breaking 51 , a pair of parallel sections B that extend from the vicinity of the end points of the diverging sections A, and a pair of converging sections C that converge to the end points of breaking 54 starting from the vicinity of the end points of the parallel sections B. Since the zipper 16 is formed symmetrically by the intermediate slits 53 formed at the center of the parallel sections B, the diverging sections A and the converging sections C are equivalent, and therefore they are interchangeable. This is true for the starting points of breaking 51 and the end points of breaking 54.

Multiple short slits 52 constituting the diverging sections A are punched out to form inverse Z-shaped slits. Each slit has three sides. Of three sides constituting inverse Z-shaped short slits 52, two sides 52a and 52b are arranged in the same direction that severance lines extend. Likewise, multiple short slits 52 constituting the parallel sections B have inverse Z-shaped and Z-shaped slits. Of three sides, two sides 52c and 52d are arranged in the same direction that severance lines extend. At the center of the parallel sections B are punched out intermediate slits 53 consisting of five sides. Side 53a close to the diverging sections A, side 53b close to the converging sections C, and the side at the center are arranged in the same direction that severance lines extend. Multiple short slits 52 constituting the converging sections C are punched out to form Z-shaped slits. Each slit has three sides. Of three sides constituting Z-shaped short slits 52, two sides 52e and 52f are arranged in the same direction that severance lines extend.

On the front end of the zipper 16 (left in the drawing) is formed a finger tab 35a as the starting edge of breaking to open a carton. On the rear end of the zipper (right in the drawing) is formed a finger tab 35b used for opening the carton from the opposite side. At the center of the zipper 16 is punched out a holding means 34. One side of the holding means is connected to the zipper 16 bendably by a pleat line. A user can carry the carton by inserting his/her fingers into this holding means 34.

To assemble a carton out of the carton blank in Fig. 1 , a series of folding operations are performed. Folding operations are performed on a linear machine line without reversing or turning around a carton or a carton blank. A description of steps is given below, but the present invention is not limited to the following example.

First of all, article such as cans are placed on the top wall panel 13 that was placed horizontally. It is usual to place the can upside down (i.e., the top end of the can is down) on the top wall panel 13, but the invention is not limited to this practice. Next, folding panels 32 are folded 180 degrees inwardly along pleat lines 25 to closely attach them to the sidewall panels, and the first sidewall panel 12 and the second sidewall panel 14 are folded upward to closely attach those sidewall panels 12 and 13 (sic) to the sides of articles to be stored. Subsequently, the first bottom wall panel 11 and the second bottom wall panel 15 are folded 90 degrees relative to the first sidewall panel 12 and the second sidewall panel 14, respectively, along pleat lines 21 and 24. The bottom walls are folded on the lower end of cans successively in order of the second bottom wall panel 15 and the first bottom wall panel 11 so that a rectangle-shaped cylindrical body is formed that is open on its both sides. The first bottom wall panel 11 and the second bottom wall panel 15 are joined together by inserting the joining flaps 31 formed on the first bottom wall panel 11 into the joining flap receptacles 41 by, for example, pressing down the joining flaps 31 with fingers. Joining methods can arbitrarily be selected instead of using the joining flaps 31 (e.g., pasting). Fig. 2 shows a package loaded with multiple cans in a carton.

To remove cans from the carton, the finger tab 35a on the zipper 16 must be pulled upward or toward the rear section of the carton. As a result, breaking occurs at the both edges of the finger tab 35a (i.e., starting points of breaking 51 ). This breaking is spread to the short slit 52, especially to the side 52a, that is the closest to the starting points of breaking 51. The further pulling of the finger tab 35a breaks the short slit 52 all the way and further breaking starts from the side 52b. This breaking is spread to the second short slit 52, especially to the side 52a. In the same way, breaking spreads from one short slit to another, resulting in the breaking of the diverging section A all the way. After that, breaking of the side 52b of the last slit 52 of the diverging section A spreads to the side 52c of the first slit 52 of the parallel section B. In the same way, breaking spread from one slit to another to break the parallel section B and the converging section C all the way, with the result that the carton is opened.

