GB2180225A - Collapsible box - Google Patents

Abstract

A pre-form for a box which pre-form may be transported flat and then opened out to form a complete box without the need for stapling, glueing, or the like defines four side faces 11 and 13 and four flaps 18 and 24, which flaps are folded towards each other on opening out of the box to form the box bottom. Each first flap 18 is of reduced width remote from its adjacent side face and has a slat 19 extending thereacross to form projecting tabs 19a. On folding the flaps together, the tabs 19a pass through openings in the second flaps 24 to resist bursting of the box bottom and the ends of the tabs 19a engage side strips 29 to resist lozenging of the opened out box. <IMAGE>

Description

1 GB 2 180 225 A 1

SPECIFICATION

Collapsible box v This invention generally relates to boxes of the kind which maybe stored and transported in a substantially flat state, and then opened out to form a usable box when required. In particular, therefore, this invention relates to a box pre-form which maybe op- ened out to form a box, a method for opening out such a box pre-form into a usable box, and a box wheneverformed from a pre-form of this invention.

Boxes for storing and transporting articles from one place to another are used in very large quantities throughout all kinds of commerce, including the agricultural and horticultural industries. Depending upon the particular requirements that a box mustsatisfy, such boxes are often madefrom cardboard,fibreboard, orsimilar materialswhich may be reinforced as necessary, for example with strips of wood or of plastics material. In the manufacture of such boxes, a suitably configured blank may be cutfrom a large sheet of the selected material,the blankthen being scored or otherwise provided with hinge lines and the appropriate edges of the blank being joined together to produce a pre-form forthe finished box. That pre-form maythen be collapsed to lie substantiallyf lat, and subsequently unfolded and opened out so as to form a usable box. To complete the unfold- ing and opening out of a box pre-form, certain finishing operations may be necessary, such as securing together at least some of the flaps of the box, for example by stapling, or bythe use of adhesive or adhesivetapes.

Boxes of the kind described above are used extensively, in view of the advantage thatthe pre-forms may be stored and transported in thefolded, substantiallyflat state, and opened out onlywhen a box is to be used. However,the extra operations neces- saryto securetogether at leastsome of the pre-form flaps when the box isto be used are time consuming and an inconvenience for the user; as a resultsuch operations often are only partially or improperly completed bythe end userof the box.

In an attemptto minimise the disadvantage mentioned above,there have been many proposaisfor boxes theflaps of which may be secured together by means of interlocking portions of thoseflaps. There have also been other proposals for facilitating erec- tion of a boxfrom a flatstate.

For example, there are known boxeswith a fold-flat capabilitywhich have a system of diagonal folds in the box bottom, and a longitudinal crease in the ends and adjoining bottom walls. These boxes have achieved widespread use, especially in theform of composite crates made from a blank of foldable board togetherwith wooden slats. The opening out of such boxes may be quickerto perform and require less skill than is the case where stapling, glueing or other operations have to be performed. Nevertheless, it has been found thatthe known designs of boxes using interlocking flaps tend to display less stabilitythan a box having its flaps more positivelysecured togetherfor example by stapling or glueing.

Often therefore such boxes maybe suitable onlyfor lighter duties, in orderto minimise the likelihood of the interlocking flaps disengaging from each other.

It is one of the principal objects of this invention to provide a preform for opening out into a box which opening out operation is easyto perform in that it does not require the use of staples, adhesives or other agents, butwhich boxwhen opened outfrom the pre-form displays good stability and has a considerable strength.

According to this invention, there is provided a box pre-form for opening out into a box, which pre-form comprises means defining fourfaces of the boxwith the adjacent corner edges hinged togetherto permit the pre-form to be folded to lie substantially flat or opened out into a box shape, the pre-form further comprising two firstf laps hinged respectively one to each of two opposed face defining means along an edge thereof, and two second flaps hinged respectively one to each of the othertwo face defining means along corresponding edges thereof whereby the first and second f laps may be folded to define a fifth face of the box when opened out, characterised in that at least one firstflap has a region of reduced width less than the internal width of the box (when opened) between said other two face defining means and a pair of opposed tabs projecting laterallyfrom said reduced width region, and each of the two second flaps has an opening appropriately disposed to receive a tab of the adjacent said one firstflap whereby unfolding of the box pre-form may be completed firstly byfolding the second flaps and then folding the firstflaps to overlie the second flaps, the tabs of said one firstf lap being passed through the respective openings of the second flaps.

