GB2173480A - Stackable tray - Google Patents

Abstract

A stackable tray made from a cardboard blank has a base portion (1) and peripheral edge portions folded to define side walls, one pair (2, 3) of a single layer of cardboard, the other pair (4, 5) of double form. The region (8) of the fold defines a support surface for an identical tray when stacked thereon. The outermost parts (5) of the end walls have folded extensions (16) at the corners of the tray, which define upstanding stacking projections (9, 10) and recesses (16). The innermost parts (6) of the folded wall portions have extensions (11, 12) which extend diagonally across the corners to brace them. <IMAGE>

Description

SPECIFICATION "Stackable tray" This invention relates to a stackable tray particularly, but not exclusively made of cardboard for transporting perishable goods.

It is known to provide open, tray like cardboard boxes which, in order to be stacked with a certain stability, are provided with triangular supporting prisms inside, each corner, formed by rolled edges projecting from the main sides or from the front pieces of the box such boxes have been defined in the International Standards of Quality ("FEFCO") (Federacion Europea de Fabricantes de Carton Ondulado" - European Federation of Corrugated Cardboard Manufacturers), particularly by type number 0945.

This type of tray offers acceptable mechanical resistance to withstand the relatively heavy loads which result from stacking, though in practice, the side walls of these trays, especially those of the longer sides and at the base, are easily deformed when being stacked, due to the weight of the mechandise contained in them, as a result of the pressure exerted by the loaded trays and of the curvature of the board which constitutes the base of the box.

The present invention provides a stackable tray which solves these problems and also does away with the well-known and defective tongue and slot fitting between each box provided on the trays used up to the present time, as these tongues are weak, they project from the upper edge of the front sections and are incapable of counteracting the lateral pressures, so that they usually bend easily and do not fit as intended, the reality being that the stacks are maintained relatively stable solely by the effect of the weight of several trays on others, and are nte provided with effective means to avoid possible lateral displacements of the stacked boxes.

An object of the invention is a new stackable tray provided with various support and balances points and with areas of insertion of one tray into another, which tray has been improved in its characteristics of design, organisation and assembly and is constructed on the basis of a sole, preformed plate, preferably, but not exclusively, consisting of corrugated cardboard.

A main object of the invention is to provide a notably improved tray which as a consequence of its special design and organisation, may be entirely assembled by exclusively mechanical means.

Another object of the invention is to provide a tray which has been equipped, on two opposite sides, either on the front pieces or on the long sides, with a second partition which forms a double wall with the front piece, both walls being situated at the same level in the centre of the said sides and at a high level at the ends.

A further object of the invention is the formation of arecesses on the lower borders of the corners, constituting indentations which coincide with the shape formed by the tope edge of each corner, in such a way that when the trays are superimposed, one tray fits over another, the upper trays resting on the two ledges, situated at different levels, formed on the upper edge of the box situated below and with its corners fitting into the space formed between the two graded recesses of the tray situated underneath.

The said special insertion is so perfect that one box "plugs" materially into the other immediately next to it, but its insertion is restricted to precise limits, as each box has inside its corners a small transversal partition which acts as a ledge on which the base of the box placed on top is supported.

Other objectives related with the benefits and economy of the invention will be described later on.

One characteristic of the improved tray proposed is that between the ends and the lower border of its long sides and in the same area of the front pieces, there are hollows or special recesses which form graded indentations in the lower outside part of the corners of the trays.

Another characteristic of the proposed tray is that the front pieces or the long sides are provided with two partitions forming a double wall, of which the innermost wall may be of the same or of a lesser height than the outside wall, and which together, with their upper borders, form a wide ledge on which another box may rest, in such a way that each double wall of a tray will be superimposed in alignment with the coinciding double walls of another tray situated beneath.

A further characteristic of the proposed tray corresponds to the means foreseen to undo the stacks, separating each tray from that situated immediately underneath, in which it is materially "plugged" at the base, the means consisting of a wide cut-out area formed in the centre of the upper border of the side pieces which have a double wall and into which gap the fingers are introduced to separate one tray from another.

