FR3048959A1 - PYRAMIDO-PRISMATIC BOX IN CARDBOARD AND FLAN CORRESPONDING - Google Patents

Abstract

The invention relates to a cardboard pyramid-prismatic box (20) with a rear top (10), front access opening (21) with two closing flaps, a top (3) and a bottom (4), said opening access being delimited on four sides by: - two flap folding lines, a top (5) and a bottom (6), - two respective lateral access edges (7) at the front of two side walls (8). ), and the internal volume is delimited by: - laterally, the two lateral walls (8) carried by planes converging towards the rear, - at the bottom, a wall of the bottom (9) in continuity with the lower flap (4) at the top, a top wall (11) in continuity with the upper flap (3), the rear top (10) being a rear fold line between the bottom (9) and top (11) walls, the side walls (8) are in lateral continuity of the top wall (11) along two respective upper lateral fold lines (12), and each side walls (8) are separated from the bottom wall (9) on the blank (1) and are secured by a fastening system (13) to the bottom wall (9) in the box formed by the blank folded to bring and maintain in contact said side walls (8) and the bottom (9) along two lower lateral meeting lines (14).

Description

Technical field to which the invention relates

The present invention relates generally to the field of packaging, in particular foodstuffs of the type of pastries or hot preparations, including quiches or equivalent. It relates more particularly to a pyramido-prismatic cardboard box and the blank to achieve it.

Technological background

In the field of packaging of fragile food products of the pastry type, the mounted package is known which is produced individually from a sheet of paper which is shaped around a grooved square bearing the pastry and which is held by a bolduc also serving as a handle. Such an embodiment brings a certain added value but it is complex and relatively long to achieve.

The present invention provides a solution to the production of packets for particular pastries with a cardboard box of similar shape and which can be implemented quickly and simply. In addition, its shape facilitates the introduction of the product into the box, on one side of the latter, by self-centering the product because the side walls of the box are not parallel. There is therefore less risk that the product hits the wall during its introduction. In addition, the product is substantially slid / pushed horizontally in the box and not vertically deposited as in conventional top-opening boxes which must, in addition, be much wider than the product for the hand of the person posing the product can also enter the open box on the top. Finally, when opening / closing the box, only one face of the box of the invention is concerned, the other faces remaining integral with each other, which increases the overall strength / cohesion of the box. It will be seen and deduced from reading the description that the invention has many other technical advantages.

