Foldbox

Abstract: The invention relates to a blank of folding sheet material such as cardboard for the production of a box with flanges (5, 5') running along a first pair of side walls (3, 3') at a distance from the top edge thereof. To improve the stacking strength of such box and to allow that such box can be made of solid cardboard, the blank to make such box is designed such that the flanges (5, 5') are connected to the second pair of side walls (4, 4') by corner pieces (7, 7') which can have extentions (6, 6') so that angle sections are present in the corners of the box. According to the present invention, the box can further be strenghthened by additional corner reinforcements (11), which are also part of the blank. To improve prevention of mutual movement of boxes in a stack, lips (8, 8') can be situated above the flanges (5, 5') at the first pair of side walls (3, 3'), forming stops that can interact with stop edges (9, 9') situated on the outside of the next box placed with the bottom on the flanges mentioned. The blank to make a box according to one of the embodiments of the present invention is designed such that waste of material is minimized.

Description: The invention relates to a stackable box made of a blank of folding sheet material such as cardboard comprising a bottom and two pairs of side walls situated opposite each other and connecting thereto. EP-A-0394549 (a prior art in accordance with article 54(3)EPC) describes a stackable box. It has supporting flanges extending along two opposite side walls in a plane parallel to the bottom of said box. A next box can be supported on those flanges with its bottom. The corners are internally reinforced by two strips extending between the bottom and the respective supporting flange, one longitudinal edge of each strip adjacent a respective side wall and the opposite longitudinal edge mutually connected at a fold line, such that the two strips form an angle-section. The supporting flanges are extended by flaps on both longitudinal ends, which flaps are folded parallel to the respective side wall and connected thereto. Two opposite side walls and the supporting flanges contain fold lines directed under 45°, such that the upstanding side walls can be folded on the bottom. From WO-A-88/02724 a stackable box is known having supporting flanges to support a further box stacked on top at its bottom, however without internal reinforcements at the corners where the adjacent side walls meet. From GB-A-2205083 a further stackable box is known, having two supporting flanges extending along the top edge of opposite side walls in a plane parallel to the bottom. The corners where the adjacent side walls meet are reinforced by one strip extending from the bottom to the supporting flange, each longitudinal edge extending adjacent a respective side wall. This reinforcement strip is held in place by a clamping force between the bottom and the opposite supporting flange. Both supporting flanges are extended at both longitudinal ends by flaps which are folded against the respective sidewall and connected thereto. The supporting flanges and the corresponding side walls contain fold lines extending under 45°, such that this known box can be folded in with the side walls laying flat on the bottom. A further stackable box is described in NL-A-9000063 (a document which was filed prior to, but published after the priority date of the present application). This box has two supporting flanges extending along the top of opposite side walls in a plane parallel to the bottom. Internal reinforcements are present in the corners. This internal reinforcement is provided by a set of four strips, the longitudinal edges of which are foldable connected to each other and to the side wall not containing a supporting flange. In figure 6b it is indicated, how the two central strips 316'c, 317'c extend within the triangular space defined by the adjacent side walls and the straight line running between their fold lines along their longitudinal edges opposite their common fold line. Both supporting angles are extended at the longitudinal ends by flaps which are folded against the respective side wall and connected thereto. The supporting flanges and the corresponding side walls contain fold lines running under 45°, such that this box can be folded in with the side walls flat on the bottom. The present invention suggests a further stackable box which is characterised by the features indicated in claim 1. The dependent claims relate to advantageous constructional embodiments of the box according to claim 1. Boxes such as described with reference to the present application are mass products. They are typically produced from a single blank. This gives the advantage that in a folding and glueing machine only one feed flow of cardboard need be taken into account. This reduces, inter alia, the risk of faults. The development of a box which can be made from a single blank does, however, call for a considerable degree of inventiveness -despite or perhaps because- a design of a new blank seems to simply involve changing the position of fold lines and cutting lines. The invention will now be explained in greater detail with reference to the appended drawings, showing the preferred embodiment of a box according to the invention, in which: Fig. 1 shows a perspective view of a conventional box; Fig. 2 shows in perspective view a part of the box of Fig. 1 in an embodiment according