If the firstflaps are configured so thatthey partially overlie each other when the box is fully opened out, only one firstflap need be provided with tabs, this flap being folded last to be outsidethe otherfirstflap when its tabs are interlocked with the second f laps. If howeverthe firstflaps do not overlap,then each first flap should be provided with tabs, each second flap being provided with a pair of openings to receivethe tabs on the same side of the two firstflaps.

In a box pre-form of this invention each of thetabs are most preferably defined by stiffening means which is arranged to extend across the first flaps generally parallel to and spaced from its hinged connection to the adjacentface defining means. In certain preferred embodiments, such stiffening means com- prises strips of substantially rigid material, such as wooden slats, or of plastics material, stapled or otherwise secured to the flaps. Alternatively, the whole of the flap defining the tabs may be made of a stronger material, to ensure thetabs have adequate strength forthe intended usage of the box.

It isfurther greatly preferred forthe distance between the free ends of the tabs to be not greaterthan the internal width of the box (when opened), but arrangements would be possible when that distance is slightly greaterthan the internal width, the face defining means then being appropriately apertured to receive the projecting ends of thetabs.

It will be appreciated that certain embodiments of box pre-form according to this invention may be par- ticularly economical to manufacture, especially 2 GB 2 180 225 A 2 when using automated machinery. Moreover, the box may take the form of a composite crate man u factu red from both foldable board and slats of wood orsimilar materials, and the usage of such materials may be optimised, so giving riseto further economic advantages.

Stability is preferably imparted to an opened out box of this invention in one of two ways. In one such way,the ends of the tabs are arranged to engage the corner regions atthe hinge between the respective sideface defining means and the second flaps, thereby preventing lozenging of the box. Alternati vely,the respective corner regions between thetabs and the reduced width regions of the firstflaps may engage the material of the second flaps immediately adjacentthe respective openings therein, again to preventsuch lozenging. In eithercase,the box is pre ventedfrom collapsing unless significant deforma tion of the material of the box itself takes place. Of course, both methods may be used together, in the same box.

In addition,though thetabs may be inserted through the openings with relative ease, forexample bydeflecting inwardly of the boxthe already-folded secondflaps to an extent sufficientto permitthetabs to be passed through the openings, the tabs may not easily slip out of the openings by pressure applied internally of the box on thefifth face defined bythe firstand second flaps. As mentioned above,the re sistanceto inadvertent bursting open of the box may significantly be enhanced by reinforcing at leastthe tabs of thefirstflaps of the box; conveniently this may be done in the case of a boxconstructed from foldable board such as fibreboard orcardboard by doubling the material thickness at least in the region 100 of thetabs. for instance byfolding overthat material and then securing togetherthe overlying doubled material. Alternatively, forcertain designs of box, the tabs may be separately formed from a rigid material which is affixedto the firstflaps during the manu facture of the pre-form; in a preferred embodiment each pairof tabs is defined by a strip of rigid material such as a wooden slatwhich is stapled orotherwise affixed to thefree edge of thefirstflap; thewidth of thatfirstflap in the region of its free edge maythen be 110 reduced by an appropriate amount.

In a box of this invention,the means defining the fourfaces ofthe box conveniently definethefour sidefaces of the box, and thefirstand secondflaps together definethe bottom of the box, when opened out. Nevertheless. the means defining thefourfaces could instead definetwo sides of the box, thetop and the bottom, a third sideface being defined bythe pairs of first and secondflaps. Forsuch an arrange ment, means should be providedto definethefourth sideface of the box, and clearly such means may be constituted byfurtherpairs of firstand secondflaps, configured similarlyto the already-described pairs of first and second flaps.

Forthe case of a boxwhereof the pairs of firstand second flaps areto definethe bottom of the box, sim ilar pairs of first and second flaps may be providedto definethetop of the box. Alternatively, differently configured flaps may be hinged tothe means defin ing thefoursidefaces,such astheflaps of a con- ventional cardboard box each of which flaps is simply rectangular in shape, to permit closure of the box for instance by means of adhesive tapes. A further possibility is to provide further pairs of first and second flaps each configured in a similar mannerto that described aboveforthe bottom ofthe box, butwith the pairs of firstand second flaps having a relatively small extent in the plane of the sixth (top) face of the box, so as notsignificantlyto ob- structthatsixth face, when folded to interengage in the described manner. Such a box may serve as an open topped box, whilst still displaying excellentstability, enhanced bythe provision of an inwardlydirected rim around thetop of the box.