Object of the invention

In order to remedy, in particular, the aforementioned drawbacks of the state of the art, the present invention proposes a pyramid-prismatic cardboard box having a straight linear rear vertex formed from a single blank folded on itself along fold lines. , said blank being symmetrical with respect to a median axis, said box having at the front an access opening to the internal volume of said box, said access opening being able to be closed or opened by folding or unfolding two closure flaps substantially planar, said closure flaps being an upper flap and a lower flap, said two closure flaps being brought into overlapping respective ends, one against the other, when folding to close the opening of access, and said access opening being delimited on four sides by respectively: two flap fold lines of the two closure flaps, respectively an upper folding line and a lower fold line, the two fold lines of the two flaps facing each other and parallel to each other, and two respective lateral access edges in front of each other; two side walls of the box, and the internal volume is delimited respectively by: - laterally, the two substantially flat side walls, said two side walls being carried by converging planes rearward, said two side walls not being so parallel to each other, said two side walls terminating at the rear at the tip, respectively at the two lateral ends of the right linear rear vertex of the box; at the bottom, a wall of the bottom plane is continuous at the front and along the the lower fold line with the lower flap, the bottom wall ending at the rear on a rear fold line corresponding to the right linear rear vertex the top of the box, - at the top, a wall of the plane top in continuity at the front and along the upper fold line with the upper flap, the top wall ending at the rear on the rear fold line corresponding to the right linear rear vertex of the box, said right linear rear vertex of the box thus being the rear fold line between the bottom wall and the top wall, said rear fold line being parallel to the upper and lower fold lines and the side walls are in lateral continuity of the top wall along two respective upper side fold lines, and each of the side walls is separated from the bottom wall on the unfolded blank and is, by a fastening system attached to the bottom wall in the box formed by the folded blank to bring and maintain the said side and bottom walls in contact with two lower lateral encounter lines es. Other non-limiting and advantageous features of the box according to the invention, taken individually or in any technically possible combination, are the following: the side walls are of triangular shape, the bottom wall is of truncated triangular shape with two parallel edges corresponding to the lower fold line and the fold line forming the right straight rear vertex, - the top wall is of truncated triangular shape with two parallel edges corresponding to the upper fold line and the folding forming the right linear rear vertex, - the flaps are of substantially parallelogram shape at right angles, preferably their two free corners being rounded, - alternatively, the side walls are in lateral continuity of the bottom wall along two respective lower side fold lines, and each of the side walls is separated from the aroi of the top on the unfolded blank and is, by a fastening system, attached to the top wall in the box formed by the folded blank to bring and maintain in contact with said side walls and top along two lines upper lateral meeting point, - if, preferably, the upper fold line, the lower fold line are straight and are parallel to the fold line corresponding to the straight linear rear vertex, alternatively, the upper fold line and the line lower fold are curved, then preferably convex outwardly from the corresponding top or bottom wall, - the two lateral fold lines are straight, - the two lateral fold lines are curved, preferably convex towards the outside the bottom wall or the top wall as appropriate, - the two lateral meeting lines are straight, - the two lateral meeting lines are curved, preferably convex towards the outside of the wall of the bottom or the top wall as appropriate, - the two lateral access edges are straight, - the two lateral access edges of the respective front ends of the two side walls of the box are straight and parallel to each other, - the two straight access side edges are not parallel to each other on the access opening of the box, - the two non-parallel right access side edges to each other on the opening access of the box are carried by two axes convergent upwards, the access opening of the box being extended further down at the bottom wall than upward at the top wall, in other words, the lower fold line is longer than the upper fold line, - the two access edges of the respective front ends of the two side walls of the box are not parallel to each other and are preferably Harbor s by axes converging upwards so that the access opening is wider downwards than upwards, - the box comprises a gripping means, - the lower flap comprises a rear extension constituting a handle and in which is formed a folding flap consisting of a cut and a fold facilitating line both forming a closed figure intended to create a gripping opening of the box when the flap is pushed to be no longer in the plane of said extension, said handle being intended to pass through an elongate slot along the upper fold line; - the top wall comprises a folding flap consisting of a cutout and a folding facilitation line, both forming a closed figure intended to create an opening for gripping the box when the flap is pushed to be no longer in the plane of the top wall, - the fixing system allowing in the formed box to maintain in contact each of said side walls with the wall of the bottom or the top along the two lateral meeting lines according as the lateral walls are in lateral continuity of the wall of the top or the wall of the bottom, is a fold in continuity of one of the side walls or the bottom or the top depending on the case and coming into contact with the inner surface of the corresponding wall opposite and glued on the latter, preferably, the fold being in continuity of the wall from the bottom or the top wall, - the top wall and / or at least one of the side walls and / or the upper closure flap comprises / nt at least one circumscribed window and to visualize the inside of the box, said window being closed by a sheet of transparent material, - the sheet of the transparent material closing the window is adhered to the inner face of the corresponding wall (s), along the periphery of the window, - the closure flaps each comprise complementary elements of a locking system, said elements being respectively a circumscribed slit cut into one of the closure flaps and at least one lug made in the other flap, said at least one flap being made to fit into the slot when the access opening of the box is closed, the tab resulting from a partial cut of the flap, - the closure flaps each comprise complementary elements of a locking system, said elements being respectively a circumscribed slit cut in one of the closure flaps and at least one flap made in the other flap, said slit having two opposite ends, said at least one tab being caused to fold into the slit when the access opening of the box is closed, the tab resulting from a partial cut of the shutter and being r attached to the remainder of the flap at a collapsible tab base, and the tab base comprises a constriction consisting of at least one recess relative to the adjacent portion of the tab, at least one end of the slit s' introducing into said hollow, the box further comprises two flaps along the side access edges at the front of the side walls, side walls or walls of the top and bottom as appropriate, said lateral access edges corresponding then at fold lines of said flaps, alternatively flaps along the side access edges at the front of the side walls, the flaps are in lateral continuity of the upper flap and / or the lower flap; The access opening can be closed or opened by folding or unfolding two substantially planar closure flaps of the blank, said closure flaps being a right side flap and a left side flap each in continuity with the flap. corresponding side wall, said closure flaps being brought into overlapping respective ends against each other during folding to close the access opening, and the access opening being delimited on four sides by respectively: two lateral flap fold lines of the two closure flaps, a right lateral fold line and a left lateral fold line opposite each other, and two parallel access access edges located at the low and high front ends. respectively the bottom and top walls, and the right side door is in continuity along the right side fold line with the corresponding side wall and the left side door is in continuity along the left side fold line with the another side wall, the right side fold line and the left side fold line may or may not be parallel to each other and in the case where where they are parallel to each other, they are also perpendicular to the two access edges of the lower and upper front ends respectively of the bottom and top walls, furthermore, optionally, the box further comprises two flaps along the edges of access to the front of the walls of the top and bottom. The invention also relates to a flat blank cardboard cut for the manufacture of the box of the invention.

