GB1603429A

GB1603429A - Containers

Info

Publication number: GB1603429A
Application number: GB3801477A
Authority: GB
Original assignee: LIN PAC CONTAINERS Ltd
Current assignee: LIN PAC CONTAINERS Ltd
Priority date: 1978-05-22
Filing date: 1978-05-22
Publication date: 1981-11-25

Description

(54) IMPROVEMENTS IN OR RELATING TO CONTAINERS (71) We, LIN PAC CONTAINERS LIM ITED, of Charles Street, Louth, Lincolnshire, LNI I OLA, a British Company, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement :- This invention relates to containers made of sheet material, which can be collapsed substantially flat. The invention is concerned especially with such containers of sheet material, typically corrugated board, which are formed by converting the sheet material into flat blanks by applying crease lines, perforations, slits, slots or other features to the board or other sheet material, so as to enable the resultant blanks to form the desired containers. An example of a form of container with which this invention is concerned is a generally rectangular box with upstanding side and end walls about its base, the top being substantially open, but with supporting straps in the form of inturned flaps located along the tops of at least the sides of the box. Other examples of the invention do not have this feature, as indicated below, but where it is provided the containers can be readily stacked and are especially useful for holding delicate articles, such as horticultural produce. These supporting straps can be made so that they are in tension in the finished boxes. Not only do such straps allow similar boxes to be stacked, but the otherwise open tops also allowing their contents to be seen. Containers of this kind are very commonly used for the transport and sale of vegetable produce, as they can be filled as the produce is gathered.

Examples of blanks and boxes of this general kind are disclosed in our previous Patent Specification No. 1249884 and the boxes disclosed therein have the further advantageous feature that they can be collapsed substantially flat, by folding the appropriate panels of the boxes about crease and other lines provided in the blanks. This enables the blanks to be made up into the boxes in the flat collapsed condition, so that a greatly increased number of boxes can be located, in the flat condition, in a given space, for example in a lorry or truck, for delivery to fields or greenhouses where vegetable produce is being grown. A further advantage is that the workers need carry out only the simplest operations in order to erect the flat boxes into the open condition so that they are ready to be filled, with the supporting straps tensioned and disposed in position for use.

The present invention provides containers and blanks therefor which have many possible uses, but which are particularly suited for use as collapsible produce boxes of the kind mentioned. One general principle which should be applied, so far as possible, in the design of a container blank and of the resultant container is to use the simplest conversion operations, both in turning the sheet material into the blanks and in forming the latter into the containers. Another general principle of good container design is the avoidance, so far as possible, of cutting operations, especially those which remove, and so waste, material in converting the board into blanks. Both of these principles are clearly apparent in the blanks and containers of the present invention.

According to one aspect of this invention, there is provided a container of sheet material which can be collapsed substantially flat and which comprises a rectangular base with side walls hingedly connected to two opposed edges and end walls hingedly connected to the other two opposed edges, a part of the base adjacent each end wall being defined between creases which extend obliquely from respective corners of the base to a crease extending centrally of the base and an intermediate panel at each corner of the base connected to an associated pair of adjacent side and end walls by respective creases, the central base crease extending centrally of each end wall and being arranged to make a reverse fold in each part adjacent an end wall and a normal fold along the remainder of its length in the base, whereby each end wall and the adjacent part of the base folds inwardly and the remainder of the base folds outwardly about a central plane of the erected container as it is collapsed substan tially flat.

Preferably, the container has an inturned supporting strap along the top of each side wall. Such straps desirably are in tension in the erected container and fold adjacent their ends as the container collapses into the substantially flat state.

A preferred feature of the container of the invention. where it is provided with supporting straps, is that each strap is hingedly connected at each end to a flap located along the top of an end wall. Most preferably, each flap is attached to the outside of the associated end wall. In an especially preferred embodiment of the container of the invention, each supporting strap and the flaps connected to it are constituted by an edge panel, a delta crease formation being provided in the edge panel where the strap is connected to a flap.