A more complete idea of the improved tray which is proposed is given by the following description, commenting on the attached drawings which represent somewhat diagrammatically and exclusively by way of a nonlimitative example, the preferred combinations and details of the idea of the invention, with reference to its possible practical realization.

In the drawings: Figure 1 represents, in perspective, a fully assembled tray, noting that the front pieces 4- -5- with their double wall -6- -7- form on their upper border a wide, longitudinal, practi cally continuous ledge -8- on which rests the base -1- of another tray, immediately above, which ledge -8- extends along the length of the front pieces and is prolonged to the ends of the long sides -2- -3- along the inside of the tray.

Figure 2 is a partial view of two trays which are superimposed but without being fitted together. The lower tray shows a section through the extensions or outer flap -14- of the front piece, which gives a view of the interior extension as well as the final part of the nearest long side -2- which is situated between the inner flap -12- and outer flap 14-.

Figure 3 is a front view of the front pieces 4- of two trays which are superimposed and fitted together, showing the wide cut-out area -17- formed between the superimposed front pieces -4- through which gap the hand is introduced to push up the base of the top tray to separate it from the lower.

Figure 4 corresponds to three partial views of trays in which the small inside partition -6-, which forms the double wall in each front piece, is narrower than these and does not extend to the base of the box. The said partition -6-, when folded down, lies against and sticks to the inside of the front piece, thus forming a very strong box which is more economical as the surface of the double wall -6-is reduced.

The first drawing presents a flap -6- with its ends extended forming two successive identical sectors, the first of which -11- is situated transversally between the inside partition -6and the immediate long side and the second 12- lies against and adheres to the inside of the said long side -3-.

These realizations should not be considered as exclusive as there are many possible solutions that may be adopted to organize this part of the tray, although the cases described have been carried out successfully and allow the tray to be entirely assembled by mechanical means.

Figure 5 represents a complementary board -18- with a central window -19- which when required may be used as a lid to cover and protect the product contained in the tray.

Figure 6 represents a tray in perspective, in accordance with the invention, which presents the same arrangement and characteristics as those shown in the preceding figures, which arrangement has been foreseen on the long sides -2- -3- of the tray, thereby forming very strong stackable trays with ledges -24- of considerable length and which permits the production of trays of relatively large size and therefore of greater capacity.

Figure 7 represents a perspective view of the corner of an improved tray according to the invention, in which there has been foreseen the formation on the upper border of the corners of an angular prominence or crest 33- which constitutes a supporting area on which the tray immediately-above will rest in stacking.

These crests planned on each corner of the tray constitute the buttresses between which the superimposed tray is inserted.

With this arrangement it is possible to obtain very stable loads or stacks in which it is practically impossible for any of the stacked trays to slip sideways.

In these drawings, reference number -1- indicates the sector forming the base of the trays with -2- and -3- being the long sides and -4- and -5- the shorter or front pieces.

As can be observed in the tray shown in Fig 1, the base and long sides are those normally found in any open box or tray, the characteristics of the invention basically affecting, in this case, the front pieces -4- -5-which consist of double walls by means of the interior partitions -6- -7-, these being joined together by articulations at the top edge so that, together with the resulting double wall, a wide supporting ledge -8- is formed on which the base of another identical tray placed on top will rest directly.

Each interior partition -6- or -7- of the front pieces -4- -5- is provided with an extension projecting from its vertical edge, divided-in two sectors -11- -12- by the middle dividing line -13-. In folding the said interior partitions -6- -7- towards the inside of the box, the central part forms a double wall with the corresponding front piece and its lateral extensions -11- are situated diagonally between the inner wall of the front piece and the immediate long side. The second sector -12- lies entirely against the inner wall of the said immediate long side, on which it is fixed, preferably by means of adhesive.

The front pieces -4- -5- are provided laterally with exterior flaps -14- -15- which are folded in an angle of 90 to lie against and adhere to the outer wall of the immediate long side -2- -3- respectively.