The means defining thefourfaces of the box most simply comprise pieces of a semi-rigid foldable sheet material, such as cardboard orfibreboard. In its simplestform therefore a pre-form fora box of this invention may comprise a single blank cutfrom a piece of appropriate board material,the blank having hinge lines defined thereon for example byscore lines or by pressure lines, and the end edges of the blank joined together whereby the fourfaces togetherform a continuous ring with the flaps dep- ending from those faces. Forthe case of a vegetable orother produce box, greaterstrength may be required, as well as cutout regionsto permit the free flow of airthrough the box; forthis purpose at leasttwo opposed sides may be formed by slats of wood or other rigid material, appropriately affixed to the material, for instance by stapling.

According to a further aspect of this invention, there is provided a method for unfolding a pre-form for a box so as to form a usable box, which box preform comprises means defining fourfaces of the box with the adjacent corner edges hinged together,two firstflaps respectively hinged oneto each of two opposed face defining means along an edgethereof and at least onefirstflap having a pair of tabs project- ing laterallyfrom a region of said one firstflap of reduced width,the distance between the ends of the tabs being not greaterthan the internal width of the box and there being two second flaps respectively hinged oneto each of the otherface defining means along corresponding edgesthereof, in which unfolding method the pre-form isfirstlyopened outto have right angles defined between adjacentface defining means, thetwo second flaps are hinged inwardly of the box so as externallyto overlie the second flaps, and thetwo tabs provided on said one firstflap are passed through openings therefor provided in the two second flaps wherebythe material of said one firstflap in the region of thetabs engagesthe material eitherof the secondflaps orof said othertwo face defining means so asto prevent collapsing of the box.

This invention further extends to a boxwhenever opened outfrom a pre-form of this invention.

Byway of example only, certain specific embodi- ments of box pre-forms arranged in accordance with this invention and adapted for opening out into boxeswill now be described in detail, reference being madetothe accompanying drawings, in which- Figure 1 is a perspectiveview of the first embodi- 3 GB 2 180 225 A 3 1 mentof box pre-form, only two sides of that pre-form being shown inthe drawing and the other two cor responding sides being omitted for clarity; Figure2isan underplan viewof one end portionof boxpre-form accordingto Figure 1, butwhen op ened outtoform a complete box; Figure3isa perspective view of asecondembodi mentof box pre-form, again only two sides thereof being shown andthe other two corresponding sides 0 being omitted for clarity; Figure4isan underplanviewof afurtherembodi mentof boxofthis invention; Figure5isa planviewof a blankusedto producea third embodiment of box pre-form of this invention; Figure 6is a perspective view on an enlarged scale of an end portion of a box, during the opening-out procedure of the pre-form of Figure 5; Figure 7is a perspective viewof a fourth embodi ment of box pre-form, yet again onlytwo sides thereof being shown in full; and Figure 8 is a sideview on one of thetwo side-and end combinations used in the box pre-form of Figure 7.

Referring initiallyto Figures 1 and 2,the firstemb odiment of box pre-form illustrated there is part com prises an end 10 and a side 11 hinged together about line 12; a further end corresponding but opposed to end 10 and a further side corresponding but opposed to side 11 are also provided but are not shown in Figure 1, forthe sake of clarity. End 10 is cutfrom a piece of cardboard skinned with a plastics material to renderthat board substantially waterproof, and com prises a main area 13 which is reinforced bya woo den slat 14 stapled to extend along thetop edge of that main area. Hinged to each side of the main area 13 are wings 15, the hinge lines 12 and 16 connecting the wings to the main area being defined for example by scores part-way through the thickness of the mat erial, or by lines of reduced board thickness prod uced by a pressing operation. Hinged to the lower edge 17 of the main area 13 is a firstflap 18, the hinge line being defined in a similar mannerto thatjust de scribed with reference to the wings 15. The firstflap 18 has a tapering width from edge 17 towardsthe free edge of thatflap, and a wooden slat 19 is stapled 110 along thatfree edge, the slat 19 having an overall length equal to the length of slat 14 and so being al most equal to the internal width of the box, measured between the wings 15. The end portion 19a of the slat thus project beyond the board portion of the flap, as 115 shown in Figure 1.

