GB2141103A - Boxes which may be folded into a flat condition - Google Patents

Abstract

A box folded from a one-piece blank 10 has triangular corner pieces 42 which lie in the plane of the open top of the box and which support another box when stacked. The triangular corner pieces 42 also strengthen the box and help to hold it erect. They fold flat with the rest of the box when it is flattened. <IMAGE>

Description

SPECIFICATION Improvements in or relating to boxes or trays Field of Invention This invention relates to a blank for a box or tray generally referred to herein as a box, made of stiff material capable of being folded about fold lines into a box or tray shape, to a folded blank forming said box or tray shape and being capable of being knocked down substantially flat by folding said shape along a fold line, and to a box or tray formed from the folded blank.

Object of the Invention It is an object of the invention to provide an open topped box or tray stiffened at the open top by means of flanges or the like, for example to enable stacking of filled boxes or trays, whilst at the same time enabling the folded blank to be collapsed into a substantially flat condition for storage and transport prior to use.

The Invention According to one aspect of the present invention, there is provided a unitary blank of rigid, creasable and foldable material having panels separted by fold lines, said panels comprising a central panel for forming a box base, opposed side panels for forming two opposed box side walls, and corner panels which cooperate in pairs to form two opposed box end walls, the blank also including flanges each extending along part of the outer edge of a side panel and continuously therefrom along at least part of the aligned edge of a corner panel, said flanges having angled fold lines so disposed that, when the blank is erected to form a box, the open top of the latter is stiffened by triangular corner pieces which collapse flat when the box is knocked down substantially flat along a fold line.

According to another aspect of the invention, there is provided a folded unitary blank of rigid, creasable and foldable material, said folded blank defining a box base, opposed box side wall and opposed box and walls, and triangular corner pieces stiffening the open top of the box, said folded blank being secured as by staples in box formation but having a fold line along which it can be knocked down into a substantially flat condition, the corner pieces being formed from flanges on the blank which have angled or diagonal fold lines, whereby said corner pieces also collapse flat when the box is knocked down into its flat condition.

According to a third aspect of the invention, there is provided a box erected from a blank of rigid, creasable and foldable material, said box having a base, opposed side wall, opposed end walls, triangular corner pieces stiffening the corners of its open top, and foldable panels along two opposed sides of its base, said panels being capable of folding flat against the base to enable the box to be collapsed to a substantially flat condition along a central fold line extending through said base and the opposed side or end walls, the corner pieces also having fold lines enabling said corner pieces to collapse flat when the box is collapsed flat, and the said foldable panels also being capable of folding flat against the opposed side or end walls of the box to secure said box in its erect condition in which the corner pieces are held in a taut flat condition to stiffen the open top of the box.

Conveniently, the said foldable panels can be provided with apertures, which align with corresponding apertures in said side or end walls, thereby to provide hand holds enabling the filled box to be carried.

In addition to the foregoing features the central panel may have a central fold line extending parallel to the edges to which the side panels are joined and additional fold lines extending from each corner to meet the central fold line at an angle.

With these fold lines on the central, base panel, the erected box can be knocked down by folding the central panel along the fold lines. The base remains attached to the box walls along all the edges, and erection of the box can be done in one stage.

Description of the Drawings The invention will now be further described, by way of example, with reference to the accompanying drawings, in which, Figure 1 shows a first embodiment of a foldable box blank in accordance with the invention; Figure 2 shows a box formed by erecting the blank of Fig. 1 Figure 3 shows a second embodiment of a foldable box black in accordance with the invention; and Figure 4 shows a box formed by erecting the blank of Fig. 3.

Description of Embodiments The blank 10 of Fig. 1, made of corrugated two or three ply cardboard, for example, has a central panel 12, side panels 14, 16 and corner panels 18, 20, 22, 24. The dotted lines, as at 26, indicate fold lines along which the blank can be folded.

The blank can be erected into a box shape (Fig. 2) by folding so that the panel 1 2 forms the box base, the side panels 14, 1 6 form two opposed side walls, and the corner panels cooperate in pairs 18, 20, 22 and 24 to form two end walls. The cooperating pairs of corner panels are secured together, as by staples 28, at the edge strips 30, which are brought into overlapping relationship when the blank is erected, with fold lines 32 being superim posed in alignment with central fold line 34 on the base 12.

The blank 10 also has intermediate end panels 36 creased by fold line 34. These panels 36 can be folded down flat against the base 1 2 to enable the box to be knocked down substantially flat along the central fold line 34. The panels 36 can also, as shown in Fig. 2, be folded up from the base to be against the end walls 18, 20 and 22, 24 when the blank is erected, thereby to hold the blank in its erected box shape. Openings 38, 40 in the corner panels 18, 22 and in the intermediate end panels 36 are thus brought into alignment to provide hand holds.

Stiffening at the open top of the box is afforded by triangular corner pieces, designated 42 in Fig. 2, which corner pieces have angled or diagonal fold lines 44 along which said corner pieces 42 collapse into a flat condition when the box is knocked down flat.

Reverting to Fig. 1, it can be seen that the corner pieces 42 are produced by foldable edge flanges 46, 48, 50, 52 provided on the blank 10, each extending from the mid-point 54 of the outer edger of a side panel 14 or 1 6 to the corner point 56 of a corner panel 18, 20, 22 or 24.

The flanges 46 to 52 are each cut away as at 58 at each of their ends. In addition to the fold lines 26 by which the flanges 46 to 52 connect to the side panels and corner panels, the flanges each have four angled fold lines 60, 62, 64, 66 and a transverse fold line 68.