This blank comprises at least, in continuity around a top wall panel: - towards the rear AR of the blank, along a fold line intended to form the right linear rear vertex, a bottom wall panel said bottom wall panel being connected further back from the blank, along a fold line for forming the lower fold line, by a bottom flap panel, - forward AV of the blank, along a fold line for forming the top fold line, an upper cover panel; - laterally, two side wall panels, and the fold lines for forming the right linear rear vertex, the lower fold line, and the upper fold line are parallel to each other, and the fold line for forming the right linear rear vertex is shorter than each of the fold lines for forming the upper and lower fold lines; The fold lines for forming the top and bottom fold lines are of the same length, - the fold lines for forming the top and bottom fold lines are of different lengths, the upper fold line being shorter than the fold line. lower fold.

Detailed Description of an Exemplary Embodiment The following description in relation to the appended drawings, given by way of non-limiting examples, will make it clear what the invention consists of and how it can be achieved.

In the accompanying drawings: FIG. 1 is a top view of a flat blank intended for the production of a pyramid-prismatic box of a first type, FIG. 2 is a view from the front and offset slightly laterally. , in perspective, the pyramid-prismatic box of the first type obtained after folding of the blank of FIG. 1, the access opening to the internal volume of the box being open, - FIG. 3 represents a view from the front and offset slightly laterally but on the other side with respect to Figure 2, in perspective, the pyramid-prismatic box of the first type obtained after folding of the blank of Figure 1, the access opening to the internal volume of the box being also 4 shows, seen from the front and shifted slightly laterally, in perspective, the pyramid-prismatic box of the first type obtained after folding of the blank of FIG. 1, the access opening to the volum the internal e of the box being closed during a closing operation of the box, - Figure 5 following the 4 represents the closed box, - Figure 6 shows two stacks of open boxes of the first type according to two different orientations, and - Figure 7 shows a box being closed a second type in which another locking system and other gripping means are implemented.

Device

In Figure 1, there is shown a blank 1 of cardboard which is flat. This blank 1 is intended for producing a pyramid-prismatic box of a first type given by way of example. The blank 1 is symmetrical with respect to an anteroposterior AV-AR axis. It has several panels in continuity with each other along fold lines. Thus, the top wall panel 11 is connected forwardly to the top flap panel 3 by the top fold line 5. The top wall panel 11 is connected rearwardly to the bottom wall panel 9 by a fold line for forming the right straight rear vertex 10 of the box. This bottom wall panel 9 is connected further back from the blank to the bottom flap panel 4 by the lower fold line 6. The top wall panel 11 is laterally joined on each lateral side to two side wall panels. 8 by respective upper lateral fold lines 12.

With regard to these panels and therefore the corresponding walls or flaps, it is noted that the top wall panel 11 is of truncated triangular shape with two parallel opposite edges which correspond to the upper fold line 5 and to the fold line intended to form the Also, the bottom wall panel 9 is of truncated triangular shape with two parallel opposite edges which correspond to the lower fold line 6 and the fold line to form the right straight rear vertex 10 The two side wall panels 8 are triangular in shape. The fold line corresponding to the straight linear rear vertex 10 is less extensive than the lower fold line 6, the latter being of the same extent as the upper fold line 5, the latter characteristic making the lateral edges of the opening of Access from the box are parallel to each other. In other types of boxes, the upper fold line 5 is less extensive than the lower fold line 6, the reverse being less convenient. In any case, the fold line corresponding to the right linear rear vertex 10 is less extensive than the lower and upper fold lines 5 so that the side walls are not parallel to each other and the bottom wall is wider than the side of the access opening.