Side 11 andthe corresponding opposed side (not shown in Figure 1) are constructed usingthewings of the opposed ends of the box and from two woo den slats 20 and a board strip 21 all arranged to ex- 120 tend parallel to one another and stapled to the wings.

Afurther board strip 22 extends at right angles to the slats 20, midway therealong, secured for example by stapling.

Hinged to the lower edge 23 of side 11 is a second flap 24, that second flap being defined by a portion 25 of the strip 21 lying belowthe lower edge of side 11, as well as by extensions 26 of the wings 15 and an extension 27 of the strip 22, there being a furtherslat 28 arranged to extend parallel to the slats 20, but be- tween the ends of the extensions 26 and 27. Strip 21 therefore has a first portion 29 which lies in the plane of side 11, and second portion 25 separated from the first portion 29 by means of a hinge line which second portion forms a part of the second flap hinged to side 11.

The ends of the slats may need to be profiled, or their lengths reduced slightly, to permit properfolding of the box about its hinge lines- for example at the ends of slats 14 and 20.

The box pre-form as described above may be packed to lie flat, by arranging forthe illustrated end 10 and side 11 to lie substantially copianar, with the first and second flaps 18 and 24 also lying in the same plane, and the end and side of the pre-form not illustrated in Figure 1 also lying in a co-planar fashion, but on top of the illustrated coplanar end and side 10 and end 11. Then,when the box isto be opened out readyfor use, the sides and ends are relatively hin- ged until a right angle is defined at each corner between the respective sides and ends. Next,the second flaps 24 are hinged inwardly of the box, so as to lie at least at a right angle to the adjacentside, whereafter first f laps 18 are also hinged inwardly, so as partiallyto overlie the already-hinged second flaps 24. Next, the end portions 19a of the two slats 19 have to be engaged behind the second portions 25 of the strips 21, which second portions form parts of the second flaps 24. This is best achieved by deflecting furtherthe second flaps 24 until the end portions 19a may be snapped behind those minor areas 29, so lying on the inside of the box. When so positioned, the actual end faces of the end portions 19a engage the major portions 29 of the strips 21, in the im- mediate region of the lower edge 23 of side 11, and so impart considerable stability to the box. Moreover, when the first and second flaps 18 and 24 are pressed back, so as to lie substantially co-planarly, the end portions 19a cannot easily return to lie on the outside of the box and so the box assembled in this way display considerable strength.

Stability of the box mayfurther by enhanced by ensuring that the angle between the slat end portions 19a and the adjacent edge of the first flap 18 engage againstthe free edge of the second portion 25, of the strip 21, when the box is fully assembled. In such a case, the length of the end portions 19a may slightly be reduced, to clear the respective inside faces of the adjacentfirst portions 29 of strips 21.

Referring nowto Figure 3, there is illustrated another embodiment of preform suitable for opening outintoa box, and again onlytwo sides of the boxare shown, for clarity. The other two sides correspond in pairstothetwo sides illustrated.

Inthissecond embodimentof pre-form, side 30 is cutfrom asheetof cardboard material skinnedwith a plasticfilm,and has a main area 31,twowings32,a topstrip33and a lowerflap34,all ofwhich latterare hinged to the main area 31 in the same manner as has been described abovewith referenceto Figures 1 and 2. Thetopfiap 33 has atab35 hingedto each end thereof,whereas each wing 32 has an extension 36 hinged thereto, which extensions 36 form parts of a firstflap 37 associatedwith end 38 of the box.

Each end 38 of the box comprises four slats 39 4 GB 2 180 225 A 4 stapled to the wings 32 of thetwo similaropposed sides30.Thetop slat39 is not howeverstapled adjacentits ends,so asto permitthe insertion ofthetabs 35 betweenthe adjacentend of thetop slat39 andthe 5 wing 32, when the box is being opened out.

Each of the two firstflaps 37 comprises a pair of wooden slats 41 stapled to the extensions 36 of the wings 32, projecting below hinge lines 42. An outer edge part of each extension 36 is cut away, as illustra- ted at 43, whereby the lowermost slat 41 projects beyond extension 36, thereby to define two tabs 44. The overall length of the lowermost slat 41 is however slightly less than the internal width of the box, when opened, and so is equal to the length of the slats 39.