to the invention; Fig. 3 shows in perspective view a corner piece of the erected box of Fig. 2 in the partially folded-up state; Fig. 4 shows a part of a blank in a top view. Fig. 1 shows a conventional box 1. This box 1 has a bottom 2 which has to carry the product stored in the box. A first pair of side walls 3, 3' lying opposite each other and a second pair of side walls 4, 4' lying opposite each other connect to the bottom 2. Flanges 5, 5', lying approximately at right angles to the walls of this first pair of side walls 3, 3', and projecting into the box 1, run along the first pair of side walls 3, 3' at a distance from the top edge thereof. These flanges 5, 5' thus form a resting surface for the bottom of a box to be placed on said box 1. The part of the first pair of side walls 3, 3' projecting above the flanges 5, 5' prevents a box placed on said box 1 from being able to slip in a direction parallel to the second pair of side walls 4, 4'. In turn, the bottom side of a box placed on said box will prevent the top edges of the first pair of side walls 3, 3' from being able to move towards each other under the load of the contents of the box 1, which can occur if the bottom 2 thereof is not supported. The so-called bulging of the second pair of side walls 4, 4' is avoided in this way, which is beneficial for the bearing capacity of the box 1. By means of the flanges 5, 5' the load of a box placed on said box 1 is transmitted uniformly to the side walls of the box 1. For this, the flanges 5, 5' have to be fixed to the side walls 3, 3' respectively. In the corners where the respective side walls 3, 3' and 4, 4' connect to each other reinforcement corner pieces 6, 6' and 7, 7' are provided, in this case being located entirely on the outside of the box 1. By means of these corner reinforcements the box 1 is reinforced at the places where the load of boxes placed on said box 1 acts, namely in the corners. Above the flanges 5, 5' lips 8, 8' project from the face of the first pair of side walls 3, 3' inwards into the box. The edges 10, 10' thereof form stops which can interact with the stop edges 9, 9' of the reinforcement corner pieces 6, 6' and 7, 7' of the next box placed on said box 1, as a result of which that box cannot slip in a direction parallel to the lengthwise direction of the first pair of side walls 3, 3'. A very good nesting of boxes stacked on top of each other is obtained in this way. Additional corner reinforcements 11 are then provided inside the box in the corners where the side walls connect to each other. Fig. 1 thus shows a particularly stable box which is preferably very suitable for making out of solid cardboard, but can also be made of other foldable sheet material, and is suitable for being folded from a single blank and glued. Since this box 1 has very strong corners, the bearing capacity is increased greatly compared to existing cardboard boxes, while the production thereof has remained simple. Such boxes can also be stacked neatly on top of each other and it is ensured that during, for example, transportation the connection between the individual stacked boxes is not lost, so that then also the boxes at the bottom of a stack remain uniformly loaded and will not give way. As Fig. 1 shows, it is easily possible without further ado to provide handling slits 12 in the first pair of side walls 3, 3', without the side walls having to be additionally raised for this. In addition, it is, of course, also possible to provide apertures for the throughflow of air and the like in the side walls 3, 3' and 4, 4' or the bottom 2. Fig. 1 also shows that a part 13 of the second pair of side walls 4, 4' is simply folded over through 180°, so that large apertures are obtained between the individual boxes stacked on top of each other. Fig. 2 shows an example of an embodiment of the present invention. The parts thereof remaining unchanged from those in Fig. 1 have the same reference numbers. The reinforcement corner pieces 7, 7' are now situated between the second pair of side walls 4, 4' and the additional corner reinforcements 11. Since Fig. 2 shows a ready box as a variant of the present invention, additional fold lines 160, 160'; 161, 161' and 162 are present in the box 1. The fold lines 160, 160' are situated in the second pair of side wall panels 4, 4' and run from the bottommost corner points thereof at an angle of approximately 45o to the bottom edge of the second pair of side walls 4, 4'. The fold lines 161, 161' are situated in the flanges 5, 5' and run from the corner points thereof lying at the side of the first pair of side walls 3, 3' at an angle of approximately 45° to the bottom edge of this first pair of side walls 3, 3'. The fold lines 162 are situated in the additional corner reinforcements 11 on the bisector of the angle between the first and the second pair of side walls 3, 3' and 4, 4' respectively. It is preferable here in the manner known per se to make the part of the additional corner reinforcement 11 in which the fold line 162 is situated (the part between fold lines 115 and 116 in Fig. 7) of such dimensions that in the state in which the box is being used this part remains creased around fold line 162. In this way the tolerances as regards folding and the position of the fold lines can be absorbed, on the one hand, and it also provides the possibility of putting the additional corner reinforcement 11 into the position creased around the fold line 162 