In general, breaking tends to spread toward the inside of a zipper at a time when a finger tab is pulled upward to open the zipper. Therefore, there occurs a problem in traditional cartons disclosed by, for example, patent literatures 2 - 4 that breaking spread inwardly instead of spreading to the adjacent slit, which causes the zipper to be damaged. This is because slits are arranged linearly. On the other hand, breaking that starts from the side 52b of the slit 52 can be stopped in the present invention if it spreads inwardly, because the middle side of three sides of the adjacent slit 52 is placed more inwardly than the direction of breaking and furthermore has an angle to it. The side 52a of the adjacent slit 52 can also stop any breaking (that spreads inwardly) because it extends more inwardly than the middle side. Thus, breaking spread from one slit 52 to another without causing any damage to zipper.

In the traditional zippers, slits are linearly arranged. Therefore, breaking must be spread accurately on a straight line from one slit to next. This requires bringing up the level of liability that severance lines are broken by, for example, shortening the distance between slits or using carton material that can easily be broken, which results in sacrificing the strength of cartons. On the other hand, breaking can accurately be spread in the present invention without sacrificing the strength of cartons if breaking spreads non-linearly. This is because breaking that occurs in one slit can be received by the middle side or more inward side of the adjacent slit, meaning that some latitude is given in the direction that breaking spreads. In the present invention, a zipper is formed symmetrically relative to the intermediate slit 53. As a reverse of the above explanation, it is also possible to open a carton by pulling the finger tab 35b upward to break the end points of breaking 54 and spreading breaking successively in order of the converging section C, the parallel section B, diverging section A, and the starting points of breaking 51 (see Fig. 1). Thus, the invention is user-friendlier than the traditional way. Fig. 3 shows a way of opening a carton from both sides.

As described above, breaking can accurately be spread from one slit to next by shortening the distance between the short slits 52, meaning that the zipper 16 can be opened without a hitch. However, shortening the distance may have a problem that the strength of the top wall panel declines, so much so that a carton may be destroyed unintentionally before opening it. On the contrary, the strength of a carton increases if the distance between slits is widened. However, widening the distance may have a problem that breaking cannot be spread well enough, and therefore places other than a zipper may be broken. In practice, the distance between slits can be selected, as the case may demand, by taking breaking of a zipper and the strength of a carton into consideration.

The present invention is not limited to a carton with a zipper to be removed by linearly crossing over the top wall panel, as described in the embodiment. Any shape of a zipper is acceptable. For example, it is possible to apply the invention to a carton with a U-shaped zipper in which a pair of zippers on the parallel sections comes closer to each other on the rear end side by making a curve and connected at the end of the zippers so that the top wall panel is kept being connected at the rear end section even after the zippers were removed.

The terms used above indicating directions such as top, bottom, end, tip, rear, inward, and outward are not used for limiting each panel to such a direction but are used only for distinguishing panels from each other. The term "pleat line" does not necessarily means a single pleat line. Within the scope of the invention, it could be one pitch line or multiple pitch lines or lines that can easily be folded or bent such as perforated lines and lines whose thickness is reduced by press embossing. The present invention can be applied to cartons used for arranging articles in a wide variety of ways, as far as it does not go beyond the scope of the invention.

Claims

1. A carton for holding a plurality of articles, wherein said carton comprises a panel having a zipper, opposed sides of said zipper being defined by a pair of severance lines respectively, wherein each of said severance lines has at least one row of a plurality of shaped short slits, wherein at least some of said short slits adjacent to one end of said zipper are disposed in an opposite orientation to at least some of said short slits adjacent to the other end of said zipper so that severance of said zipper from said carton may be initiated from either end of said zipper.

2. The carton according to claim 1 wherein each of said short slits is generally Z- shaped or generally inverse Z-shaped.

3. The carton according to claim 2 wherein said each short slit comprises a pair of opposite end segments and an intermediate segment interconnecting said opposite segments, said opposite end segments extending in a direction in which said each severance line generally extends.

4. The carton according to claim 3 wherein said severance lines has a pair of diverging sections that extend from a first end of said zipper, a pair of parallel sections that extend generally from the diverging sections, and a pair of converging sections that extends generally from the parallel sections and converge at a second end of said zipper, wherein said short slits in said diverging sections are disposed in a mirror-image opposite orientation to said short slits in said converging sections.