As illustrated in Figure 3, the lower flap 34 of each side 30 is provided with two cuts 45, appropriately positioned to receive the tabs 44 as the box is being opened out from the folded-flat pre-form. Such cuts could be simple linear cuts, or may, if required, be substantially L- shaped orflat-bottomed channel shaped, so asto assistthe insertion of thetabs44 therethrough. Two possibilities are shown in Figure 3.

As with thefirst embodimentof box pre-form described above, the box may befolded to lie substantiallyflat, with one adjacentside and end lying substantially co-planar and the otherside and end also lying substantially co-pianar but overthefirst- mentioned pair. The variousfiaps of the box may also be hinged to lie co- planarwith the sides and endsto which the flaps are respectively hinged. When the box is to be opened out, the sides and ends are relatively hinged until a right angle is defined at each corner; then the lowerflaps 34 hinged tothe sides 31 are hinged inwardly so as to form part of the bottom of the box. After this, the two firstflaps 37 are also hinged inwardlyso as externallyto overliethe lowerflaps34, and thetabs 44 defined bythe lower- most slats 41 are pressed through the cuts 45 in the lowerflaps 34, such that the tabs are disposed within the box, above the lowerflaps 34. When so positioned, the actual ends of the tabs 44 arejust clear of the main areas 31 of the two sides 30, in the region of the hinge line between the main areas and the lower 110 flaps 34, but considerable stability is imparted to the box by having the edge 43 of each extension adjacent tabs 44 engage againstthe material of the lowerflap 34 atthe cut45 where tab 44 projects through that flap. Finally, to complete the box, the top flaps 33 are 115 folded inwardlyto lie parallel to the box bottom, the tabs 35 during this being pressed inbetween the wings 32 and ends of the top slats 39 of the two sides 38. Completed in this way, the box pre-form is op ened outto form an open topped box, which displays 120 extremely good stability, with a good strength.

Figure 4 is an underplan view of another, butsim pier, embodiment of box of this invention, when fully opened out. It can be seen thatthe bottom of the box comprises two firstflaps 50 and two second flaps 51, 125 each of which has a slat affixed by stapling to thefree edge thereof remote from its hinge connection to the adjacent box side. Second flaps 51 have a width sub stantially equal to the internal width of the box, whereas first flaps 50 are tapered towards theirf ree edges; the slats 52 associated with the first flaps have a greater length than the first flap free edges such that the projecting end portion of those slats 52 define tabs 53. Slats 54 associated with the second flaps 51 are of substantially the same length as thefree edges of those flaps.

When the box of Figure 4 is fully assembled, as shown in that Figure, the portions of the firstflaps which overlap the second flaps lie outside those second flaps, butthe projecting tabs 53 of the first flaps lie inside the second flaps. Stability is imparted by having the reinforced edges of the second flaps trapped in the angle between the reinforcement of the firstf laps and the edges of those firstflaps runn- ing backto the hinge edges.

Figure 5 shows a blank of yet another embodiment of this invention, priorto the folding of that blankto provide a pre-form for a box. The blank is cut from a sheet of plastics coated cardboard and is scored so as to define hinge lines separating the blank into various areas including a box bottom 60, side walls 61 and 62, respectively connected to the long edges of the bottom 60, and top edge strips 63 and 64, respectively connected to the side walls 61 and 62.

Areas 65, connected to the short edges of the bottom 60, each define a firstflap forforming an end wall of the box, and areas 66 and 67 define pairs of second flaps, respectively connected to the ends of side walls 61 and 62. The width of each firstflap 65 is redu- ced remote from the bottom 60, as shown. Each second flap 66 and 67 has a generally U-shaped cut 68 formed therein, and each side wall 61 and62hasa hand opening 69 formed centrally therein.

The blank has wooden reinforcing strips 70stapied thereto, along the free end edges of the second flaps 66, and across the side walls 61 ancl62,asshown. Further wooden strips 71 are stapled to the long free edges of the first flaps 65, so that those strips project beyond the adjacent short edges of the first flaps 65; in this way, tabs 72 are defined by the strips 71.

The box pre-form is completed by stapling a pair of end flaps 73 between the top strips 63 and 64, atthe endsthereof.in Figure 5, those end flaps are shown stapled only to top strip 64; on folding of the blank aboutthe longitudinal hinge lines, the opposite corner regions of the end flaps 73 may be stapled to the top strips 63, in a similar manner. In thisway, flaps 65 and 73 at each end of the box serve to define a pairof cooperating firstflaps.