An advantageous feature which boxes and other containers according to the invention preferably have are a hole or holes, preferably but not necessarily circular, at least at one of those places where folding in more than one direction occurs locally, either as the box is changing from the erected condition to the collapsed or vice versa or when the container is in one or other such condition. Preferably, the holes are provided where the centre of each end wall is connected to the base and/or where the inwardly-folding parts of the base meet the remainder of the base. Where the container includes the supporting straps already described, the holes are provided at each end of a supporting strap where it meets the associated side wall. These holes preclude the build-up of multiple thicknesses of material which would otherwise arise at such places and so relieve excessive compression. It is also possible, within the scope of this invention, to provide holes or cut-outs for additional purposes; for example, the blanks can include hand holes, to assist the user in lifting the containers made from the blanks, and also ventilation holes. Some forms of container can have both hand holes and ventilation holes.

Another advantageous feature preferably possessed by containers according to the invention is the provision of one or more additional creases, within the parts of the base which fold inwardly, preferably disposed perpendicularly to the central crease provided in the container base. These one or more creases serve as aids to collapsing of the container.

A further advantageous feature preferably possessed by containers according to the invention is that they are formed from rectangular or other simple shapes of blanks provided with creases but (except for any pressure-relieving holes or other holes for lifting, ventilation or other purposes, as mentioned above) no cuts are made in the rectangular sheets forming the blanks and none of the material is removed.

The invention also provides a blank, preferably unitary, for forming a container as defined, such blank comprising a rectangular base portion with side wall portions hingedly connected to opposed edges and end wall portions hingedly connected to the other two opposed edges, a part of the base portion adjacent each end wall portion being defined between creases which extend obliquely from respective corners of the base portion to a crease extending centrally of the the base portion and an intermediate panel at each corner of the base portion hingedly connected to an associated pair of adjacent side and end wall portions by respective creases, the central base portion crease extending centrally of each end wall portion and being arranged to make a reverse fold in each part adjacent an end wall portion and a normal fold along the remainder of its length, and each intermediate panel being pivotally connected to its associated side wall portion by the respective crease, whereby, in the container erected from the blank, each end wall portion and the adjacent part of the base portion folds inwardly and the remainder of the base portion folds outwardly about a central plane of the container as it is collapsed substantially flat.

One or more, preferably four, crease lines perpendicular to the central, base portion crease line preferably is/are provided in the part bounded by each pair of oblique creases.

Pressure-relieving holes are desirably provided on the central creases, preferably both where it intersects the creases separating the base portion from the end wall portions and also where the pairs of oblique creases meet it. The region of the central crease between one pair of oblique creases and the other, or between holes provided in the blank at these places, is the part which folds outwardly as the erected container made from the blank is collapsed flat. This part preferably is defined by two or three close and parallel crease lines, to assist the sheet material to fold.

References to creases in this specification mean both actual creases formed in the sheet material and lines along which creases can be made by folding the material. The container blanks of the invention are preferably rectan- gular and symmetrical about the central crease line. However, a container consisting inter alia of a base and opposed pairs of side and end wall portions can be made from a blank which is symmetrical about the central line through the base portion or from any of many other blanks, which have the same wall portions arranged differently. For example, instead of adjoining one edge of the base portion, a side wall portion can adjoin one of the end wall portions or both can adjoin an intermediate panel which is eliminated, e. g. by cutting or folding, when the blank is made into a container. Blanks are preferably rectangular and symmetrical, as this arrangement usually minimises cutting and wastage, but the many different arrangements possible are equivalent. The present invention thus includes any form of blank which is equivalent to one which is rectangular and symmetrical, together with any form of container having the features characteristic of the invention made from any such preferred form of blank or any feasible equivalent of it.