after the box is brought into the state for use, as shown in Fig. 2, which improves the dimensional stability of the box. A part of the second pair of side walls 4, 4' runs through to above the flange 5', which also means that nesting in the plane of the flange 5' of boxes 1 stacked on top of each other is ensured. In Fig. 3 it can be seen from another perspective view how a corner of the ready box of Fig. 2 can be folded up. The side wall 4' is in this case folded inwards along fold line 160', the additional corner reinforcement 11 folds inwards along the fold line 162 and the flange 5' folds upwards, folding taking place around the fold line 161'. In this way the whole box can be folded together to form a flat pack, the side wall 4' with the part 13 resting on the bottom 2, while the side wall 3' again rests on the side wall 4'. Fig. 4 shows in top view a quarter part of a blank for the production of the box 1 from Fig. 2. The lines of symmetry of the whole blank along which the part shown in Fig. 4 is cut off are indicated by the dashed and dotted lines 50 and 51. Parts of a bottom panel 100, one side wall panel of the first pair of side wall panels lying opposite each other and a side wall panel 101 of the second pair of side wall panels lying opposite each other are shown. The side wall panels 101, 102 connect by means of fold lines 122, 123 to the bottom panel 100. The side wall panel 102 has a first fold line 111 and a second fold line 112. The first fold line 111 runs at a distance from the edge 120 of the side wall panel 102 facing away from the bottom panel 100, which distance corresponds approximately to the width of the flange 5, 5' from Fig. 2. The second fold line 112 runs at a distance parallel to the first fold line 111, which distance corresponds approximately to the distance of the flange 5, 5' from the top edge of the first pair of side walls 3, 3' of the box 1 from Fig. 2. Situated between the first fold line 111 and the second fold line 112 is an opening 105 in the blank, with at one of the edges a lip-shaped element 106 which can form one of the lips 8, 8' in Fig. 2. For the production of the reinforcement corner pieces 6, 6' and 7, 7' from Fig. 2 the side wall panel 102 also has a first side flap 103 which is foldably fixed, by means of a third fold line 113 running parallel to the side 121 of this side wall panel, to the part of the side 121 of the side wall panel 102 situated between the edge 120 facing away from the bottom panel 101 thereof and the first fold line 111. This first side flap 103 also has a fold line 114 running approximately parallel to the first fold line 111 and the second fold line 112. For the additional corner reinforcements 11 of the box 1 according to Fig. 2 the side wall panel 102 of the blank of Fig. 4 has a second side flap 104. This side flap 104 is foldably fixed between the edge 122 of the side wall panel 102 lying against the bottom panel 100 and the second fold line 112 to the side 121 thereof. This second side flap 104 also has two additional parallel fold lines 115 and 116 respectively lying at a distance from each other. Also provided in the side wall panel 102 for the handling slit 12 is such a cut 130 that folding over the part 131 round the fold line 132 produces the handling slit 12. An incision 125 and a fold line 124 are furthermore provided in the side wall panel 101 in order to be able to fold over the part 13 of the side wall 4, 4' from Fig. 2. The following fold lines are present: Fold line 160 in the second side wall panel 101, running at an angle of approximately 45° to the fold line 123 running along the bottom panel 100 from the corner point of the side wall panel 101 at the side of the bottom panel 100. Fold line 161 in the first side wall panel 102, running at an angle of approximately 45° to the first fold line 111 from the end thereof, in the direction of the edge 120 facing away from the bottom panel 100. Fold line 162 in the second side flap 104, between the two fold lines 115, 116 and at a distance from them and parallel to them. When this ready box is being stuck together, the strip 150 of the first side flap 103 goes on the side wall panel 101. A connection must not be made between these parts in the region 171, 171'. Fig. 4 also shows that the side wall panel 101 is enlarged compared with a blank for the box of fig. 1 until past the dashed line with double dot, so that, inter alia, the part 170 projecting above the flange 5' in Fig. 2 is produced. It is also indicated that the flange 5' of Fig. 5 can be made of a strip of cardboard folded double. For this, the blank of Fig. 4 is extended past the edge 120 along, for example, the dashed lines with double dot 180, 181. In this extended part there is also a fold line 163, which is necessary for the ready box. If desired, the extended part situated between the fold line 163 and the line 180 and 120 can be omitted. The line 120 then becomes a fold line. The adjacent part bounded by the dashed lines with double dot 182, 183, 184 can be, for example, cut away or stuck against the side wall panel 101, with the exception of the zones 172, 172'. It is immaterial how exactly the edges of a blank run. This is, for example, illustrated by Fig. 4, where different edges extend in a staggered manner. In essence, according to the present invention a box is provided with improved stacking strength, to be made from a single blank designed to minimise waste of material.