Finally, the bottom flap panel 4 is of substantially rectangular or square shape with however its two respective free corners rounded. The top shutter panel 3 is substantially truncated triangular shape with its two rounded respective free corners but in another embodiment, it may also be substantially rectangular or square shape. The extent of the flap panels 3, 4 along the axis of symmetry 2 AV-AR, and therefore the height of these flaps in the box formed, is such that these two flaps overlap / overlap partially when the access opening to the internal volume of the box is closed, the upper flap 3 partially overlapping the lower flap 4.

In Figure 1, the bottom flap panel 4 continues further back by a gripping means which is a handle 19 having a flap 15a to achieve a gripping opening. This handle 19 is intended to be passed through a slot 19 'made along the upper fold line 5. Note that because the length of the handle is less important than the total length of the fold line, the handle 19 passed in the slot 19 'also provides some maintenance to the closed box.

The lower flap panels 4 and upper 3, the bottom wall panel 9 and the top wall panel 11 are symmetrical with respect to the axis of symmetry 2 AV-AR.

In other types of boxes, the extents / heights of the two partially overlapping flaps may be different from those shown in Figure 1. For example, these flaps may have the same extent / height, or the upper flap may be wider. / higher than the lower pane unlike Figure 1. In other types of boxes, it is the lower pane which comes partial recovery of the upper pane.

This partial overlap of the shutters allows the implementation of a locking system with tab (s) and slot (s) between the lower shutter panels 4 and upper shutter 3. In the embodiment of Figures 1 to 6, the locking system with tab (s) and slot (s) comprises a slot 17a in the lower flap 4 and a tab 16a made in the upper flap 3. The tab 16a is here made in an earlier extension of the upper flap panel 3 which has a cutout. The folding of the said anterior prolongation makes it possible to angularly orient the tab 16a with respect to the general plane of the upper shutter panel 3 and to be able to introduce it into the slot 17a of the lower shutter panel 4 during the closing of the box as visible on Figure 5.

In a variant shown in FIG. 7, the locking system with tab (s) and slot (s) comprises a slot 17b in the upper shutter 3 and two tabs 16b made in the lower shutter 4. The tabs are in the form of a triangle in order to facilitate their introduction into the slot by the tip of the paw. Note in Figure 1 that each tab is connected to the lower flap by its wide base along a fold line to the axis of symmetry 2. The cutting of the tab to the fold line / base is such that the fold line does not extend over the entire length of the base of the leg and that there exists at both ends of the base of the leg two rounded depressions, the cutout of the leg relative to the adjacent side portions of the leg the tab, this hollow allows the locking of the tab in the end of the slot that the adjacent portion of the tab is pressed against the cardboard of the flap of the slot when the end of the slot is in the hollow of the slot end of the base of the paw. In other words, the cutting of the tab continues for a certain distance along the base of the tab, at both lateral ends of the fold line of the tab. With this locking system, the bottom wall 9 is better maintained at the front by the upper flap 3 through the lower flap 4 and the closed box is structurally and functionally stronger.

In this figure 7, the box 20 is being closed and the two flaps 18 and the lower flap 4 have already been folded / folded. By cons, the upper flap 3 is not yet folded / folded. The folding flap 15b of the top wall 3 has been pushed towards the inside of the box in order to release the gripping aperture. The two tabs 16b of the lower flap 4 have been folded outwards in order to disengage them from the general plane of this lower flap. Due to the shape of these tabs 16b, this butterfly closure locking system can be described. Still in relation to FIG. 7, there is shown a variant of the gripping means which is a folding flap 15b intended to create a gripping aperture through the wall of the top 11, the box being transported with its bottom wall 9 towards the low.

The box of Figures 2 and 3 is made by folding the blank 1. In particular, the free rear edge of the side wall 8 is brought against the side edge of the bottom wall 9 along a lower lateral meeting line 14 which is then realized. In Figure 1 of the blank, the two lower lateral meeting lines 14 are marked by dashed arrows because they are created only after the folding of the blank. In order to maintain between them the side walls and the bottom wall along the two lower lateral meeting lines 14 created by the folding of the blank, a fastening system is implemented. This fastening system comprises a fold 13 which is, in this example, lateral continuity of the wall of the bottom 9. This fold 13 is glued against the inner face of the corresponding side wall 8 in the box.