With the details described, four important arrangements are obtained which can be seen in detail in Fig. 1, and are indicated as follows: a) The formation of front pieces with double walls, with high mechanical resistance.

b) The formation of a triple wall in the end sections of the long sides of the tray, which are thus evidently reinforced in the same way as the front pieces and the corners, resulting in a very sturdy tray.

c) The outer wall of the front pieces, made up of the central section -4- or -5- and by the outside lateral flaps -14- and -15-, which materially embrace the ends of the long sides -2 -3-, form a first supporting point on which the front pieces and the flaps of another identical tray which is superimposed, rest in perfect alignment, when forming a stack.

d) The inner partitions -6- or -7- of each front piece -4- -5- as well as their lateral extensions -11- -12- are situated at a lower level than the upper edges -9- -10- of the front pieces and their lateral extensions -14- 15-, creating a second ledge -8- which is concentric with the former, on the inside ledge of which the base of another superimposed tray will rest directly. When stacking each tray on top of another, it will fit into the tray immediately below, with the base resting directly on the inside ledge -8- surrounded by the front piece. At the same time, the said front piece and its extensions -14- and -15- will rest directly on the top edge of the front piece and extensions of the tray situated immediately underneath.

In Fig. 2 it can be observed that the front pieces -4- and -5-, on their top edges, show a reduction in height coinciding with the double fold line -8- along which the inner wall -6and -7- of each front piece is folded, and which reduction forms the wide ledge -8- already mentioned on which rests the base -1of the tray placed on top.

In order that the upper tray may rest on the lower supporting point -8-, it is provided, on the lower border of its front pieces, next to the vertical edges, of indentations -16- which are extended along the lateral extensions -14-15- of the front pieces, in such a way that each front piece -4- -5- and its lateral extensions -14- -15- form a recess -16- at the base parallel with the upper edge -9--10-.

In said Fig. 2, arrows indicate the parts of each lower tray which act as supports for the coinciding lower sections of another identical tray placed immediately on top when stacking.

When stacked, the trays formed in accordance with the rules proposed in the invention are inserted, or materially "plugged" into one another, and in order to separate them, it has been planned that the front pieces should have in their central supporting section -8- a cut-out recess -17- open at the top, through which the fingers may be introduced to push up on the underside of the base of the tray which is superimposed, to withdraw it.

In Fig. 3 these cut-out parts can be clearly observed by the representation of two superimposed trays.

Referring now to Fig. 4, this shows three versions of the tray proposed in the invention, with the object of reducing the tray's cost, and for this purpose it has been planned to reduce by half the width of the internal partitions -6- and -7- which form the double wall of the front piedes; these partitions are impregnated on the inside with adhesive and when folded down they lie against and stick to the inside of the corresponding front pieces -4- or -5- in the same way as their end flaps 12- which stick to the long side -2- or -3- on the inside.

With reference to Fig. 6, this shows, in perspective, a tray made up according to the rules proposed by the invention, the characteristics of which have been applied entirely to the long sides -2- and -3- of the tray, the top edges of which are provided with extensions constituting longitudinal flaps -22- -23- which fold through an angle of 180C towards the inside of the tray, to lie against the inside of the respective long sides -2- and -3- with which they form a double wall, the top edge of which forms a wide ledge or supporting area -24- which constitutes the lower supporting ledge.

These supporting ledges -24- extend to the ends of the interiqr partitions -22- -23- with their extensions -25- -26- at both ends and constitute two successive sections, reciprocally articulated, of which that indicated by the number -25- is situated transversally in the corner of the tray and the final sectors -26-lie against and adhere to the inside walls of the respective front pieces -4- -5-.

By means of this arrangement, a double wall -24- is formed in the upper border of the long sides, which extends with its upper borders 27- -28- to the end areas of the front pieces -4--S-.

The outside walls -2- -3- of the long sides of the tray, following the ledge -24- are raised to form a crest -27- -28- which is deflected orthogonally and extends upwards at the end of the respective front piece at -28-, and these crests form a projection or angular crest -27- -28- at each corner of the tray which constitute supporting areas coinciding with the indentations -29- provided in the lower borders of the corners of each tray.