The completed box pre-form described above may be transported in a flat condition, for example with side wall 62 and flaps 73 overlying bottom 60 and side wall 61, all the end flaps also in the same general plane. Then, when it is desired to open outthe box, the side walls are erected with respectto the bottom 60 with flaps 73 lying parallel to the bottom 60. Second flaps 66 and 67 are folded inwardly and flaps 73 folded downwardly, and the box is completed by folding upwardlyflaps 65 so as partiallyto overlie flaps 73. Theflaps 65 are then pushed inwardly of the box until thetabs 72 thereof passthrough cuts 68 in the second flaps 67, whereafter outward bursting pressure from within the box is resisted by engagement of those tabs 72 with the reinforced second flaps 66 and 67. Moreover, considerable stability is C P J GB 2 180 225 A 5 impartedtothe boxbyvirtueof the reinforcing strips on the second flaps 66 and 67 engaging attheir endsthe bottom 60 and top strips of flaps 73, and the interengagement of the cut back portions of flaps 65 with the edges of the cuts 68formed in the second flaps 66 and 67.

In Figures 7 and 8, there is shown one side and end of yet another box pre-form, this pre-form being gen erally similarto that described above with reference to Figures 1 and 2, but being modified so as to opti mise the use of materials. Insofar as it is possible, the same reference numerals have been used on Figures 7 and 8 to indicatethe like parts to those illustrated in Figure 1; those partswill not be described again here.

The principal difference between the pre-form of Figure 1 and that of Figures 7 and 8 is that in the case of the latter, only a single piece of board is used in combination with wooden slats in making each end and-side wall combination. The piece of board is thus generally L-shaped, with the wing 75 lying in the il lustrated side 11 being extended from its lower re gion, so as to define first and second portion 76 and 77 of a second flap 24, first portion 76 lying in the plane of side 11, and second portion 77 being hinged to thefirst portion 76 about a line 78. Fourwooden slats 79 to 82 are stapled together in a grid formation and are also appropriately stapled to wing 75 and first portion 76, so thatthe side 11 is defined bythose wooden slats, in combination with the wing 75 and first portion 76.

As in the case of the box pre-form illustrated in Figure 3, the second portion 77 of the second flap 24 is provided with two cuts 45, appropriately disposed in orderto receive the end portions 19a of the slats 19 100 stapled to the first flap 18 of the end 10.

The box pre-form is completed by stapling together two essentially identical side-and-end com binations, each of which is as illustrated in Figure 4, the free ends of the slats 79 and 80 as well as the end region of first portion 76 being stapled to a cor responding wing 15 of the other side-and-end com bination. Such a box pre-form may be stored in a substantiallyf lat condition, and then easily assem bled in much the same manner as are the boxes des cribed with reference to Figures 1 and 3, the end port ions 19a in the present case being inserted through the respective cuts 45. Stability is imparted to the assembled box by having the region of thejunction between slat end portion 19a and thefirstflap 18 en gaged againstthe material of the second flap 24, in the region of the associated cut45. Itwill be appreciated thatthe board portions of two side-and-end

combinations, necessaryfor a single box pre-form, may be cutfrom a single piece of re ctangular board material,with very littlewastage sincethetwo pieces may substantially interfit. Each side-and-end combination maythen be manufactu red byforming the hinge lines (if these were notdone atthe time of cutting the piece of rectangular mat erial) and then stapling the sixslats 14,19,79to 82to the pre-cut board. The box pre-form isthen comple ted by stapling togetherthetwo side-and-end com binations.

In view of the particular construction of the emb- odiments of pre-forms described above, utilising plastics-skinned water- resistant board and wooden slats, the boxes find particular application in horticulture, for use as vegetable boxes. It will however be appreciated that such boxes may be used for a very wide variety of purposes, and that by substituting the materials used for others, the pre- forms may be employed to make boxes suitable for a verywide va ri ety of uses.

Claims (16)

1. A box pre-form for opening out into a box, which pre-form comprises means defining fourfaces of the box with the adjacent corner edges hinged together to permit the pre-form to be folded to lie substantiallyflat or opened out into a box shape, the pre-form further comprising two firstf laps hinged re- spectively one to each of two opposed face defining means along an edge thereof, and two second flaps hinged respectively one to each of two opposed face defining means along an edge thereof, and two second flaps hinged respectively one to each of the go othertwo face defining means along corresponding edges thereof wherebythe first and second flaps may be folded to define a fifth face of the boxwhen opened out, at least one firstflap having a region of reduced width less than the internal width of the box (when opened) between said othertwo face defining means and a pair of opposed tabs projecting laterally from said reduced width region, and each of thetwo second flaps having an opening appropriately disposed to receive a tab of the adjacent said one first flap whereby unfolding of the box pre-form may be completed firstly byfolding the second flaps and then folding the f irstflaps to overlie the second f laps, the tabs of said one first flap being passed through the respective openings of the second f laps.