In order, in particular, to improve the appearance of the closed box and to slightly strengthen the side walls 8, the latter have two flaps 18 along their front edges, these front edges corresponding to the lateral access edges 7 of the opening. access of the box to the front of the side walls 8 and being also, in the case of the presence of these flaps 18, fold lines 7 of these flaps. When the box is open and to have the widest possible access to the internal volume of the box at least laterally / horizontally, each flap can be left in the continuity of the corresponding side panel / the bearing or be folded more towards the outside, the fold line 7 then corresponding more clearly to a lateral access edge of the access opening of the box

We will now describe in more detail with Figures 2 and 3, the box 20 obtained by folding the blank 1 and gluing the folds 13 of the bottom wall 9 on the side walls 8. This box 20 has a general shape pyramid-prismatic and it is implemented lying down, that is to say that its vertex 10 which is extended, straight linear, is at the rear of the box in use position. The base of this form corresponds to the access opening 21 to the internal volume of the box, access opening 21 which can be closed by folding flaps 18 and flaps 3, 4. This access opening is found therefore at the front of the box in the use position. The bottom wall 9 is intended to receive on its upper face, internal food or other that it is desired to place in the box. These or other foods can be conveniently slipped into the box. In FIG. 5 following FIG. 4 in the closing operation of the box, the box 20 is closed and the upper flap has been folded / folded over the two flaps 18 and the lower flap 4. The flap 16a has been passed through the slot 17a. At the previous closing step shown in FIG. 4, the bottom flap panel 4 had already been folded / folded over the two flaps 18 but the top flap panel 3 was not yet completely folded down, however the tab 16a was folded to orient it angularly with respect to the general plane of the upper shutter panel 3. It is at the beginning of this previous closing step that the handle 19 was passed in the slot 19 'made along the fold line greater 5. Note about this handle 19 that in Figures 4 and 5, the folding flap 15a has been folded back to create a gripping opening, which is schematized by dotted lines for the flap and its numerical reference .

FIG. 6 makes it possible to visualize, in two different orientations, two stacks of open boxes 20 and it is thus noted that the storage and / or transport of the formed boxes can be carried out under a relatively small volume, the boxes being ready for use.

The paperboard used has, for example, a thickness of 0.141 mm and a basis weight of 250 g / m 2.

It is understood that a box of such a general pyramid-prismatic shape can be obtained with a blank different from that of FIG. 1. For example, the side wall panels 8, instead of being connected to the top panel, can be connected to the bottom panel: the side wall panel 8 and the fold 13 being interchanged between the top and bottom wall panel and the two flaps 18 being moved behind the side wall panels 8 instead of being at the front as shown in Figure 1. Under these conditions, the blank remains symmetrical with respect to the anteroposterior axis 2 AV-AR. In a variant with loss of symmetry, only one of the two side wall panels 8 is moved on the bottom wall panel 9.

In other variants, however, less preferred because of the lack of maintenance of the front access edge of the bottom wall by the top wall when the flaps are locked, the flaps 18 and the flaps 3, 4 are interchanged between the side wall panels 8 and the bottom and top wall panels, the opening of the flaps being laterally / horizontally and no longer vertically as in the box in connection with Figures 1 to 3.

In some embodiments of the box of the second type, the shutter locking system may be completed with repositionable glue for maintaining the lugs 16b of the lower flap 4 firmly applied against the outer surface of the upper flap 3 once these passed in the slot 17b and folded against the upper flap. It is also possible to implement a repositionable adhesive for the closing system of the first type box. In other embodiments, another locking system is implemented and preferably using the carton of the box, thus avoiding the addition of an external element that can cause additional cost. By way of example of other variants for the box of the second type, a second flap 15b folding can be made on the upper flap opposite that of the top wall to achieve a complete passage for the hand of the user who comes out of the box.

Claims (9)