In order that this invention may be fully appreciated, preferred forms of blank and preferred forms of container are described below, by way of illustration only, in conjunction with the accompanying drawings, wherein: Fig. I shows a unitary container blank, made for instance of corrugated board or other suitable rigid creasable and foldable sheet material; Figs. 2 and 3 show a container in the form of a collapsible produce box having supporting straps, Fig. 2 showing it in perspective view in the flat collapsed state and Fig. 3 showing it, also in perspective view, in the erected state ready for use; Fig. 4 shows a part of a modified form of unitary blank, differing from that of Fig. I mainly in relation to the proportions of the resultant container; Fig. 5 shows a fragmentary perspective view of the container made from the form of blank shown in Fig. 4 to indicate that the same ability to collapse flat is provided.

In Figs. I and 4, broken lines indicate creases, so that double broken lines indicate closely parallel double creases, which allow the material to bend either in a reverse crease or about one or more thicknesses of another part of the blank. Triple broken lines indicate closely parallel triple creases. Chaindotted lines indicate reverse creases. Circles (not necessarily to scale) denote pressurerelieving holes (which are not necessarily circular) which are punched through the sheet material; corrugated board is the sheet material preferably used to make the blank.

The blank 11 shown in Fig. 1 is a rectangle and (apart from the pressure-relieving holes, mentioned in detail below, hand holes for lifting, such as indicated at 10as ventilation holes, such as indicated in one side wall only au lob or other special features) no material has been removed in converting the sheet material into the blank 11 and no cuts have been made in it. An opposed pair of crease lines 12, 12 extend from one side to the other and cross a second opposed pair of crease lines 13, 13 at right-angles. These divide the blank into areas which comprise a rectangular base portion 14, a pair of side wall portions 15,15, a pair of end wall portions 16, 16 and four intermediate or corner panels 17, each of the latter being joined to a side wall portion 15 and an end wall portion 16.

At each corner, therefore, each side wall portion and end wall portion are hingedly connected, both in the blank and in the container formed from it, to and by the panel 17. A central crease 18 is made through the base portion 14 and the end wall portions 16, 16. If special features, such as the hand holes 10a and/or ventilation holes 10h, are provided, the holes are of course provided in all of the relevant parts of the blank 11 and, if any parts have more than one thickness in the assembled box, the relevant holes are provided so that they will be in register.

An opposed pair of creases 19,19 are formed in the sheet material parallel to the creases 12,12 and 18, one being adjacent each of the respective longer edges of the rectangular sheet forming the blank 11.

These creases 19,19 define narrow edge panels 20,20 which comprise tensioned supporting straps 21 in the box or other container made from the blank 11, as explained below and shown best in Fig. 3.

Pressure-relieving holes 22 are provided where the creases 13,13 intersect the central crease 18 and further such holes 23 are provided where the creases 13,13 intersect the creases 19,19. These holes are preferably circular and are centered on the point of intersection of the creases where the folding will occur. Delta crease formations in the form of creases 24 radiate from the holes 23 to the longer edges of the blank 11 on either side of the extremities of the creases 13,13.

The creases 19,19 are doubled, as at 25, from the holes 23 to the shorter edges of the blank II.

The four intermediate or corner panels 17 are bisected by creases 26, which extend obliquely from the extremities of the creases 19, 19 at the shorter edges of the blank 11, across the corner panels 17 (as reverse creases) and then across the base portion 14 (as normal creases), each two oblique creases 26 meeting at the central crease 18 in a pressure-relieving hole 27. The central part of the central crease 18 between the two holes 27 is formed as a double or (as shown) a triple crease, as at 28. At either end of the rectangular base portion 14, therefore, a triangular area is defined within the pair of oblique creases 26 and the creases 13 which they intersect at the creases 12, 12. Within these triangular areas, a number of additional creases 29, four as shown, extend parallel to the creases 13,13 and thus normal to the central crease 18. The narrow panels 20 which provide the supporting straps 21 along each longer edge of the box, i. e. between the creases 13,13 also provide flaps 30 at the corners of the blank 11, which are joined to the intermediate panels 17 by the double creases 19,25 and, as explained below, are employed to assemble the blank I I into a stitched or otherwise formed container.

