GB2196609A - Containers - Google Patents

Abstract

A four-sided container is formed from a blank having four flaps (6,6',7,7') which interlock to form the base. The flaps are so designed that those attached to opposite side panels (1,1',2,2') of the container are identical. One pair of flaps (6,6') are provided with interlocking portions (9) which engage one another when the base is formed. The container has rotational symmetry about 180 DEG and thus the orientation of the container before assembly of the base is not essential, making assembly of the base much easier. Alternatively, the container may comprise two identical blanks each defining a pair of adjacent side panels (1,2 or 1',2') bearing the corresponding flaps (6,7 or 6',7'). <IMAGE>

Description

SPECIFICATION Containers This invention relates to containers made of cardboard, corrugated board or similar lightweight semi-rigid sheet material.

It is known to make the hase of such a container from a number of flaps, hingedly connected to side walls thereof, which are arranged to interlock to form a stable base without any need to connect the flaps together by, for example, staples or glue. Such a base is assembled by first forcing up the side walls of the container, then pushing the base-forming flaps inwardly in an appropriate sequence so that they interengage in the intended manner, and then pushing them outwardly whereupon they interlock to form the base. Such a container is said to have a "push-lock" base and will be referred to as such hereinafter.

A person assembling this kind of container tends to assemble the container by folding in the base flaps in a particular sequence, and will generally prefer to apply substantially the same folding operation to each container. In one known four-sided container, for example, with four base-forming flaps, if these flaps are designated A, B, C, D around the container they are pushed in in the order A, B, D, C. In containers of this type the base flaps are arranged in such a way that, if an identical folding operation is to be applied to each container, the assembler must ensure that each container is oriented in a particular way before commencing the folding operation. Otherwise some of the containers will be incorrectly assembled, or alternatively the assembler will have to use a different folding operation depending on the orientation of the container.

Viewed from one aspect the present invention provides a four-sided container made of cardboard, corrugated board or similar lightweight semi-rigid sheet material, having a push-lock base as hereinbefore described formed by four flaps hingedly connected to the respective side walls, wherein opposed said base-forming flaps have substantial rotational symmetry about 1800 around a central vertical axis of the container, whereby a person assembling the base of a said container may use substantially the same folding operation to interlock the flaps when one side of said container faces the person as when a side opposite to such one side faces the person.

Such an arrangement makes the process of assembly much easier than in the known containers mentioned above, because it is no longer desirable to place the container in a particular orientation before assembly.

In a preferred embodiment the container may be adapted to be readily assembled by pushing in one opposite pair of said flaps and then pushing in the other opposite pair.

Preferably the flaps of each opposite pair have substantially the same shape. This has the additional advantage that when a large case is being formed from two pieces, each piece may have the same shape and thus only one die-cutting forme is necessary, thus achieving a saving in terms of forme costs and production set up times since with conventional flap designs at least two different formes must be used. Furthermore, owing to this flap symmetry, it is possible to interlock two or more case blanks (depending on size) on one die-cutting forme, thus saving material.

In a preferred embodiment the base flaps that are connected to the side panels of the container (side flaps) are provided, substantially half-way along their length, with locking portions by means of which, when the side flaps are pushed in, the side flaps engage one another. The flaps connected to the end panels (end flaps) may be provided with tablike portions which, when the container is assembled, lie on the inside of the side flaps. In such a preferred embodiment the container may be assembled by firstly pushing in the opposed end flaps and subsequently pushing in the opposed side flaps so that they engage one another by means of the locking portions, and overly the tab-like portions of the end flaps. All the base flaps may then be pushed outwardly from inside the container to form a stable locked base.

Viewed from a second aspect the invention extends to a blank or a combination of blanks for making a container as aforesaid.

Some embodiments of the invention will now be described by way of example and with reference to the accompanying drawings, in which: Fig. 1 is a plan view of a one piece blank according to a first embodiment, Fig. 2 is a plan view of one half of a two piece blank forming an identical container to the embodiment of Fig.1, Fig. 3 is a perspective view from the inside, of the base of a container formed from the blank(s) shown in Fig. 1 or Fig. 2, Fig. 4 is a perspective view from the outside of the container base shown in Fig. 3 prior to the flaps being pushed out, Fig. 5 is a plan view of a one piece blank according to a second embodiment, Fig. 6 is a view showing how two blanks as shown in Fig. 5 may be formed from one piece of sheet material with one die-cutting forme, and Fig. 7 is a perspective view from the inside of the base of a container formed from the blank shown in Fig. 5.

Referring firstly to Fig. 1 there is shown a container blank comprising two side panels 1, 1' and two end panels 2, 2'. The side and end panels are divided from each other by scored fold lines. Attached to the side panel 1' at the end of the blank is a tab 4 which, by means of adhesive, may be used to secure side panel 1' to end panel 2 so as to form the basic container configuration.

Along one side of the blank, attached to the side and end panels, are upper closure flaps 5 which may be of any conventional configuration. Along the other side of the blank, also hingedly attached to the side and end panels, are flaps 6, 6', 7, 7' which, when the container is assembled, will form the base of the container.