1. Box (20) pyramid-prismatic cardboard with a vertex (10) linear straight rear formed from a single blank (1) folded on itself along fold lines, said blank being symmetrical with respect to a median axis (2), said box having at the front an access opening (21) to the internal volume of said box, said access opening (21) being able to be closed or opened by folding or unfolding two closure flaps substantially planar, said closure flaps being an upper flap (3) and a lower flap (4), said two closure flaps being brought into overlapping respective ends, one against the other, when folding for closure of the access opening, and said access opening being delimited on four sides by respectively: two flap fold lines of the two closure flaps, respectively an upper fold line (5) and a lower fold line; (6), the two fold lines of the two flaps facing one another and parallel to each other, and two respective lateral access edges (7) at the front of two side walls (8) of the box, and in that the internal volume is defined respectively by: - laterally, the two substantially plane lateral walls (8), said two lateral walls being carried by rearwardly convergent planes, said two lateral walls ending at the rear in at the two lateral ends of the right-hand rear vertex (10) of the box, respectively - at the bottom, a bottom wall (9) planes continuously in front and along the lower fold line (6) with the lower shutter (4), the bottom wall (9) ending at the rear on a rear fold line corresponding to the right straight rear vertex (10) of the box, - at the top, a top wall (11) flat in continuity at the front and along the line upper folding head (5) with the upper flap (3), the top wall (11) terminating at the rear on the rear folding line corresponding to the right straight rear vertex (10) of the box, said folding line rear being parallel to the upper (5) and lower (6) fold lines, and in that the side walls (8) are: - either in lateral continuity of the top wall (11) along two lateral fold lines respective upper ones (12), and each of the side walls (8) is separated from the bottom wall (9) on the non-folded blank (1) and is secured to the bottom wall by a fastening system (13). (9) in the box formed by the folded blank in order to bring and maintain in contact said side walls (8) and the bottom (9) along two lower lateral meeting lines (14), - or in lateral continuity of the bottom wall (9) along two respective lower lateral fold lines, and each of side walls is separated from the top wall (11) on the unfolded blank and is, by a fastening system, attached to the top wall in the box formed by the folded blank to bring and keep in contact the said walls lateral and top along two upper lateral meeting lines. 2. Box according to claim 1, characterized in that the two side access edges (7) of the respective front ends of the two side walls (8) of the box are straight and parallel to each other. 3. Box according to claim 1, characterized in that the two access edges of the respective front ends of the two side walls of the box are not parallel to each other and are preferably carried by convergent axes upwards so that the access opening is wider down than up. 4. Box according to any one of the preceding claims, characterized in that the lower flap (4) comprises a rear extension constituting a handle (19) and in which is formed a flap (15a) folding consisting of a cutout and d a folding facilitating line both forming a closed figure intended to create a gripping aperture of the box when the flap is pushed to be no longer in the plane of said extension, said handle being intended to pass through a slot (19 ') lying along the upper fold line (5). 5-, Box according to any one of the preceding claims, characterized in that the fastening system allowing in the formed box to maintain in contact each of said side walls (8) with the bottom wall (9) or the top (11). ) along the two lateral meeting lines (14) depending on whether the side walls are in lateral continuity of the wall of the top or the bottom wall, is a fold (13) in continuity with one of the side walls or the bottom or top depending on the case and coming into contact with the inner surface of the corresponding wall facing and glued to the latter, preferably, the fold (13) being in continuity with the bottom wall or the top wall. 6. Box according to any one of the preceding claims, characterized in that the top wall (11) and / or at least one of the side walls (8) and / or the upper shutter (3) comprises / nt at at least one window circumscribed and for viewing the inside of the box, said window being closed by a sheet of a transparent material. 7. Box according to any one of the preceding claims, characterized in that the closure flaps (3, 4) each comprise complementary elements (16a, 17b) of a locking system, said elements being respectively a slot (17a). ) circumscribed in one of the closure flaps and at least one tab (16a) made in the other flap, said at least one lug (16a) being inserted into the slot (17a) when the opening of access of the box is closed, the tab (16a) resulting from a partial cut of the shutter. 8. Box according to any one of the preceding claims, characterized in that it further comprises two flaps (18) along the side access edges (7) at the front of the side walls (8), side walls or top and bottom walls as appropriate, said lateral access edges (7) then corresponding to fold lines of said flaps. 9. Flan (1) cut cardboard plate for manufacturing the box (20) of any one of the preceding claims, characterized in that it comprises at least, in continuity around a top wall panel (11). ); rearwardly (AR) of the blank (1), along a fold line intended to form the right linear rear vertex (10), a bottom wall panel (9), said bottom wall panel; (9) connecting further back of the blank, along a fold line for forming the lower fold line (6), by a bottom flap panel (4), - forward (AV) of the blank, along a fold line for forming the upper fold line (5), an upper shutter panel (3),> · laterally, two side wall panels (8), and in that the lines for folding to form the right linear rear vertex (10), the lower fold line (6) and the upper fold line (5) are parallel to each other, and that the fold line for forming the vertex ( 10) straight linear back is shorter than each of the fold lines for forming the upper (5) and lower (6) fold lines.