In order to form a box or other container, such as the produce tray shown in Figs. 2 and 3, from a blank as shown in Fig. 1, the following sequence of operations is carried out: (I) The side wall portions 15 and the corner panels 17 are stood up relative to the base portion 14, by folding the blank 11 about the creases 12, 12 ; (2) the end wall portions 16 are stood up relative to the base portion 14, by folding the blank 11 about the creases 13,13 and reverse folding the corner panels 17 about the reverse crease parts of the creases 26, so that the folded corner panels 17 are located on the inside of the end wall portions 16 and the narrow corner panels 30 stand above them; (3) the narrow corner panels 30 are reverse folded to the outside of the end wall portions 16 about the doubled creases 19,25, the edge panels 20 folding at the outer one of each pair of delta creases 24 and at the end of each crease 13; the panels 30 are then secured, possibly by glueing, but PREFER ABLY by being stitched into place, e. g. with wire staples as shown at 31, Fig. 3.

The container shown in Fig. 3 is thus formed. This has the rectangular base 14 and, along its upstanding side walls formed by the panels 15, the tensioned inturned supporting straps 21. The container prefera bly is dimensioned so that the various features shown In Fig 1, which is not intended to be to scale, ensure that a pre ferred feature of the invention is manifested, namely that its depth is not more than half its width, the container has a width which equals or is greater than twice its depth. The container shown in Fig. 3 can be collapsed substantially flat, without removing the staples 31 or otherwise disassembling it. If inward pressure is exerted on the end walls 16, desirably in the regions of the holes 22, the end walls 16 fold inwardly about the central plane of the box, i. e. in the example of the container shown in Figs. 2 and 3 the plane which, when the container is erected, contains the central crease 18 and is perpen dicular to the base 14. The end walls 16 undergo reverse folding about the parts of the crease 18 which passes through them and this also occurs in the triangular areas containing the parallel creases 29, which undergo folding in turn as the container approches the fully collapsed state. The triple crease 18, 28 allows the central region of the base 14 to fold outwardly during this time, whilst the inner one of each pair of delta creases 24 allows the edge panels 20 to fold about it; at the. same time the small triangular parts on either side of the extremities of the creases 13, 13 flatten. The fully flat container is shown in Fig. 2. Supplies of the container are desirably stored and delivered in the flat form. When required for use, a flattened container (Fig. 2) is readily erected to the open condition (Fig. 3), by outward pressure on the end walls 16, which causes them to flatten out, as also does the base 14, thus putting the straps 21 under tension, as the box effectively snaps into the fully erected state.

Referring to Figs. 4 and 5, it is not essential for the oblique creases 26 to meet the edge of the blank 1 I at the ends of the creases 19, as shown in Figs. 1 to 3. Instead, a blank 111 (as shown in Fig. 4) can be made, for production of a container as shown in Fig. 5 which is of different proportions, in that its depth is more than half its width. In the blank shown in Fig. 4 (where the equivalent parts to those of the blank of Fig. 1 have references increased by 100), the end wall portion 116 projects further from the crease 113 than the corner panels 117 by a distance, D, which equals the depth of the box and thus the height of the side wall portions 115. Fig. 5 is a fragmentary view of the blank III being formed into the desired box. It can be seen that D is greater than W/2, where W is the width of the box.