Claims: Box (1) made of a blank, the box having a bottom (2) and two pairs of side walls (3, 3';4, 4') which are hingedly connected therewith, flanges (5, 5') running along the first pair of side walls (3, 3') at a distance from the top edge thereof, said flanges (5, 5') extending approximately at right angles with respect to said first pair of side walls (3, 3') and projecting into the box (1), such that the bottom of a second box can rest on said flanges (5, 5'), each of said flanges (5, 5') constituting an elongated panel of each of said first pair of side walls (3, 3'), said elongated panel being divided into two sections by spaced, parallel first (111) and second (112) fold lines, one section being flat folded on to the respective side wall (3, 3') and the other section forming said flange (5, 5'), there being provided reinforcement corner pieces (7, 7') in the corners of the box (1), said reinforcement corner pieces being foldably connected to the side edges of the flanges (5, 5') and lying flat on the second pair of the sidewalls (4, 4') and being connected thereto; an additional corner reinforcement piece (11) being further provided inside the box in the corners where the side walls connect to each other, said additional corner reinforcement piece (11) being foldably connected to the respective side edge (121) of the first pair of side walls (3, 3') below the respective flange (5, 5'), each of said additional corner reinforcement pieces (11) having three spaced fold lines (115, 116, 162) running parallel to the respective side edge (121) of the erected box and defining four strips, the outer two of which lie flat against a first and a second side wall (3, 4; 3', 4'), respectively, and the inner two strips having such dimensions, that in the erected state of the box they extend within the triangular corner space defined by the side walls (3, 4; 3', 4') and the straight line extending between the outer two (115, 116) of said three spaced fold lines (115, 116, 162), such that said two inner strips remain creased around the middlefold line (162) situated on the bisector of the angle between the first and the second pair of side walls (3, 4; 3', 4'). Box according to claim 1, wherein the reinforcement corner pieces (7, 7') have flaps (6, 6') extending around the corner of the box (1) and connected to the first pair of side walls (3, 3'). Box according to claim 1 or 2, wherein at least that part of the reinforcement corner pieces (6, 6'; 7, 7') running along the first pair of side walls (3, 3') is folded onto the outer surface of the box. Box according to any of the preceding claims, wherein the second pair of side walls (4, 4') has fold lines (160) running from the bottommost corner points at an angle of approximately 45° to the bottom edge of said second pair of side walls (4, 4'), and in that the flanges (5, 5') have fold lines (161) running from the corner points at the side of the first pair of side walls (3, 3') at an angle of approximately 45° to the bottom edge of said first pair of side walls (3, 3'). Box according to any of the preceding claims, wherein thickened panel portions (8, 8') extend above the flanges (5, 5') at the first pair of side walls (3, 3'), the edges of said thickened panel portions forming stops which interact with corresponding stop edges (9, 9') provided on the outside of a second box placed with its bottom on said flanges. Box according to claim 5, wherein the stop edges (9, 9') are formed by those sides of the reinforcement corner pieces (6, 6'; 7, 7') situated on the outside of the box (1).

Inventors: VAN EIJNDHOVEN PETER PAUL, VAN EIJNDHOVEN, PETER PAUL
Applicants: BUEHRMANN TETTERODE NEDERLAND, BUEHRMANN-TETTERODE NEDERLAND B.V.
Application year: 1991
Main classification: B65D5
IPC codes: B65D5