In addition, the aforesaid angular crests -27 -28- of the corners also constitute buttresses or corner walls into which one tray placed on top of another is inserted at the corners and is prevented from moving sideways.

All these devices are exactly the same as those previously described with reference to Figs. 1, 2 and 3, but in these, the devices are applied to the front pieces of the tray while in the representation of Fig. 6, the said devices are provided on the long sides of the tray, which, as opposed to what usually happens when forming stacks, large ventilation spaces are formed between the superimposed trays, as the front pieces are lower than the longer sides.

The ledge -24- formed on the upper border of the double wall of each long side have cutout openings -30- which allow the handling of the trays in superimposing or withdrawing them.

The characteristics of the tray in Fig. 6 are specified as follows: a) Contrary to normal practice, the long sides of the tray are higher than the short sides or front ends.

b) The long sides have a double wall by which a first supporting area -24- is formed on which the base of another tray placed im mediately on top will rest.

c) The upper border of the aforesaid long sides is higher at the ends than in the doublewalled area and from the side edges there extend flaps- which fold through 90" to lie against the ends of the front pieces or short ends of the tray, forming with these projections -27- -28- a second line of support at a higher level at each corner on which the corners of the tray placed on top will rest.

These corner projections also constitute insertions by way of buttresses into which the superimposed tray fits without any possibility of lateral movement.

Referring once more to Fig. 7, this shows an important characteristic which may be applied either in the case of the supporting areas being formed on the upper borders of the front pieces (Figure 1) or on the upper borders of the long sides (Fig. 6), which innovation consists in forming an angular crest -33on the upper border of the outer partition of the double wall which finishes the top of the corners of the box, forming two upper lines of support -32- -33- in each corner, the crests of which are adequately adapted to fit the coinciding indentations -34- provided in the lower part of the corners of the tray which is placed on top.

By these means a stackable tray is obtained which is provided with three lines of support 31- -32- and -33- situated at different levels, on which another identical tray will rest when placed on top during the process of stacking.

It is understood that the new tray which has been described is not limited to the method of realization given and represented, as it is possible to introduce changes of detail as long as its essence-is not altered thereby.

Claims (14)

1. A stackable tray comprising a preformed blank including a base portion and peripheral edge portions folded to- define side walls, the side walls for two opposite sides each comprising two parts of a said edge portion folded to overlie one- another with the region of the fold therebetween defining a support surface for a said tray stacked thereon, said edge portions defining at the corners of the tray projections and recesses so arranged that the projections can be received in the recesses of an overlying said tray for stacking thereof.

2. A tray according to claim 1 wherein the base is rectangular and said side walls with said fold regions are on the two shortest opposite sides of the base.

3. A tray according to claim 1 wherein the base is rectangular and side walls with said fold regions are on the two longest sides of base.

4. A tray according to any preceding claim wherein the outermost ones of said parts have end extensions folded around -said corners and have upstanding portions defining said projections.

5. A tray according to claim 4 wherein said outermost parts define at the tray corners castellated projections and corresponding recesses for the projections of another said tray.

6. A tray according to any preceding claim wherein the innermost ones of said parts include end extensions which extend diagonally across the corners between the side walls, said diagonal extensions forming support surfaces for the base of a stacked further said tray.

7. A- tray according to claim wherein said diagonally extending extensions include folded end parts attached to the side walls.

8. A tray according to claim 7 wherein said folded end parts are inserted in a cut or recess.

9. A tray according to claim 7 wherein said folded end parts are glued onto the side walls.

10. A tray according toany preceding claim wherein said side walls with said fold regions are provided with openings therein in said fold regions to permit a hand to be inserted to separate stacked ones of said trays.

11. A tray according to any preceding claim wherein the innermost parts of the side walls with fold regions do not touch the base.

12. A tray according to claim 4 or any claim when appendent thereto wherein said end extensions, said projections and said folded regions define support surfaces for a stacked said tray, at three respective different levels.

13. A tray according to any preceding claim with a removable cover having a cnetral opening therein.

14. A stackable tray substantially as hereinbefore described with references to the accompanying drawings.