Claims

WHAT WE CLAIM IS :- 1. A container of sheet material which can be collapsed substantially flat and which comprises a rectangular base with side walls hingedly connected to two opposed edges thereof and end walls hingedly connected to the other two opposed edges thereof, a part of the base adjacent each end wall being defined between creases which extend obliquely from respective corners of the base to a crease extending centrally of the base, and an intermediate panel at each corner of the base connected to an associated pair of adjacent side and end walls by respective creases, the central base crease extending centrally of each end wall and being arranged to make a reverse fold in each part adjacent an end wall and a normal fold along the remainder of its length in the base, and each intermediate panel being pivotally connected to its associated side wall by the respective crease, whereby each end wall and the adjacent part of the base folds inwardly and the remainder of base folds outwardly about a central plane of the erected container as it is collapsed substantially flat.
2. A container according to claim 1, wherein each intermediate panel has a crease which is an extension of the respective obliquely extending base crease and which is folded to provide a double thickness of intermediate panel confronting the associated end wall.
3. A container according to claim 1 or 2, wherein each intermediate panel is secured to its associated end wall.
4. A container according to any preceding claim having an inturned supporting strap along the top of each side wall.
5. A container according to claim 4, wherein the supporting straps are in tension in the erected container and fold adjacent their ends as it collapses into the substantially flat state.
6. A container according to claim 4 or 5, wherein each supporting strap is hingedly connected at each end to a flap located aling the top of an end wall.
7. A container according to claim 6, wherein each flap is attached to the outside of the associated end wall.
8. A container according to claim 6 or 7, wherein each supporting strap and the flaps connected to it are constituted by an edge panel, a delta crease formation being provided in the edge panel where the strap is connected to a flap.
9. A container according to any preceding claim, formed from a unitary blank.
10. A container according to claim 9, wherein the blank is rectangular.
I I. A container according to any preceding claim, wherein the remainder of the length of the central crease in the base is a double or treble crease line.
12. A container according to any preceding claim, wherein at least one crease is provided in each part of the base adjacent an end wall, as an aid to collapsing of the container.
13. A container according to claim 12, wherein the one or more creases are disposed perpendicularly to the central base crease.
14. A container according to any preceding claim, wherein a hole is made in the sheet material at least at one of those places where folding in more than one direction occurs, either as the container is changing from the erected condition to the collapsed or vice versa or when the container is in one or other such condition.
15. A container according to claim 14, wherein the holes are circular.
16. A container according to claim 14 or 15, wherein the holes are provided where the centre of each end wall is connected to the base and/or where the inwardly-folding parts of the base meet the remainder of the base.
17. A container according to any of claims 14 to 16 as dependent upon any of claims 4 to 8, wherein the holes are provided at each end of a supporting strap where it meets the associated side wall.
18. A container according to any preceding claim, having when erected a depth not more than half its width.
19. A container according to any of claims I to 17, having when erected a depth more than half its width.
20. A container according to any preceding claim, made of corrugated board.
21. A container according to any preceding claim, substantially as described with reference to Figs. I to 3 or 4 and 5 of the accompanying drawings.
22. A blank, for a container of sheet material which can be collapsed substantially flat, comprising a rectangular base portion with side wall portions hingedly connected to opposed edges and end wall portions hingedly connected to the other two opposed edges, a part of the base portion adjacent each end wall portion being defined between creases which extend obliquely from respective corners of the base portion to a crease extending centrally of the base portion and an intermediate panel at each corner of the base portion hingedly connected to an associated pair of adjacent side and end wall portions by respective creases, the central, base portion crease extending centrally of each end wall portion and being arranged to make a reverse fold in each part adjacent an end wall portion and a normal fold along the remainder of its length, and each intermediate panel being pivotally connected to its associated side wall portion by the respective crease, whereby, in the container erected from the blank, each end wall portion and the adjacent part of the base portion folds inwardly and the remainder of the base portion folds outwardly about a central plane of the container as it is collapsed substantially flat.
23. A unitary blank according to claim 22, substantially as described with reference to Fig. 1 of the accompanying drawings.
24. A unitary blank according to claim 22, substantially as described with reference to Fig. 4 of the accompanying drawings.