2. A box pre-form according to claim 1, wherein said one first flap provided with tabs partially over lies the otherfirst flap whent he box is opened out, the tabs of said one firstflap holding both firstflaps in their respective positions when the box is fully op- ened out.

3. A box pre-form according to claim 1, wherein each first flap is provided with laterally-projecting tabs, each second flap being provided with a pairof openings to receive the tabs on the same side of the twofirstflaps.

4. A box pre-form according to any of claims 1 to 3, wherein each of the tabs are defined by stiffening means which is arranged to extend across the first flaps generally parallel to and spaced from the hin- ged connection thereof to the adjacent face defining means.

5. A box pre-form according to claim 4,wherein the stiffening means comprises a strip of rigid material secured to the firstflap so asto project laterally beyond the reduced width region thereof.

6. A box pre-form according to any of claims 1 to 3, wherein the first flap is stiffened bythe margin region of the first flap remote from its hinged connection being folded back and secured to itself, said fol- ded back region also defining the tabs.

7. A box pre-form according to any of the preced- 6 GB 2 180 225 A 6 ing claims, wherein the ends of the tabs are arranged to engage the corner regions atthe hinge between the respective side face defining means and the second flaps when the box is opened out, so as 5 thereby to impart stability to the box.

8. A box pre-form according to any of the claims 1 to 6, wherein the respective corner regions between the tabs and the reduced width regions of the first flaps engages the material of the second flaps im- mediately adjacent the respective openings therein when the box is opened out, so as to impart stability to the box.

9. A box pre-form according to any of the preceding claims, wherein the means defining the four faces of the box define the four side faces of the box, and the first and second flaps together define the bottom of the box, when opened out.

10. A box pre-form according to any of claims 1 to 8, wherein the means defining the four faces of the box define two sides of the box, the top andthe bottom, each end face of the box being defined by pairs of said first and second flaps.

11. A box pre-form according to any of the preceding claims, wherein the means defining the four faces of the box and the associated flaps comprises pieces of a semi- rigid foldable sheet material, strips of rigid material being secured to the first flaps to reinforce said tabs thereof.

12. A box pre-form according to any of the pre- ceding claims, wherein the face defining means which define at least two sides of the box comprises slats a rigid material, appropriately affixed to each other and to the face defining means forthe other two faces of the box.

13. A box pre-form substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.

14. A method for unfolding a pre-form fora box so as to form a usable box, which box pre-form com- prises means defining fourfaces of the box with the adjacent corner edges hinged together, two first flaps respectively hinged one to each of the two opposed face defining means along an edge thereof and at least one first flap having a pair of tabs project- ing laterallyfrom a region of said one firstflap of reduced width, the distance between the ends of the tabs being not greaterthan the internal width of the box and there being two second flaps respectively hinged one to each of the other face defining means along corresponding edges thereof, in which unfolding method the pre-form is firstly opened out to have right angles defined between adjacent face defining means, the two second flaps are hinged inwardly of the box, and then the first flaps are hinged inwardly of the box so as externally to overlie the second flaps, and the two tabs provided on said one first flap are passed through openings therefor provided in the two second flaps whereby the material of said one firstf lap in the region of the tabs engages the mat- erial either of the second f laps or of said othertwo face defining means so asto prevent collapsing of the box.

15. A method according to claim 14, and in which each first flap has a pair of laterally projecting tabs, wherein the tabs of each first flap are passed through openings therefore providing in the two second flaps whereby the material of each firstflap in the region of the tabs engages the material either of the second flaps or of said other two face defining means so as further to improve the prevention of collapsing of the box.

16. A box whenever unfolded from a box preform according to any of claims 1 to 13.

Printed for Her Majesty's Stationery Office by Croydon Printing Company (11 K) Ltd,2187, D8817356. Published by The Patent Office, 25 Southampton Buildings, London, WC2A lAY, from which copies maybe obtained.