The last mentioned fold line 68 is the fold line 44 of Fig. 1 along which the corner piece collapses when the box is knocked down flat, the corner piece simultaneously unfolding or straightening at the diagonal fold lines 62, 64. The fold lines 62, 64 conveniently are at 45 degrees to the length of the flanges.

The fold lines 60, 66, at 22.5 degree to the length of the flange allow the flange to be folded back on itself to provide wings 70, 72 (see Fig. 2), of double thickness over a part of their areas. These wings are secured, as by stapling 74, to the side wall 14 or 1 6 and to the end wall 18, 20 or 22, 24 of the box.

The above-described arrangement of fold lines provides the finished box with corner pieces in the shape of isosceles right-angled triangles, the hypotenuse lying symmetrically across the box corner at 45 degrees to both the plane of the respective side wall and the plane of the respective end wall. However, other arrangements and orientations of the fold lines can be envisaged in which the corner pieces have different triangular shapes.

When a blank is erected to form the box, the folding of an intermediate end panel 36 back against the end walls 18 and 20, 22 and 24 secures the erected blank in its box shape, and tautens the corner pieces 42 in order to provide effective stiffening for the open top of the box.

The box and blank shown in Figs. 3 and 4 are similar to those shown in Figs. 1 and 2 and the same reference numerals are used to denote equivalent parts.

The flanges 50 of the blank in Fig. 3 have a modified shape relative to those shown in Fig. 1. Fig. 1 and 3 show two alternative shapes.

The base 1 2 shown in Fig. 3 has additional angled fold lines 76, 78, 80, 82 which extend from corners of the base to the central fold line 34.

In the erected box the end wall panels 36 are stapled to the corner panels 18, 20 and 22, 24.

When the box shown in Fig. 2 is to be collapsed, the base is folded out of its plane when erected, along the fold lines 34, 76, 78, 80, 82. The presence of the angled lines 76, 78, 80, 82 make it possible for the end wall panels 36 to remain permanently connected to the corner panels and to the base.

Erection and knock down are simple, in that the additional step of folding the end panels 36 after opening of the box is avoided.

The presence of the additional fold lines 76, 78, 80 and 82 ensure that, when the base 1 2 is flattened, the box is held in an erected shape.

Normally, the base will be folded so that it projects outside the area of the side walls when the box is flattened. However, it could possibly be folded in the opposite direction to lie within the area of the side walls.

It will be appreciated that the above-mentioned arrangement is by way of example only and that various modifications thereof are possible within the scope of the invention herein defined.

Claims (11)

1. A unitary blank of rigid, creasable and foldable material having panels separated by fold lines, said panels comprising a central panel for'forming a box base, opposed side panels for forming two opposed box side walls, and corner panels which cooperate in pairs to form two opposed box end walls, the blank also including flanges each extending along part of the outer edge of a side panel and continuously therefrom along at least part of the aligned edge of a corner panel, said flanges having angled fold lines so disposed that, when the blank is erected to form a box, the open top of the latter is provided with triangular corner pieces which collapse flat when the box is knocked down substantially flat along fold lines.

2. A unitary blank as claimed in Claim 1, wherein each flange has a centre fold line which, in the erected condition of the box will bisect the angle formed at the corner of the box and two angularly spaced angles fold lines on either side of the centre fold line.

3. A unitary blank as claimed in Claim 2, wherein all the fold lines on each flange radiate from a common source.

4. A unitary blank as claimed in any preceding claim, wherein the central panel and each pair of corner panels which form a box end wall have a central fold line along which the box can be knocked down flat.

5. A unitary blank as claimed in any one of Claims 1 to 3, wherein the central panel has a central fold line and corner-bisecting fold lines, along which the central panel will fold when a box erected from the blank is knocked down flat.

6. A folded unitary blank of rigid, creasable and foldable material, said folded blank defining a box base, opposed box side wall and opposed box end walls, and triangular corner pieces at the open top of the box, said folded blank being secured as by staples in box formation but having fold lines along which it can be knocked down into a substantially flat condition, the corner pieces being formed from flanges on the blank which have angled or diagonal fold lines, whereby said corner pieces also collapse flat when the box is knocked down into its flat condition.

7. A box erected from a blank of rigid, creasable and foldable material, said box having a base, opposed side walls, opposed end walls, triangular corner pieces at the corners of its open top, and foldable panels along two opposed sides of its base, said panels being capable of folding flat against the base to enable the box to be collapsed to a substantially flat condition along a central fold line extending through said base and the opposed side or end walls, the corner pieces also having fold lines enabling said corner pieces to collapse flat when the box is collapsed flat, and the said foldable panels also being capable of folding flat against the opposed side or end walls of the box to secure said box in its erect condition in which the corner pieces are held in a taut flat condition.

8. A box erected from a blank of rigid, creasable and foldable material, said box having a base with a central fold line extending parallel to its sides and angle fold lines extending from each corner of the base to the central fold line, opposed side walls, opposed end walls, triangular corner pieces at the corners of its open top, the corner pieces also having fold lines enabling said corner pieces to collapse flat when the box is collapsed flat by collapsing the base along its central and angled fold lines.

9. A box as claimed in Claim 7 or Claim 8, wherein the panels forming the end walls are provided with apertures, which in the erect condition of the box, align with each other thereby to provide hand holds enabling the filled box to be carried.

10. A blank substantially as herein described with reference to either Fig. 1 or Fig.

3 of the accompanying drawings.

11. A box substantially as herein described with reference to either Fig. 2 or Fig.

4 of the accompanying drawings.