The two base flaps 6, 6' which are connected to the side panels 1. 1', and which therefore will be opposite one another when the side and end panels are folded to form the basic container shape, are identical to one another. Similarly the base flaps 7, 7' connected to the end panels 2,2', which will also form an opposite pair in the completed container, are identical.

The embodiment of Fig.1 shows a onepiece blank for forming a container, however, if the container is particularly large, it may be desirable to use a blank formed from two pieces. Since the base forming flaps comprise two identical pairs, as of course do the side and end panels, it is possible to form the container from a two-piece blank comprising two identical pieces. Since the pieces are identical only one die-cutting forme is required. Fig. 2 shows one piece 8 of a twopiece blank that will form a container identical to that produce by the blank of Fig. 1. Two pieces 8 may be joined together by means of tab 4' to form a blank identical to that shown in Fig. 1.

To describe the base forming flaps in more detail the flaps connected to the side panels, 6, 6' will be referred to as side flaps while flaps 7, 7' will be referred to as end flaps.

The side flaps 6, 6' have a locking step portion 9 substantially half-way along the flap and a sloping edge 10 at one end of the flap, the other end 10' being perpendicular to the edge of the side panel. The end flaps 7, 7' have a sloping edge 11 at one end and a tab portion 12 at the other end.

To assemble the base the two end flaps 7, 7' are pushed in first and then the side flaps 6, 6' are pushed in until their perpendicular ends 10' pass the sloping edges 11 of the end flaps as is shown in Fig. 4. The base flaps are then pushed out to form the locked base shown in Fig 3. As will be seen from Fig. 3 the two side flaps 6, 6' are interlocked by means of their respective locking step portions which engage one another. The tab portions 12 of the end flaps 7,7' overly, that is are on the inside of, the sloping edges 10 of the side flaps.

It will thus be appreciated that the symmetrical nature of the base flaps enables the base to be assembled by the same folding operation whichever end of the container is presented first. Thus it is not necessary for the partly assembled container to be presented to a person assembling the container in any special orientation, or for the person to employ a different folding operation depending on the orientation.

Fig. 5 shows an embodiment in which the container is relatively narrow compared with the embodiment of Figs 1 to 4. In the embodiment of Fig. 5 the side and end flaps 16, 16', 17, 17' are adapted to provide a firm base for a relatively narrow container. The principal difference between the embodiments of Fig. 5 and Figs 1 to 4 lies in the shape of the side flaps. In the embodiment of Fig. 5 the locking step 19 is sloped, rather than being normal to the edge of the flap, and is additionally provided with a slit 20. Furthermore while one end of the flap is provided with the same sloped edge as in Fig. 1, the other end also has an edge that is slanted slightly rather than being normal to the flap edge as in the embodiment of Fig.1.

The end flaps 17, 17' of the embodiment of Fig. 5 are also slightly different from the corresponding end flaps 7, 7' of the embodiment of Fib. 1. In particular the sloped edges 21 are less steep and lead to a somewhat undercut tab portion 22.

Figure 6 shows the interlocked base after assembly of the blank shown in Fig. 5. As will be seen the side flaps 16, 16' are interlocked by means of their locking steps 9 while the tab portions 22 of the end flaps overly the side flaps.

Fig.7 shows how two one-piece blanks, of the type shown in Fig. 5 may be formed from one piece of material using a single die-cutting forme. The two blanks are interlocked with their base flaps adjacent. As a result of the symmetry of the base flaps, the two blanks may be interlocked in such a manner and produced using one die-cutting forme with a saving of material.

While the above described preferred embodiments relate to containers that have a generally rectangular cross-section having a length substantially greater than its width, and reference has been made to side and end panels, and side and end flaps, it will be appreciated that the invention may be applied to a container of generally square cross-section having a length substantially equal to its width. The terms "side" and "end" are used therefore merely for convenience of description and are not intended to have any limiting effect.

Claims (7)

1. A four-sided container made of cardboard, corrugated board or similar lightweight semi-rigid sheet material, having a push-lock base as hereinbefore described formed by four flaps hingedly connected to the respective side walls, wherein opposed said base-forming flaps have substantial rotational symmetry about 180C around a central vertical axis of the container, whereby a person assembling the base of a said container may use substantially the same folding operation to interlock the flaps when one side of said container faces the person as when a side opposite to such one side faces the person.

2. A container as claimed in claim 1 wherein said container is adapted to be readily assembled by pushing in one opposite pair of said flaps and then pushing in the other opposite pair.

3. A container as claimed in claim 2 wherein the flaps of each said opposite pair have substantially the same shape.

4. A container as claimed in claim 1,2 or 3 wherein a first pair of base flaps that are connected to one opposed pair of side panels are provided, substantially half-way along their length, with locking portions by means of which, when said flaps are pushed in they engage one another.

5. A container as claimed in claim 4 wherein the other pair of flaps are provided with tab-like portions which, when the container is assembled, lie on the inside of the first pair of flaps.

6. A four-sided container substantially as hereinbefore described with reference to the accompanying drawings.

7. A blank or a combination of blanks for making a container as claimed in any preceding claim.